NASA POWER Cheatsheet

README.md

NASA POWER Cheatsheet

Table of contents

• Meteorology
• Radiation

Meteorology

Spatial resolution of 0.5 x 0.625 degrees of latitude and longitude respectively

Abbreviation	Name	Climatology definition
CDD0	Cooling Degree Days Above 0 C	The daily accumulation of degrees when the daily mean temperature is above 0 degrees Celsius.
CDD10	Cooling Degree Days Above 10 C	The daily accumulation of degrees when the daily mean temperature is above 10 degrees Celsius.
CDD18_3	Cooling Degree Days Above 18.3 C	The daily accumulation of degrees when the daily mean temperature is above 18.3 degrees Celsius.
PSC	Corrected Atmospheric Pressure (Adjusted For Site Elevation)	Atmospheric pressure associated with the MERRA-2 grid has been adjusted using the hypsometric equation to account for the difference between the elevation of an underlying surface site and the average elevation of the MERRA-2 grid cell.
WSC	Corrected Wind Speed (Adjusted For Elevation)	Wind Speed associated with the MERRA-2 grid has been adjusted based upon the elevation and underlying surface roughness.
T2MDEW	Dew/Frost Point at 2 Meters	The dew/frost point temperature at 2 meters above the surface of the earth.
TS	Earth Skin Temperature	The average temperature at the earth's surface.
TS_AMP	Earth Skin Temperature Amplitude	For each month the earth skin temperature amplitude is one half of the difference between monthly average minimum maximum or equivalently one half the skin temperature range.
TS_MAX	Earth Skin Temperature Maximum	The maximum hourly earth skin temperature in the period of interest.
TS_MAX_AVG	Earth Skin Temperature Maximum Average	The average of the daily maximum earth skin temperature in the period of interest.
TS_MIN	Earth Skin Temperature Minimum	The minimum hourly earth skin temperature in the period of interest.
TS_MIN_AVG	Earth Skin Temperature Minimum Average	The average of the daily minimum earth skin temperature in the period of interest.
TS_RANGE	Earth Skin Temperature Range	The minimum and maximum hourly earth skin temperature range in the period of interest.
TS_RANGE_AVG	Earth Skin Temperature Range Average	The average minimum and maximum daily earth skin temperature range in the period of interest.
U10M	Eastward Wind at 10 Meters	The estimate of the eastward wind average speed for winds blowing 10 meters above the surface of the earth.
U2M	Eastward Wind at 2 Meters	The estimate of the eastward wind average speed for winds blowing 2 meters above the surface of the earth.
U50M	Eastward Wind at 50 Meters	The estimate of the eastward wind average speed for winds blowing 50 meters above the surface of the earth.
EVLAND	Evaporation Land	The evaporation over land at the surface of the earth.
EVPTRNS	Evapotranspiration Energy Flux	The evapotranspiration energy flux at the surface of the earth.
FROST_DAYS	Frost Days	A frost day occurs when the 2m temperature cools to the dew point temperature and both are less than 0 C or 32 F.
HDD0	Heating Degree Days Below 0 C	The daily accumulation of degrees when the daily mean temperature is below 0 degrees Celsius.
HDD10	Heating Degree Days Below 10 C	The daily accumulation of degrees when the daily mean temperature is below 10 degrees Celsius.
HDD18_3	Heating Degree Days Below 18.3 C	The daily accumulation of degrees when the daily mean temperature is below 15.3 degrees Celsius.
FRSEAICE	Ice Covered Fraction	The fraction of ocean covered by sea ice.
FRSNO	Land Snowcover Fraction	The fraction of land covered by snowfall.
V10M	Northward Wind at 10 Meters	The estimate of the northward wind average speed for winds blowing 10 meters above the surface of the earth.
V2M	Northward Wind at 2 Meters	The estimate of the northward wind average speed for winds blowing 2 meters above the surface of the earth.
V50M	Northward Wind at 50 Meters	The estimate of the northward wind average speed for winds blowing 50 meters above the surface of the earth.
PBLTOP	Planetary Boundary Layer Top Pressure	The pressure at the top of the planet boundary layer.
PRECTOTCORR	Precipitation Corrected	The bias corrected average of total precipitation at the surface of the earth in water mass (includes water content in snow).
PRECTOTCORR_SUM	Precipitation Corrected Sum	The bias corrected sum of total precipitation at the surface of the earth.
GWETPROF	Profile Soil Moisture	The percent of profile soil moisture a value of 0 indicates a completely water-free soil and a value of 1 indicates a completely saturated soil; where profile is the layer from the surface down to the bedrock.
RH2M	Relative Humidity at 2 Meters	The ratio of actual partial pressure of water vapor to the partial pressure at saturation, expressed in percent.
GWETROOT	Root Zone Soil Wetness	The percent of root zone soil wetness a value of 0 indicates a completely water-free soil and a value of 1 indicates a completely saturated soil; where root zone is the layer from the surfice 0 cm to 100 cm below grade.
SLP	Sea Level Pressure	The sea level pressure at the surface of the earth.
SNODP	Snow Depth	The snow depth on land at surface of the earth.
PRECSNO	Snow Precipitation	The snow precipitation at the surface of the earth.
PRECSNOLAND	Snow Precipitation Land	The snow precipitation only over land at the surface of the earth.
PRECSNOLAND_SUM	Snow Precipitation Land Sum	The snow precipitation sum over land at the surface of the earth.
QV10M	Specific Humidity at 10 Meters	The ratio of the mass of water vapor to the total mass of air at 10 meters (kg water/kg total air).
QV2M	Specific Humidity at 2 Meters	The ratio of the mass of water vapor to the total mass of air at 2 meters (kg water/kg total air).
RHOA	Surface Air Density	The air density at surface of the earth.
PS	Surface Pressure	The average of surface pressure at the surface of the earth.
Z0M	Surface Roughness	The height above the displacement plane at which the mean wind becomes zero when extrapolating the logarithmic wind speed profile downward through the surface layer.
GWETTOP	Surface Soil Wetness	The percent of soil moisture a value of 0 indicates a completely water-free soil and a value of 1 indicates a completely saturated soil; where surface is the layer from the surfice 0 cm to 5 cm below grade.
T10M	Temperature at 10 Meters	The air (dry bulb) temperature at 10 meters above the surface of the earth.
T10M_MAX	Temperature at 10 Meters Maximum	The maximum hourly air (dry bulb) temperature at 10 meters above the surface of the earth in the period of interest.
T10M_MAX_AVG	Temperature at 10 Meters Maximum Average	The average of the daily maximum air (dry bulb) temperature at 10 meters above the surface of the earth in the period of interest.
T10M_MIN	Temperature at 10 Meters Minimum	The minimum hourly air (dry bulb) temperature at 10 meters above the surface of the earth in the period of interest.
T10M_MIN_AVG	Temperature at 10 Meters Minimum Average	The average of the daily minimum air (dry bulb) temperature at 10 meters above the surface of the earth in the period of interest.
T10M_RANGE	Temperature at 10 Meters Range	The minimum and maximum hourly air (dry bulb) temperature range at 10 meters above the surface of the earth in the period of interest.
T10M_RANGE_AVG	Temperature at 10 Meters Range Average	The average minimum and maximum daily air (dry bulb) temperature average range at 10 meters above the surface of the earth in the period of interest.
T2M	Temperature at 2 Meters	The average air (dry bulb) temperature at 2 meters above the surface of the earth.
T2M_MAX	Temperature at 2 Meters Maximum	The maximum hourly air (dry bulb) temperature at 2 meters above the surface of the earth in the period of interest.
T2M_MAX_AVG	Temperature at 2 Meters Maximum Average	The average of the daily maximum air (dry bulb) temperature at 2 meters above the surface of the earth in the period of interest.
T2M_MIN	Temperature at 2 Meters Minimum	The minimum hourly air (dry bulb) temperature at 2 meters above the surface of the earth in the period of interest.
T2M_MIN_AVG	Temperature at 2 Meters Minimum Average	The average of the daily minimum air (dry bulb) temperature at 2 meters above the surface of the earth in the period of interest.
T2M_RANGE	Temperature at 2 Meters Range	The minimum and maximum hourly air (dry bulb) temperature range at 2 meters above the surface of the earth in the period of interest.
T2M_RANGE_AVG	Temperature at 2 Meters Range Average	The average minimum and maximum daily air (dry bulb) temperature average range at 2 meters above the surface of the earth in the period of interest.
TO3	Total Column Ozone	The total amount of ozone in a column extending vertically from the earth's surface to the top of the atmosphere.
TQV	Total Column Precipitable Water	The total atmospheric water vapor contained in a vertical column of unit cross-sectional area extending from the surface to the top of the atmosphere.
TROPPB	Tropopause Pressure based on blended estimate.	The tropopause pressure based on the blended estimate.
TROPQ	Tropopause Specific Humidity using blended TROPP estimate.	The ratio of the mass of water vapor to the total mass of air at the tropopause pressure given by TROPPB (kg water/kg total air).
TROPT	Tropopause Temperature using blended TROPP estimate.	The air (dry bulb) temperature at the tropopause pressure given by TROPPB.
T2MWET	Wet Bulb Temperature at 2 Meters	The adiabatic saturation temperature which can be measured by a thermometer covered in a water-soaked cloth over which air is passed at 2 meters above the surface of the earth.
WD10M	Wind Direction at 10 Meters	The average of the wind direction at 10 meters above the surface of the earth.
WD2M	Wind Direction at 2 Meters	The average of the wind direction at 2 meters above the surface of the earth.
WD50M	Wind Direction at 50 Meters	The average of the wind direction at 50 meters above the surface of the earth.
WS10M	Wind Speed at 10 Meters	The average of wind speed at 10 meters above the surface of the earth.
WS10M_MAX	Wind Speed at 10 Meters Maximum	The maximum hourly wind speed at 10 meters above the surface of the earth.
WS10M_MAX_AVG	Wind Speed at 10 Meters Maximum Average	The average of the maximum daily wind speed at 10 meters above the surface of the earth.
WS10M_MIN	Wind Speed at 10 Meters Minimum	The minimum hourly wind speed at 10 meters above the surface of the earth.
WS10M_MIN_AVG	Wind Speed at 10 Meters Minimum Average	The average of the minimum daily wind speed at 10 meters above the surface of the earth.
WS10M_RANGE	Wind Speed at 10 Meters Range	The minimum and maximum hourly wind speed range at 10 meters above the surface of the earth.
WS10M_RANGE_AVG	Wind Speed at 10 Meters Range Average	The average minimum and maximum daily wind speed range at 10 meters above the surface of the earth.
WS2M	Wind Speed at 2 Meters	The average of wind speed at 2 meters above the surface of the earth.
WS2M_MAX	Wind Speed at 2 Meters Maximum	The maximum hourly wind speed at 2 meters above the surface of the earth.
WS2M_MAX_AVG	Wind Speed at 2 Meters Maximum Average	The average of the maximum daily wind speed at 2 meters above the surface of the earth.
WS2M_MIN	Wind Speed at 2 Meters Minimum	The minimum hourly wind speed at 2 meters above the surface of the earth.
WS2M_MIN_AVG	Wind Speed at 2 Meters Minimum Average	The average of the minimum daily wind speed at 2 meters above the surface of the earth.
WS2M_RANGE	Wind Speed at 2 Meters Range	The minimum and maximum hourly wind speed range at 2 meters above the surface of the earth.
WS2M_RANGE_AVG	Wind Speed at 2 Meters Range Average	The average minimum and maximum daily wind speed range at 2 meters above the surface of the earth.
WS50M	Wind Speed at 50 Meters	The average of wind speed at 50 meters above the surface of the earth.
WS50M_MAX	Wind Speed at 50 Meters Maximum	The maximum hourly wind speed at 50 meters above the surface of the earth.
WS50M_MAX_AVG	Wind Speed at 50 Meters Maximum Average	The average of the maximum daily wind speed at 50 meters above the surface of the earth.
WS50M_MIN	Wind Speed at 50 Meters Minimum	The minimum hourly wind speed at 50 meters above the surface of the earth.
WS50M_MIN_AVG	Wind Speed at 50 Meters Minimum Average	The average of the minimum daily wind speed at 50 meters above the surface of the earth.
WS50M_RANGE	Wind Speed at 50 Meters Range	The minimum and maximum hourly wind speed range at 50 meters above the surface of the earth.
WS50M_RANGE_AVG	Wind Speed at 50 Meters Range Average	The average minimum and maximum daily wind speed range at 50 meters above the surface of the earth.
DISPH	Zero Plane Displacement Height	The height at which the mean velocity is zero due to large obstacles such as buildings/canopy.

Radiation

Spatial resolution of 1 x 1 degrees of latitude and longitude respectively

Abbreviation	Name	Climatology definition
AOD_55_ADJ	Adjusted Aerosol Optical Depth 55	The adjusted optical thickness at 0.55 um measured vertically; the component of the atmosphere to quantify the removal of radiant energy from an incident beam.
AOD_55	Aerosol Optical Depth 55	The optical thickness at 0.55 um measured vertically; the component of the atmosphere to quantify the removal of radiant energy from an incident beam.
AOD_84	Aerosol Optical Depth 84	The optical thickness at 0.84 um measured vertically; the component of the atmosphere to quantify the removal of radiant energy from an incident beam.
AIRMASS	Air Mass	Air Mass according to Perez et al. 1990.
ALLSKY_KT	All Sky Insolation Clearness Index	A fraction representing clearness of the atmosphere; the all sky insolation that is transmitted through the atmosphere to strike the surface of the earth divided by the average of top of the atmosphere total solar irradiance incident.
ALLSKY_KT_MAX	All Sky Insolation Clearness Index Maximum	The maximum clearness of the atmosphere; the all sky insolation that is transmitted through the atmosphere to strike the surface of the earth divided by the average of top of the atmosphere total solar irradiance incident.
ALLSKY_KT_MIN	All Sky Insolation Clearness Index Minimum	The minimum clearness of the atmosphere; the all sky insolation that is transmitted through the atmosphere to strike the surface of the earth divided by the average of top of the atmosphere total solar irradiance incident.
ALLSKY_KT_SD	All Sky Insolation Clearness Index Standard Deviation	The standard deviation of the clearness atmosphere; the all sky insolation that is transmitted through the atmosphere to strike the surface of the earth divided by the average of top of the atmosphere total solar irradiance incident.
ALLSKY_NKT	All Sky Normalized Insolation Clearness Index	The average zenith angle-independent expression of the all sky insolation clearness index.
ALLSKY_SRF_ALB	All Sky Surface Albedo	The all sky rate of reflectivity of the earth's surface; the ratio of the solar energy reflected by the surface of the earth compared to the total solar energy incident reaching the surface of the earth.
ALLSKY_SFC_LW_DWN	All Sky Surface Longwave Downward Irradiance	The downward thermal infrared irradiance under all sky conditions reaching a horizontal plane the surface of the earth. Also known as Horizontal Infrared Radiation Intensity from Sky.
ALLSKY_SFC_LW_DWN_MAX	All Sky Surface Longwave Downward Irradiance Maximum	The maximum downward thermal infrared irradiance under all sky conditions reaching a horizontal plane the surface of the earth. Also known as Horizontal Infrared Radiation Intensity from Sky.
ALLSKY_SFC_LW_DWN_MIN	All Sky Surface Longwave Downward Irradiance Minimum	The minimum downward thermal infrared irradiance under all sky conditions reaching a horizontal plane the surface of the earth. Also known as Horizontal Infrared Radiation Intensity from Sky.
ALLSKY_SFC_LW_DWN_SD	All Sky Surface Longwave Downward Irradiance Standard Deviation	The standard deviation of downward thermal infrared irradiance under all sky conditions reaching a horizontal plane the surface of the earth. Also known as Horizontal Infrared Radiation Intensity from Sky.
ALLSKY_SFC_LW_UP	All Sky Surface Longwave Upward Irradiance	The upward thermal infrared irradiance under all sky conditions.
ALLSKY_SFC_LW_UP_MAX	All Sky Surface Longwave Upward Irradiance Maximum	The maximum upward thermal infrared irradiance under all sky conditions.
ALLSKY_SFC_LW_UP_MIN	All Sky Surface Longwave Upward Irradiance Minimum	The minimum upward thermal infrared irradiance under all sky conditions.
ALLSKY_SFC_LW_UP_SD	All Sky Surface Longwave Upward Irradiance Standard Deviation	The standard deviation of upward thermal infrared irradiance under all sky conditions.
ALLSKY_SFC_PAR_TOT	All Sky Surface PAR Total	The total Photosynthetically Active Radiation (PAR) incident on a horizontal plane at the surface of the earth under all sky conditions.
ALLSKY_SFC_PAR_TOT_MAX	All Sky Surface PAR Total Maximum	The maximum total Photosynthetically Active Radiation (PAR) incident on a horizontal plane at the surface of the earth under all sky conditions.
ALLSKY_SFC_PAR_TOT_MIN	All Sky Surface PAR Total Minimum	The minimum total Photosynthetically Active Radiation (PAR) incident on a horizontal plane at the surface of the earth under all sky conditions.
ALLSKY_SFC_PAR_TOT_SD	All Sky Surface PAR Total Standard Deviation	The standard deviation of total Photosynthetically Active Radiation (PAR) incident on a horizontal plane at the surface of the earth under all sky conditions.
ALLSKY_SFC_SW_DIFF	All Sky Surface Shortwave Diffuse Irradiance	The diffuse (light energy scattered out of the direction of the sun) solar irradiance incident on a horizontal plane at the surface of the earth under all sky conditions.
ALLSKY_SFC_SW_DIFF_MAX	All Sky Surface Shortwave Diffuse Irradiance Maximum	The maximum diffuse (light energy scattered out of the direction of the sun) solar irradiance incident on a horizontal plane at the surface of the earth under all sky conditions.
ALLSKY_SFC_SW_DIFF_MIN	All Sky Surface Shortwave Diffuse Irradiance Minimum	The minimum diffuse (light energy scattered out of the direction of the sun) solar irradiance incident on a horizontal plane at the surface of the earth under all sky conditions.
ALLSKY_SFC_SW_DIFF_SD	All Sky Surface Shortwave Diffuse Irradiance Standard Deviation	The standard deviation of diffuse (light energy scattered out of the direction of the sun) solar irradiance incident on a horizontal plane at the surface of the earth under all sky conditions.
ALLSKY_SFC_SW_DIRH	All Sky Surface Shortwave Direct Horizontal Irradiance	The direct solar irradiance incident on a horizontal plane at the surface of the earth under all sky conditions.
ALLSKY_SFC_SW_DIRH_MAX	All Sky Surface Shortwave Direct Horizontal Irradiance Maximum	The maximum direct solar irradiance incident on a horizontal plane at the surface of the earth under all sky conditions.
ALLSKY_SFC_SW_DIRH_MIN	All Sky Surface Shortwave Direct Horizontal Irradiance Minimum	The minimum direct solar irradiance incident on a horizontal plane at the surface of the earth under all sky conditions.
ALLSKY_SFC_SW_DIRH_SD	All Sky Surface Shortwave Direct Horizontal Irradiance Standard Deviation	The standard deviation of direct solar irradiance incident on a horizontal plane at the surface of the earth under all sky conditions.
ALLSKY_SFC_SW_DNI	All Sky Surface Shortwave Downward Direct Normal Irradiance	The direct solar irradiance incident to a horizontal plane normal (perpendicular) to the direction of the sun's position under all sky conditions.
ALLSKY_SFC_SW_DNI_MAX	All Sky Surface Shortwave Downward Direct Normal Irradiance Maximum	The maximum direct solar irradiance incident to a horizontal plane normal (perpendicular) to the direction of the sun's position under all sky conditions.
ALLSKY_SFC_SW_DNI_MAX_RD	All Sky Surface Shortwave Downward Direct Normal Irradiance Maximum Relative Difference	The percentage of the difference of the maximum surface solar irradiance relative to the mean solar irradiance.
ALLSKY_SFC_SW_DNI_MIN	All Sky Surface Shortwave Downward Direct Normal Irradiance Minimum	The minimum direct solar irradiance incident to a horizontal plane normal (perpendicular) to the direction of the sun's position under all sky conditions.
ALLSKY_SFC_SW_DNI_MIN_RD	All Sky Surface Shortwave Downward Direct Normal Irradiance Minimum Relative Difference	The percentage of the difference of the minumum surface solar irradiance relative to the mean solar irradiance.
ALLSKY_SFC_SW_DNI_SD	All Sky Surface Shortwave Downward Direct Normal Irradiance Standard Deviation	The standard deviation of direct solar irradiance incident to a horizontal plane normal (perpendicular) to the direction of the sun's position under all sky conditions.
ALLSKY_SFC_SW_DWN	All Sky Surface Shortwave Downward Irradiance	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions. An alternative term for the total solar irradiance is the "Global Horizontal Irradiance" or GHI.
ALLSKY_SFC_SW_DWN_MAX	All Sky Surface Shortwave Downward Irradiance Maximum	The maximum total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions.
ALLSKY_SFC_SW_DWN_MAX_RD	All Sky Surface Shortwave Downward Irradiance Maximum Relative Difference	The percentage of the difference of the maximum surface solar irradiance relative to the mean surface solar irradiance, under all sky conditions.
ALLSKY_SFC_SW_DWN_MIN	All Sky Surface Shortwave Downward Irradiance Minimum	The minimum total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions.
ALLSKY_SFC_SW_DWN_MIN_RD	All Sky Surface Shortwave Downward Irradiance Minimum Relative Difference	The percentage of the difference of the minumum surface solar irradiance relative to the mean surface solar irradiance, under all sky conditions.
ALLSKY_SFC_SW_DWN_SD	All Sky Surface Shortwave Downward Irradiance Standard Deviation	The standard deviation total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions.
ALLSKY_SFC_SW_DWN_00	All Sky Surface Shortwave Downward Irradiance at 00 GMT	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at 00 GMT.
ALLSKY_SFC_SW_DWN_01	All Sky Surface Shortwave Downward Irradiance at 01 GMT	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at 01 GMT.
ALLSKY_SFC_SW_DWN_02	All Sky Surface Shortwave Downward Irradiance at 02 GMT	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at 02 GMT.
ALLSKY_SFC_SW_DWN_03	All Sky Surface Shortwave Downward Irradiance at 03 GMT	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at 03 GMT.
ALLSKY_SFC_SW_DWN_04	All Sky Surface Shortwave Downward Irradiance at 04 GMT	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at 04 GMT.
ALLSKY_SFC_SW_DWN_05	All Sky Surface Shortwave Downward Irradiance at 05 GMT	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at 05 GMT.
ALLSKY_SFC_SW_DWN_06	All Sky Surface Shortwave Downward Irradiance at 06 GMT	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at 06 GMT.
ALLSKY_SFC_SW_DWN_07	All Sky Surface Shortwave Downward Irradiance at 07 GMT	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at 07 GMT.
ALLSKY_SFC_SW_DWN_08	All Sky Surface Shortwave Downward Irradiance at 08 GMT	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at 08 GMT.
ALLSKY_SFC_SW_DWN_09	All Sky Surface Shortwave Downward Irradiance at 09 GMT	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at 09 GMT.
ALLSKY_SFC_SW_DWN_10	All Sky Surface Shortwave Downward Irradiance at 10 GMT	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at 10 GMT.
ALLSKY_SFC_SW_DWN_11	All Sky Surface Shortwave Downward Irradiance at 11 GMT	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at 11 GMT.
ALLSKY_SFC_SW_DWN_12	All Sky Surface Shortwave Downward Irradiance at 12 GMT	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at 12 GMT.
ALLSKY_SFC_SW_DWN_13	All Sky Surface Shortwave Downward Irradiance at 13 GMT	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at 13 GMT.
ALLSKY_SFC_SW_DWN_14	All Sky Surface Shortwave Downward Irradiance at 14 GMT	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at 14 GMT.
ALLSKY_SFC_SW_DWN_15	All Sky Surface Shortwave Downward Irradiance at 15 GMT	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at 15 GMT.
ALLSKY_SFC_SW_DWN_16	All Sky Surface Shortwave Downward Irradiance at 16 GMT	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at 16 GMT.
ALLSKY_SFC_SW_DWN_17	All Sky Surface Shortwave Downward Irradiance at 17 GMT	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at 17 GMT.
ALLSKY_SFC_SW_DWN_18	All Sky Surface Shortwave Downward Irradiance at 18 GMT	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at 18 GMT.
ALLSKY_SFC_SW_DWN_19	All Sky Surface Shortwave Downward Irradiance at 19 GMT	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at 19 GMT.
ALLSKY_SFC_SW_DWN_20	All Sky Surface Shortwave Downward Irradiance at 20 GMT	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at 20 GMT.
ALLSKY_SFC_SW_DWN_21	All Sky Surface Shortwave Downward Irradiance at 21 GMT	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at 21 GMT.
ALLSKY_SFC_SW_DWN_22	All Sky Surface Shortwave Downward Irradiance at 22 GMT	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at 22 GMT.
ALLSKY_SFC_SW_DWN_23	All Sky Surface Shortwave Downward Irradiance at 23 GMT	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at 23 GMT.
ALLSKY_SFC_SW_DWN_HR	All Sky Surface Shortwave Downward Irradiance at GMT Times	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under all sky conditions at GMT Times.
ALLSKY_SFC_SW_UP	All Sky Surface Shortwave Upward Irradiance	The upward shortwave irradiance under all sky conditions.
ALLSKY_SFC_SW_UP_MAX	All Sky Surface Shortwave Upward Irradiance Maximum	The maximum upward shortwave irradiance under all sky conditions.
ALLSKY_SFC_SW_UP_MIN	All Sky Surface Shortwave Upward Irradiance Minimum	The minimum upward shortwave irradiance under all sky conditions.
ALLSKY_SFC_SW_UP_SD	All Sky Surface Shortwave Upward Irradiance Standard Deviation	The standard deviation of upward shortwave irradiance under all sky conditions.
ALLSKY_SFC_UV_INDEX	All Sky Surface UV Index	The ultraviolet radiation exposure index.
ALLSKY_SFC_UV_INDEX_MAX	All Sky Surface UV Index Maximum	The maximum ultraviolet radiation exposure index.
ALLSKY_SFC_UV_INDEX_MIN	All Sky Surface UV Index Minimum	The minimum ultraviolet radiation exposure index.
ALLSKY_SFC_UV_INDEX_SD	All Sky Surface UV Index Standard Deviation	The standard deviation of ultraviolet radiation exposure index.
ALLSKY_SFC_UVA	All Sky Surface UVA Irradiance	The ultraviolet A (UVA 315nm-400nm) irradiance under all sky conditions.
ALLSKY_SFC_UVA_MAX	All Sky Surface UVA Irradiance Maximum	The maximum ultraviolet A (UVA 315nm-400nm) irradiance under all sky conditions.
ALLSKY_SFC_UVA_MIN	All Sky Surface UVA Irradiance Minimum	The minimum ultraviolet A (UVA 315nm-400nm) irradiance under all sky conditions.
ALLSKY_SFC_UVA_SD	All Sky Surface UVA Irradiance Standard Deviation	The standard deviation of ultraviolet A (UVA 315nm-400nm) irradiance under all sky conditions.
ALLSKY_SFC_UVB	All Sky Surface UVB Irradiance	The ultraviolet B (UVB 280nm-315nm) irradiance under all sky conditions.
ALLSKY_SFC_UVB_MAX	All Sky Surface UVB Irradiance Maximum	The maximum ultraviolet B (UVB 280nm-315nm) irradiance under all sky conditions.
ALLSKY_SFC_UVB_MIN	All Sky Surface UVB Irradiance Minimum	The minimum ultraviolet B (UVB 280nm-315nm) irradiance under all sky conditions.
ALLSKY_SFC_UVB_SD	All Sky Surface UVB Irradiance Standard Deviation	The standard deviation of ultraviolet B (UVB 280nm-315nm) irradiance under all sky conditions.
SG_MID_COZ_ZEN_ANG	Average Cosine Solar Zenith Angle At Mid-Time Between Sunrise And Solar Noon for Climatological Month	Approximate monthly average ratio of horizontal plane solar beam radiation to direct normal radiation. The determination of monthly averaged cosine solar zenith angle at mid-time between sunrise and solar noon for each month is based on the monthly average day (see Methodology).
SG_DEC	Average Declination for Climatological Month	The angular distance of the sun north (positive) or south (negative) of the equator. Declination varies through the year from 23.45 degrees north to 23.45 degrees south and reaches the minimum/maximum at the southern/northern summer solstices. The determination of monthly averaged declination for each month is based on the monthly average day (see Methodology).
SG_HRZ_HR	Average Hourly Solar Angles Relative To The Horizon for Climatological Month	The vertical angle of the sun above the horizon at GMT Times. The determination of monthly averaged maximum solar angle relative to the horizon for each month is based on the monthly average day (See Methodology).
SG_HRZ_00	Average Hourly Solar Angles Relative To The Horizon for Climatological Month at 00 GMT	The vertical angle of the sun above the horizon at 00 GMT.
SG_HRZ_01	Average Hourly Solar Angles Relative To The Horizon for Climatological Month at 01 GMT	The vertical angle of the sun above the horizon at 01 GMT.
SG_HRZ_02	Average Hourly Solar Angles Relative To The Horizon for Climatological Month at 02 GMT	The vertical angle of the sun above the horizon at 02 GMT.
SG_HRZ_03	Average Hourly Solar Angles Relative To The Horizon for Climatological Month at 03 GMT	The vertical angle of the sun above the horizon at 03 GMT.
SG_HRZ_04	Average Hourly Solar Angles Relative To The Horizon for Climatological Month at 04 GMT	The vertical angle of the sun above the horizon at 04 GMT.
SG_HRZ_05	Average Hourly Solar Angles Relative To The Horizon for Climatological Month at 05 GMT	The vertical angle of the sun above the horizon at 05 GMT.
SG_HRZ_06	Average Hourly Solar Angles Relative To The Horizon for Climatological Month at 06 GMT	The vertical angle of the sun above the horizon at 06 GMT.
SG_HRZ_07	Average Hourly Solar Angles Relative To The Horizon for Climatological Month at 07 GMT	The vertical angle of the sun above the horizon at 07 GMT.
SG_HRZ_08	Average Hourly Solar Angles Relative To The Horizon for Climatological Month at 08 GMT	The vertical angle of the sun above the horizon at 08 GMT.
SG_HRZ_09	Average Hourly Solar Angles Relative To The Horizon for Climatological Month at 09 GMT	The vertical angle of the sun above the horizon at 09 GMT.
SG_HRZ_10	Average Hourly Solar Angles Relative To The Horizon for Climatological Month at 10 GMT	The vertical angle of the sun above the horizon at 10 GMT.
SG_HRZ_11	Average Hourly Solar Angles Relative To The Horizon for Climatological Month at 11 GMT	The vertical angle of the sun above the horizon at 11 GMT.
SG_HRZ_12	Average Hourly Solar Angles Relative To The Horizon for Climatological Month at 12 GMT	The vertical angle of the sun above the horizon at 12 GMT.
SG_HRZ_13	Average Hourly Solar Angles Relative To The Horizon for Climatological Month at 13 GMT	The vertical angle of the sun above the horizon at 13 GMT.
SG_HRZ_14	Average Hourly Solar Angles Relative To The Horizon for Climatological Month at 14 GMT	The vertical angle of the sun above the horizon at 14 GMT.
SG_HRZ_15	Average Hourly Solar Angles Relative To The Horizon for Climatological Month at 15 GMT	The vertical angle of the sun above the horizon at 15 GMT.
SG_HRZ_16	Average Hourly Solar Angles Relative To The Horizon for Climatological Month at 16 GMT	The vertical angle of the sun above the horizon at 16 GMT.
SG_HRZ_17	Average Hourly Solar Angles Relative To The Horizon for Climatological Month at 17 GMT	The vertical angle of the sun above the horizon at 17 GMT.
SG_HRZ_18	Average Hourly Solar Angles Relative To The Horizon for Climatological Month at 18 GMT	The vertical angle of the sun above the horizon at 18 GMT.
SG_HRZ_19	Average Hourly Solar Angles Relative To The Horizon for Climatological Month at 19 GMT	The vertical angle of the sun above the horizon at 19 GMT.
SG_HRZ_20	Average Hourly Solar Angles Relative To The Horizon for Climatological Month at 20 GMT	The vertical angle of the sun above the horizon at 20 GMT.
SG_HRZ_21	Average Hourly Solar Angles Relative To The Horizon for Climatological Month at 21 GMT	The vertical angle of the sun above the horizon at 21 GMT.
SG_HRZ_22	Average Hourly Solar Angles Relative To The Horizon for Climatological Month at 22 GMT	The vertical angle of the sun above the horizon at 22 GMT.
SG_HRZ_23	Average Hourly Solar Angles Relative To The Horizon for Climatological Month at 23 GMT	The vertical angle of the sun above the horizon at 23 GMT.
SG_SAA_HR	Average Solar Azimuth Angle for Climatological Month	The angle of the vector from the earth point to the suns position at GMT Times.
SG_SAA_00	Average Solar Azimuth Angle for Climatological Month at 00 GMT	The angle of the vector from the earth point to the suns position at 00 GMT.
SG_SAA_01	Average Solar Azimuth Angle for Climatological Month at 01 GMT	The angle of the vector from the earth point to the suns position at 01 GMT.
SG_SAA_02	Average Solar Azimuth Angle for Climatological Month at 02 GMT	The angle of the vector from the earth point to the suns position at 02 GMT.
SG_SAA_03	Average Solar Azimuth Angle for Climatological Month at 03 GMT	The angle of the vector from the earth point to the suns position at 03 GMT.
SG_SAA_04	Average Solar Azimuth Angle for Climatological Month at 04 GMT	The angle of the vector from the earth point to the suns position at 04 GMT.
SG_SAA_05	Average Solar Azimuth Angle for Climatological Month at 05 GMT	The angle of the vector from the earth point to the suns position at 05 GMT.
SG_SAA_06	Average Solar Azimuth Angle for Climatological Month at 06 GMT	The angle of the vector from the earth point to the suns position at 06 GMT.
SG_SAA_07	Average Solar Azimuth Angle for Climatological Month at 07 GMT	The angle of the vector from the earth point to the suns position at 07 GMT.
SG_SAA_08	Average Solar Azimuth Angle for Climatological Month at 08 GMT	The angle of the vector from the earth point to the suns position at 08 GMT.
SG_SAA_09	Average Solar Azimuth Angle for Climatological Month at 09 GMT	The angle of the vector from the earth point to the suns position at 09 GMT.
SG_SAA_10	Average Solar Azimuth Angle for Climatological Month at 10 GMT	The angle of the vector from the earth point to the suns position at 10 GMT.
SG_SAA_11	Average Solar Azimuth Angle for Climatological Month at 11 GMT	The angle of the vector from the earth point to the suns position at 11 GMT.
SG_SAA_12	Average Solar Azimuth Angle for Climatological Month at 12 GMT	The angle of the vector from the earth point to the suns position at 12 GMT.
SG_SAA_13	Average Solar Azimuth Angle for Climatological Month at 13 GMT	The angle of the vector from the earth point to the suns position at 13 GMT.
SG_SAA_14	Average Solar Azimuth Angle for Climatological Month at 14 GMT	The angle of the vector from the earth point to the suns position at 14 GMT.
SG_SAA_15	Average Solar Azimuth Angle for Climatological Month at 15 GMT	The angle of the vector from the earth point to the suns position at 15 GMT.
SG_SAA_16	Average Solar Azimuth Angle for Climatological Month at 16 GMT	The angle of the vector from the earth point to the suns position at 16 GMT.
SG_SAA_17	Average Solar Azimuth Angle for Climatological Month at 17 GMT	The angle of the vector from the earth point to the suns position at 17 GMT.
SG_SAA_18	Average Solar Azimuth Angle for Climatological Month at 18 GMT	The angle of the vector from the earth point to the suns position at 18 GMT.
SG_SAA_19	Average Solar Azimuth Angle for Climatological Month at 19 GMT	The angle of the vector from the earth point to the suns position at 19 GMT.
SG_SAA_20	Average Solar Azimuth Angle for Climatological Month at 20 GMT	The angle of the vector from the earth point to the suns position at 20 GMT.
SG_SAA_21	Average Solar Azimuth Angle for Climatological Month at 21 GMT	The angle of the vector from the earth point to the suns position at 21 GMT.
SG_SAA_22	Average Solar Azimuth Angle for Climatological Month at 22 GMT	The angle of the vector from the earth point to the suns position at 22 GMT.
SG_SAA_23	Average Solar Azimuth Angle for Climatological Month at 23 GMT	The angle of the vector from the earth point to the suns position at 23 GMT.
SG_HR_SET_ANG	Average Sunset Hour Angle for Climatological Month	The angle that the earth has rotated between the time of solar noon and sunset. Note that the earth rotates 15 degrees with respect to the sun each hour. The determination of monthly averaged sunset hour angle for each month is based on the monthly average day (See Methodology).
CLRSKY_DAYS	Clear Sky Day	The number of Clear Sky Days if the daytime cloud amount is less than 10 percent.
CLRSKY_KT	Clear Sky Insolation Clearness Index	A fraction representing clearness of the atmosphere; the clear sky insolation that is transmitted through the atmosphere to strike the surface of the earth divided by the average of top of the atmosphere total solar irradiance incident.
CLRSKY_KT_MAX	Clear Sky Insolation Clearness Index Maximum	The maximum clearness of the atmosphere; the clear sky insolation that is transmitted through the atmosphere to strike the surface of the earth divided by the average of top of the atmosphere total solar irradiance incident.
CLRSKY_KT_MIN	Clear Sky Insolation Clearness Index Minimum	The minimum clearness of the atmosphere; the clear sky insolation that is transmitted through the atmosphere to strike the surface of the earth divided by the average of top of the atmosphere total solar irradiance incident.
CLRSKY_KT_SD	Clear Sky Insolation Clearness Index Standard Deviation	The standard deviation of the clearness atmosphere; the clear sky insolation that is transmitted through the atmosphere to strike the surface of the earth divided by the average of top of the atmosphere total solar irradiance incident.
CLRSKY_NKT	Clear Sky Normalized Insolation Clearness Index	The average zenith angle-independent expression of the clear sky insolation clearness index.
CLRSKY_SRF_ALB	Clear Sky Surface Albedo	The clear sky rate of reflectivity of the earth's surface; the ratio of the solar energy reflected by the surface of the earth compared to the total solar energy incident reaching the surface of the earth.
CLRSKY_SFC_LW_DWN	Clear Sky Surface Longwave Downward Irradiance	The downward thermal infrared irradiance under clear sky conditions reaching a horizontal plane the surface of the earth. Also known as Horizontal Infrared Radiation Intensity from Sky.
CLRSKY_SFC_LW_DWN_MAX	Clear Sky Surface Longwave Downward Irradiance Maximum	The maximum downward thermal infrared irradiance under clear sky conditions reaching a horizontal plane the surface of the earth. Also known as Horizontal Infrared Radiation Intensity from Sky.
CLRSKY_SFC_LW_DWN_MIN	Clear Sky Surface Longwave Downward Irradiance Minimum	The minimum downward thermal infrared irradiance under clear sky conditions reaching a horizontal plane the surface of the earth. Also known as Horizontal Infrared Radiation Intensity from Sky.
CLRSKY_SFC_LW_DWN_SD	Clear Sky Surface Longwave Downward Irradiance Standard Deviation	The standard deviation of downward thermal infrared irradiance under clear sky conditions reaching a horizontal plane the surface of the earth. Also known as Horizontal Infrared Radiation Intensity from Sky.
CLRSKY_SFC_LW_UP	Clear Sky Surface Longwave Upward Irradiance	The upward thermal infrared irradiance under clear sky conditions.
CLRSKY_SFC_LW_UP_MAX	Clear Sky Surface Longwave Upward Irradiance Maximum	The maximum upward thermal infrared irradiance under clear sky conditions.
CLRSKY_SFC_LW_UP_MIN	Clear Sky Surface Longwave Upward Irradiance Minimum	The minimum upward thermal infrared irradiance under clear sky conditions.
CLRSKY_SFC_LW_UP_SD	Clear Sky Surface Longwave Upward Irradiance Standard Deviation	The standard deviation of upward thermal infrared irradiance under clear sky conditions
CLRSKY_SFC_PAR_TOT	Clear Sky Surface PAR Total	The total Photosynthetically Active Radiation (PAR) incident on a horizontal plane at the surface of the earth under clear sky conditions.
CLRSKY_SFC_PAR_TOT_MAX	Clear Sky Surface PAR Total Maximum	The maximum total Photosynthetically Active Radiation (PAR) incident on a horizontal plane at the surface of the earth under clear sky conditions.
CLRSKY_SFC_PAR_TOT_MIN	Clear Sky Surface PAR Total Minimum	The minimum total Photosynthetically Active Radiation (PAR) incident on a horizontal plane at the surface of the earth under clear sky conditions.
CLRSKY_SFC_PAR_TOT_SD	Clear Sky Surface PAR Total Standard Deviation	The standard deviation of total Photosynthetically Active Radiation (PAR) incident on a horizontal plane at the surface of the earth under clear sky conditions.
CLRSKY_SFC_SW_DIRH	Clear Sky Surface Shortwave Direct Horizontal Irradiance	The direct solar irradiance incident on a horizontal plane at the surface of the earth under clear sky conditions.
CLRSKY_SFC_SW_DIRH_MAX	Clear Sky Surface Shortwave Direct Horizontal Irradiance Maximum	The maximum direct solar irradiance incident on a horizontal plane at the surface of the earth under clear sky conditions.
CLRSKY_SFC_SW_DIRH_MIN	Clear Sky Surface Shortwave Direct Horizontal Irradiance Minimum	The minimum direct solar irradiance incident on a horizontal plane at the surface of the earth under clear sky conditions.
CLRSKY_SFC_SW_DIRH_SD	Clear Sky Surface Shortwave Direct Horizontal Irradiance Standard Deviation	The standard deviation of direct solar irradiance incident on a horizontal plane at the surface of the earth under clear sky conditions.
CLRSKY_SFC_SW_DIFF	Clear Sky Surface Shortwave Downward Diffuse Horizontal Irradiance	The diffuse (light energy scattered out of the direction of the sun) solar irradiance incident on a horizontal plane at the surface of the earth under clear sky conditions.
CLRSKY_SFC_SW_DIFF_MAX	Clear Sky Surface Shortwave Downward Diffuse Horizontal Irradiance Maximum	The maximum diffuse (light energy scattered out of the direction of the sun) solar irradiance incident on a horizontal plane at the surface of the earth under clear sky conditions.
CLRSKY_SFC_SW_DIFF_MIN	Clear Sky Surface Shortwave Downward Diffuse Horizontal Irradiance Minimum	The minimum diffuse (light energy scattered out of the direction of the sun) solar irradiance incident on a horizontal plane at the surface of the earth under clear sky conditions.
CLRSKY_SFC_SW_DIFF_SD	Clear Sky Surface Shortwave Downward Diffuse Horizontal Irradiance Standard Deviation	The standard deviation of diffuse (light energy scattered out of the direction of the sun) solar irradiance incident on a horizontal plane at the surface of the earth under clear sky conditions.
CLRSKY_SFC_SW_DNI_SD	Clear Sky Surface Shortwave Downward Direct Normal Irradiance	The standard deviation of direct solar irradiance incident to a horizontal plane normal (perpendicular) to the direction of the sun's position under clear sky conditions.
CLRSKY_SFC_SW_DNI	Clear Sky Surface Shortwave Downward Direct Normal Irradiance	The direct solar irradiance incident to a horizontal plane normal (perpendicular) to the direction of the sun's position under clear sky conditions.
CLRSKY_SFC_SW_DNI_MAX	Clear Sky Surface Shortwave Downward Direct Normal Irradiance Maximum	The maximum direct solar irradiance incident to a horizontal plane normal (perpendicular) to the direction of the sun's position under clear sky conditions.
CLRSKY_SFC_SW_DNI_MIN	Clear Sky Surface Shortwave Downward Direct Normal Irradiance Minimum	The minimum direct solar irradiance incident to a horizontal plane normal (perpendicular) to the direction of the sun's position under clear sky conditions.
CLRSKY_SFC_SW_DWN	Clear Sky Surface Shortwave Downward Irradiance	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under clear sky conditions. An alternative term for the total solar irradiance is the "Global Horizontal Irradiance" or GHI.
CLRSKY_SFC_SW_DWN_MAX	Clear Sky Surface Shortwave Downward Irradiance Maximum	The maximum total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under clear sky conditions.
CLRSKY_SFC_SW_DWN_MIN	Clear Sky Surface Shortwave Downward Irradiance Minimum	The minimum total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under clear sky conditions.
CLRSKY_SFC_SW_DWN_SD	Clear Sky Surface Shortwave Downward Irradiance Standard Deviation	The standard deviation of total solar irradiance incident (direct plus diffuse) on a horizontal plane at the surface of the earth under clear sky conditions.
CLRSKY_SFC_SW_UP	Clear Sky Surface Shortwave Upward Irradiance	The upward shortwave irradiance under clearsky conditions.
CLRSKY_SFC_SW_UP_MAX	Clear Sky Surface Shortwave Upward Irradiance Maximum	The maximum upward shortwave irradiance under clearsky conditions.
CLRSKY_SFC_SW_UP_MIN	Clear Sky Surface Shortwave Upward Irradiance Minimum	The minimum upward shortwave irradiance under clearsky conditions.
CLRSKY_SFC_SW_UP_SD	Clear Sky Surface Shortwave Upward Irradiance Standard Deviation	The standard deviation of upward shortwave irradiance under clearsky conditions.
CLOUD_AMT	Cloud Amount	The average percent of cloud amount during the temporal period.
CLOUD_AMT_00	Cloud Amount at 00 GMT	The average percent of cloud amount during daylight at 00 GMT.
CLOUD_AMT_01	Cloud Amount at 01 GMT	The average percent of cloud amount during daylight at 01 GMT.
CLOUD_AMT_02	Cloud Amount at 02 GMT	The average percent of cloud amount during daylight at 02 GMT.
CLOUD_AMT_03	Cloud Amount at 03 GMT	The average percent of cloud amount during daylight at 03 GMT.
CLOUD_AMT_04	Cloud Amount at 04 GMT	The average percent of cloud amount during daylight at 04 GMT.
CLOUD_AMT_05	Cloud Amount at 05 GMT	The average percent of cloud amount during daylight at 05 GMT.
CLOUD_AMT_06	Cloud Amount at 06 GMT	The average percent of cloud amount during daylight at 06 GMT.
CLOUD_AMT_07	Cloud Amount at 07 GMT	The average percent of cloud amount during daylight at 07 GMT.
CLOUD_AMT_08	Cloud Amount at 08 GMT	The average percent of cloud amount during daylight at 08 GMT.
CLOUD_AMT_09	Cloud Amount at 09 GMT	The average percent of cloud amount during daylight at 09 GMT.
CLOUD_AMT_10	Cloud Amount at 10 GMT	The average percent of cloud amount during daylight at 10 GMT.
CLOUD_AMT_11	Cloud Amount at 11 GMT	The average percent of cloud amount during daylight at 11 GMT.
CLOUD_AMT_12	Cloud Amount at 12 GMT	The average percent of cloud amount during daylight at 12 GMT.
CLOUD_AMT_13	Cloud Amount at 13 GMT	The average percent of cloud amount during daylight at 13 GMT.
CLOUD_AMT_14	Cloud Amount at 14 GMT	The average percent of cloud amount during daylight at 14 GMT.
CLOUD_AMT_15	Cloud Amount at 15 GMT	The average percent of cloud amount during daylight at 15 GMT.
CLOUD_AMT_16	Cloud Amount at 16 GMT	The average percent of cloud amount during daylight at 16 GMT.
CLOUD_AMT_17	Cloud Amount at 17 GMT	The average percent of cloud amount during daylight at 17 GMT.
CLOUD_AMT_18	Cloud Amount at 18 GMT	The average percent of cloud amount during daylight at 18 GMT.
CLOUD_AMT_19	Cloud Amount at 19 GMT	The average percent of cloud amount during daylight at 19 GMT.
CLOUD_AMT_20	Cloud Amount at 20 GMT	The average percent of cloud amount during daylight at 20 GMT.
CLOUD_AMT_21	Cloud Amount at 21 GMT	The average percent of cloud amount during daylight at 21 GMT.
CLOUD_AMT_22	Cloud Amount at 22 GMT	The average percent of cloud amount during daylight at 22 GMT.
CLOUD_AMT_23	Cloud Amount at 23 GMT	The average percent of cloud amount during daylight at 23 GMT.
CLOUD_AMT_DAY	Cloud Amount at Daytime	The average percent of cloud amount during daylight.
CLOUD_AMT_HR	Cloud Amount at GMT Times	The average percent of cloud amount during daylight at GMT Times.
CLOUD_AMT_NIGHT	Cloud Amount at Nighttime	The average percent of cloud amount during nighttime.
CLOUD_OD	Cloud Optical Visible Depth	The vertical optical thickness between the top and bottom of a cloud.
CLOUD_OD_00	Cloud Optical Visible Depth at 00 GMT	The vertical optical thickness between the top and bottom of a cloud at 00 GMT.
CLOUD_OD_01	Cloud Optical Visible Depth at 01 GMT	The vertical optical thickness between the top and bottom of a cloud at 01 GMT.
CLOUD_OD_02	Cloud Optical Visible Depth at 02 GMT	The vertical optical thickness between the top and bottom of a cloud at 02 GMT.
CLOUD_OD_03	Cloud Optical Visible Depth at 03 GMT	The vertical optical thickness between the top and bottom of a cloud at 03 GMT.
CLOUD_OD_04	Cloud Optical Visible Depth at 04 GMT	The vertical optical thickness between the top and bottom of a cloud at 04 GMT.
CLOUD_OD_05	Cloud Optical Visible Depth at 05 GMT	The vertical optical thickness between the top and bottom of a cloud at 05 GMT.
CLOUD_OD_06	Cloud Optical Visible Depth at 06 GMT	The vertical optical thickness between the top and bottom of a cloud at 06 GMT.
CLOUD_OD_07	Cloud Optical Visible Depth at 07 GMT	The vertical optical thickness between the top and bottom of a cloud at 07 GMT.
CLOUD_OD_08	Cloud Optical Visible Depth at 08 GMT	The vertical optical thickness between the top and bottom of a cloud at 08 GMT.
CLOUD_OD_09	Cloud Optical Visible Depth at 09 GMT	The vertical optical thickness between the top and bottom of a cloud at 09 GMT.
CLOUD_OD_10	Cloud Optical Visible Depth at 10 GMT	The vertical optical thickness between the top and bottom of a cloud at 10 GMT.
CLOUD_OD_11	Cloud Optical Visible Depth at 11 GMT	The vertical optical thickness between the top and bottom of a cloud at 11 GMT.
CLOUD_OD_12	Cloud Optical Visible Depth at 12 GMT	The vertical optical thickness between the top and bottom of a cloud at 12 GMT.
CLOUD_OD_13	Cloud Optical Visible Depth at 13 GMT	The vertical optical thickness between the top and bottom of a cloud at 13 GMT.
CLOUD_OD_14	Cloud Optical Visible Depth at 14 GMT	The vertical optical thickness between the top and bottom of a cloud at 14 GMT.
CLOUD_OD_15	Cloud Optical Visible Depth at 15 GMT	The vertical optical thickness between the top and bottom of a cloud at 15 GMT.
CLOUD_OD_16	Cloud Optical Visible Depth at 16 GMT	The vertical optical thickness between the top and bottom of a cloud at 16 GMT.
CLOUD_OD_17	Cloud Optical Visible Depth at 17 GMT	The vertical optical thickness between the top and bottom of a cloud at 17 GMT.
CLOUD_OD_18	Cloud Optical Visible Depth at 18 GMT	The vertical optical thickness between the top and bottom of a cloud at 18 GMT.
CLOUD_OD_19	Cloud Optical Visible Depth at 19 GMT	The vertical optical thickness between the top and bottom of a cloud at 19 GMT.
CLOUD_OD_20	Cloud Optical Visible Depth at 20 GMT	The vertical optical thickness between the top and bottom of a cloud at 20 GMT.
CLOUD_OD_21	Cloud Optical Visible Depth at 21 GMT	The vertical optical thickness between the top and bottom of a cloud at 21 GMT.
CLOUD_OD_22	Cloud Optical Visible Depth at 22 GMT	The vertical optical thickness between the top and bottom of a cloud at 22 GMT.
CLOUD_OD_23	Cloud Optical Visible Depth at 23 GMT	The vertical optical thickness between the top and bottom of a cloud at 23 GMT.
CLOUD_OD_HR	Cloud Optical Visible Depth at GMT Times	The vertical optical thickness between the top and bottom of a cloud at GMT Times.
SG_DAY_COZ_ZEN_AVG	Daylight Average Of Hourly Cosine Solar Zenith Angles for Climatological Month	The average cosine of the angle between the sun and directly overhead during daylight hours. The determination of monthly averaged daylight average of hourly cosine solar zenith angles for each month is based (i.e. calculated for the monthly averaged day) on the monthly average day.
DIFFUSE_ILLUMINANCE	Diffuse Illuminance	The average amount of illuminance received directly from the solar disk on a surface perpendicular to the sun's rays.
DIRECT_ILLUMINANCE	Direct Illuminance	The average amount of illuminance received from the sky (excluding the solar disk) on a horizontal plane.
TS_ADJ	Earth Skin Temperature Adjusted	The adjusted average temperature at the earth's surface.
NO_SUN_BLACKDAYS_MAX	Equivalent No-Sun Days	The maximum number of consecutive days that a backup storage system must provide energy to account for the expected days without solar insolation. The climatologically averaged value is over the time period given in the header section of the data file.
EQUIV_NO_SUN_CONSEC_01	Equivalent No-Sun Days Over A Consecutive 1-day Period	The solar irradiance deficit over a consecutive 1-day period in a given month; the difference between the climatological averaged monthly value over the p-day period and the minimum of the climatological averaged values over the same p-day period in the given month. The monthly average for the p-day period is calculated as a multiyear average over the climatological period given in the header section of the data file.
EQUIV_NO_SUN_CONSEC_14	Equivalent No-Sun Days Over A Consecutive 14-day Period	The solar irradiance deficit over a consecutive 14-day period in a given month; the difference between the climatological averaged monthly value over the p-day period and the minimum of the climatological averaged values over the same p-day period in the given month. The monthly average for the p-day period is calculated as a multiyear average over the climatological period given in the header section of the data file.
EQUIV_NO_SUN_CONSEC_21	Equivalent No-Sun Days Over A Consecutive 21-day Period	The solar irradiance deficit over a consecutive 21-day period in a given month; the difference between the climatological averaged monthly value over the p-day period and the minimum of the climatological averaged values over the same p-day period in the given month. The monthly average for the p-day period is calculated as a multiyear average over the climatological period given in the header section of the data file.
EQUIV_NO_SUN_CONSEC_03	Equivalent No-Sun Days Over A Consecutive 3-day Period	The solar irradiance deficit over a consecutive 3-day period in a given month; the difference between the climatological averaged monthly value over the p-day period and the minimum of the climatological averaged values over the same p-day period in the given month. The monthly average for the p-day period is calculated as a multiyear average over the climatological period given in the header section of the data file.
EQUIV_NO_SUN_CONSEC_07	Equivalent No-Sun Days Over A Consecutive 7-day Period	The solar irradiance deficit over a consecutive 7-day period in a given month; the difference between the climatological averaged monthly value over the p-day period and the minimum of the climatological averaged values over the same p-day period in the given month. The monthly average for the p-day period is calculated as a multiyear average over the climatological period given in the header section of the data file.
EQUIV_NO_SUN_CONSEC_MONTH	Equivalent No-Sun Days Over A Month Period	Equivalent number of NO-SUN or BLACK days is the number of days in a given month that a backup storage system must provide energy to account for the expected days without solar insolation over a month period. The number of days is based upon an estimate of the solar irradiance deficit below the expected climatological monthly averaged value. The climatological period is given in the header section of the data file.
GLOBAL_ILLUMINANCE	Global Illuminance	The average total amount of direct and diffuse illuminance on a horizontal plane.
MAX_EQUIV_NO_SUN_DEFICIT	Maximum Equivalent No-Sun Days Deficit	The worse Consecutive-Day Deficits below Expected Values.
SG_HRZ_MAX	Maximum Solar Angle Relative To The Horizon for Climatological Month	The maximum vertical angle of the sun above the horizon. The determination of monthly averaged maximum solar angle relative to the horizon for each month is based on the monthly average day (See Methodology).
MIDDAY_INSOL	Midday Insolation Incident	The total amount of solar irradiance (i.e. direct plus diffuse) incident on a horizontal plane at the earth's surface during the solar noon hour midday period.
MIDDAY_INSOL_MAX	Midday Insolation Incident Maximum	The maximum total amount of solar irradiance (i.e. direct plus diffuse) incident on a horizontal plane at the earth's surface during the solar noon hour midday period.
MIDDAY_INSOL_MIN	Midday Insolation Incident Minimum	The minimum total amount of solar irradiance (i.e. direct plus diffuse) incident on a horizontal plane at the earth's surface during the solar noon hour midday period.
MIDDAY_INSOL_SD	Midday Insolation Incident Standard Deviation	The standard deviation of the total amount of solar irradiance (i.e. direct plus diffuse) incident on a horizontal plane at the earth's surface during the solar noon hour midday period.
INSOL_CONSEC_01_MIN	Minimum Insolation Over A Consecutive 1-day Period	The minimum available insolation over a consecutive 1-day period in a particular month is given as the irradiance value between the minimum monthly average value over the p-day period and the monthly average value for the p-day period. The p-day average is computed as a running average within each month. The monthly average for the p-day period is calculated as a multiyear average over the climatological period given in the header section of the data file.
INSOL_CONSEC_14_MIN	Minimum Insolation Over A Consecutive 14-day Period	The minimum available insolation over a consecutive 14-day period in a particular month is given as the irradiance value between the minimum monthly average value over the p-day period and the monthly average value for the p-day period. The p-day average is computed as a running average within each month. The monthly average for the p-day period is calculated as a multiyear average over the climatological period given in the header section of the data file.
INSOL_CONSEC_21_MIN	Minimum Insolation Over A Consecutive 21-day Period	The minimum available insolation over a consecutive 21-day period in a particular month is given as the irradiance value between the minimum monthly average value over the p-day period and the monthly average value for the p-day period. The p-day average is computed as a running average within each month. The monthly average for the p-day period is calculated as a multiyear average over the climatological period given in the header section of the data file.
INSOL_CONSEC_03_MIN	Minimum Insolation Over A Consecutive 3-day Period	The minimum available insolation over a consecutive 3-day period in a particular month is given as the irradiance value between the minimum monthly average value over the p-day period and the monthly average value for the p-day period. The p-day average is computed as a running average within each month. The monthly average for the p-day period is calculated as a multiyear average over the climatological period given in the header section of the data file.
INSOL_CONSEC_07_MIN	Minimum Insolation Over A Consecutive 7-day Period	The minimum available insolation over a consecutive 7-day period in a particular month is given as the irradiance value between the minimum monthly average value over the p-day period and the monthly average value for the p-day period. The p-day average is computed as a running average within each month. The monthly average for the p-day period is calculated as a multiyear average over the climatological period given in the header section of the data file.
INSOL_CONSEC_MONTH_MIN	Minimum Insolation Over A Month Period	The minimum available insolation over a month period in a particular month is given as the irradiance value between the minimum monthly average value over the p-day period and the monthly average value for the p-day period. The p-day average is computed as a running average within each month. The monthly average for the p-day period is calculated as a multiyear average over the climatological period given in the header section of the data file.
PW	Precipitable Water	The total atmospheric water vapor contained in a vertical column of the atmosphere.
SG_SAA	Solar Azimuth Angle	The angle of the vector from the earth point to the suns position.
SG_NOON	Solar Geometry Based Noon	The time of solar noon.
SG_DAY_HOURS	Solar Geometry Day Hours	The number of hours where solar irradiance is present; determined if the solar zenith angle is between 0 and 90 degrees.
SOLAR_DEFICITS_BLW_CONSEC_01	Solar Irradiance Deficit Over A Consecutive 1-day Period	The solar irradiance deficit over a consecutive 1-day period in a given month is the difference between the climatological averaged monthly value over the p-day period and the minimum of the climatological averaged values over the same p-day period in the given month. The monthly average for the p-day period is calculated as a multiyear average over the climatological period given in the header section of the data file.
SOLAR_DEFICITS_BLW_CONSEC_14	Solar Irradiance Deficit Over A Consecutive 14-day Period	The solar irradiance deficit over a consecutive 14-day period in a given month is the difference between the climatological averaged monthly value over the p-day period and the minimum of the climatological averaged values over the same p-day period in the given month. The monthly average for the p-day period is calculated as a multiyear average over the climatological period given in the header section of the data file.
SOLAR_DEFICITS_BLW_CONSEC_21	Solar Irradiance Deficit Over A Consecutive 21-day Period	The solar irradiance deficit over a consecutive 21-day period in a given month is the difference between the climatological averaged monthly value over the p-day period and the minimum of the climatological averaged values over the same p-day period in the given month. The monthly average for the p-day period is calculated as a multiyear average over the climatological period given in the header section of the data file.
SOLAR_DEFICITS_BLW_CONSEC_03	Solar Irradiance Deficit Over A Consecutive 3-day Period	The solar irradiance deficit over a consecutive 3-day period in a given month is the difference between the climatological averaged monthly value over the p-day period and the minimum of the climatological averaged values over the same p-day period in the given month. The monthly average for the p-day period is calculated as a multiyear average over the climatological period given in the header section of the data file.
SOLAR_DEFICITS_BLW_CONSEC_07	Solar Irradiance Deficit Over A Consecutive 7-day Period	The solar irradiance deficit over a consecutive 7-day period in a given month is the difference between the climatological averaged monthly value over the p-day period and the minimum of the climatological averaged values over the same p-day period in the given month. The monthly average for the p-day period is calculated as a multiyear average over the climatological period given in the header section of the data file.
SOLAR_DEFICITS_BLW_CONSEC_MONTH	Solar Irradiance Deficit Over A Month Period	The solar irradiance deficit over a month period in a given month is the difference between the climatological averaged monthly value over the p-day period and the minimum of the climatological averaged values over the same p-day period in the given month. The monthly average for the p-day period is calculated as a multiyear average over the climatological period given in the header section of the data file.
SI_EF_TILTED_SURFACE_OPTIMAL	Solar Irradiance Optimal	An equator facing surface tilted at the optimum angle receives the optimum, or maximum, solar irradiance. The monthly climatology values are the average for each month over the time period given in the header section of the data file.
SI_EF_TILTED_SURFACE_OPTIMAL_ANG	Solar Irradiance Optimal Angle	The optimum, or maximum, solar irradiance incident on an equator facing surface is obtained with the surface tilted at the optimal angle. The monthly climatology values are the average for each month over the time period given in the header section of the data file.
SI_EF_TILTED_SURFACE_OPTIMAL_ANG_ORT	Solar Irradiance Tilted Surface Orientation	The north/south direction of the tilted surface.
SI_EF_TILTED_SURFACE_TRACKER	Solar Irradiance Tracking the Sun	Solar Irradiance incident where the panel surface tracks the sun continuously.
SI_EF_TILTED_SURFACE_HORIZONTAL	Solar Irradiance for Equator Facing Horizontal Surface	Solar Irradiance incident on an equator facing surface tilted at a 0 degree angle (horizontal plane).
SI_EF_TILTED_SURFACE_LAT_MINUS15	Solar Irradiance for Equator Facing Latitude Minus 15 Tilt	Solar Irradiance incident on an equator facing surface tilted at the latitude minus 15.
SI_EF_TILTED_SURFACE_LAT_PLUS15	Solar Irradiance for Equator Facing Latitude Plus 15 Tilt	Solar Irradiance incident on an equator facing surface tilted at the latitude plus 15.
SI_EF_TILTED_SURFACE_LATITUDE	Solar Irradiance for Equator Facing Latitude Tilt	Solar Irradiance incident on an equator facing surface tilted at the latitude angle.
SI_EF_TILTED_SURFACE	Solar Irradiance for Equator Facing Tilted Surfaces (Set of Surfaces)	Solar Irradiance incident on an equator facing surface tilted at an angle equal to the latitude of the location and plus, minus 15 degrees of the latitude. The climatology values are monthly averaged values over the time period given in the header record.
SI_EF_TILTED_SURFACE_VERTICAL	Solar Irradiance for Equator Facing Vertical Surface	Solar Irradiance incident on an equator facing surface tilted at a 90 degree angle (vertical surface).
SZA	Solar Zenith Angle	The angle between the geodetic zenith vector and a vector from the earth point to the sun integrated over the period.
SG_SZA	Solar Zenith Angle	The angle between the geodetic zenith vector and a vector from the earth point to the sun integrated over the period.
SRF_ALB_ADJ	Surface Albedo Adjusted	The adjusted all sky rate of reflectivity of the earth's surface; the ratio of the solar energy reflected by the surface of the earth compared to the total solar energy incident reaching the surface of the earth.
INSOL_CONSEC_01	Surplus Insolation Over A Consecutive 1-day Period	Available Surplus Insolation Over A Consecutive 1-day period in a particular month is given as the irradiance value between the maximum monthly average value over the p-day period and the monthly average value for the p-day period. The p-day average is computed as a running average within each month. The monthly average for the p-day period is calculated as a multiyear average over the climatological period given in the header section of the data file.
INSOL_CONSEC_14	Surplus Insolation Over A Consecutive 14-day Period	Available Surplus Insolation Over A Consecutive 14-day period in a particular month is given as the irradiance value between the maximum monthly average value over the p-day period and the monthly average value for the p-day period. The p-day average is computed as a running average within each month. The monthly average for the p-day period is calculated as a multiyear average over the climatological period given in the header section of the data file.
INSOL_CONSEC_21	Surplus Insolation Over A Consecutive 21-day Period	Available Surplus Insolation Over A Consecutive 21-day period in a particular month is given as the irradiance value between the maximum monthly average value over the p-day period and the monthly average value for the p-day period. The p-day average is computed as a running average within each month. The monthly average for the p-day period is calculated as a multiyear average over the climatological period given in the header section of the data file.
INSOL_CONSEC_03	Surplus Insolation Over A Consecutive 3-day Period	Available Surplus Insolation Over A Consecutive 3-day period in a particular month is given as the irradiance value between the maximum monthly average value over the p-day period and the monthly average value for the p-day period. The p-day average is computed as a running average within each month. The monthly average for the p-day period is calculated as a multiyear average over the climatological period given in the header section of the data file.
INSOL_CONSEC_07	Surplus Insolation Over A Consecutive 7-day Period	Available Surplus Insolation Over A Consecutive 7-day period in a particular month is given as the irradiance value between the maximum monthly average value over the p-day period and the monthly average value for the p-day period. The p-day average is computed as a running average within each month. The monthly average for the p-day period is calculated as a multiyear average over the climatological period given in the header section of the data file.
INSOL_CONSEC_MONTH	Surplus Insolation Over A Month Period	Available Surplus Insolation Over A month period in a particular month is given as the irradiance value between the maximum monthly average value over the p-day period and the monthly average value for the p-day period. The p-day average is computed as a running average within each month. The monthly average for the p-day period is calculated as a multiyear average over the climatological period given in the header section of the data file.
TOA_SW_DNI	Top-Of-Atmosphere Shortwave Direct Normal Radiation	The total solar irradiance incident (direct plus diffuse) on a horizontal plane where oriented to the sun's position at the top of the atmosphere (extraterrestrial radiation).
TOA_SW_DNI_MAX	Top-Of-Atmosphere Shortwave Direct Normal Radiation Maximum	The maximum total solar irradiance incident (direct plus diffuse) on a horizontal plane where oriented to the sun's position at the top of the atmosphere (extraterrestrial radiation).
TOA_SW_DNI_MIN	Top-Of-Atmosphere Shortwave Direct Normal Radiation Minimum	The minimum total solar irradiance incident (direct plus diffuse) on a horizontal plane where oriented to the sun's position at the top of the atmosphere (extraterrestrial radiation).
TOA_SW_DNI_SD	Top-Of-Atmosphere Shortwave Direct Normal Radiation Standard Deviation	The standard deviation of total solar irradiance incident (direct plus diffuse) on a horizontal plane where oriented to the sun's position at the top of the atmosphere (extraterrestrial radiation).
TOA_SW_DWN	Top-Of-Atmosphere Shortwave Downward Irradiance	The total solar irradiance incident (direct plus diffuse) on a horizontal plane at the top of the atmosphere (extraterrestrial radiation).
TOA_SW_DWN_MAX	Top-Of-Atmosphere Shortwave Downward Irradiance Maximum	The maximum total solar irradiance incident (direct plus diffuse) on a horizontal plane at the top of the atmosphere (extraterrestrial radiation).
TOA_SW_DWN_MIN	Top-Of-Atmosphere Shortwave Downward Irradiance Minimum	The minimum total solar irradiance incident (direct plus diffuse) on a horizontal plane at the top of the atmosphere (extraterrestrial radiation).
TOA_SW_DWN_SD	Top-Of-Atmosphere Shortwave Downward Irradiance Standard Deviation	The standard deviation of total solar irradiance incident (direct plus diffuse) on a horizontal plane at the top of the atmosphere (extraterrestrial radiation).
ZENITH_LUMINANCE	Zenith luminance	The average amount of luminance at the sky's zenith.

Hi, where can I find more information about measurement system of the weather variables?