Save an org-archive buffer.

org-archive-save-buffer

(require 'org)

(setq org-archive-location "~/Dropbox/logs/archive.org::")

(defun org-archive-save-buffer ()
  (let ((afile (org-extract-archive-file (org-get-local-archive-location))))
    (if (file-exists-p afile)
      (let ((buffer (find-file-noselect afile)))
        (if (y-or-n-p (format "Save (%s)" buffer))
          (with-current-buffer buffer
            (save-buffer))
          (message "You expressly chose _not_ to save (%s)." buffer)))
      (message "Ooops ... (%s) does not exist." afile))))

(add-hook 'org-archive-hook 'org-archive-save-buffer)