Recently, the datastream for the ceilometer instrument for all sites were reprocessed. This end-to-end reprocessing task corrected a couple of problems in the formatting of CEIL data and resulted in a new datastream name.

First, the “V” in VCEIL was dropped because it represented the name of the vendor. New data standards for ARM require that vendor names are not included in an instrument datastream. Second, data were known as VCEIL25k. The use of 25k is inconsistent with the reported data as it represents 25,000 feet and these data are reported in meters. Removing “25k” from the title corrects this confusion. Finally, missing value attributes and companion quality control variables were added for the fields: detection_status, receiver_sensitivity, and window_contamination. These will now report slashes (i.e., ///) as -9999.

Reprocessing of the CEIL instrument datastream occurred in September 2014; however, this reprocessing did not result in changes to the data. Users are encouraged to retrieve the reprocessed data for use in their analysis if they would like to use the new quality control fields or to verify reprocessed data plots against old datastream plots.

Browse the CEIL data set in the ARM Data Archive or visit the CEIL instrument web page for more information. You will need an ARM Data Archive account to download the data. (Request an account here.)