Extended Edited Synoptic Cloud Reports from Ships and Land Stations Over the Globe, 1952-1996

Hahn, Carole J., Department of Atmospheric Sciences, University of Arizona, Tucson, Arizona; Stephen G. Warren, Department of Atmospheric Sciences, University of Washington, Seattle, Washington

Prepared by Dale Kaiser, CDIAC

NDP-026C (1999) (http://cdiac.ornl.gov/epubs/ndp/ndp026c/ndp026c.html)

This fourth database in the NDP-026 series contains surface synoptic weather reports for the entire globe, gathered from various available data sets. These reports were then processed, edited, and rewritten to provide a single data set of individual observations of clouds, spanning 44 years (1952-1996) for ship data and 26 years (1971-1996) for land station data. In addition to the cloud portion of the synoptic report, each edited report also includes the associated pressure, present weather, wind, air temperature, and dew point (and sea surface temperature) over oceans.

Reports from the source data sets that did not meet certain quality control standards were re-jected for the "Extended Edited Cloud Report Archive" (EECRA). Minor correctable incon-sistencies within reports were edited for consistency. Cases of "sky obscured" were interpreted by reference to the present-weather code as to whether they indicated fog, rain, snow, or thunderstorm. Special coding was added to indicate probable nimbostratus clouds which are not specifically coded for in the standard synoptic code. Any changes made to an original report are also noted in the archived edited report so that the original report can be reconstructed if desired. This "extended edited cloud report" also includes the amounts, either inferred or directly reported, of low, middle, and high clouds, both overlapped and non-over-lapped amounts. The relative lunar illuminance and the solar zenith angle associated with each report are also given, as well as an indicator that tells whether the recommended illuminance criterion was satisfied so that the "night- detection bias" for clouds can be minimized.

The EECRA contains over 72 million cloud observations from ships and 311 million from land stations, and the archive consists of 853 files of edited synoptic reports, one file for each month of data for land and ocean separately.