A Comprehensive Aerological Reference Data Set (CARDS): Rough and Systematic Errors

Abstract

The possibility of anthropogenic climate change and the possible problems associated with it are of great interest. However, one cannot study climate change without climate data. The Comprehensive Aerological Reference Data Set (CARDS) project will produce high-quality, daily upper-air data for the research community and for policy makers. CARDS intends to produce a dataset consisting of radiosonde and pibal data that is easy to use, as complete as possible, and as free of errors as possible. An attempt will be made to identify and correct biases in upper-air data whenever possible. This paper presents the progress made to date in achieving this goal.An advanced quality control procedure has been tested and implemented. It is capable of detecting and often correcting errors in geopotential height, temperature, humidity, and wind. This unique quality control method uses simultaneous vertical and horizontal checks of several meteorological variables. It can detect errors that other methods cannot.Research is being supported in the statistical detection of sudden changes in time series data. The resulting statistical technique has detected a known humidity bias in the U.S. data. The methods should detect unknown changes in instrumentation, station location, and data-reduction techniques. Software has been developed that corrects radiosonde temperatures, using a physical model of the temperature sensor and its changing environment. An algorithm for determining cloud coverforthis physical model has been developed. A numerical check for station elevation based on the hydrostatic equations has been developed, which has identified documented and undocumented station moves. Considerable progress has been made toward the development of algorithms to eliminate a known bias in the U.S. humidity data.

Climatological characteristics of the tropical tropopause as revealed by radiosondes

“…Radiosonde data are available from several sources, but the most complete archive is probably the Comprehensive Aerological Reference Data Set [Eskridge et al, 1995], which is the source of observations for this study. We employ data from 108 radiosonde locations in the tropical belt (30øN-30øS) in a subset of stations identified by Wallis [1998] as a "core" network, with good spatial and temporal coverage.…”

Spatial sampling requirements for monitoring upper‐air climate change with radiosondes

“…In addition radiosonde humidity data have been extracted from the Integrated Global Radiosonde Archive (IGRA, Durre et al, 2006) and augmented with some additional observations from the earlier Comprehensive Aerological Reference Data Set (CARDS, Eskridge et al, 1995).…”

A New Look at Radiosonde Data prior to 1958

“…Data from approximately 1500 radiosonde stations were collected from several archives: 1) the Integrated Global Radiosonde Archive (IGRA) (Durre et al 2006) at the National Climatic Data Center (NCDC); 2) the U. S. Air Force Environmental Technical Applications Center tape deck 54 dataset (TD54) at NCAR; 3) the NCDC tape deck 6201 compilation (TD-6201); 4) the Comprehensive Aerological Reference Dataset (CARDS) tape deck 542 archive (CARDS542) covering 1946 and 1947 (Eskridge et al 1995) from NCAR; 5) data digitized internally within the working group of the authors at ETH Zurich (Brö nnimann 2003b;Brö nnimann et al 2005;Ewen et al 2008); 6) data from the Arctic region of the former Soviet Union, which were recently digitized at the Arctic and Antarctic Research Institute (AARI); and 7) several miscellaneous sources such as Lindenberg, Germany, and Payerne, Switzerland. Significant overlap existed among the archives, complicated by the fact that some were numbered according to the Weather Bureau Army Navy (WBAN) system and others according to the World Meteorological Organization (WMO) scheme: It was not initially clear which stations overlapped.…”

“…Unfortunately, this data record is fraught with problems. Although the apparently divergent temperature trends seen in the radiosonde and satellite records have, after over 15 years of debate, finally been harmonized (Sherwood et al 2005;Santer et al 2005;Mears and Wentz 2005;Fu et al 2004), many questions remain about the homogeneity of the radiosonde record (e.g., Lanzante et al 2003;Free et al 2002;Eskridge et al 2003), limiting confidence in trend analysis.…”