Bias correction of daily precipitation measurements for Greenland

• Published in: Journal of Geophysical Research 1999-03, Vol.104 (D6), p.6171-6181
• Main Authors: Yang, Daqing, Ishida, Shig, Goodison, Barry E., Gunther, Thilo
• Format: Article
• Language: English
• Subjects: Earth, ocean, space; Exact sciences and technology; External geophysics; Geophysics. Techniques, methods, instrumentation and models; Greenland
• ISSN: 0148-0227; 2156-2202
• DOI: 10.1029/1998JD200110

A methodology for correcting the Hellmann gauge‐measured daily precipitation for wind‐induced undercatch, wetting loss, and trace amount of precipitation was presented and applied at 12 climate stations in Greenland for years 1994–1997. The results show the following: (1) daily corrections of the biases increase the gauge‐measured annual precipitation by 35–280 mm for the 4 years (about 25–90% of the gauge‐measured yearly total) in Greenland; (2) of the biases, wind‐induced undercatch is the source of greatest error; wetting loss and trace amount of precipitation are also significant biases in the northern Greenland regions of low precipitation; (3) monthly correction factors (corrected/measured precipitation) differ by station and, at an individual station, by type of precipitation; (4) considerable intra‐annual variation of the yearly corrections has been found in Greenland due to the fluctuation of wind speed, air temperature, and frequency of snowfall. These results suggest that annual precipitation in Greenland is much higher than previously reported, particularly in the southern regions of high precipitation; and the latitudinal precipitation gradient may also be greater over Greenland. These results will have a significant impact to water budget and glacier mass balance studies in Greenland.