Adjustment of Daily Precipitation Data at Barrow and Nome Alaska for 1995–2001

Abstract

Systematic errors in precipitation measurements are known to affect all types of precipitation gages. These errors are more sensitive for solid precipitation than for rain. In arctic regions, these systematic errors become significantly more pronounced than for other regions due to the relatively slow precipitation rates, low temperatures, high winds, and low annual precipitation amounts that are characteristic of the arctic climate. This study performed the daily adjustments of measured precipitation data for the National Weather Service (NWS) stations at Barrow and Nome, Alaska, over a 7-year study period, from 1995 through 2001. The results of this study indicate that the bias adjustments increase the average monthly gage-measured precipitation by approximately 20%–180% for Barrow and 30%–380% for Nome, with the larger percentages occurring in winter months. The average gage-measured annual precipitation amounts are increased by approximately 70% for Barrow and 130% for Nome. It is expected that these increases will impact climate monitoring, the understanding of the arctic freshwater balance, and the assessment of atmospheric model performance in the Arctic.