Simplification of heat balance calculation and its application to the glacier runoff from the July 1st Glacier in northwest China since the 1930s

✍ Scribed by Akiko Sakai; Koji Fujita; Masayoshi Nakawo; Tandong Yao

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 600 KB
• Volume: 23
• Category: Article
• ISSN: 0885-6087
• DOI: 10.1002/hyp.7187

✦ Synopsis

Abstract

Since ancient times meltwater from glaciers in mountain zones has been an important water resource in the arid region of northwest China. Meteorological elements for heat balance calculations at the glacier surface were simplified with the aim of simulating discharge fluctuations from the July 1st Glacier over a span of decades. By estimating relative humidity and downward solar radiation from precipitation, heat balance calculations at the glacier can be made using only daily temperature and precipitation, which are easily obtainable. Calculations of daily discharge using the above method during the melting season in 2002 produced a better simulation than those using the conventional positive degree‐day (PDD) factor method. (The ablation of glacier during any particular period is assumed to be proportional to the sum of daily mean temperatures above the melting point during that period.)

We calculated the glacier runoff and mass balance at the July 1st Glacier since 1935 from monthly meteorological data taken near the glacier using the above method. We used three patterns of daily temperature and precipitation to estimate daily meteorological data from monthly or annual data. Calculated mass balance using the patterns of air temperature and precipitation in years when the pressure distributions were similar to its long‐term average corresponded well with observed data. Our simulation of the glacier runoff since 1935 also showed good results. Copyright © 2008 John Wiley & Sons, Ltd.