kayastha_etal_2003.htm

Bulletin of Glaciological Research 20 (2003) 7-14
©Japanese Society of Snow and Ice

Positive degree-day factors for ice ablation on four glaciers in the Nepalese Himalayas and Qinghai-Tibetan Plateau

Rijan Bhakta KAYASTHA¹, Yutaka AGETA¹, Masayoshi NAKAWO², Koji FUJITA¹, Akiko SAKAI¹ and Yoshihiro MATSUDA¹

1 Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8601 Japan
2 Research Institute for Humanity and Nature, Kyoto 602-0878 Japan

Abstract

　Positive degree-day factors for ice ablation on Yala Glacier, central Nepal, Xiao Dongkemadi Glacier and July 1st Glacier in the Qinghai-Tibetan Plateau, west China, are calculated during a summer season of 1996, 1993 and 2002, respectively, and compared with the degree-day factors calculated on Glacier AX010, east Nepal during a summer season of 1978. The degree-day factors for summer ice ablation at two altitudes 5120 m and 5270 m a.s.l. on Yala Glacier range from 8.0 to 10.5 mm d-1 oC-1. In the case of Xiao Dongkemadi Glacier, the factors range from 13.3 (at 5425 m) to 14.2 mm d-1 oC-1 (at 5475 m) and on July 1st Glacier, the factors at altitudes from 4305 m to 4619 m a.s.l. range from 5.5 to 8.8 mm d-1 oC-1. Larger degree-day factors are found on glaciers situated at higher altitude. The results of the individual glaciers also indicate that the degree-day factor for ice at higher altitude is larger than at the lower altitude, which is mainly due to ablation attributed to absorbed global radiation at the high altitude where the positive degree-day sum is low due to low summer air temperature.