Mitigation of black carbon emissions could immediately reduce 6.3% of glacier melting in the Qilian Mountains

Global warming in tandem with surface albedo reduction caused by black carbon(BC)deposition on glaciers accelerated glacier melting;however,their respective contributions remain unclear.Glaciers in the Qilian Mountains are crucial for the development of oases in the Hexi Corridor;however,their area has decreased by more than 20%over the past half-century.Thus,this study developed a dynamic deposition model for light-absorbing particles(LAPs),coupled with a surface energy and mass balance model.We comprehensively assessed the effects of BC and warming on the melting of a typical glacier in the Qilian Mountains based on the coupled model.BC on the glacier surface caused 13.1%of annual glacier-wide melting,of which directly deposited atmospheric BC reduced the surface albedo by 0.02 and accounted for 9.1%of glacier melting.The air temperature during 2000-2010 has increased by 1.5℃ relative to that during the 1950s,accounting for 51.9%of current glacier melting.Meanwhile,BC emission have increased by 4.6 times compared to those of the early Industrial Revolution recorded in an ice core,accounting conservatively for 6.3%of current glacier melting.Mitigating BC emissions has a limited influence on current glacier melting;however,in the long-term,mitigation should exert a noteworthy impact on glacier melting through the self-purification of glaciers.

Which adjustment methods are suitable for the wind-induced errors of Geonor T-200BM3 precipitation weighing gauges in a periglacial site?

Single Alter shielded T-200BM3 weighing precipitation gauges are widely used in the measurement of all precipitation types(rainfall,snow and mixed precipitation)in unattended boreal or alpine regions,but their original datasets must be adjusted for undercatch errors caused by wind in snowy,windy and harsh environments.Therefore,previous researchers have developed many adjustment methods for all precipitation types on different time scales.However,which adjustment method is suitable for T-200BM3 weighing gauge wind-induced error adjustment in harsh alpine regions is unclear.Therefore,precipitation measurement intercomparison experiments were conducted in the Qilian Mountains from July 2018 to July 2021,and eight adjustment methods;were evaluated for wind-induced errors for daily,individual precipitation event,hourly,and half-hourly time scales.Z2004 outperformed the other adjustment methods in regard to the daily measurements of snow and mixed precipitation.Regarding individual snowfall events,M2007 reduced the absolute value of RMSE(bias)from 1.44 to 1.32 mm(0.77-0.24 mm)and could be recommended for snowfall event adjustment.K2017-1 attained a better performance than K2017-2 in regard to half-hourly snowfall and mixed sample adjustment and was more suitable for half-hourly snowfall sample adjustment.K2017-1 reduced the absolute value of bias from 0.07 to 0.00 mm for snowfall.Finally,Z2004,M2007,and K2017-1 yielded better adjustment results for the daily accumulation precipitation amount(>2 mm d−1),individual snowfall events(>2 mm per event),and half-hourly accumulation snowfall or mixed samples(>1 mm 30 min−1),respectively.However,further intercomparison in different climate regions is needed for trace precipitation samples.