采用高亚洲精细再分析数据(High AsiaRefinedanalysis,HAR)以及Coupled SnowpackandIceSurfaceEn⁃ergy andMassbalanceModel(COSIMA)模拟了青藏高原最大冰原——普若岗日2012-04-23—2014-05-11的能量-物质平衡,并分析了普若岗日冰原消...采用高亚洲精细再分析数据(High AsiaRefinedanalysis,HAR)以及Coupled SnowpackandIceSurfaceEn⁃ergy andMassbalanceModel(COSIMA)模拟了青藏高原最大冰原——普若岗日2012-04-23—2014-05-11的能量-物质平衡,并分析了普若岗日冰原消融机理。模拟的2012-04-23—2013-05-23与2013-05-23—2014-05-11的物质平衡分别为-0.18 m w.e.、-0.36 m w.e.。在整个研究时段内,冰原西部、中北部等海拔低于5800 m的区域处于物质亏损状态,最大达到-2.69 m w.e.;冰原北部区域因为海拔较高的原因,处于物质积累状态,在东北部区域最高值达到0.85 m w.e.。2013-05-23—2014-05-11用于消融的能量相比2012-04-23—2013-05-23减少,冰川表面消融减速,但普若岗日冰原上空2013-05-23—2014-05-11的固态降水量少于2012-04-23—2013-05-23,因此冰川在2013-05-23—2014-05-11日的表面净物质平衡反而减少。展开更多
The ice cap Ulugh Muztagh in the central Kunlun Shan at the northern fringe of the Tibetan Plateau is a very isolated region with arid cold conditions. No observational, meteorological or glaciological ground truth da...The ice cap Ulugh Muztagh in the central Kunlun Shan at the northern fringe of the Tibetan Plateau is a very isolated region with arid cold conditions. No observational, meteorological or glaciological ground truth data is available. Using the Moderate-resolution Imaging Spectroradiometer(MODIS) Level 1 radiance Swath Data(MOD02QKM) with a spatial resolution of 250 m, transient snow lines during the months of July to September in 2001 to 2014 are derived. Results are used to calibrate the physical based Coupled Snowpack and Ice surface energy and Mass balance model(COSIMA). The model runs on a representative detail region of Ulugh Muztagh(UM) on a digital elevation model with the same spatial resolution as the MODIS bands. In the absence of field observations, the model is driven solely by dynamically downscaled global analysis data from the High Asia Refined analysis(HAR). We compare remote sensing derived and modelled mean regional transient snow line altitudes in the course of consecutive summer seasons in 2008 to 2010. The resulting snow line altitude(SLA) and annual equilibrium line altitude(ELA) proxy of both methods coincide very well in their interannual variability in accordance with interannual variability of climatic conditions. Since SLAs of both methods do notconsistently agree on a daily basis a usage of remote sensing derived SLAs for model calibration in the absence of field observation data is only limitedly feasible for daily analysis. ELA approximation using the highest SLA at the end of ablation period may not be applied to UM because the negative winter mass balance(MB) is not reflected in the summer SLA. The study reveals moderate negative MB for UM throughout the modelling period. The mean regional MB of UM accounts for-523±410 mm w.e. a-1 in the modelling period. Hence UM seems not to belong to the area of the ‘Karakorum anomaly' comprising a region of positive mass balances in recent years which has its centre presumably in the Western Kunlun Shan.展开更多
文摘采用高亚洲精细再分析数据(High AsiaRefinedanalysis,HAR)以及Coupled SnowpackandIceSurfaceEn⁃ergy andMassbalanceModel(COSIMA)模拟了青藏高原最大冰原——普若岗日2012-04-23—2014-05-11的能量-物质平衡,并分析了普若岗日冰原消融机理。模拟的2012-04-23—2013-05-23与2013-05-23—2014-05-11的物质平衡分别为-0.18 m w.e.、-0.36 m w.e.。在整个研究时段内,冰原西部、中北部等海拔低于5800 m的区域处于物质亏损状态,最大达到-2.69 m w.e.;冰原北部区域因为海拔较高的原因,处于物质积累状态,在东北部区域最高值达到0.85 m w.e.。2013-05-23—2014-05-11用于消融的能量相比2012-04-23—2013-05-23减少,冰川表面消融减速,但普若岗日冰原上空2013-05-23—2014-05-11的固态降水量少于2012-04-23—2013-05-23,因此冰川在2013-05-23—2014-05-11日的表面净物质平衡反而减少。
基金supported by the German Research Foundation(DFG)Priority Programme 1372,‘Tibetan Plateau:Formation Climate Ecosystems’through the DynRG-TiP(‘Dynamic Response of Glaciers on the Tibetan Plateau to Climate Change’)project under codes SCHN 680/3-3 and SCHE 750/4-3the German Federal Ministry of Education and Research(BMBF)Central Asia Monsoon Dynamics and GeoEcosystems(CAME)program,through the WET project(‘Variability and Trends in Water Balance Components of Benchmark Drainage Basins on the Tibetan Plateau’)under code 03G0804A
文摘The ice cap Ulugh Muztagh in the central Kunlun Shan at the northern fringe of the Tibetan Plateau is a very isolated region with arid cold conditions. No observational, meteorological or glaciological ground truth data is available. Using the Moderate-resolution Imaging Spectroradiometer(MODIS) Level 1 radiance Swath Data(MOD02QKM) with a spatial resolution of 250 m, transient snow lines during the months of July to September in 2001 to 2014 are derived. Results are used to calibrate the physical based Coupled Snowpack and Ice surface energy and Mass balance model(COSIMA). The model runs on a representative detail region of Ulugh Muztagh(UM) on a digital elevation model with the same spatial resolution as the MODIS bands. In the absence of field observations, the model is driven solely by dynamically downscaled global analysis data from the High Asia Refined analysis(HAR). We compare remote sensing derived and modelled mean regional transient snow line altitudes in the course of consecutive summer seasons in 2008 to 2010. The resulting snow line altitude(SLA) and annual equilibrium line altitude(ELA) proxy of both methods coincide very well in their interannual variability in accordance with interannual variability of climatic conditions. Since SLAs of both methods do notconsistently agree on a daily basis a usage of remote sensing derived SLAs for model calibration in the absence of field observation data is only limitedly feasible for daily analysis. ELA approximation using the highest SLA at the end of ablation period may not be applied to UM because the negative winter mass balance(MB) is not reflected in the summer SLA. The study reveals moderate negative MB for UM throughout the modelling period. The mean regional MB of UM accounts for-523±410 mm w.e. a-1 in the modelling period. Hence UM seems not to belong to the area of the ‘Karakorum anomaly' comprising a region of positive mass balances in recent years which has its centre presumably in the Western Kunlun Shan.
