Zeb Bahadar, Alam Khan, Sorooshian Armin, Chishtie Farrukh, Ahmad Ifthikhar, Bibi Humera
Department of Physics, University of Malakand, Khyber Pakhtunkhwa, Pakistan.
Department of Mathematics, Shaheed Benazir Bhutto University, Sheringal, Dir Upper, Khyber Pakhtunkhwa, Pakistan.
J Atmos Sol Terr Phys. 2019 May;186:35-46. doi: 10.1016/j.jastp.2019.02.004. Epub 2019 Feb 20.
Glacier melting due to light-absorbing aerosol has become a growing issue in recent decades. The emphasis of this study is to examine aerosol loadings over the high mountain glacier region of northern Pakistan between 2004 and 2016, with sources including local emissions and long-range transported pollution. Optical properties of aerosols were seasonally analyzed over the glacier region (35-36.5°N; 74.5-77.5°E) along with three selected sites (Gilgit, Skardu, and Diamar) based on the Ozone Monitoring Instrument (OMI). The aerosol sub-type profile was analyzed with Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO). Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to understand the origin of air masses arriving in the study region. The highest values of aerosol optical depth (AOD) and single scattering albedo (SSA) occurred during spring, whereas aerosol index (AI) and absorption AOD (AAOD) exhibited maximum values in winter and summer, respectively. The minimum values of AOD, AI, AAOD, and SSA occurred in winter, autumn, winter, and autumn, respectively. The results revealed that in spring and summer the prominent aerosols were dust, whereas, in autumn and winter, anthropogenic aerosols were prominent. Trend analysis showed that AI, AOD, and AAOD increased at the rate of 0.005, 0.006, and 0.0001 yr, respectively, while SSA decreased at the rate of 0.0002 yr. This is suggestive of the enhancement in aerosol types over the region with time that accelerates melting of ice. CALIPSO data indicate that the regional aerosol was mostly comprised of sub-types categorized as dust, polluted dust, smoke, and clean continental. The types of aerosols defined by OMI were in good agreement with CALIPSO retrievals. Analysis of the National Oceanic and Atmospheric Administration Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model revealed that air parcels arriving at the glacier region stemmed from different source sites.
近几十年来，由于吸光气溶胶导致的冰川融化已成为一个日益严重的问题。本研究的重点是调查2004年至2016年期间巴基斯坦北部高山冰川地区的气溶胶负荷，其来源包括本地排放和远距离传输的污染。基于臭氧监测仪（OMI），对冰川地区（北纬35 - 36.5°；东经74.5 - 77.5°）以及三个选定地点（吉尔吉特、斯卡都和迪亚马尔）的气溶胶光学特性进行了季节性分析。利用云 - 气溶胶激光雷达和红外探路者卫星观测（CALIPSO）分析了气溶胶亚型分布。使用混合单粒子拉格朗日积分轨迹（HYSPLIT）模型来了解抵达研究区域的气团来源。气溶胶光学厚度（AOD）和单次散射反照率（SSA）的最高值出现在春季，而气溶胶指数（AI）和吸收性AOD（AAOD）分别在冬季和夏季呈现最大值。AOD、AI、AAOD和SSA的最小值分别出现在冬季、秋季、冬季和秋季。结果表明，春季和夏季主要的气溶胶是沙尘，而秋季和冬季则以人为气溶胶为主。趋势分析表明，AI、AOD和AAOD分别以每年0.005、0.006和0.0001的速率增加，而SSA以每年0.0002的速率下降。这表明该地区气溶胶类型随时间增加，加速了冰川融化。CALIPSO数据表明，区域气溶胶主要由沙尘、污染沙尘、烟雾和清洁大陆气溶胶等亚型组成。OMI定义的气溶胶类型与CALIPSO反演结果高度一致。对美国国家海洋和大气管理局混合单粒子拉格朗日积分轨迹（HYSPLIT）模型的分析表明，抵达冰川地区的气团来自不同的源地。
