Observed high-altitude warming and snow cover retreat over Tibet and the Himalayas enhanced by black carbon aerosols

Abstract. Himalayan mountain glaciers and the snowpack over the Tibetan Plateau provide the headwater of several major rivers in Asia. In situ observations of snow cover extent since the 1960s suggest that the snowpack in the region have retreated significantly, accompanied by a surface warming of 2–2.5 °C observed over the peak altitudes (5000 m). Using a high-resolution ocean–atmosphere global climate model and an observationally constrained black carbon (BC) aerosol forcing, we attribute the observed altitude dependence of the warming trends as well as the spatial pattern of reductions in snow depths and snow cover extent to various anthropogenic factors. At the Tibetan Plateau altitudes, the increase in atmospheric CO2 concentration exerted a warming of 1.7 °C, BC 1.3 °C where as cooling aerosols cause about 0.7 °C cooling, bringing the net simulated warming consistent with the anomalously large observed warming. We therefore conclude that BC together with CO2 has contributed to the snow retreat trends. In particular, BC increase is the major factor in the strong elevation dependence of the observed surface warming. The atmospheric warming by BC as well as its surface darkening of snow is coupled with the positive snow albedo feedbacks to account for the disproportionately large role of BC in high-elevation regions. These findings reveal that BC impact needs to be properly accounted for in future regional climate projections, in particular on high-altitude cryosphere.

[1]  Zong-Liang Yang,et al.  An observation-based formulation of snow cover fraction and its evaluation over large North American river basins , 2007 .

[2]  W. G. Strand,et al.  Climate Change Projections in CESM1(CAM5) Compared to CCSM4 , 2013 .

[3]  S. Warren,et al.  A Model for the Spectral Albedo of Snow. I: Pure Snow , 1980 .

[4]  C. Xiao,et al.  Darkening of the mid-Himalaya glaciers since 2000 and the potential causes , 2012 .

[5]  M. R. van den Broeke,et al.  A Reconciled Estimate of Glacier Contributions to Sea Level Rise: 2003 to 2009 , 2013, Science.

[6]  V. Ramanathan,et al.  Global and regional climate changes due to black carbon , 2008 .

[7]  M. Chin,et al.  Estimated range of black carbon dry deposition and the related snow albedo reduction over Himalayan glaciers during dry pre-monsoon periods , 2013 .

[8]  Thomas H. Painter,et al.  End of the Little Ice Age in the Alps forced by industrial black carbon , 2013, Proceedings of the National Academy of Sciences.

[9]  Rui Jin,et al.  Cryospheric change in China , 2008 .

[10]  Jianping Huang,et al.  Simulating black carbon and dust and their radiative forcing in seasonal snow: a case study over North China with field campaign measurements , 2014 .

[11]  S. Bajracharya,et al.  Global Climate Change and Melting of Himalayan Glaciers , 2008 .

[12]  Z. Pu,et al.  MODIS/Terra observed seasonal variations of snow cover over the Tibetan Plateau , 2007 .

[13]  Olivier Boucher,et al.  Snow cover sensitivity to black carbon deposition in the Himalayas: from atmospheric and ice core measurements to regional climate simulations , 2013 .

[14]  Martin Wild,et al.  Atmospheric brown clouds: impacts on South Asian climate and hydrological cycle. , 2003, Proceedings of the National Academy of Sciences of the United States of America.

[15]  Bin Wang,et al.  Tibetan Plateau warming and precipitation changes in East Asia , 2008 .

[16]  Richard Neale,et al.  Toward a Minimal Representation of Aerosols in Climate Models: Description and Evaluation in the Community Atmosphere Model CAM5 , 2012 .

[17]  Mo Wang,et al.  Light-absorbing particles in snow and ice: Measurement and modeling of climatic and hydrological impact , 2014, Advances in Atmospheric Sciences.

[18]  Philip J. Rasch,et al.  Present-day climate forcing and response from black carbon in snow , 2006 .

[19]  B. D. Mauro,et al.  Mineral dust impact on snow radiative properties in the European Alps combining ground, UAV, and satellite observations , 2015 .

[20]  G. Cheng,et al.  Responses of permafrost to climate change and their environmental significance, Qinghai‐Tibet Plateau , 2007 .

[21]  H. Fowler,et al.  Elevation-dependent warming in mountain regions of the world , 2015 .

[22]  Xiao-dong Liu,et al.  Elevation dependency of recent and future minimum surface air temperature trends in the Tibetan Plateau and its surroundings , 2009 .

[23]  Y. Arnaud,et al.  Black carbon in snow in the upper Himalayan Khumbu Valley, Nepal: observations and modeling of the impact on snow albedo, melting, and radiative forcing , 2014 .

[24]  J. Kiehl,et al.  Atmospheric brown clouds: impacts on South Asian climate and hydrological cycle. , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[25]  H. V. D. Dool,et al.  A global monthly land surface air temperature analysis for 1948-present , 2008 .

[26]  Donald K. Perovich,et al.  Radiative forcing and albedo feedback from the Northern Hemisphere cryosphere between 1979 and 2008 , 2011 .

[27]  F. Cao,et al.  The impact of Saharan dust and black carbon on albedo and long-term mass balance of an Alpine glacier , 2015 .

[28]  Thomas C. Peterson,et al.  Maximum and Minimum Temperature Trends for the Globe , 1997 .

[29]  Daniel Orlikowski,et al.  Black Carbon Aerosols Black Carbon Aerosols and the Third Polar Ice Cap Acpd Black Carbon Aerosols , 2022 .

[30]  Tristan S. L'Ecuyer,et al.  Observational constraints on Arctic Ocean clouds and radiative fluxes during the early 21st century , 2013 .

[31]  Ian Eisenman,et al.  Observational determination of albedo decrease caused by vanishing Arctic sea ice , 2014, Proceedings of the National Academy of Sciences.

[32]  Zhi-Yong Yin,et al.  Temporal trends and variability of daily maximum and minimum, extreme temperature events, and growing season length over the eastern and central Tibetan Plateau during 1961-2003 , 2006 .

[33]  Zhaoxia Pu,et al.  MODIS/Terra observed snow cover over the Tibet Plateau: distribution, variation and possible connection with the East Asian Summer Monsoon (EASM) , 2009 .

[34]  S. Xie,et al.  Ocean mediation of tropospheric response to reflecting and absorbing aerosols , 2015 .

[35]  Yun Qian,et al.  Sensitivity studies on the impacts of Tibetan Plateau snowpack pollution on the Asian hydrological cycle and monsoon climate , 2010 .

[36]  Woo-Seop Lee,et al.  Enhanced surface warming and accelerated snow melt in the Himalayas and Tibetan Plateau induced by absorbing aerosols , 2010 .

[37]  David S. Lee,et al.  Historical (1850–2000) gridded anthropogenic and biomass burning emissions of reactive gases and aerosols: methodology and application , 2010 .

[38]  M. V. Ramana,et al.  Warming trends in Asia amplified by brown cloud solar absorption , 2007, Nature.

[39]  D. Lawrence,et al.  The contribution of snow condition trends to future ground climate , 2010 .

[40]  P. S. Praveen,et al.  Solar absorption by elemental and brown carbon determined from spectral observations , 2012, Proceedings of the National Academy of Sciences.

[41]  Shi-chang Kang,et al.  Rapid warming in the Tibetan Plateau from observations and CMIP5 models in recent decades , 2016 .

[42]  S. Manabe,et al.  The Effects of Doubling the CO2 Concentration on the climate of a General Circulation Model , 1975 .

[43]  R. Bahadur,et al.  Estimating the radiative forcing of carbonaceous aerosols over California based on satellite and ground observations , 2013 .

[44]  C. Deser,et al.  Communication of the role of natural variability in future North American climate , 2012 .

[45]  X. Zeng,et al.  Improving the treatment of the vertical snow burial fraction over short vegetation in the NCAR CLM3 , 2009 .

[46]  D. Lawrence,et al.  Parameterization improvements and functional and structural advances in Version 4 of the Community Land Model , 2011 .

[47]  Ka-Ming Lau,et al.  Observational relationships between aerosol and Asian monsoon rainfall, and circulation , 2006 .

[48]  K. Lau,et al.  Asian summer monsoon anomalies induced by aerosol direct forcing : the role of the Tibetan Plateau , 2006 .

[49]  T. Kirchstetter,et al.  Black-carbon reduction of snow albedo , 2012 .

[50]  T. Yao,et al.  Black soot and the survival of Tibetan glaciers , 2009, Proceedings of the National Academy of Sciences.

[51]  H. Jacobi,et al.  Precipitation and snow cover in the Himalaya: from reanalysis to regional climate simulations , 2013 .

[52]  M. Jacobson.  Investigating cloud absorption effects: Global absorption properties of black carbon, tar balls, and soil dust in clouds and aerosols , 2012 .

[53]  Jianping Huang,et al.  Quantifying sources, transport, deposition, and radiative forcing of black carbon over the Himalayas and Tibetan Plateau , 2015 .

[54]  W. Collins,et al.  Effects of Black Carbon Aerosols on the Indian Monsoon , 2008 .

[55]  Jianping Huang,et al.  Black carbon and other light‐absorbing impurities in snow across Northern China , 2013 .

[56]  K.,et al.  The Community Earth System Model (CESM) large ensemble project: a community resource for studying climate change in the presence of internal climate variability , 2015 .

[57]  V. Ramaswamy,et al.  Albedo of soot‐contaminated snow , 1983 .

[58]  B. DeAngelo,et al.  Bounding the role of black carbon in the climate system: A scientific assessment , 2013 .

[59]  P. Talkner,et al.  20th-CENTURY CHANGES OF TEMPERATURE IN THE MOUNTAIN REGIONS OF CENTRAL EUROPE , 1997 .

[60]  Yi Ming,et al.  Nonlinear Climate and Hydrological Responses to Aerosol Effects , 2009 .

[61]  Andrew Gettelman,et al.  A new two-moment bulk stratiform cloud microphysics scheme in the Community Atmosphere Model, version 3 (CAM3). Part I: Description and numerical tests , 2008 .

[62]  Thomas H. Painter,et al.  Springtime warming and reduced snow cover from carbonaceous particles , 2008 .

[63]  T. Painter,et al.  Impact of disturbed desert soils on duration of mountain snow cover , 2007 .