Climate Change in Himalaya

“To know your future you must know your past.” There is no better way to start the new semester with expanding the field of view on the Himalayas by looking at the paleoclimate and environment changes through time.  The Quaternary period where the transition from the Quaternary Ice Age, to Oldest Dryas, Older Dryas/Allerød and Younger Dryas and to current Holocene Interglacial, represents a distinctive period with typical climate events and environmental changes influencing earth ecosystems. The behaviours of glaciation and hydrology in Himalaya–Tibetan orogen at different regions have oscillated throughout the Quaternary  driven by different climatic forcing, in turn, could have had a major impact on global climate. It is of great importance for paleoecological research to understand the nature and dynamics of the Quaternary changes on this high land and adjacent regions. Many studies have applied the proxies records on Quaternary geological archives from  Himalaya–Tibet...

Black Carbon (BC) has a  noticeable   history  over the past 150 years in Hindu-Kush-Himalayan (HKH) and Tibetan Plateau (TP),  from pre-industry to modern periods. An analysis  on Mt. Everest ice core during 1860–2000 and based on  Single Particle Soot Photometer  demonstrates that BC concentration from 1975-2000 shows about 3-fold increase compared to the background level of 1860-1975, indicating BC from anthropogenic source has been introduced and transported to highland of Himalayas.   What is black carbon BC is derived from incomplete combustion of organic matter from both natural and anthropogenic sources, in the form of carbonaceous aerosols, heating the  aerosol-planetary boundary layer  with a net warming effect  by absorbing and scattering sunlight. BC can also be deposited onto snow and ice, darkening the surfaces and reducing their albedo feedback . Both mechanisms ar...

As we mentioned in the previous post, about 1.3 billion people living in the Himalayan river basins rely on monsoon rainfall and  glacier meltwater   for their livelihoods. Monsoon ( in this blog referring to Indian Summer monsoon) as seasonally reversing winds over the Indian Ocean sustains 1/5 populations on earth for their irrigation, drinking, sanitation, infrastructure, industrial uses and economic development. Map source http://www.meteo.co.in/Monsoons/image004.jpg However, does the magnificent Himalayas let the monsoon system go shallow? The Monsoon has  inter-annual and inter-decadal change ,  temporal and spatial variation factored into their respective onset and retreating rates and dates.The Monsoon-rainfall on set during June to September is a complex system. The  Himalayas have significant influence on the Monsoon system by virtue of high altitude, intercept two branches of summer monsoon coming from Bay Bengal and Arabian sea ...