Climate Dynamics of Western-Central Hindu Kush Himalayas

Singh, Aasadeep (2021) Climate Dynamics of Western-Central Hindu Kush Himalayas. Masters thesis, Indian Institute of Science Education and Research Kolkata.

Text (MS Dissertation of Aasadeep Singh (16MS013)) 16MS013_Thesis_file.pdf - Submitted Version Restricted to Repository staff only Download (4MB)

Abstract

The HKH region being one of the largest snow reservoir and regarded as being climatically inconsistently sensitive. The Changes in multi meteorological variables was studied for Western-Central HKH region of North-Western India using ERA-5 reanalysis monthly averaged mean data from 1979-2018 (40 years). Kendall Tau trend was calculated for monthly averaged mean data for these 40 years to define and examine the study areas. Mann-Kendall Test, Sen’s Slope estimator & Innovative Trend Analysis was performed at these spatial study regions for multi-temporal scales i.e., Annual, Winter & Monsoon. Then, spearman correlation was employed to find out association of SCA with snowfall & temperature. Model fitting for climatic variables with temporal scale and among them was accomplished by regression via MATLAB. Results revealed that the there exists a significant decreasing trend of SCA in annual and monsoon scale of NWH region with a rate of 0.35%/year & 0.13%/year respectively, though temperature increased annually and during monsoon in NWH region which explain the decreasing trend in SCA. Mean winter snowfall was calculated for all 3 study areas and it was found that snowfall in NWH is highest followed by WH and then TH due to decreasing influence of Western Disturbances to southwards and eastwards. SCA trends of study area revealed that only in NWH, trend exists i.e., decreasing. Correlation Analysis revealed statistically significant negative correlation, ranging from -0.81 to -0.77 in all spatial areas w.r.t annual scale in the past 40 years and non-significant correlation value of 0.23 exists between SCA & snowfall for Monsoon period in WH. Moreover, SCA was controlled mainly by temperature and snowfall, and amount of contribution from either changes spatio-temporally, so for instance the temperature dominates in monsoon season of WH but snowfall controls more in ratio during monsoon season of TH. Modelling of parameters was employed in tools of MATLAB that revealed that the model that fits for Snowfall time series for North Western Himalayas in winter period is a Fourier series with 7 terms but for SCA and snowfall; it is linear fit in a temporal scale of same region with R2 = 0.51 & 0.62 respectively.

Actions (login required)

View Item