Impact of Climate Change and Surface Energy (Im) Balance on North-East India Monsoonal Rainfall

2021 ◽  
Vol 7 (2) ◽  
pp. 35-47
Author(s):  
Pramod Kumar
Keyword(s):  
Climate Change ◽  
Surface Energy ◽  
Thermal Radiation ◽  
Sensible Heat ◽  
Study Region ◽  
Near Surface ◽  
Energy Imbalance ◽  
North East India ◽  
North East ◽  
Monsoonal Precipitation

In recent decades, climate change and its impact on the ecosystem has remained a concern from global to regional to local scale. Many studies performed over India have highlighted the change in precipitation associated with the Indian summer monsoon (ISM) and its linkage with changed land surface processes. Over North-East India (NEI), changed surface and atmospheric energy imbalance due to increase in wasteland, deforestation and over cultivation have made the soil barren. In addition, soil moisture of barren land has decreased, latent (sensible) heat decreased (increased) with stimulating ground heat increment. This led to lower evapotranspiration and convection leading to precipitation decrement. To analyse this in detail, the present study shows a lower increase in the near surface temperature during 1956-1985 (period I), but a higher increasing trend has been seen during 1986-2015 (period II). In the case of precipitation trends, an increase during period I and a decrease at a 95% significant level during period II are seen. The average air temperature warming rate increase of 0.09 °C/year is observed. The monsoonal precipitation has decreased significantly in recent years (1986-2015) than that in the past (1956-1985). In addition, a decrease in monsoonal precipitation at 0.35 mm/year rate during period II is seen over NEI. A prominent increment of 0.12 W/m2 is observed in surface sensible heat flux over NEI. Land use land cover change (LULCC) is continuously altering the local rate of change of thermal radiation, evapotranspiration and convection, and has also played a critical role in defining monsoonal precipitation over NEI. However, the surface net solar and thermal radiation change are in equilibrium with the surface sensible and latent heat for sustaining the surface energy budget. Hence, a small change in surface net radiation causes an imbalance of surface energetics. It is one of the most prominent causes for the precipitation pattern changes over NEI. The LULCCs and earth’ surface energy imbalance reinforce climate variability and climate change over the study region.

Short-term rainfall forecasts as a soft adaptation to climate change in irrigation management in North-East India

2013 ◽  
Vol 127 ◽  
pp. 97-106 ◽  
Author(s):  
Ashok Mishra ◽  
Christian Siderius ◽  
Kenny Aberson ◽  
Martine van der Ploeg ◽  
Jochen Froebrich
Keyword(s):  
Climate Change ◽  
Irrigation Management ◽  
Adaptation To Climate Change ◽  
Short Term ◽  
North East India ◽  
North East

scholarly journals Water tracks intensify surface energy and mass exchange in the Antarctic McMurdo Dry Valleys

2019 ◽  
Vol 13 (8) ◽  
pp. 2203-2219 ◽  
Author(s):  
Tobias Linhardt ◽  
Joseph S. Levy ◽  
Christoph K. Thomas
Keyword(s):  
Climate Change ◽  
Energy Balance ◽  
Surface Energy ◽  
Surface Energy Balance ◽  
Heat Fluxes ◽  
Dry Valleys ◽  
Sensible Heat ◽  
Net Radiation ◽  
Taylor Valley ◽  
The Antarctic

Abstract. The hydrologic cycle in the Antarctic McMurdo Dry Valleys (MDV) is mainly controlled by surface energy balance. Water tracks are channel-shaped high-moisture zones in the active layer of permafrost soils and are important solute and water pathways in the MDV. We evaluated the hypothesis that water tracks alter the surface energy balance in this dry, cold, and ice-sheet-free environment during summer warming and may therefore be an increasingly important hydrologic feature in the MDV in the face of landscape response to climate change. The surface energy balance was measured for one water track and two off-track reference locations in Taylor Valley over 26 d of the Antarctic summer of 2012–2013. Turbulent atmospheric fluxes of sensible heat and evaporation were observed using the eddy-covariance method in combination with flux footprint modeling, which was the first application of this technique in the MDV. Soil heat fluxes were analyzed by measuring the heat storage change in the thawed layer and approximating soil heat flux at ice table depth by surface energy balance residuals. For both water track and reference locations over 50 % of net radiation was transferred to sensible heat exchange, about 30 % to melting of the seasonally thawed layer, and the remainder to evaporation. The net energy flux in the thawed layer was zero. For the water track location, evaporation was increased by a factor of 3.0 relative to the reference locations, ground heat fluxes by 1.4, and net radiation by 1.1, while sensible heat fluxes were reduced down to 0.7. Expecting a positive snow and ground ice melt response to climate change in the MDV, we entertained a realistic climate change response scenario in which a doubling of the land cover fraction of water tracks increases the evaporation from soil surfaces in lower Taylor Valley in summer by 6 % to 0.36 mm d−1. Possible climate change pathways leading to this change in landscape are discussed. Considering our results, an expansion of water track area would make new soil habitats accessible, alter soil habitat suitability, and possibly increase biological activity in the MDV. In summary, we show that the surface energy balance of water tracks distinctly differs from that of the dominant dry soils in polar deserts. With an expected increase in area covered by water tracks, our findings have implications for hydrology and soil ecosystems across terrestrial Antarctica.

scholarly journals Near-surface climate and surface energy budget of Larsen C ice shelf, Antarctic Peninsula

2012 ◽  
Vol 6 (2) ◽  
pp. 353-363 ◽  
Author(s):  
P. Kuipers Munneke ◽  
M. R. van den Broeke ◽  
J. C. King ◽  
T. Gray ◽  
C. H. Reijmer
Keyword(s):  
Surface Energy ◽  
Antarctic Peninsula ◽  
Energy Budget ◽  
Heat Fluxes ◽  
Surface Energy Budget ◽  
Shortwave Radiation ◽  
Sensible Heat ◽  
Ice Shelf ◽  
Near Surface ◽  
The Impact

Abstract. Data collected by two automatic weather stations (AWS) on the Larsen C ice shelf, Antarctica, between 22 January 2009 and 1 February 2011 are analyzed and used as input for a model that computes the surface energy budget (SEB), which includes melt energy. The two AWSs are separated by about 70 km in the north–south direction, and both the near-surface meteorology and the SEB show similarities, although small differences in all components (most notably the melt flux) can be seen. The impact of subsurface absorption of shortwave radiation on melt and snow temperature is significant, and discussed. In winter, longwave cooling of the surface is entirely compensated by a downward turbulent transport of sensible heat. In summer, the positive net radiative flux is compensated by melt, and quite frequently by upward turbulent diffusion of heat and moisture, leading to sublimation and weak convection over the ice shelf. The month of November 2010 is highlighted, when strong westerly flow over the Antarctic Peninsula led to a dry and warm föhn wind over the ice shelf, resulting in warm and sunny conditions. Under these conditions the increase in shortwave and sensible heat fluxes is larger than the decrease of net longwave and latent heat fluxes, providing energy for significant melt.

scholarly journals Estimation of Runoff under changed climatic scenario of a Meso Scale River by Neural Network Based Gridded Model Approach

2021 ◽  
Author(s):  
Debajit Das ◽  
Tilottama Chakraborty ◽  
Mrinmoy Majumder ◽  
Tarun Kanti Bandyopadhyay
Keyword(s):  
Climate Change ◽  
River Basin ◽  
General Circulation ◽  
General Circulation Models ◽  
Group Method ◽  
North East India ◽  
North East ◽  
Hadley Centre ◽  
Gomati River ◽  
The Impact

Abstract As climate change is linked with changes in precipitation, evapotranspiration and changes in other climatological parameters, these changes will be affected runoff of a river basin. Gomati River basin is the largest river basin among all the river basin of Tripura. Due to the increase in settlement in the Gomati river basin and climate change may threaten natural flow patterns that endure its diversity. This study assesses the impact of climate change on total flow of a catchment in North East India (Gomati River catchment). For this assessment, the Group Method of Data Handling Modeling System (GMDH) model was used to simulate the rainfall-runoff relationship of the catchment, with respect to the observed data during the period of 2008–2009. The statistically downscaled outputs of HadGEM2-ES (Hadley Centre Global Environment Model version 2), general circulation models (GCMs) scenario was used to assess the impacts of climate change on the Gomati River Basin. Future projections were developed for the 2030s, 2040s and 2050s projections, respectively. The results from the present study can contribute to the development of adaptive strategies and future policies for the sustainable management of water resources in North East, Tripura.

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