Indian Forum for Water Adroit

Linkage between global sea surface temperature and hydroclimatology of a major river basin of India

Karthikeyan L

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  • Institute : Indian Institute of Science, Bangalore
  • Programming language : Matlab, R
A work carried out by Sonali Pattanayak titled "Linkage between global sea surface temperature and hydroclimatology of a major river basin of India before and after 1980" got published recently in the Environmental Research Letters.

Abstract: Frequent occurrence of flood and drought worldwide has drawn attention to assess whether the hydroclimatology of major river basins has changed. Mahanadi river basin (MRB) is the major source of fresh water for both Chattisgarh and Odisha states (71 million population approximately) of India. The MRB (141,600 km2 area) is one of the most vulnerable to climate change and variations in temperatures and precipitation regions. In the recent years, it has been repetitively facing the adverse hydrometeorological conditions. Large-scale ocean-atmospheric phenomena have substantial influence on river hydroclimatology. Hence Global sea surface temperature (SST) linkage with precipitation and surface temperature of MRB is analyzed over period 1950-2012. Significant changes in seasonal correlation patterns are witnessed from 1950-1980 (PR-80) to 1981-2012 (PO-80) periods. The correlation is higher during PR-80 compared to PO-80 between NiƱo region SST versus maximum temperature (Tmax) in all seasons except pre monsoon season and minimum temperature (Tmin) in all seasons except monsoon season. However, precipitation correlation changes are not prominent. Like SST, correlation patterns of sea level pressure with precipitation, Tmax and Tmin are shifted conspicuously from PR-80 to PO-80. These shifts could be related to change in Pacific decadal SST patterns and human induced anthropogenic effects. Fingerprint-based detection and attribution analysis revealed that the observed changes in Tmin (pre monsoon and monsoon season) during second half of the 20th century cannot be explained solely by natural variability and these changes can be attributed to human induced anthropogenic effect.

Sonali can be contacted at iisc.sonali@gmail.com