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Urbanization is happening at a very fast pace in India causing more warming. As per IPCC report, principal driver of long-term warming is total emissions of CO2. Urban areas have higher built-up areas hence urban climates are normally understood by differences in climatic variables like Air temperature, Humidity, Wind speed direction and amount of precipitation from its surrounding areas. In this study an attempt is made to examine the temperature difference during pre-lockdown and lock-down period that was enforced to control Covid-19 spread in March2020. MODIS datasets were taken for five class I and class II Indian cities for pre-lockdown and lockdown to examine diurnal variation. Generally, temperatures will rise on 29th due to season advancement, however it is noticed that temperature increase is relatively less especially in night time minimum temperatures during lockdown. Results indicate that diurnal variation for all class I cities went up during Lock-down by 0.5 to 2.540C except Chennai where it went down by 1.740C. In Chennai atmospheric factors like very high sea breeze could have contributed to lower diurnal. In class II cities the diurnal variation difference of 20C is noticed except Raipur and more data would be needed to investigate it further. A detailed study for Chennai-Class I and Ludhiana-Class II was also done for diurnal and spatial analysis for different land use and land cover by using both MOD11A2, ASTER 1B data sets. LST with different Land surfaces was also correlated for both day and night for both dates and ASTER BT was also analyzed for land surfaces. The findings indicate that mean temperature rise on impervious surfaces is 3oC lower than increase on other surfaces and this could be due to reduced anthropogenic activities in lock-down period. This can be studied further with more data sets, field validations, and atmospheric corrections.
Keywords: LST, LULC Classification, Impervious Surfaces, Anthropogenic Activities, Diurnal Variation
