Comparative assessment of WRF’s parameterization scheme combinations in assessing land-surface feedback flux and its drivers: a case study of Phailin tropical cyclone

During the life cycle of a tropical cyclone from the homogeneous ocean-phase to the heterogeneous land-phase, estimating the catchment-scale evapotranspiration (ET) for agricultural water management is a challenging task. For assessing the catchment-scale ET and the causative weather variables associated with the land–atmosphere interactions during the Tropical Cyclone Phailin (TC Phailin), some popular parameterization scheme combinations in the Weather Research and Forecasting (WRF) model were selected. The suitability of different WRF parameterization scheme combinations (PSCs) were evaluated in the Brahmani River basin in eastern India to reproduce the observed weather variables of surface (2-m) air temperature, precipitation and atmospheric pressure at hourly and daily temporal resolutions during the pre-, at-, and post events of the TC Phailin. This study found that the ‘Rapid Update Cycle’ (RUC) LSM with ‘Purdue Lin’ microphysics and ‘Arakawa convective’ cumulus scheme performed the best. Overall, the PSCs could simulate the surface air temperature better than the precipitation during the short timeframe of the extreme event, whereas the overall regional pressure simulation showed a constant bias. The results reveal that WRF-LSM model that accounts for both local (clothesline) and global (oasis) advection effects could better simulate the ET flux compared to the corresponding MOD16A2 remote sensing product and the Food and Agricultural Organization (FAO)-56 Penmen-Monteith (PM) equation, especially during cloudy days. The local feedback of the TC Phailin over the land-surface ET flux and its climatic and land-surface drivers (soil moisture) during the pre-, at-, post-cyclone events reveal that: (a) the negative Bowen Ratio estimates during the heavy rainfall resulted in a reduced ET flux, (b) the negative sensible heat flux during this period facilitates for flow of heat from surface to atmosphere, cooling the soil of the river basin. Overall, this study aids in a better understanding of the moisture flux and energy transfer dynamics between the land–atmosphere system during the onset of a cyclone.