Role of radiation and canopy model in predicting heat waves using WRF over the city of Bhubaneswar, Odisha

The heat waves (HW) are more frequent with upsurge intensity and spread in the recent warming era over Bhubaneswar, the capital city of Odisha state in India. The city has experienced HW more than four events per year and reported casualties are higher during the recent era as compared to the past century. In addition, the HW caused ecosystem mortality and affected significantly the agriculture and water resource sectors. The city notably grows with urban areas in recent decades, thus, in this study, we explored the potential role of various radiation and urban canopy model schemes with different initial conditions (48, 24, and 12 h lead time) to assess the predictability of HW over Bhubaneswar using the Weather Research and Forecasting (WRF) model. A large number of simulations were carried out with three nested domains at a resolution of 4.5, 1.5, and 0.5 km for the three HW events. The model forecasts have been validated against the Indian Monsoon Data Assimilation and Analysis. The WRF model satisfactorily predicted the spatial distributions and timing of an HW with the Community Atmospheric Model (CAM) radiation and Single-Layer Urban Canopy Model (UCM) urban schemes over the Bhubaneswar urban region 2 days in advance. However, the performance of radiation and urban canopy model schemes varies from event to event. The composite of statistical errors and skill score analysis confirm that the CAM radiation scheme and UCM urban scheme performed well. Overall, CAM and UCM have around 30% and 20% lower percentages of errors, respectively. This study emphasizes the behavior of various radiation and urban canopy model schemes in predicting HW, specifically in the urban agglomeration of Bhubaneswar.