RegCM4 simulation with AVHRR land use data towards temperature and precipitation climatology over Indian region

The Regional Climate Modeling system (RegCM) is being widely used for climate simulation at seasonal to multi-decadal scales over many regions across the world in recent decades. In this study, we conducted a 10 years simulation using RegCM4 by replacing the United States Geological Survey (USGS) land use data (the default land use data in RegCM) with the land use data from Advanced Very High Resolution Radiometer (AVHRR) satellite images to test the usefulness of AVHRR land use data in RegCM. We focused on the 10 years (1991-2000) of temperature and precipitation climatologies over Indian region from the model with AVHRR land use data and that of with USGS land use data. The results are compared with Climate Research Unit (CRU) observation through the model biases, standard error, the temporal and spatial correlation between the model and observation in two results (USGS vs. AVHRR). Results indicate that the annual and seasonal climatology of surface temperature and precipitation in both simulations (i.e. with USGS and AVHRR) are close to each other over Indian region. However, the simulation with AVHRR land use data improved up to similar to 2 degrees C in temperature field and similar to 1 mm/d in precipitation field over few regions. The inter-annual variability of surface temperature and precipitation in both simulations are also found almost same. Based on the results of this study, we conclude that the AVHRR land use data can be used in RegCM to conduct regional climate simulations over Indian region. Additionally this study suggests that, as AVHRR dataset is available for longer period in 15 days interval, so the impact of land use change on different climatic variables during a period can be studied by using RegCM. The Regional Climate Modeling system (RegCM) is being widely used for climate simulation at seasonal to multi-decadal scales over many regions across the world in recent decades. In this study, we conducted a 10 years simulation using RegCM4 by replacing the United States Geological Survey (USGS) land use data (the default land use data in RegCM) with the land use data from Advanced Very High Resolution Radiometer (AVHRR) satellite images to test the usefulness of AVHRR land use data in RegCM. We focused on the 10 years (1991-2000) of temperature and precipitation climatologies over Indian region from the model with AVHRR land use data and that of with USGS land use data. The results are compared with Climate Research Unit (CRU) observation through the model biases, standard error, the temporal and spatial correlation between the model and observation in two results (USGS vs. AVHRR). Results indicate that the annual and seasonal climatology of surface temperature and precipitation in both simulations (i.e. with USGS and AVHRR) are close to each other over Indian region. However, the simulation with AVHRR land use data improved up to similar to 2 degrees C in temperature field and similar to 1 mm/d in precipitation field over few regions. The inter-annual variability of surface temperature and precipitation in both simulations are also found almost same. Based on the results of this study, we conclude that the AVHRR land use data can be used in RegCM to conduct regional climate simulations over Indian region. Additionally this study suggests that, as AVHRR dataset is available for longer period in 15 days interval, so the impact of land use change on different climatic variables during a period can be studied by using RegCM.