Seasonality of reference evapotranspiration in Bahia and analysis of future projection

Abstract

The present study aimed to validate and quantify reference evapotranspiration (ETo) estimates with ERA5-Land data for the state of Bahia and investigate what trends are expected in the period from 1993 to 2002 and for the year 2065. ECMWF’s hourly ERA5-Land surface data were used. The analysis also used the CNRM-CM6-1-HR model in the SSP2-4.5 scenario provided by CMIP6. Data from seven conventional weather stations in the Meteorological Database for Teaching and Research (BDMEP) of the National Institute of Meteorology (INMET) were used for validation. Based on the results, ETo estimates with reanalysis data showed a good relationship with observed weather station data. Therefore, in the absence of observational data, ETo can be estimated with reanalysis data, once it has been proven that these estimates are reliable. The seasonal analysis showed consistent patterns of evapotranspiration associated with precipitation, solar radiation, temperature, and air humidity. The climate trends of the CNRM-CM6-1-HR model point to an increase in ETo rates in all seasons of the year due to a decrease in rainfall and increase in temperature in Bahia