Consistency between MOD16A2 potential evapotranspiration time series and agro-meteo based models in Piemonte (NW Italy)

The summer of 2022 in Europe was characterized by severe droughts and heatwaves that affected agricultural sector, especially in Italy. The frequency of such events is expected to increase in the future due to climate change effects, making it crucial to manage water resources at regional scale. Potential and Actual Evapotranspiration can be used for agricultural water requirements analysis in order to plan available water resources management. Remote sensing products such as 8-days MOD16A2 offer estimates of potential evapotranspiration at a global scale. However, due to its coarse geometric resolution, some doubts arise about the consistency of MOD16A2 estimates which may locally show significant errors in respect to ground data. These errors analysis its crucial especially for agronomic purposes where local treatments, possibly driven by remotely sensed deductions, are expected to mitigate yields losses. This study explores the consistency between MOD16A2 potential evapotranspiration and the 8-days cumulated one derived from 135 meteorological stations in Piemonte region (NW-Italy) during 2022, using both temporal and spatial approaches. The temporal approach shows a significant high correlation between the potential evapotranspiration temporal profiles. However, a poor correlation was found concerning spatial consistency suggesting that MOD16A2 estimates have low accuracy, but their trend and seasonality are coherent. Biases between MOD16A2 and meteorological station have been addressed for, thus making MOD16A2 a reliable tool for managing water resources if previously ground calibrated