An evapotranspiration deficit-based drought index to detect variability of terrestrial carbon productivity in the Middle East

Abstract The primary driver of the land carbon sink is gross productivity (GPP), absorption dioxide (CO 2 ) by plant photosynthesis, which currently accounts for about one-quarter anthropogenic CO emissions per year. This study aimed to detect variability using standardized evapotranspiration deficit index (SEDI). Sixteen countries in Middle East (ME) were selected investigate drought. To this end, yearly GPP dataset area, spanning 35 years (1982–2017) was used. Additionally, Global Land Evaporation Amsterdam Model (GLEAM, version 3.3a), estimates various components terrestrial (annual actual and potential evaporation), used same period. main findings indicated that croplands grasslands more sensitive SEDI Syria, Iraq, Turkey 34%, 30.5%, 29.6% cropland area respectively, 25%, 31.5%, 30.5% grass area. A significant positive correlation against long-term data recorded. Notably, recorded a decline >60% during 2008 extreme drought north Iraq northeast concentrated within agrarian ecosystem reached total vegetation with 100% negative anomalies. reductions annual anomalies from 2009 2012 might have resulted decrease at peak event. Ultimately, led long delay restoring terms its cover. Thus, proposed reported capable capturing closely linked than commonly indices. Therefore, understanding response can facilitate simulation changes under climate change projections.