A study of dry spells in Iran based on satellite data and their relationship with ENSO

The study of the maximum number consecutive dry days (MCDDs) is one approach to analyze precipitation behavior in arid and semi-arid regions Iran. This a first attempt investigate MCDDs their relationship with El Niño/Southern Oscillation (ENSO) winter months over was carried out using Tropical Rainfall Measuring Mission (TRMM) satellite data on daily basis at 1° latitude × longitude spatial resolution reanalysis for period 1998–2019. Results showed that highest values are observed southeastern Iran lowest northwestern Based coefficients linear trend MCDDs, significant increasing trends remarkably more abundant than declining trends, especially northern half country December January. results regarding between ENSO indicated non-stationary behavior, negative correlation (especially southwest) positive January February southeast). largest differences were In general, during Niño (La Niña) phases, length decreases (increases) increases (decreases) southern half. By comparing different large-scale climate parameters 2 months, we found (positive) anomaly geopotential height (negative) zonal wind specific humidity region December, while opposite situation occurs innovation this use provide continuous coverage consideration teleconnection pattern regards spells. We find has contradictory effects country. These findings great importance like lies regions, as they can be useful water resources management.