@article { author = {Nikraftar, Zahir and Sam-Khaniani, Ali}, title = {Assessing the impact of cold and warm ENSO on drought over Iran}, journal = {Earth Observation and Geomatics Engineering}, volume = {2}, number = {1}, pages = {45-55}, year = {2018}, publisher = {University of Tehran}, issn = {2588-4352}, eissn = {2588-4360}, doi = {10.22059/eoge.2018.257714.1022}, abstract = {The impacts of El Niño Southern Oscillation (ENSO) on climate change and in the global scale are wellknown, and have attracted the attention of researchers since the twentieth century. The study of ENSOimpact on climate using precipitation and near surface temperature data from re-analysis products makesglobal and long-term analyses of this phenomenon possible. The common method to analyze the ENSOimpact is to quantify the probability of extreme drought occurrences when the surface temperatures ofcentral-east equatorial Pacific sea are abnormal. Although the results are always uncertain due to thecomplexity of atmospheric teleconnections, application of the recently available gridded datasets helps oneto conduct more precise modeling and predictions. Spatiotemporal patterns of ENSO impact from 1980 tothe end of 2013 for four ENSO indices (e.g. Nino 3.4, MEI, ONI, SOI) over Iran was investigated in thisstudy. Spatial maps of the Pearson correlation coefficients and a composite analysis were obtained betweenthe GPCC precipitation and temperature dataset with ENSO states. In addition, the frequency maps ofextreme drought conditions during ENSO states were acquired. The results show that the western (along therange of Zagros Mountain) and northern (along the Alborz Mountain and the coastlines of the Caspian Seato Khorasan Province) regions are more affected by ENSO events. The Pearson correlation coefficient forall four ENSO indices over the mentioned regions was determined to be about 0.70 for precipitation datasetsand -0.70 for temperature datasets. The frequency analysis of extreme drought based and CZI (Chinese ZIndex) and ENSO phases shows that the western and northeast parts of Iran are more affected by centraleast equatorial Pacific teleconnections. Composite analysis for all four ENSO indices shows the precipitation(over the rainy months)/temperature (over the summer months) anomalies, for the El Niño states about +25(mm)/ -0.5˚ (C) and for the La Niña states about -25 (mm)/+0.6˚ to 1˚ (C).}, keywords = {Southern Oscillation Index,Climate,GPCC datasets,Chinese Z Index,Teleconnectios,Composite analysis}, url = {https://eoge.ut.ac.ir/article_66950.html}, eprint = {https://eoge.ut.ac.ir/article_66950_1a455a59e5fb212b5d6ce937cdbc2b80.pdf} }