[M-IS06] Extreme Weather and Disasters in Southeast Asia

[MIS06-06] Delayed Impacts of ENSO on the Frequency of Summer Extreme Hot Day in the Asian Monsoon Region

*Xinyu Lu^1,2, Chaoxia Yuan^1,2 (1.Nanjing University of Information Science and Technology, 2.The Japan Agency for Marine-Earth Science and Technology)

Keywords:Summer Extreme Hot Day, model prediction ability, IPOC

Understanding and predicting extreme weather and climate are ultimately important for adaptation and resilience. Here, we assess the prediction skills of frequency of summer extreme hot day (SEHD) in the Asian monsoon region (AMR) by using the 1981-2014 hindcasts of POAMA-2 subseasonal-to-seasonal prediction system. Generally, the good prediction skills of SEHD frequency appear in the southern AMR south of 30N including the Indian subcontinent, Indo-China peninsula and the Philippines; the anomaly correlation coefficients between the observed and predicted region-mean SEHD anomalies are 0.72, 0.72, 0.70, 0.60, 0.61 and 0.61 at 6-1 month lead, respectively, all statistically significant at the 99.9% confidence levels. The high prediction skills in the POAMA-2 are due to its capacity on reproducing the observed delayed ENSO impacts on the large-scale atmospheric circulation, the seasonal surface air temperature and thus the SEHD frequency in the southern AMR via provoking the Indo-western Pacific ocean capacitor effect. Since the POAMA-2 only provides the prediction at most half a year in advance, we also conduct the hindcasts in the SINTEX-F that can reproduce well the robust ENSO-SEHD relationship and has high prediction skill of ENSO itself. Results show that skillful prediction of the region-mean SEHD frequency can be up to 14 months in advance.