Predictability and prediction of the total number of winter extremely cold days over China
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The current dynamical climate models have limited skills in predicting winter temperature in China. The present study uses physics-based empirical models (PEMs) to explore the sources and limits of the seasonal predictability in the total number of extremely cold days (NECD) over China. A combined cluster-rotated EOF analysis reveals two sub-regions of homogeneous variability among hundreds of stations, namely the Northeast China (NE) and Main China (MC). This reduces the large-number of predictands to only two indices, the NCED-NE and NCED-MC, which facilitates detection of the common sources of predictability for all stations. The circulation anomalies associated with the NECD-NE exhibit a zonally symmetric Arctic Oscillation-like pattern, whereas those associated with the NECD-MC feature a North–South dipolar pattern over Asia. The predictability of the NECD originates from SST and snow cover anomalies in the preceding September and October. However, the two regions have different SST predictors: The NE predictor is in the western Eurasian Arctic while the MC predictor is over the tropical-North Pacific. The October snow cover predictors also differ: The NE predictor primarily resides in the central Eurasia while the MC predictor is over the western and eastern Eurasia. The PEM prediction results suggest that about 60% (55%) of the total variance of winter NECD over the NE (Main) China are likely predictable 1 month in advance. The NECD at each station can also be predicted by using the four predictors that were detected for the two indices. The cross-validated temporal correlation skills exceed 0.70 at most stations. The physical mechanisms by which the autumn Arctic sea ice, snow cover, and tropical-North Pacific SST anomalies affect winter NECD over the NE and Main China are discussed.
KeywordsEast Asian winter monsoon Extreme weather events Extremely cold days Seasonal predictability Physical-empirical model (PEM)
This work has been supported by the National Natural Science Foundation of China (Grant Nos. 41420104002 and 41371209), the Global Research Laboratory (GRL) Program of the National Research Foundation of Korea Grant No. 2011–0021927, and Atmosphere–Ocean Research Center sponsored by the Nanjing University of Information Science and Technology and University of Hawaii. This is the SOEST publication 10011, IPRC publication 1253 and NUIST/ESMC publication 161.
- Collins D, Della-Marta P, Plummer N, Trewin B (2000) Trends in annual frequencies of extreme temperature events in Australia. Aust Meteorol Mag 49:277–292Google Scholar
- Huffman GJ, Bolvin DT (2013) GPCP version 2.2 SG combined precipitation data set documentation. NASA, p 46. ftp://precip.gsfc.nasa.gov/pub/gpcp-v2.2/doc/V2.2_doc.pdf
- Liu K, Song W, Zhu Y (2012) A statistical prediction method for an East Asian winter monsoon index reflecting winter temperature changes over the Chinese mainland. Acta Meteorol Sin (in Chinese) 71:275–285Google Scholar
- Storch HV, Zwiers FW (2001) Statistical analysis in climate research. Cambridge University Press, Cambridge, pp 811–812 ppGoogle Scholar
- Sun S, Liu G, Song W (2014) A precursory signal for the dipole mode of winter temperature anomaly over eastern China [J]. Chin J Atmos Sci (in Chinese) 38:727–741Google Scholar
- Wang L, Lu M-M (2016) The East Asian winter monsoon. The global monsoon system: research and forecast (3rd edition), vol 5. World Scientific, SingaporeGoogle Scholar
- Weisheimer A et al (2009) ENSEMBLES: a new multi-model ensemble for seasonal-to-annual predictions—skill and progress beyond DEMETER in forecasting tropical Pacific SSTs. Geophys Res Lett 36Google Scholar
- Wilks DS (2011) Statistical methods in the atmospheric sciences, vol 100. Academic, USAGoogle Scholar
- Wu B, Huang R, Gao D (1999) Impact of variations of winter sea-ice extents in the Kara/Barents Seas on winter monsoon over East Asia. Acta Meteorol Sin 13:141–153Google Scholar