Studies of regional-scale climate variability and change. Hidden Markov models and coupled ocean-atmosphere modes

Ghil, M.¹  Kravtsov, S.²  Robertson, A. W.³  Smyth, P.⁴ 

[1] Univ. of California, Los Angeles, CA (United States);Univ. of Wisconsin, Madison, WI (United States);IRI, Palisades, NY (United States);Univ. of California, Irvine, CA (United States)

关键词: Climate change;    regional climate;    data mining;    coupled ocean-atmosphere modeling;    empirical mode reduction;    cyclone tracks;   

DOI  :  10.2172/940218
RP-ID  :  Final Report
PID  :  OSTI ID: 940218

学科分类：环境科学（综合）

美国|英语

来源: SciTech Connect

【 摘 要 】

This project was a continuation of previous work under DOE CCPP funding, in which we had developed a twin approach of probabilistic network (PN) models (sometimes called dynamic Bayesian networks) and intermediate-complexity coupled ocean-atmosphere models (ICMs) to identify the predictable modes of climate variability and to investigate their impacts on the regional scale. We had developed a family of PNs (similar to Hidden Markov Models) to simulate historical records of daily rainfall, and used them to downscale GCM seasonal predictions. Using an idealized atmospheric model, we had established a novel mechanism through which ocean-induced sea-surface temperature (SST) anomalies might influence large-scale atmospheric circulation patterns on interannual and longer time scales; we had found similar patterns in a hybrid coupled ocean-atmosphere-sea-ice model. The goal of the this continuation project was to build on these ICM results and PN model development to address prediction of rainfall and temperature statistics at the local scale, associated with global climate variability and change, and to investigate the impact of the latter on coupled ocean-atmosphere modes. Our main results from the grant consist of extensive further development of the hidden Markov models for rainfall simulation and downscaling together with the development of associated software; new intermediate coupled models; a new methodology of inverse modeling for linking ICMs with observations and GCM results; and, observational studies of decadal and multi-decadal natural climate results, informed by ICM results.