Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: January 3, 2005
Publication Date: May 19, 2005
Citation: Mauget, S.A. 2005. Intra- to multi-decadel terrestrial precipitation regimes at the end of the 20th century[abstract]. 2005 World Warer and Environmental Resources Congress.Anchorage, Alaska. May 15-19, 2005. Paper No. 173,495. doi:10.1061/40792(173)495. Technical Abstract: Intra- to multi-decadal (IMD) variation in terrestrial precipitation during 1901-98 was evaluated here by sampling annual precipitation rankings over 6-30 year moving time windows and converting those rankings to Mann-Whitney U statistics. Those U statistics were then used to identify the most significant sequences of wet and dry years relative to a null hypothesis that assumes stationary climate variability. This time series analysis approach was used to evaluate IMD variation in time series of annual precipitation spatially averaged over specified areas. These methods showed a highly significant incidence of wet years over North America during 1972-98, with 8 of the 10 wettest years of 1901-98 occurring during that 27-year period. A comparably significant incidence of late century wetness was also found over a northern European grid region, with 7 of the 10 wettest years occurring during 1978-98. While wet regimes were also found over other continental areas in the final decades of the 20th century, the late century North American and European wet periods stood out in terms of being the most statistically significant found during 1901-98. It is suggested that these recent wet periods are terrestrial evidence of a single multi-decadal precipitation mode extending across the North Atlantic. The potential effects of this wet regime on North Atlantic climate are discussed.