Influence of the Sea Surface Temperature Variability on Formation of Pluvial Conditions in North America

Markéta Poděbradská

Bachelor's thesis

Abstract:

Long lasting pluvial periods leading to large scale flooding can be a serious threat for human economy and society in general. These extreme wet conditions are caused by a combination of different factors. The dominant influence seems to have SST variability in combination with land surface variability. Nowadays droughts are better mapped than pluvials, but pluvials are essentially just the opposite of droughts, so if we observe the opposite processes that are causing droughts, we can probably find causes of pluvials. Understanding processes determining climate variability can improve predictions at interannual-decadal time scales which can be, with ongoing climate changes, very important for human society.In this paper the influence of Atlantic Multidecadal Oscillation (AMO) and El Nino Southern Oscillation (ENSO) variability on climate conditions, specifically surface temperature, precipitation and integrated moisture convergence, over North America is discussed. Climate model data were obtained from previous study. The results show that the formation of pluvial conditions over central part of the U.S is strongly influenced by warm phase of ENSO. Cold phase of AMO combined with warm ENSO has mostly effect on spatial extent of the pluvial conditions created by ESNO forcing. Coincidence of moisture surplus anomaly with cold AMO forcing during winter season is also important finding especially in connection to twentieth century pluvial, however it is not supported by statistical analysis.

Keywords

Atlantic Multidecadal Oscillation, El Nino Southern Oscillation, wet spells, climate variability

Jazyk práce: English

Datum vytvoření / odevzdání či podání práce: 12. 4. 2016

Obhajoba závěrečné práce

• Vedúci: doc. Ing. Martin Hanel, Ph.D.

Czech University of Life Sciences Prague

Faculty of Environmental Sciences

Bachelor programme / odbor:
Environmental Scinces / Applied Ecology