HR: 1330h
AN: A13A-21    [Abstracts]
TI: Natural variability and climate change, causes of NAO/AO observed trend
AU: * Skific, N
EM: nskific@optonline.net
AF: Center for Environmental Prediction, Department of Environmental Sciences, Rutgers University, 14 College Farm Rd, New Brunswick, NJ 08901-8551 United States
AB: Over recent decades the North Atlantic Oscillation has undergone major low frequency variations, superimposed on an upward trend in NAO index. Because variations of NAO have a large impact on society and the environment, understanding the processes that govern its variability is essential. Mechanisms proposed to account for this variability include atmospheric response to changes in sea surface temperatures, variability of deep atmospheric convection in the tropics and natural internal modes of the atmosphere, rather than changing external forces such as anthropogenic emissions of greenhouse gases and ozone depletion. We have investigated NAO behavior using power spectrum wavelet analyses of simulations by the NASA Goddard Institute for Space Sciences global climate model, for control conditions and for increasing greenhouse gases. This analysis provides convincing evidence that anthropogenically induced changes in tropospheric-stratospheric interactions are the most important contributor to this change.
DE: 1610 Atmosphere (0315, 0325)
DE: 3319 General circulation
DE: 3339 Ocean/atmosphere interactions (0312, 4504)
DE: 3349 Polar meteorology
DE: 3362 Stratosphere/troposphere interactions
SC: Atmospheric Sciences [A]
MN: 2005 Joint Assembly