Effects of climate change scenarios on wind regimes and atmospheric mass distribution, and consequent atmospheric angular momentum effects

Author: Katherine J. Quinn and David Salstein
Date: 
April 14, 2010
Type: 
Presentation
Venue: 
EGU General Assembly, 2010
Citation: 

Quinn, K. J. and D. Salstein, Effects of climate change scenarios on wind regimes and atmospheric mass distribution, and consequent atmospheric angular momentum effects, EGU General Assembly, 2010.

Changes to greenhouse gas concentrations and other climate forcings are already impacting the Earth’s climate
system and are likely to have an increasing impact in the future. However, part of the uncertainty in estimating such
effects depends on how future climate forcing scenarios are formulated. The IPCC has created various scenarios
based on projections of economic and population growth, energy usage, and technology efficiency, which in turn
effect the greenhouse gas emissions and other climate forcings. The coupled ocean-atmosphere models contributing
to the Coupled Model Intercomparison Project - Phase 3 (CMIP3) simulate the consequences of the various IPCC
scenarios as well as over the 20th century using known climate forcings. Using outputs from certain CMIP3 models,
we will evaluate the effects of such climate change on the wind and mass distribution, and note how they are related
to other aspects of climate forcing by dynamics and thermodynamics. In this way we can judge how changes in
the overall atmospheric angular momentum (AAM) can lead to changes in the Earth rotation parameters over this
century and over the next 100-200 years. We will examine variations and trends in AAM by latitude band and
height in order to unravel the contributions of atmospheric mass distribution and wind changes. We note already
from our prototype model from NASA/Goddard Institute for Space Studies, that particularly strong increases in
zonal winds can occur in the upper troposphere subtropics in both hemispheres, strengthening the zonal jets there.
We note the start of the increase in axial AAM likely occurred in the last quarter of the century.