Highlights of the past recent decades
Improvement in forecast skill from 1981-2003
for ECMWF 5-km hemispheric flow pattern
Increased evidence of human impact:Antarctic ozone hole
TOMS (Total OzoneMapping Spectrometer) satellite
CCL4 mixing ratio declining, also that of other ozone-depletors
Increased evidence of human impact: Greenhouse Warming
Carbon Dioxide
Monthly-mean C02 concentrations, 1958-2002
Increased evidence of human impact: Aerosols
Links to Climate Dynamics: The Arctic
Fig. xx, left panel: Sea ice concentration
Anomalies for September 2002, 2003,
and 2004, along with the 1979-2000
median September ice edge (pink line),
derived from passive microwave satellite
imagery. These reveal that sea ice
extent reached a record minimum in
Sept. 2002, followed by two more
low-ice years. While sea ice decline
can result from natural variability associated
with the dynamical Arctic Oscillation (AO),
greenhouse warming also favors the
AO phase most conducive to warming.
Image courtesy of NSIDC, Boulder, CO
(http://nsidc.org/)
Arctic surface air temperatures have
observed to increase in the past 50 years
in Alaska and Siberia, with a cooling in
Southern Greenland.
Additional declines of roughly
10-50% in annual average sea-ice
extent are projected by 2100 in
model simulations. Loss of sea
ice is projected to be greater during
summer than in the annual average.
Top and left Figures provided by
The Arctic Climate Impact Assessment
(http://www.acia.uaf.edu).
Overview of the atmosphere: Coordinate System Convention
dx = r dcos
dy = r d
is longitude, is latitude
x positive east, y positive north
1 degree latitude = 111 km

at greenwich
Atmosphere very thin: 99.9% of air
Mass in a layer < 1% of Earth’s radius
r approximated as the Earth’s radius
~ 6.37 * 106 m
QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture.
Velocity