News Archive
Ozone depletion over Earth's Arctic region varies widely from year to
year in its amount, timing and pattern of loss. That's the conclusion
of a research team using data from the Microwave Limb Sounder on NASA's
Upper Atmosphere Research Satellite. The findings, published in the
current issue of the Journal of Geophysical Research, provide the
first consistent, three-dimensional picture of ozone loss during multiple
Arctic winters. The findings confirm previous Arctic ozone loss estimate
variations. "This work provides a consistent picture of how Arctic ozone
loss varies between winters," said lead researcher Dr. Gloria Manney, a
senior research scientist with NASA's Jet Propulsion Laboratory, Pasadena,
Calif. "Scientists will have a better understanding of current Arctic
ozone conditions and be better able to predict variations in the future."
NASA Jet Propulsion Laboratory
(JPL). Press release available here.
global change data
Updated Vostok Ice Core Data Released
The U.S. Department of Energy's Carbon Dioxide Information Analysis
Center (CDIAC) has released an updated historical carbon dioxide record
from the Vostok ice core. Contributed by J.-M. Barnola, D. Raynaud,
and C. Lorius. (Laboratoire de Glaciologie et de Géophysique de
l'Environnement, Saint Martin d'Heres Cedex, France) and N. I. Barkov
(Arctic and Antarctic Research Institute, St. Petersburg, Russia),
the new data extend the record back in time by about 3000 years;
the period of record is now 417,160-2,342 years before present. In
January 1998, the collaborative ice-drilling project between Russia,
the United States, and France at the Russian Vostok station in East
Antarctica yielded the deepest ice core ever recovered, reaching a depth
of 3,623 m. Ice cores are unique with their long records of entrapped
air inclusions, enabling direct records of past changes in atmospheric
trace-gas composition. Preliminary data indicate the Vostok ice-core
record extends through four climate cycles, with ice slightly older than
400 kyr. There is a close correlation between Antarctic temperature and
atmospheric concentrations of CO2.
U.S. Department of
Energy. Data are available here.
global change news
CCSP Announces New Release Date for Revised Strategic Plan
The U.S. Climate Change Science Program (CCSP) has scheduled June
25, 2003 for release of its revised Strategic Plan. Although later
than originally planned, this revised schedule will allow sufficient
time for full consideration of the wide array of useful suggestions
received by CCSP from many sources since publication of its November 2002
Discussion Draft Strategic Plan. CCSP received extensive comments
and suggestions during the Climate Science Workshop attended by more
than 1,300 climate specialists in December 2002. In the weeks following
the Workshop, CCSP also received 270 sets of written public comments,
involving nearly 900 pages of text. The most recent set of comments,
from a CCSP-requested evaluation by the National Research Council (NRC),
was released in late February 2003. The November 2002 Discussion Draft
Strategic Plan and all of the response comments (from the Workshop,
the public comment period, and the NRC report) are available on the CCSP
web site.
"We welcome the wide range of useful comments, which will help to
substantially strengthen the revised plan," said Dr. James R. Mahoney,
Assistant Secretary of Commerce for Oceans and Atmosphere and CCSP
Director. "Since climate change is such a critical issue, we must
understand and reconcile the diverse comments, including those that
provide conflicting recommendations for future research and decision
support activities."
U.S. Climate Change Science Program
(CCSP). Press release available here.
A NOAA researcher developed a new online tool to help explain how
small-scale climate dynamics impact global climate change. The Climate
TimeLine site captures the history of climate exploration and its
impact on human development. The site also examines meteorological and
climatic processes and specific climate events of the past at other time
scales. Mark McCaffrey, with the NOAA Paleoclimatology Program based in
Boulder, Colorado, developed the Climate TimeLine Web site. McCaffrey and
his colleagues use the Earth's daily cycle to examine weather events
of one year to study the key climatic forces behind the variability of
weather and climate, and the roles human impact can play.
NOAA Paleoclimatology
Program. Press release available here.
The Climate Time Line website is available here.
Scientists studying trees ranging from saplings to 130 years old in
Canada's northern forests have discovered that the period since a fire
last swept through an area determines how much carbon the forest can
store. Twenty to forty year old stands absorb more carbon than those
70 years old and older, despite being smaller and having less biomass
or plant material. Boreal or northern forests account for close to 25
percent of total carbon stored in vegetation and soils in the Earth's
biosphere. Wildfires burn down individual areas every 40 to 250 years
and are an important part of this ecosystem. Whether or not these forests
are likely to lower or raise levels of carbon dioxide in the atmosphere
depends on how these carbon reserves respond to, and recover from, both
climate change and disturbances such as wildfires. Marcy Litvak, plant
ecologist at the University of Texas at Austin and lead author of the
study that appeared in a recent issue of the Journal of Geophysical
Research - Atmospheres, said that the ability of tree stands to
store carbon changes as they regenerate from fire. Forests will store
more or less carbon depending on the dominant tree species, the amount
of moss cover, and changes in forest structure due to fire. Those factors
determine how much total carbon is exchanged with the atmosphere.
NASA Earth Observatory.
More information available here.
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