NCAR SCIENTISTS, ELECTRA HEAD TO CANADA FOR 
BOREAS

Are the vast woodlands of Canada playing a major role in the 
evolution of climate over North America and the entire globe?  A 
large field experiment now under way in south central Canada is 
using satellites, aircraft, and ground-based observing stations, 
along with computer models, to profile the relationship between 
the boreal (northern) forests and the surrounding atmosphere.

BOREAS, the Boreal Ecosystem Atmosphere Study, is a two-year 
international project culminating in three field phases this 
summer that will trace the beginning, peak, and end of the 
northern growing season, from mid-May to mid-September.  
NCAR scientists participating in BOREAS include Al Cooper 
(Mesoscale and Microscale Meteorology Division, or MMM, and 
Atmospheric Technology Division, or ATD), Ken Davis 
(Advanced Study Program), Jim Greenberg (Atmospheric 
Chemistry Division, and ACD), Don Lenschow (MMM/ATD), and 
Steve Oncley (ATD).  The Electra research aircraft is also joining 
the project this summer.

The primary U.S. sponsor of BOREAS is the National Aeronautics 
and Space Administration.  Other major U.S. sponsors include the 
National Oceanic and Atmospheric Administration, the National 
Science Foundation (NSF), and the Environmental Protection 
Agency.  Canadian support is coming primarily from National 
Resources Canada, the Atmospheric Environment Service, Parks 
Canada, Agriculture Canada, and the National Research Council.  
At the field sites this summer will be several hundred participants 
from Canada, Denmark, France, Germany, Russia, the United 
Kingdom, and the United States.

Remote and sparsely populated, the boreal forest separates the 
prairies of the Great Plains from the tundra of the Arctic.  It 
extends in a northwest-southeast belt running from the Yukon 
Territory to Ontario.  The BOREAS study region is a rectangle 
covering most of Manitoba and Saskatchewan.  Two smaller 
intensive study areas are located within this region on either side 
of the boreal belt, near Prince Albert, Saskatchewan, and 
Thompson, Manitoba.

One major question the BOREAS researchers hope to answer 
concerns the role that the boreal region plays in storing carbon.  
Scientists are presently unable to track the destination of some of 
the carbon that is released into the atmosphere in the form of 
carbon dioxide and other gases.  Recent studies suggest that the 
boreal region may be one of the missing "sinks" for this carbon.

Because the processes of atmospheric chemistry are so tightly 
linked, the researchers in BOREAS will be sampling many kinds 
of gases.  The Electra research aircraft, owned by NSF and based at 
Jeffco, will fly between the Prince Albert and Thompson field sites, 
taking air samples along the way.  Some samples will be shipped 
to Boulder for analysis by ACD to determine the amounts of 
carbon dioxide, methane, and other constituents present.

Air-flow measurements taken from aboard the Electra - flying as 
low as 100 feet (30 meters) - will reveal how trace gases are 
circulating in and around the BOREAS region and what factors 
control the exchanges of energy between the boreal forest and the 
atmosphere.  One new instrument on the Electra measures the 
concentrations of trace gases in air parcels moving upward or 
downward to determine the net transport of carbon by those gases.  
Another instrument, developed and operated by the Institute of 
Atmospheric Physics of the German Aerospace Research 
Establishment, is a lidar (similar to radar but using laser beams 
instead of radio waves) that measures atmospheric water vapor 
and aerosol distributions between flight level and the ground.

The second major question being addressed by BOREAS is the 
potential impact of climate change on the boreal forest itself.  
Computer models show that the subpolar northern latitudes from 
around 45¡ to 65¡N could be the region of earth most affected by 
global warming due to increased carbon dioxide and other 
greenhouse gases.  Such warming - which could average as much 
as 10¡C (18¡F) in these regions over the next century - might 
substantially change the makeup and functioning of the boreal 
forest.  Changes in the forest, in turn, would alter local weather 
and climate patterns.  Studies of the north and south fringes of the 
forest, where temperature contrasts are the greatest, will shed light 
on what might happen to the forest in a changing climate.  
Seasonal variations also will be analyzed across the three study 
periods.

In order to improve computer models of global climate, a better 
understanding is needed of how small-scale interactions between 
plants and the atmosphere translate to larger scales.  Specialists in 
plant ecology at BOREAS will be measuring variables such as soil 
moisture, leaf area, and radiation absorption for regions as small 
as a single tree.  These data will be connected to local 
measurements of air, heat, and momentum flow, then extended 
to progressively larger scales and eventually connected to global 
satellite data and climate models.  --BH