Artic Transitions in the Land Atmosphere System
(ATLAS)
COUNCIL
Science photos 1999
Vegetation work
led by Catharine Copass looked at the types and biomass of different
functional groups. Structural measurements were also taken. Cath
will be developing a dynamic vegetation model.
Chamber based measurements
were used to examine the contribution of each functional type to
the overall grid scale H2O and CO2 fluxes. Comparisons of fluxes
from moss and lichen were undertaken. A functional investigation
of fluxes from mosses was also undertaken
Tower
based measurements of the five transition vegetation types were undertaken
to quantify the surface energy exchanges and to examine the mechanisms
controlling these fluxes. Carbon fluxes are also an important component
of the studies and were performed at each site. These measurements
will be used in conjunction with the regional climate model (ArcSYSM)
to develop reasonable scenarios for future climate change in the
arctic. In addition direct comparisons between
tundra and spruce were made to investigate the possible control of
large scale synoptic features by vegetation contrasts.
Profile
measurements of moisture, temperature and wind speed were made simultaneously
over both spruce and tundra to examine differences in atmospheric
heat and moisture inputs. Measurements were made using a tethered
balloon system.
Upper air measurements were conducted
in conjunction with NCAR using an Integrated Sounding System (ISS).
A radio acoustic sounding system was used to obtain high resolution
temperature and wind speed profiles. Measurements
of water vapour through the atmosphere will be used to develop enhanced
parameterizations for the regional climate model (ArcSYM).
