HR: 1330h
AN: H22B-0927    [PDF]
TI: The Carbon Cycle and the Northern Hemisphere Annular Mode: Relationships and Associated Mechanisms
AU: * Conner-Gausepohl, S L
EM: sheri@atmos.colostate.edu
AF: Colorado State University, Department of Atmospheric Science, Fort Collins, CO 80523 United States
AU: Denning, A
EM: denning@atmos.colostate.edu
AF: Colorado State University, Department of Atmospheric Science, Fort Collins, CO 80523 United States
AU: Thompson, D W
EM: davet@atmos.colostate.edu
AF: Colorado State University, Department of Atmospheric Science, Fort Collins, CO 80523 United States
AU: Schaefer, K
EM: kevin@atmos.colostate.edu
AF: Colorado State University, Department of Atmospheric Science, Fort Collins, CO 80523 United States
AU: Leonard, O
EM: owen@atmos.colostate.edu
AF: Colorado State University, Department of Atmospheric Science, Fort Collins, CO 80523 United States
AU: Brown, M E
EM: molly@pengimms.gsfc.nasa.gov
AF: NASA Goddard Space Flight Center, Code 923, Greenbelt, MD 20771 United States
AU: Tucker, C J
EM: compton.j.tucker@gsfc.nasa.gov
AF: NASA Goddard Space Flight Center, Code 923, Greenbelt, MD 20771 United States
AU: Los, S O
EM: s.o.los@swan.ac.uk
AF: University of Wales Swansea, Department of Geography Singleton Park, Swansea, SA2 8PP United Kingdom
AB: Atmospheric inversion studies as well as most land ecosystem models show that a substantial fraction of the interannual variability observed in atmospheric carbon dioxide is associated with changes in the net exchange of carbon dioxide between the atmosphere and the land biosphere. Through published work exploring the relationship of the El Nino - Southern Oscillation (ENSO) and the carbon cycle, it is well accepted that these changes in the net exchange of carbon dioxide in the tropics are strongly linked to ENSO variability. In that same manner, our analysis explores the relationship between these changes in the extratropics and the Northern Hemisphere Annular Mode/Arctic Oscillation (NAM/AO). Recent work has shown that high NAM/AO index periods are characterized by stronger than normal zonal flow along 55 - 60 degrees north latitudes, which results in the advection of relatively warm, moist air masses over northern land masses. In addition, in recent decades the NAM/AO has exhibited a trend toward high polarity in the winter months. Using Normalized Difference Vegetation Indices (NDVI) developed from over 20 years of AVHRR (Advanced Very High Resolution Radiometer) data, NCEP Reanalysis climate data from NOAA/NCAR and SiB2.5, the Simple Biosphere land surface model, we have analyzed the variations in key components of the carbon cycle with respect to high and low index variability in the NAM/AO. We see a statistically significant correlation between wintertime NAM/AO indices and Leaf Area Index and Fraction of Photosynthetically Active Radiation during the past two decades. In addition, we see soil temperature and moisture anomalies associated with wintertime NAM/AO indices are related to respiration anomalies later in the year.
UR: http://biocycle.atmos.colostate.edu
DE: 0315 Biosphere/atmosphere interactions
DE: 0322 Constituent sources and sinks
DE: 1615 Biogeochemical processes (4805)
DE: 1640 Remote sensing
SC: Hydrology [H]
MN: 2003 Fall Meeting