HR: 14:10h
AN: B53A-03    [Abstracts]
TI: Upscaling carbon Budgets From Field to Region by Combining Flux Towers, Airborne Measurements and Remote Sensing - a Case Study From Zealand Denmark
AU: * Soegaard, H
EM: hs@geogr.ku.dk
AF: University of Copenhagen, Institute of Geography Oster Voldgade 10, Copenhagen, 1350 Denmark
AU: Tuulik, J
EM: Janno.tuulik@nateko.lu.se
AF: Lund University, Dptof Physical Geography Soelvergatan 12, Lund, 223 62 Sweden
AU: Houborg, R
EM: rmh@geogr.ku.dk
AF: University of Copenhagen, Institute of Geography Oster Voldgade 10, Copenhagen, 1350 Denmark
AU: Lindroth, A
B53A-03 AF: Lund University, Dptof Physical Geography Soelvergatan 12, Lund, 223 62 Sweden
AU: Boegh, E
EM: eboegh@ruc.dk
AF: RUC, Universitetsvej 1, Roskilde, 4000 Denmark
AU: Gryning, S
EM: Sven-Erik.Gryning@risoe.dk.
AF: Risoe National Laboratory, Frederiksborgvej, Roskilde, 4000 Denmark
AU: Pilegaard, K
EM: Kim.Pilegaard@risoe,dk
AF: Risoe National Laboratory, Frederiksborgvej, Roskilde, 4000 Denmark
AU: Pilegaard, K
EM: Kim.Pilegaard@risoe,dk
AF: RUC, Universitetsvej 1, Roskilde, 4000 Denmark
AB: A study on upscaling eddy correlation measurements of CO2 form field to region has been conducted over the island of Zealand, Denmark within an area of 8000 km2. The ground reference measurements are conducted within the framework of the Nordic Centre for Studies of Ecosystem Carbon Exchange and CarboEurope and comprises continuous eddy correlation measurements over four distinct surface type, beech forest, wheat fields, grassland and urban areas. The collection of CO2 flux data is supplemented by an airborne flux campaign conducted in August 2003. MODIS data on leaf area index and surface temperature are used together with standard meteorological data for running a simulation model. The airborn flux measurements which are conducted from an altitude of 150 m are compared to the ground level measurements by use of footprints model. The comparisons show that while the time integrated flux levels are in agreement the small scale variability in the CO2 flux is captured less accurately compared to the water vapour - and the sensible heat flux.. The soil respiration and the CO2 assimilation are then examined separately. For the soil respiration, it is found that soil temperature and soil moisture are of nearly equal significance for predicting the soil respiration. The spatial distribution of soil temperatures are derived from MODIS surface temperature data whereas the soil moisture in the upper soil column is estimated by use of a hydrological model operating in Geographical information system. With respect to carbon assimilation the spatial distribution is calculated on the basis of MODIS vegetation index product (EVI) with a spatial resolution of 250 m in combination with a mechanistic photosynthesis model using meteorological input data. The ground level flux distribution along the flight track is calculated as the sum of modelled carbon sequestration plus the soil respiration. Comparison between the airborn and the simulated CO2 fluxes is found to be in encouraging agreement especially when taking into account the development of the internal boundary layers compared to the flight level. Supplemented by national statistics and land use maps it is finally found that the island as a whole functions as carbon source with a large range in annual carbon budgets between the metropolitan areas of Copenhagen (+7900 gCm-2 yr-1) and the deciduous forests (-550 gCm-2 yr-1) and agriultural land (-300gCm-2 yr-1 for winter wheat).
DE: 1631 Land/atmosphere interactions (1218, 1843, 3322)
DE: 1637 Regional climate change
DE: 1640 Remote sensing (1855)
SC: Biogeosciences [B]
MN: Fall Meeting 2005