|
Title:
|
|
Determination of the relative importance of sources and sinks ofcarbon dioxide (NRP-proj. no. 852076)
|
|
|
|
Author(s):
|
|
|
|
|
|
Published by:
|
Publication date:
|
|
ECN
|
1995
|
|
|
|
ECN report number:
|
Document type:
|
|
ECN-C--95-035
|
ECN publication
|
|
|
|
Number of pages:
|
Full text:
|
|
68
|
Download PDF
|
Abstract:
The objective of the CO2 cluster of the Dutch National Research Programon Global Air Pollution and Climate Change, theme B (NOP MLK) was to
formulate and validate CO2 exchange models that describe parts of the global
carbon cycle. CO2 flux-measurements over grasslands were performed by ECN at
two locations (Cabauw and Zegveld, the Netherlands). The data are used by
Wageningen Agricultural University to tune and validate a CO2 exchange model
for grasslands. This model should be able to simulate daily to seasonal
variation of the exchange CO2 fluxes between the different parts of the
grassland system and the exchange with the atmosphere. CO2 flux-measurements
over a peat soil, using the eddy correlation technique started at Zegveld in
March 1994 and ended in October 1994. The CO2 flux over a clay soil at
Cabauw was determined from vertical CO2 concentration gradients.
Measurements have been carried out since March 1993. CO2 concentration and
carbon isotopic composition were measured at Cabauw at 200 m altitude. These
measurements are meant for the verification and validation of CO2 exchange
models on a sub-continental scale, and were analysed using different analyses
tools. Preliminary model evaluation was performed using a GIS application.
Using measured CO2 concentration and air mass trajectories over Europe, CO2
maps were calculated. These maps can be used to define areas of interest for
further analysis. A transport model was developed to perform this analysis.
The measured concentrations at 200 m and carbon isotope ratios were compared
with the model results. Recently, a land use database with a grid of 10'x10'
was provided by RIVM. Use of this database will improve the model performance
due to the better description of spatial distribution of the sources (fossil
fuel combustion) and source/sink systems (grassland/forest). So far, no model
runs could be performed due to insufficient data on the spatial distribution
of emissions. The model runs will be performed in 1995-1996. 37 figs., 6
tabs., 35 refs., 2 appendices
Back to List