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Boreal forest surface parameterization in the ECMWF model - 1D test with NOPEX long-term data

Gustafsson, D; Lewan, E; van den Hurk, BJJM; Viterbo, P; Grelle, A; Lindroth, Anders LU ; Cienciala, E; Mölder, Meelis LU ; Halldin, S and Lundin, LC (2003) In Journal of Applied Meteorology 42(1). p.95-112
Abstract
The objective of the present study was to assess the performance and recent improvements of the land surface scheme used operationally in the European Centre for Medium-Range Weather Forecasts (ECMWF) in a Scandinavian boreal forest climate/ecosystem. The previous (the 1999 scheme of P. Viterbo and A. K. Betts) and the new (Tiled ECMWF Surface Scheme for Exchange Processes over Land, TESSEL) surface schemes were validated by single-column runs against data from NOPEX (Northern Hemisphere Climate-Processes Land-Surface Experiment). Driving and validation datasets were prepared for a 3-yr period (1994-96). The new surface scheme, with separate surface energy balances for subgrid fractions (tiling), improved predictions of seasonal as well as... (More)
The objective of the present study was to assess the performance and recent improvements of the land surface scheme used operationally in the European Centre for Medium-Range Weather Forecasts (ECMWF) in a Scandinavian boreal forest climate/ecosystem. The previous (the 1999 scheme of P. Viterbo and A. K. Betts) and the new (Tiled ECMWF Surface Scheme for Exchange Processes over Land, TESSEL) surface schemes were validated by single-column runs against data from NOPEX (Northern Hemisphere Climate-Processes Land-Surface Experiment). Driving and validation datasets were prepared for a 3-yr period (1994-96). The new surface scheme, with separate surface energy balances for subgrid fractions (tiling), improved predictions of seasonal as well as diurnal variation in surface energy fluxes in comparison with the old scheme. Simulated wintertime evaporation improved significantly as a consequence of the introduced additional aerodynamic resistance for evaporation from snow lying under high vegetation. Simulated springtime evaporation also improved because the limitation of transpiration in frozen soils was now accounted for. However, downward sensible heat flux was still underestimated during winter, especially at nighttime, whereas soil temperatures were underestimated in winter and overestimated in summer. The new scheme also underestimated evaporation during dry periods in summer, whereas soil moisture was overestimated. Sensitivity tests showed that further improvements of simulated surface heat fluxes and soil temperatures could be obtained by calibration of parameters governing the coupling between the surface and the atmosphere and the ground heat flux, and parameters governing the water uptake by the vegetation. Model performance also improved when the seasonal variation in vegetation properties was included. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Applied Meteorology
volume
42
issue
1
pages
95 - 112
publisher
American Meteorological Society
external identifiers
  • wos:000180347600008
  • scopus:0141762465
ISSN
0894-8763
DOI
language
English
LU publication?
yes
id
bed17708-9b65-4d33-b327-c34ff5350ec3 (old id 319851)
date added to LUP
2007-09-03 13:09:20
date last changed
2018-05-29 11:12:15
@article{bed17708-9b65-4d33-b327-c34ff5350ec3,
  abstract     = {The objective of the present study was to assess the performance and recent improvements of the land surface scheme used operationally in the European Centre for Medium-Range Weather Forecasts (ECMWF) in a Scandinavian boreal forest climate/ecosystem. The previous (the 1999 scheme of P. Viterbo and A. K. Betts) and the new (Tiled ECMWF Surface Scheme for Exchange Processes over Land, TESSEL) surface schemes were validated by single-column runs against data from NOPEX (Northern Hemisphere Climate-Processes Land-Surface Experiment). Driving and validation datasets were prepared for a 3-yr period (1994-96). The new surface scheme, with separate surface energy balances for subgrid fractions (tiling), improved predictions of seasonal as well as diurnal variation in surface energy fluxes in comparison with the old scheme. Simulated wintertime evaporation improved significantly as a consequence of the introduced additional aerodynamic resistance for evaporation from snow lying under high vegetation. Simulated springtime evaporation also improved because the limitation of transpiration in frozen soils was now accounted for. However, downward sensible heat flux was still underestimated during winter, especially at nighttime, whereas soil temperatures were underestimated in winter and overestimated in summer. The new scheme also underestimated evaporation during dry periods in summer, whereas soil moisture was overestimated. Sensitivity tests showed that further improvements of simulated surface heat fluxes and soil temperatures could be obtained by calibration of parameters governing the coupling between the surface and the atmosphere and the ground heat flux, and parameters governing the water uptake by the vegetation. Model performance also improved when the seasonal variation in vegetation properties was included.},
  author       = {Gustafsson, D and Lewan, E and van den Hurk, BJJM and Viterbo, P and Grelle, A and Lindroth, Anders and Cienciala, E and Mölder, Meelis and Halldin, S and Lundin, LC},
  issn         = {0894-8763},
  language     = {eng},
  number       = {1},
  pages        = {95--112},
  publisher    = {American Meteorological Society},
  series       = {Journal of Applied Meteorology},
  title        = {Boreal forest surface parameterization in the ECMWF model - 1D test with NOPEX long-term data},
  url          = {http://dx.doi.org/},
  volume       = {42},
  year         = {2003},
}