Westdc Logo

Estimating Turbulent Heat Fluxes With a Weak-Constraint Data Assimilation Scheme: A Case Study (HiWATER-MUSOEXE)


Authors


Abstract

A weak-constraint variational data assimilation (WC-VDA) scheme was developed to estimate turbulent heat fluxes by assimilating sequences of land surface temperature measurements. In contrast to the commonly used strong-constraint VDA system, the WC-VDA approach accounts for the effects of structural and model errors and generates better results. This is achieved by adding a model error term (ω) to the surface energy balance equation. The WC-VDA model was tested at two sites with very distinct hydrological and vegetated conditions: the Daman site (a wet site located in an oasis area and covered by seeded corn) and the Huazhaizi site (a dry site located in a desert area and covered by sparse grass). The two sites represent typical desert-oasis landscapes in the middle reaches of the Heihe River Basin, northwestern China. The results proved that the WC-VDA method performed well over very dry and wet conditions, and the estimated sensible and latent heat fluxes agree well with eddy covariance measurements.


Keywords

  • atmospheric boundary layer
  • atmospheric techniques
  • atmospheric temperature
  • atmospheric turbulence
  • Daman site
  • data assimilation
  • desert area
  • desert-oasis landscapes
  • dry conditions
  • dry site
  • eddy covariance measurements
  • Equations
  • Evapotranspiration
  • Heating
  • Heihe River Basin
  • HiWATER-MUSOEXE
  • Huazhaizi site
  • hydrological conditions
  • land surface
  • Land surface temperature
  • land surface temperature (LST)
  • land surface temperature measurements
  • latent heat
  • latent heat flux
  • Mathematical model
  • middle reaches
  • model error term
  • Northwestern China
  • oasis area
  • seeded corn
  • Sensible heat flux
  • soil
  • sparse grass
  • strong-constraint variational data assimilation system
  • surface energy balance equation
  • turbulent heat fluxes
  • variational techniques
  • vegetated conditions
  • Vegetation
  • WC-VDA model
  • weak-constraint variational data assimilation scheme
  • weak-constraint variational data assimilation (WC-VDA)
  • wet conditions
  • wet site

Citation

Xu TR, Bateni S.M., Liang SL. Estimating turbulent heat fluxes with a weak-constraint data assimilation scheme: A case study (HiWATER-MUSOEXE). IEEE Geoscience and Remote Sensing Letters, 2015, 12 (1), 68-72.doi:10.1109/LGRS.2014.2326180

PDF Related: