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| Titel |
Application of a two-dimensional hydrodynamic model for calculating the
CO2 and H2O fluxes over complex terrain |
| VerfasserIn |
Yulia Mukhartova, Alexandr Krupenko, Natalia Levashova, Alexandr Olchev |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250153215
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| Publikation (Nr.) |
 EGU/EGU2017-18160.pdf |
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| Zusammenfassung |
| Within the framework of the study a two dimensional hydrodynamic model of turbulent
transfer of greenhouse gases was developed and applied for calculating the CO2 and H2O
turbulent fluxes within the atmospheric surface layer over the heterogeneous land surface
with mosaic vegetation and complex topography. The vegetation cover in the model is
represented as the two-phase medium containing the elements of vegetation and the
air.
The model is based on solving the system of averaged Navier-Stokes and continuity
equations for the wind velocity components (⃗V = {V1,V2}), using the 1.5-order closure
scheme (Wilcox 1998, Wyngaard 2010). The system of the main equations includes also the
diffusion and advection equations for turbulent transfer of sensible heat, CO2 concentration
(Cs) and specific humidity (q) at soil - vegetation -atmosphere interface (Sogachev, Panferov
2006, Mukhartova et al. 2015, Mamkin et al. 2016):
( ) { ( )}
∂Vi+ ⃗V,∇ V = −-1⋅-∂-δP −-∂-- 2δ ¯e− K ⋅ ∂Vi-+ ∂Vj- +g⋅δTv+F , i,j = 1,2,
∂t i ρ0 ∂xi ∂xj 3 ij ∂xj ∂xi T0 i
div⃗V = 0,
∂T ( ) Tv γa ∂T 1 ( ) H
∂t-+ ⃗V ,∇ T+ γa⋅T-⋅V2 = div (KT ⋅∇T )+ T-⋅KT ⋅∂x--+ρ-c- ⃗V,∇ δP −ρ-c-,
0 0 2 0 p 0 p
∂Cs- (⃗ ) ∂q- (⃗ ) E-
∂t + V ,∇ Cs = div(KC ⋅∇Cs )+FC, ∂t+ V ,∇ q = div(Kv ⋅∇q )+ ρ ,
where x1,x2 – horizontal and vertical coordinates respectively, ρ0 – the density of dry air,
δP – the deviation of mean air pressure from the hydrostatic distribution, ¯e – the turbulent
kinetic energy, T – the temperature of the air, δTv = T ⋅(1+ 0.61q) −T0 – the deviation of
virtual temperature from the adiabatic temperature T0(x2) for dry air, Fi – the components
of the viscous drag forces induced by the presence of vegetation, K,KT,KC,Kv – turbulent
exchange coefficients for momentum, sensible heat, CO2and H2O respectively,
γa = g/ cp, cp – the specific heat of the air at constant atmospheric pressure, FC –
the sources/sinks of CO2in vegetation, H – sensible heat flux, E – evaporation
rate.
For the numerical solution of the corresponding initial-boundary problem the efficient
finite-difference scheme, based on the splitting for processes, was developed.
Acknowledgements: This study was supported by grants of the by the Russian Science
Foundation (Grant 14-14-00956).
Wyngaard J.C. Turbulence in the Atmosphere. Cambridge University press.
2010.
Mamkin V., Kurbatova J., Avilov V., Mukhartova Yu., Krupenko A., Ivanov D.,
Levashova N., Olchev A. Changes in net ecosystem exchange of CO2, latent
and sensible heat fluxes in a recently clear-cut spruce forest in western Russia:
results from an experiment and modeling analysis // Environ. Res. Lett. 11 (2016)
125012. doi: 10.1088/1748-9326/aa5189.
Sogachev A., Panferov O. Modification of two-equation models to account for
plant drug // Boundary-Layer Meteorol. 2006. Vol.121. Issue 2. PP. 229-266.
Mukhartova Yu.V., Levashova N.T., Olchev A.V., Shapkina N.T. Application
of a 2D model for describing the turbulent transfer of CO2 in a spatially
heterogeneous vegetation cover // Moscow University Physics Bulletin. 2015.
Vol. 70. No. 1. PP. 14-21.
Wilcox D.C. Turbulence modeling for CFD. DCW Industries, Inc., La Cañada,
CA. 1998. |
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