Integrated Models in Hydrology and Meteorology - Transport in the Atmosphere-Vegetation-Soil Continuum - page 341

q

r r r r r r

r r

r

r

r

Figure 9.17 Schematic representation of water vapour transport in TESSEL for the
six land tiles. Some tiles evaporate without an addition resistance, some have a can-
opy resistance, and snow below high vegetation has a parallel resistance for evapora-
tion from snow and a canopy resistance. (After ECMWF, 2009 )

Question 9.14: Make a sketch similar to Figure 9.17 , but now for heat transport (i.e.,
the upper node is not for q a , but for T a ). Pay special attention to the resistances.

Question 9.15: Explain for each of the land tiles depicted in Figure 9.17 why they are
used in the model (i.e., in what respect do the tiles differ that makes it important to dis-
tinguish them).

9.2.6 Coupling to the Atmosphere and the Soil
In the previous section, the coupling of the land surface to the atmosphere has been
dealt with schematically, but how does it work in practice? Again, TESSEL is used
as an example. To simplify the discussion, in the rest of this section, the processes
related to snow, snow melt and soil freezing will not be dealt with.

Coupling to the Atmosphere
For each of the tiles (with index i ), the surface energy balance is:

− ( ) + − ( ) −

( )

↓

TT −

1 r K ε σ s LT

↓ 4

Λ  = HLE

i

(9.34)

s , i soil , 1

i

 

, i veg , i

 

v i

  

G

Q *