meteorological observatory lindenberg – richard aßmann observatory gerd vogel (dwd felg) g....

Meteorological Observatory Lindenberg – Richard Aßmann Observatory

Gerd Vogel (DWD FELG)

Validation of soil moisture simulationsat Lindenberg (DWD)

Athens, September 2006

DWD, *Meteoswiss

G. Vogel, F. Ament*, C. Heret, U. Rummel



COSMO-EU COSMO-EU



Bowen ratio at Falkenberg

-1,5

-1,0

-0,5

0,0

0,5

1,0

1,5

2,0

2,5

1 2 3 4 5 6 7 8 9 10 11 12

month 2006

measurement COSMO-EU



May 2006 June 2006Vertical profile of specific humidity at

MO Lindenberg



Measurement COSMO-EU TERRA (stand-alone)

End of snow period

Transition zone (min->max)

Transition zone (max->min)

Plant cover Plant cover

soil moisture (3-9cm) sand Falkenberg (MOL DWD)



Solar albedo

Snow height

(6 UTC)

0,0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1,0

0 10 20 30 40 50 60 70 80 90

Julian days 2006

Falken-berg 2006

-2

0

2

4

6

8

10

12

14

1 4 7 10

13

16

19

22

25

28

31

34

37

40

43

46

49

52

55

58

61

64

67

70

73

76

79

82

85

88

Julian days 2006

rain

measurement reference sim. sim (mod. melting & snow albedo)



Thermal radiation of the atmosphere January - March 2006 Falkenberg

100

150

200

250

300

350

400

0 10 20 30 40 50 60 70 80 90

Julian days 2006

-25

-20

-15

-10

-5

0

5

10

15

20

0 10 20 30 40 50 60 70 80 90

Soil temperature (-6cm) Falkenberg

-25

-20

-15

-10

-5

0

5

10

15

20

0 10 20 30 40 50 60 70 80 90

measurement reference sim. sim (mod. melting & snow albedo)

-25

-20

-15

-10

-5

0

5

10

15

20

0 10 20 30 40 50 60 70 80 90

Julian days 2006

Thermal radiation of the atmosphere January - March 2006 Falkenberg

100

150

200

250

300

350

400

0 10 20 30 40 50 60 70 80 90

rain



evaporation of bare soil according to Noilhan et Planton (1989)

infiltration based on hydraulic conductivity*

modified root density function with exponential reduction*

modified transpiration rate of dry leaves*

Modifications to improve the soil moisture simulation with TERRA7

(COSMO-EU)

*adopted from GME



Soil moisture (3-9cm) Falkenberg site



Improvement of soil temperatures (6cm)

COSMO-EU



Sensible heat flux May 2006 Latent heat flux May 2006

Improvement of turbulent heat fluxes (Falkenberg)

Bowen ratio (12UTC): 0.43 1.80 0.60 0.28




Improvement of turbulent heat fluxes (Forest site)

(No1D)COSMO-EU



Measurement-driven stand-alone simulations are a useful tool to study the model behaviour of the soil module TERRA in detail. Our validation activities focussed to soil moisture processes as a key factor in near-surface boundary layer modelling.

CONCLUSIONS

By introducing some minor modifications the Bowen ratio could be improved in our one-month test data set at the measurement sites Falkenberg (grass) and Kehrigk (coniferous forest). The studies should be extended to several months in the annual cycle.

In order to further improve the turbulent heat fluxes above forested areas the parameterisation of interception should be revised. In par-ticular its quantitative effect on the latent heat flux should be more precisely derived from the measurements.



Measurement COSMO-EU TERRA (stand-alone)

End of snow period

Transition zone (min->max)

Transition zone (max->min)

Plant cover Plant cover

soil moisture (3-9cm) sand Falkenberg (MOL DWD)



Bowen ratio at Falkenberg (2006)

-1,5

-1,0

-0,5

0,0

0,5

1,0

1,5

2,0

2,5

1 2 3 4 5 6 7 8 9 10 11 12

month 2006

COSMO-EU measurement



Soil moisture (3-9cm) Falkenberg site




Improvement of turbulent heat fluxes (Falkenberg)

Bowen ratio (12UTC): 0.43 1.80 0.60 0.28




Improvement of turbulent heat fluxes (Forest site)

(No1D)COSMO-EU

meteorological observatory lindenberg – richard aßmann observatory gerd vogel (dwd felg) g....

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