ANALYSEN & KONZEPTE, 8404-WINTERTHUR

Seasonal variations of evapoTRANSPIRATION

Olivier Liechti, A&K

OSTIV Meteorological PanelAntalya, September 2011

ANALYSEN & KONZEPTE, 8404-WINTERTHUR

Surface energy flux

3 6 9 12 15 180

100

200

300

400

500

600

700

800

900

1000

[h]

[W/m2]

VIS

IR

GH

SH

LH

3 6 9 12 15 180

100

200

300

400

500

600

700

800

900

1000

[h]

[W/m2]

VIS

IR

GH

SH

LH

• CBL depth• glider flight level

ANALYSEN & KONZEPTE, 8404-WINTERTHUR

Seasonal variation

-10

-5

0

5

10

15

20

25

30

T (C)

2007 20082006 20092005

ANALYSEN & KONZEPTE, 8404-WINTERTHUR

Seasonal variation

-5

0

5

10

15

20

T(C)

J F M A M J J A S O N D

increased albedo

inactive vegetation

active vegetation

inactive vegetation

ANALYSEN & KONZEPTE, 8404-WINTERTHUR

Complex topography

1000 2000 3000

1000

2000

3000

1000 2000 3000

1000

2000

3000

1000 2000 3000

1000

2000

3000

Surface area [km2]

A

A

B

B

C

D D

1000 2000 3000

1000

2000

3000

[m M

SL]

[m M

SL]

[m M

SL]

C

River Adda

ANALYSEN & KONZEPTE, 8404-WINTERTHUR

Elevation dependence of seasonal temperature

-10 -5 0 5 10 15 200

400

800

1200

1600

2000

2400

2800

3200

3600

4000

T (C)

z (mMSL)

April, October July January

increased albedo minimum

transpiration transpiration maximum

ANALYSEN & KONZEPTE, 8404-WINTERTHUR

Seasonal variation in elevated terrain

-5

0

5

10

15

20

T(C)

J F M A M J J A S O N D

increased albedo

reduced transpiration

full transpiration

reduced transpiration

3200 mMSL

sea level

ANALYSEN & KONZEPTE, 8404-WINTERTHUR

Seasonal variation of transpiration in complex terrain

-5

0

5

10

15

20

T(�C)

J F M A M J J A S O N D

increased albedo

minimum transpiration

transpiration maximum

ANALYSEN & KONZEPTE, 8404-WINTERTHUR

CBL predictions for the Rhone valley in April

ANALYSEN & KONZEPTE, 8404-WINTERTHUR

CBL predictions for the Rhone valley in August

ANALYSEN & KONZEPTE, 8404-WINTERTHUR

CBL predictions for the Alps in April

ANALYSEN & KONZEPTE, 8404-WINTERTHUR

Glider flight in April

ANALYSEN & KONZEPTE, 8404-WINTERTHUR

CBL predictions for the Alps in August

ANALYSEN & KONZEPTE, 8404-WINTERTHUR

Glider flight in August

ANALYSEN & KONZEPTE, 8404-WINTERTHUR

Summary

• seasonal variations of surface characteristics(transpiration, albedo) affect the depth of the convectiveboundary layer significantly

• glider flight data has been used for the development of seasonal parameterisations

• summertime convective mixing in deep valleys withelevation dependent transpiration tends to form twomixed layers