modeling the land-atmosphere hydrologic cycle and its coupling through river flow

Modeling the Land-Modeling the Land-Atmosphere Hydrologic Cycle Atmosphere Hydrologic Cycle

and its and its Coupling through River FlowCoupling through River Flow

William J. Gutowski, Jr.William J. Gutowski, Jr.Dept. Geological & Atmospheric SciencesDept. Geological & Atmospheric Sciences

Iowa State UniversityIowa State University

START Temperate East Asia Regional Center (February 2000)

… … with much help from:with much help from:

Charles J. VörösmartyCharles J. Vörösmarty22, Mark Person, Mark Person33,,

Zekai ÖtlesZekai Ötles11, Balazs Fekete, Balazs Fekete22

and Jennifer Yorkand Jennifer York33

1 1 - ISU- ISU2 2 - Univ. New Hampshire- Univ. New Hampshire3 3 - Univ. Minnesota- Univ. Minnesota


OutlineOutline

CLASPCLASP

- motivation - motivation

- calibration/validationcalibration/validation


OutlineOutline

CLASPCLASP



Water cycle coupling through river flowWater cycle coupling through river flow


OutlineOutline

CLASPCLASP




Further directionsFurther directions


Hydrologic Cycle - Modeling IssuesHydrologic Cycle - Modeling Issues

Time scale mismatchTime scale mismatch• land: land: slow slow • atmosphere: atmosphere: fast fast

Spatial scale mismatchSpatial scale mismatch• land: land: smallsmall• atmosphere: atmosphere: largelarge

PBL

ATMOS

SVAT

Export throughStreamflow

SW/GW

External Forcing

CLASP

CCoupled LLand - AAtmosphere SSimulation PProgram

PBL

ATMOS

SVAT


SW/GW

External Forcing

CLASP

ATMOS:ATMOS:• single columnsingle column• computedcomputed

vertical processesvertical processes

• specified lateral specified lateral forcingforcing

PBL

ATMOS

SVAT


SW/GW

External Forcing

CLASP

SVAT & SVAT & SW/GW:SW/GW:• spatially spatially resolvedresolved

• vertical couplingvertical coupling

by soil/veg by soil/veg processesprocesses

• lateral couplinglateral coupling by river networkby river network

1600 Cells1600 Cells

ApplicationApplication

KansasKansas


FIFE - Konza Prairie, KansasFIFE - Konza Prairie, Kansas 1987-19891987-1989


FIFE - Konza Prairie, KansasFIFE - Konza Prairie, Kansas (from Oak Ridge DAAC FIFE page)

PBL

ATMOS

SVAT


SW/GW

External Forcing

CLASP

Boundary Boundary Conditions:Conditions:

NCEP NGM analysesNCEP NGM analyses 9 Years (1985-93)9 Years (1985-93)

0

5

10

15

20

0 90 180 270 360

950 hPa Specific HumidityTopeka vs. NGM

Topeka

NGM

Day of 1987

Calibration/ValidationCalibration/Validation

Observations: Betts and Ball (1998)Observations: Betts and Ball (1998)

(from Oak Ridge DAAC FIFE page)


1987: Calibration1987: Calibration

1988 & 1989: Validation1988 & 1989: Validation




Surface: GrasslandSurface: Grassland




Surface: GrasslandSurface: Grassland

Primary Targets: Primary Targets:

– Surface EvapotranspirationSurface Evapotranspiration

– Precipitation Precipitation

Calibration/Validation: AdjustmentsCalibration/Validation: Adjustments

PrecipitationPrecipitation

– Effective RH Effective RH (93.5%)(93.5%)

– Convective precip.Convective precip.



– Effective RH (93.5%)Effective RH (93.5%)


Soil MoistureSoil Moisture

– Root depth Root depth (1.42 m)(1.42 m)

– Water fractionWater fraction



– Effective RH (93.5%)Effective RH (93.5%)


Soil MoistureSoil Moisture

– Root depth (1.42 m)Root depth (1.42 m)

– Water fractionWater fraction

“ “Green-up”Green-up”

Ccan∝GLEAF

0

0.2

0.4

0.6

0.8

1

0 10 20 30 40 50

Gleaf - Original

Gleaf

T [˚C]

Ccan∝GLEAF

0

0.2

0.4

0.6

0.8

1

0 10 20 30 40 50

Gleaf - Original

Gleaf - Calibrated

Gleaf

T [˚C]

0

50

100

150

200

0 60 120 180 240 300 360

Surface Latent Heat Flux

FIFE+sdevFIFE-sdevCLASP

Day of 1987

BIAS = - 3 ; SDEV = 5 [W-m-2]

-80

-60

-40

-20

0

20

120 150 180 210 240 270 300 330 360

Precipitation

FIFECLASP

Day of 1987

OBS = 2.5 ; BIAS = +0.04 ; SDEV = 7.7 [mm-d-1]

0

20

40

60

80

100

150 180 210 240 270 300

Cloud Cover

FIFECLASP

Day of 1987

BIAS = +0.3 % ; SDEV = 10 %

-50

0

50

100

150

0 60 120 180 240 300 360

Surface Sensible Heat Flux

FIFE+sdev

FIFE-sdev

CLASP

Day of 1987

BIAS = + 1 ; SDEV = 6 [W-m-2]

0

50

100

150

200

250

300

350

0 60 120 180 240 300 360

Incident Solar Radiation


Day of 1987

BIAS = - 4; SDEV = 21 [W-m-2]

200

250

300

350

400

450

0 60 120 180 240 300 360

Downward Infrared Flux

FIFE+sdev

FIFE-sdev

Day of 1987

CLASP

BIAS = + 3 ; SDEV = 9 [W-m-2]

-100

-50

0

50

100

0 60 120 180 240 300 360

Soil Heat Flux


Day of 1987

BIAS = + 6 ; SDEV = 7 [W-m-2]

0

50

100

150

200

120 150 180 210 240

Latent Heat Flux


Day of 1988

(a)

2100

50

100

150

200

Day of 1989

(b)

VALIDATION

BIAS = - 48 , SDEV = 25 BIAS = + 6 , SDEV = 23 [W-m-2]

-80

-60

-40

-20

0

20

0 60 120 180 240 300 360

Precipitation

FIFE

CLASP

Day of 1988

VALIDATION

OBS = 1.4 ; BIAS = - 0.2 ; SDEV = 5.4 [mm-d-1]

-80

-60

-40

-20

0

20

0 60 120 180 240 300 360

Precipitation

FIFE

CLASP

Day of 1989

VALIDATION

OBS = 2.5 ; BIAS = - 1.0; SDEV = 8.0 [mm-d-1]

-50

0

50

100

150

120 150 180 210 240

Sensible Heat Flux


Day of 1988

(a)

210-50

0

50

100

150

Day of 1989

(b)

VALIDATION

BIAS = + 33 , SDEV = 23 BIAS = - 13 , SDEV = 22 [W-m-2]

150

200

250

300

350

400

120 150 180 210 240

Incident Solar Radiation


Day of 1988

(a)

210

Day of 1989

(b)

VALIDATION

BIAS = + 22 , SDEV = 18 BIAS = - 34 , SDEV = 41 [W-m-2]

200

250

300

350

400

450

0 60 120 180 240 300 360



Day of 1988

(a)

VALIDATION

BIAS = - 19; SDEV = 18 [W-m-2]

200

250

300

350

400

450

0 60 120 180 240 300 360



Day of 1989

(b)

VALIDATION

BIAS = - 13 ; SDEV = 7 [W-m-2]

OutlineOutline

CLASPCLASP





Water cycle coupling through Water cycle coupling through

river flowriver flow

Configuration 1:Configuration 1:• Pure grasslandPure grassland• No river inflowNo river inflow

0

40

80

120

160

1985 1987 1989 1991 1993

Latent Heat Flux

ENCR (grass)

[W-m

-2]

Year

0

40

80

120

160

1985 1987 1989 1991 1993

Latent Heat Flux

ENCR (grass)E-NoE (grass)

[W-m

-2]

Year

QuickTime™ and aGIF decompressor

are needed to see this picture.

0

10

20

30

40

50

60

70

80

1985 1987 1989 1991 1993 1995

Discharge

ph.18-GR-NoE

Year

0

10

20

30

40

50

60

70

80

1985 1987 1989 1991 1993 1995

Discharge

ph.22-GR-ENCR

ph.18-GR-NoE

Year

0

2

4

6

8

10

12

14

16

0 90 180 270 360

Lyon Creek, Kansas - Climatology(Dec. 1953 - Sep. 1974)

DAY OF YEAR

Water cycle coupling through Water cycle coupling through

river flowriver flow

Configuration 2:Configuration 2:• Mixed forest/grassMixed forest/grass• No river inflowNo river inflow

0

40

80

120

160

1985 1987 1989 1991 1993

Latent Heat Flux

ENCR (for/gr)E-NoE (for/gr)

[W-m

-2]

Year

0

10

20

30

40

50

60

70

80

1985 1987 1989 1991 1993 1995

Discharge

ph.21-FG-Enc

ph.19-FG-NoE

Year

OutlineOutline

CLASPCLASP






Further DevelopmentsFurther Developments

CLASP CLASP MODFLOW MODFLOW Jennifer York (U. Mn)Jennifer York (U. Mn)




CLASP + LSMCLASP + LSM Dave Flory (ISU)Dave Flory (ISU)


BIAS = - 3 ; SDEV = 17 [W-m-2]

0

50

100

150

200

0 60 120 180 240 300 360

Surface Latent Heat Flux

FIFE+sdevFIFE-sdevCLASPLSM

Day of 1987

BIAS = - 6 ; SDEV = 3 [W-m-2]

-50

0

50

100

150

0 60 120 180 240 300 360

Surface Sensible Heat Flux

FIFE+sdevFIFE-sdevCLASPLSM

Day of 1987



CLASP + LSMCLASP + LSM Dave Flory (ISU)Dave Flory (ISU)

Grass-Forest DistributionGrass-Forest Distribution Meredith Lips (ISU)Meredith Lips (ISU)



Effect of Spatial Variability inEffect of Spatial Variability in

Sea-Surface TemperatureSea-Surface Temperature

(Mon. Weather Rev., 1998)(Mon. Weather Rev., 1998)


0

100

200

300

0 60 120 180 240 300 360

Het.Hom.

FL

[W/m

2]

Day of Year

+ 47%

ConclusionsConclusions Credible calibration/validationCredible calibration/validation

• Hindered by model/driving data: vertical Hindered by model/driving data: vertical motion and precipitationmotion and precipitation

• Hindered by observations?Hindered by observations?


ConclusionsConclusions Credible calibration/validationCredible calibration/validation

• Hindered by model/driving data: vertical Hindered by model/driving data: vertical motion and precipitationmotion and precipitation

• Hindered by observations?Hindered by observations?

Horizontal coupling of water cycle Horizontal coupling of water cycle by river flowby river flow

• More important during dry than wet episodesMore important during dry than wet episodes

• Can increase area-averaged ET by 50% in Can increase area-averaged ET by 50% in some summerssome summers


modeling the land-atmosphere hydrologic cycle and its coupling through river flow

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