Advanced Remote Sensing Data Analysis and ApplicationAdvanced Remote Sensing Data Analysis and ApplicationReferences:References:Chou, M.-D., W. Zhao, and Chou, M.-D., W. Zhao, and S.-H. ChouS.-H. Chou, 1998: Radiation budgets and cloud radiative forci, 1998: Radiation budgets and cloud radiative forci

ng in the Pacific warm pool during TOGA COARE. ng in the Pacific warm pool during TOGA COARE. J. Geophys. Res.,J. Geophys. Res., 103, 16967-16977. 103, 16967-16977.Chou, M.-D., P.-K. Chan, and M. M.-H. Yan, 2001: A sea surface radiation dataset for climChou, M.-D., P.-K. Chan, and M. M.-H. Yan, 2001: A sea surface radiation dataset for clim

ate applications in the tropical western Pacific and South China Sea. ate applications in the tropical western Pacific and South China Sea. J. Geophys. ResJ. Geophys. Res., ., 106106, 7219-7228., 7219-7228.

Chou, S.-HChou, S.-H., 1993 : A comparison of airborne eddy correlation and bulk aerodynamic me., 1993 : A comparison of airborne eddy correlation and bulk aerodynamic methods for ocean-air turbulent fluxes during cold-air outbreaks. Bound.-Layer Meteor., thods for ocean-air turbulent fluxes during cold-air outbreaks. Bound.-Layer Meteor., 64,64, 75 -100. 75 -100.

Chou, S.-HChou, S.-H., R. M. Atlas, C.-L. Shie, and J. Ardizzone, 1995: Estimates of surface humidity ., R. M. Atlas, C.-L. Shie, and J. Ardizzone, 1995: Estimates of surface humidity and latent heat fluxes over oceans from SSM/I data. and latent heat fluxes over oceans from SSM/I data. Mon. Wea. Rev.,Mon. Wea. Rev., 123123, 2405-2425., 2405-2425.

Chou, S.-HChou, S.-H., C.-L. Shie, R. M. Atlas, and J. Ardizzone, 1997: Air-sea fluxes retrieved from ., C.-L. Shie, R. M. Atlas, and J. Ardizzone, 1997: Air-sea fluxes retrieved from Special Sensor Microwave Imager data. Special Sensor Microwave Imager data. J. Geophys. Res.,J. Geophys. Res., 102, 12705-12726. 102, 12705-12726.

Chou, S.-HChou, S.-H., W. Zhao, and M.-D. Chou, 2000: Surface heat budgets and sea surface tempe., W. Zhao, and M.-D. Chou, 2000: Surface heat budgets and sea surface temperature in the Pacific warm pool during TOGA COARE. rature in the Pacific warm pool during TOGA COARE. J. Climate, J. Climate, 13, 634-649.13, 634-649.

Chou, S.-HChou, S.-H., E. Nelkin, J. Ardizzone, R. M. Atlas, and C.-L. Shie, 2003: Surface turbulent h., E. Nelkin, J. Ardizzone, R. M. Atlas, and C.-L. Shie, 2003: Surface turbulent heat and momentum fluxes over global oceans based on the Goddard satellite retrievals,eat and momentum fluxes over global oceans based on the Goddard satellite retrievals, version 2 (GSSTF2). version 2 (GSSTF2). J. ClimateJ. Climate, 16, 3256-3273., 16, 3256-3273.

Curry, J. A., A. Bentamy, M. A. Bourassa, D. Bourras, E. F. Bradley, M. Brunke, S. Castro, Curry, J. A., A. Bentamy, M. A. Bourassa, D. Bourras, E. F. Bradley, M. Brunke, S. Castro, S.-H. ChouS.-H. Chou, C. A. Clayson, W. J. Emery, L. Eymard, C. W. Fairall, M. Kubota, B. Lin, , C. A. Clayson, W. J. Emery, L. Eymard, C. W. Fairall, M. Kubota, B. Lin, W. Perrie, R. A. Reeder, I. A. Renfrew, W. B. Rossow, J. Schulz, S. R. Smith, P. J. WebsW. Perrie, R. A. Reeder, I. A. Renfrew, W. B. Rossow, J. Schulz, S. R. Smith, P. J. Webster, G. A. Wick, and X. Zeng, 2004: SEAFLUX. ter, G. A. Wick, and X. Zeng, 2004: SEAFLUX. Bull. Amer. Meteor. Soc.,Bull. Amer. Meteor. Soc.,8585, , 409-424409-424..

Chou, S.-HChou, S.-H., M.-D. Chou, P.-K. Chan, P.-H. Lin, and K.-H Wang, 2004a: Tropical warm po., M.-D. Chou, P.-K. Chan, P.-H. Lin, and K.-H Wang, 2004a: Tropical warm pool surface heat budgets and temperature: Contrasts between 1997/98 El Nino and 1998/ol surface heat budgets and temperature: Contrasts between 1997/98 El Nino and 1998/99 La Nina. 99 La Nina. J. ClimateJ. Climate, 17, 1845-1858., 17, 1845-1858.

Chou, S.-HChou, S.-H., E. Nelkin, J. Ardizzone, and R. M. Atlas, 2004b: A comparison of latent heat f., E. Nelkin, J. Ardizzone, and R. M. Atlas, 2004b: A comparison of latent heat fluxes over global oceans for four flux products. luxes over global oceans for four flux products. J. Climate,J. Climate, in press. in press.

Chou, S.-HChou, S.-H., E. Nelkin, J. Ardizzone, and R. M. Atlas, 2004c: A comparison of latent heat f., E. Nelkin, J. Ardizzone, and R. M. Atlas, 2004c: A comparison of latent heat fluxes over global oceans for four flux products. 13th Conf. on Interaction of the Sea anluxes over global oceans for four flux products. 13th Conf. on Interaction of the Sea and Atmosphere, 9-13 August 2004, Portland, Maine. (color figures)d Atmosphere, 9-13 August 2004, Portland, Maine. (color figures)

Graduate Course: Advanced Remote Sensing Data Analysis Graduate Course: Advanced Remote Sensing Data Analysis

and Applicationand Application

VERSION 2 GODDARD SATELLITE-VERSION 2 GODDARD SATELLITE-BASED SURFACE TURBULENT BASED SURFACE TURBULENT

FLUXES (GSSTF2)FLUXES (GSSTF2)

Shu-Hsien ChouShu-Hsien ChouDept. of Atmospheric Sciences Dept. of Atmospheric Sciences

National Taiwan UniversityNational Taiwan Universityshchou@atmos1.as.ntu.edu.tw shchou@atmos1.as.ntu.edu.tw

886-2-2362-5896, ext 262886-2-2362-5896, ext 262

Outlines:Outlines: GSSTF2 Data SetGSSTF2 Data Set GSSTF2 Bulk Flux ParameterizationGSSTF2 Bulk Flux Parameterization GSSTF2 Input Parameters GSSTF2 Input Parameters Validation of Input Parameters and Validation of Input Parameters and

Turbulent Fluxes Turbulent Fluxes Spatial Distributions of 1988-2000 Spatial Distributions of 1988-2000

Annual Mean Turbulent Fluxes and Annual Mean Turbulent Fluxes and Input Parameters over Global OceansInput Parameters over Global Oceans

Spatial Distributions of 1988-2000 Spatial Distributions of 1988-2000 Seasonal Mean Turbulent Fluxes and Seasonal Mean Turbulent Fluxes and Input Parameters over Global Oceans Input Parameters over Global Oceans

Any problem about reading GSSTF2 data Any problem about reading GSSTF2 data set, please contact: set, please contact:

Shuk-Mei TseShuk-Mei TseDept. of Atmospheric Sciences Dept. of Atmospheric Sciences

National Taiwan UniversityNational Taiwan University smeitse@atmos1.as.ntu.edu.twsmeitse@atmos1.as.ntu.edu.tw

886-2-2362-5896, ext 220886-2-2362-5896, ext 220

Version 2 Goddard Satellite-Based Surface TurbulenVersion 2 Goddard Satellite-Based Surface Turbulent Fluxes (GSSTF2; Chou et al. 2003)t Fluxes (GSSTF2; Chou et al. 2003)

(1)* Latent heat flux (1)* Latent heat flux (9) Total column water vapor(9) Total column water vapor (2)* Zonal wind stress (2)* Zonal wind stress (10) SST(10) SST (3)* Meridional wind stress (3)* Meridional wind stress (11) 2-m temperature(11) 2-m temperature (4)* Sensible heat flux (4)* Sensible heat flux (12) SLP(12) SLP (5)* 10-m specific humidity(5)* 10-m specific humidity (6)* 500-m bottom layer water vapor(6)* 500-m bottom layer water vapor (7)* 10-m wind speed(7)* 10-m wind speed (8)* Sea-air humidity difference(8)* Sea-air humidity difference

Duration: July 1987–Dec 2000Duration: July 1987–Dec 2000Spatial resolution: 1Spatial resolution: 1oo x 1 x 1oo lat-lon lat-lonTemporal resolutions: one day, and one month (Combine DMSP F8, Temporal resolutions: one day, and one month (Combine DMSP F8, F10, F11, F13, F14 satellites) F10, F11, F13, F14 satellites) Climatology: monthly- and annual-mean (1988-2000, combine all sateClimatology: monthly- and annual-mean (1988-2000, combine all sate

llites)llites)

*Archive at NASA/GSFC DAAC:*Archive at NASA/GSFC DAAC:http://daac.gsfc.nasa.gov/CAMPAIGN_DOCS/hydrology/hd_gsstf2.0.http://daac.gsfc.nasa.gov/CAMPAIGN_DOCS/hydrology/hd_gsstf2.0.

htmlhtml

Chou, S.-H., E. Nelkin, J. Ardizzone, R. M. Atlas, and C.-L. Shie, 2003: Surface tChou, S.-H., E. Nelkin, J. Ardizzone, R. M. Atlas, and C.-L. Shie, 2003: Surface turbulent heat and momentum fluxes over global oceans based on the Goddurbulent heat and momentum fluxes over global oceans based on the Goddard satellite retrievals, version 2 (GSSTF2). J. Climate, 16, 3256-3273.ard satellite retrievals, version 2 (GSSTF2). J. Climate, 16, 3256-3273.

Table 1. Characteristics of SSM/I on board DMSP satelliteTable 1. Characteristics of SSM/I on board DMSP satellitess

Center of freq (Center of freq (GHZGHZ)) 19.35 19.35 22.24 37.00 85.50 22.24 37.00 85.50

Center of channels (mm)Center of channels (mm) 15.5 15.5 13.5 8.1 13.5 8.1 3.5 3.5

PolarizationPolarization V, H V V, H V, H V V, H V, H V, H

3 dB footprint (km x km)3 dB footprint (km x km) 69x43 50x40 37x29 15x1 69x43 50x40 37x29 15x133

Swath width (km)Swath width (km) 1394 1394 1394 1394 1394 1394 1394 1394

Spatial sampling (deg)Spatial sampling (deg) 0.25 0.25 0.25 0.25 0.125 0.25 0.25 0.125SSM/I --- Special Sensor Microwave/ImagerSSM/I --- Special Sensor Microwave/ImagerDMSP --- Defense Meteorological Satellite ProgramDMSP --- Defense Meteorological Satellite Program

Table 2. Approximate local times (LT) of equatorial Table 2. Approximate local times (LT) of equatorial crossing and data records for each SSM/I of the DMSP crossing and data records for each SSM/I of the DMSP satellites used in the derivation of GSSTF2.satellites used in the derivation of GSSTF2.

––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––SatellitesSatellites Equatorial Equatorial Data recordsData records____________________ crossing (LT)__________________________crossing (LT)__________________________F08F08 1815/06151815/0615 9 Jul 1987 – 31 Dec 19919 Jul 1987 – 31 Dec 1991F10F10 0945/21450945/2145 1 Jan 1991 – 14 Nov 1 Jan 1991 – 14 Nov

19971997F11F11 0600/18000600/1800 1 Jan 1992 – 31 Dec 1 Jan 1992 – 31 Dec

19961996F13F13 0600/18000600/1800 3 May 1995 – 31 Dec 3 May 1995 – 31 Dec

20002000F14F14 0845/20450845/2045 8 May 1997 – 31 Dec 8 May 1997 – 31 Dec

20002000––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

descend

/ascend

24-hour coverage provided by :

(a) The F8 SSM/I

(b) The F10 and F11 SSM/Is in combination

Definition of parameters for bulk flux modelDefinition of parameters for bulk flux model :: Z -- Reference height for wind, temperature, and humidity Z -- Reference height for wind, temperature, and humidity

(can be different for different variables) (can be different for different variables) U -- Surface wind speed at Z U -- Surface wind speed at Z s -- Sea surface temperature (SST) s -- Sea surface temperature (SST) Qs – Sea surface saturation specific humidity Qs – Sea surface saturation specific humidity (salinity, cool s(salinity, cool s

kin effect) kin effect) Q -- Surface air specific humidity at ZQ -- Surface air specific humidity at Z -- Surface air potential temperature at Z-- Surface air potential temperature at Z -- Air density-- Air density Cp -- Isobaric specific heatCp -- Isobaric specific heat Lv -- Latent heat of vaporationLv -- Latent heat of vaporation CCDD, C, CHH, C, CEE – Bulk transfer coefficients for momentum, sens – Bulk transfer coefficients for momentum, sens

ible and latent heat fluxes ible and latent heat fluxes L -- Monin-Obukhov length { = L -- Monin-Obukhov length { = vv uu**

22/(/(gg kk vv**) } ) } kk -- von Karmen constant ( =0.4)-- von Karmen constant ( =0.4) ----kinematic viscosity of airkinematic viscosity of air

GSSTF2 BULK FLUX MODELGSSTF2 BULK FLUX MODEL: : (Chou 1993; Chou et al. 2003)(Chou 1993; Chou et al. 2003)

Wind stress Wind stress = = C CDD (U–Us) (U–Us)22

Sensible heat flux FSensible heat flux FSHSH = = Cp C Cp CHH (U–Us) ( (U–Us) (s–s–))Latent heat flux FLatent heat flux FLHLH = = Lv C Lv CEE (U–Us) (Qs–Q) (U–Us) (Qs–Q)

Input parameters: U(Z), Input parameters: U(Z), s, s, , Qs, Q(Z) and Z, Qs, Q(Z) and Z

* C* CDD, C, CHH, and C, and CEE depend on U, ( depend on U, (s–s–), and (Qs–), and (Qs–Q)Q)(Monin-Obukhov similarity theory or surfac(Monin-Obukhov similarity theory or surface layer similarity theory)e layer similarity theory)

Us = 0.55 uUs = 0.55 u**

GSSTF2 BULK FLUX MODELGSSTF2 BULK FLUX MODEL: : (Chou 1993; Chou et al. 2003)(Chou 1993; Chou et al. 2003)

Wind Stress Wind Stress = = uu**22

Sensible Heat Flux FSensible Heat Flux FSHSH = – = – Cp Cp uu* * ** Latent Heat Flux FLatent Heat Flux FLHLH = – = – Lv Lv uu* * qq**

Flux –Profile Relationship in Atmospheric Surface Layer:Flux –Profile Relationship in Atmospheric Surface Layer:(U – Us)/u(U – Us)/u** = [ln(Z/Z = [ln(Z/Zoo) – ) – uu(Z/L)]/k (Z/L)]/k (( – – ss)/)/** = [ln(Z/Z = [ln(Z/ZoToT) – ) – TT(Z/L)]/k (Z/L)]/k (Q – Qs)/q(Q – Qs)/q** = [ln(Z/Z = [ln(Z/Zooqq) – ) – qq(Z/L)]/k (Z/L)]/k

=∫(1 –=∫(1 –) d ln(Z/L), L = ) d ln(Z/L), L = vv u u**22/(g k /(g k v*v*) )

uu= (1 – 16 Z/L)= (1 – 16 Z/L)0.250.25 , , TT= = qq= (1 – 16 Z/L )= (1 – 16 Z/L )0.50.5 (unstable) (unstable)

uu= = TT= = qq = 1 + 7 Z/L (stable), k = 0.40 = 1 + 7 Z/L (stable), k = 0.40

GSSTF2 BULK FLUX MODELGSSTF2 BULK FLUX MODEL: : (Chou 1993; Chou et al. 20(Chou 1993; Chou et al. 2003)03)

* C* CDD, C, CHH, and C, and CEE depend on U, ( depend on U, (SS––), and (Q), and (QSS–Q)–Q)(Monin-Obukhov similarity theory)(Monin-Obukhov similarity theory)

CCDD = k = k22/[ln(/[ln(ZZ//ZZOO) – ) – uu((Z/LZ/L)])]22

CCHH = C = CDD1/21/2 k/[ln( k/[ln(ZZ//ZZOTOT) – ) – TT((Z/LZ/L)])]

CCEE = C = CDD1/21/2 k/[ln( k/[ln(ZZ//ZZOOqq) – ) – qq((Z/LZ/L)])]

ZZoo = = 0.01440.0144 u u**22//gg + + 0.110.11 /u/u** ((momentummomentum roughness len roughness len

gth)gth)

ZZooTT = = /u/u** [[aa11((ZZOO uu** //))b1b1]] ((temperaturetemperature roughness length) roughness length)

ZZoqoq = = /u/u**[[aa22((ZZOO uu** //))b2b2]] ((humidityhumidity roughness length) roughness length)

RETRIEVAL OF GSSTF2 FLUXESRETRIEVAL OF GSSTF2 FLUXES: (Chou et al. 2003): (Chou et al. 2003)

Wind Stress Wind Stress = = C CDD (U–U (U–USS))22

Sensible Heat Flux FSensible Heat Flux FSHSH = = Cp C Cp CHH (U–U (U–USS) () (SS––))Latent Heat Flux FLatent Heat Flux FLHLH = = Lv C Lv CEE (U–U (U–USS) (Q) (QSS–Q)–Q)

•• U -- daily SSM/I-v4 10-m wind (Wentz 1997) U -- daily SSM/I-v4 10-m wind (Wentz 1997) •• SS -- daily SST (NCEP reanalysis) -- daily SST (NCEP reanalysis) •• QQSS -- 0.98 x 0.622 -- 0.98 x 0.622 eeSS/p/pSS (salinity, cool skin effect) (salinity, cool skin effect) •• Q -- daily SSM/I-v4 10-m specific humidity (Chou et al. 1995, Q -- daily SSM/I-v4 10-m specific humidity (Chou et al. 1995,

1997)1997)•• -- daily 2-m potential temp (NCEP reanalysis) -- daily 2-m potential temp (NCEP reanalysis) •• Stress direction -- SSM/I-v4 10-m wind direction (Atlas, et al. Stress direction -- SSM/I-v4 10-m wind direction (Atlas, et al.

1996)1996)•• CCDD, C, CHH, C, CEE depend on U, ( depend on U, (SS––) & (Q) & (QSS–Q) (Monin-–Q) (Monin-

Obukhov similarity or surface layer similarity theory)Obukhov similarity or surface layer similarity theory)

Chou, S.-H., E. Nelkin, J. Ardizzone, R. M. Atlas, and C.-L. Shie, 2003: SurfacChou, S.-H., E. Nelkin, J. Ardizzone, R. M. Atlas, and C.-L. Shie, 2003: Surface turbulent heat and momentum fluxes over global oceans based on the e turbulent heat and momentum fluxes over global oceans based on the Goddard satellite retrievals, version 2 (GSSTF2). J. Climate, 16, 3256-327Goddard satellite retrievals, version 2 (GSSTF2). J. Climate, 16, 3256-3273. 3.

ASTEXASTEX: Atlantic Stratocumulus Transition Experiment : Atlantic Stratocumulus Transition Experiment COARECOARE: Coupled Ocean-Atmosphere Response Experiment : Coupled Ocean-Atmosphere Response Experiment FASTEXFASTEX: Fronts and Atlantic Storm Track Experiment : Fronts and Atlantic Storm Track Experiment JASMINEJASMINE: Joint Air-Sea Monsoon Interaction Experiment : Joint Air-Sea Monsoon Interaction Experiment KWAJEXKWAJEX: Kwajalein Experiment : Kwajalein Experiment NAURU99NAURU99: Nauru ’99 Experiment: Nauru ’99 Experiment SCOPESCOPE: San Clemente Ocean Probing Experiment : San Clemente Ocean Probing Experiment TIWETIWE: Tropical Instability Wave Experiment : Tropical Instability Wave Experiment PACSF99PACSF99: Pan-American Climate Study in eastern Pacific during 1999: Pan-American Climate Study in eastern Pacific during 1999 MOORINGSMOORINGS: Buoy service in the North Pacific : Buoy service in the North Pacific

1913-hourly fluxes 1913-hourly fluxes calculated from shicalculated from ship data using GSSTFp data using GSSTF2 bulk flux model v2 bulk flux model vs observed (a) wind s observed (a) wind stresses determinestresses determined by ID method, d by ID method, (b) latent and (c) se(b) latent and (c) sensible heat fluxes dnsible heat fluxes determined by covaretermined by covariance method of 10 iance method of 10 field experiments. field experiments.

C: COARE F: FASTEX X: other experime

nts

GSSTF2 GSSTF2 dailydaily (a) wind speeds,(a) wind speeds, (b) specific hu (b) specific humidity, and (c) tmidity, and (c) temperature of semperature of surface air vs thurface air vs those of nine fielose of nine field experiments.d experiments.

C: COARE F: FASTEX X: other experi

ments

GSSTF2 GSSTF2 daildailyy flux retriev flux retrievals vs observals vs observed (a) ID wined (a) ID wind stresses, d stresses, (b) covarian(b) covariance latent heace latent heat fluxes, and t fluxes, and (c) covarianc(c) covariance sensible hee sensible heat fluxes of nat fluxes of nine field expine field experiments.eriments.

C: COARE F: FASTEX X: other exp

eriments

1988-2000 Annual Average

1988-2000 Annual Average

1988-2000 Annual Average

Conclusion:Conclusion: GSSTF2 is a 13.5-yr (July 1987-Dec 2000) global dataset of daily GSSTF2 is a 13.5-yr (July 1987-Dec 2000) global dataset of daily

ocean surface turbulent fluxes of momentum, latent and sensocean surface turbulent fluxes of momentum, latent and sensible heat, with 1ible heat, with 1oo resolution resolution

GSSTF2 bulk flux model validated well by comparing computGSSTF2 bulk flux model validated well by comparing computed hourly fluxes from research ship data with those of 10 fieled hourly fluxes from research ship data with those of 10 field experiments conducted over tropical and northern midlatitd experiments conducted over tropical and northern midlatitude oceans during 1991-99ude oceans during 1991-99

GSSTF2 daily wind stress, LHF, wind speed, surface air humiGSSTF2 daily wind stress, LHF, wind speed, surface air humidity, and SST compare reasonably well with those of collocatedity, and SST compare reasonably well with those of collocated nine field fields experiments during 1991-1999d nine field fields experiments during 1991-1999

Global distributions of GSSTF2 1988-2000 annual- and seasonaGlobal distributions of GSSTF2 1988-2000 annual- and seasonal-mean turbulent fluxes show reasonable patterns related to al-mean turbulent fluxes show reasonable patterns related to atmospheric general circulation and seasonal variationstmospheric general circulation and seasonal variations

GSSTF2 is useful for studying intra-seasonal to inter-annual vGSSTF2 is useful for studying intra-seasonal to inter-annual variability, Asian monsoon, ENSO, water cycle, and surface heariability, Asian monsoon, ENSO, water cycle, and surface heat budgetsat budgets

NASA QuikSCAT scatterometer 10-m vector wind averaged for November 1999 and the corresponding divergence field. Red and blue denote convergence and divergence respectively.

Three-day composite average maps of sea surface temperature for 11-13 July 1998, during a time of year when the equatorial Pacific and Atlantic are typically cool. The maps are based on measurements from a satellite microwave radiometer (TMI). White areas represent land or rain contamination. The sharp northern edge of the cold tongue is distorted by westward-propagating tropical instability waves, which originate in the ocean but produce a distinct signature in the fields of cloudiness and wind speed.