Transcript Document
Advanced Remote Sensing Data Analysis and Application References:
Chou, M.-D., W. Zhao, and S.-H. Chou, 1998: Radiation budgets and cloud radiative forcing in the Pacific warm pool during TOGA COARE. J. Geophys. Res., 103, 16967-16977.
Chou, M.-D., P.-K. Chan, and M. M.-H. Yan, 2001: A sea surface radiation dataset for climate applications in the tropical western Pacific and South China Sea. J. Geophys. Res., 106, 7219-7228.
Chou, S.-H., 1993 : A comparison of airborne eddy correlation and bulk aerodynamic methods for ocean-air turbulent fluxes during cold-air outbreaks. Bound.-Layer Meteor., 64, 75 -100.
Chou, S.-H., R. M. Atlas, C.-L. Shie, and J. Ardizzone, 1995: Estimates of surface humidity and latent heat fluxes over oceans from SSM/I data. Mon. Wea. Rev., 123, 2405-2425.
Chou, S.-H., C.-L. Shie, R. M. Atlas, and J. Ardizzone, 1997: Air-sea fluxes retrieved from Special Sensor Microwave Imager data. J. Geophys. Res., 102, 12705-12726.
Chou, S.-H., W. Zhao, and M.-D. Chou, 2000: Surface heat budgets and sea surface temperature in the Pacific warm pool during TOGA COARE. J. Climate, 13, 634-649.
Chou, 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 Goddard satellite retrievals, version 2 (GSSTF2). J. Climate, 16, 3256-3273.
Curry, J. A., A. Bentamy, M. A. Bourassa, D. Bourras, E. F. Bradley, M. Brunke, S. Castro, S.-H. Chou, 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. Webster, G. A. Wick, and X. Zeng, 2004: SEAFLUX. Bull. Amer. Meteor. Soc.,85, 409-424. Chou, S.-H., 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 1998/99 La Nina. J. Climate, 17, 1845-1858.
Chou, S.-H., E. Nelkin, J. Ardizzone, and R. M. Atlas, 2004b: A comparison of latent heat fluxes over global oceans for four flux products. J. Climate, in press.
Chou, S.-H., 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 and Atmosphere, 9-13 August 2004, Portland, Maine. (color figures)
Graduate Course: Advanced Remote Sensing Data Analysis and Application
VERSION 2 GODDARD SATELLITE-BASED SURFACE TURBULENT FLUXES (GSSTF2)
Shu-Hsien Chou Dept. of Atmospheric Sciences National Taiwan University [email protected]
886-2-2362-5896, ext 262
Outlines:
GSSTF2 Data Set GSSTF2 Bulk Flux Parameterization GSSTF2 Input Parameters
Validation of Input Parameters and Turbulent Fluxes Spatial Distributions of 1988-2000 Annual Mean Turbulent Fluxes and Input Parameters over Global Oceans Spatial Distributions of 1988-2000 Seasonal Mean Turbulent Fluxes and Input Parameters over Global Oceans
Any problem about reading GSSTF2 data set, please contact: Shuk-Mei Tse Dept. of Atmospheric Sciences National Taiwan University [email protected]
886-2-2362-5896, ext 220
Version 2 Goddard Satellite-Based Surface Turbulent Fluxes (GSSTF2; Chou et al. 2003) (1)* Latent heat flux (2)* Zonal wind stress (9) Total column water vapor (10) SST (3)* Meridional wind stress (4)* Sensible heat flux (5)* 10-m specific humidity (6)* 500-m bottom layer water vapor (7)* 10-m wind speed (8)* Sea-air humidity difference (11) 2-m temperature (12) SLP Duration: July 1987–Dec 2000 Spatial resolution: 1 o x 1 o lat-lon Temporal resolutions: one day, and one month (Combine DMSP F8, F10, F11, F13, F14 satellites) Climatology: monthly- and annual-mean (1988-2000, combine all satellites) *Archive at NASA/GSFC DAAC: http://daac.gsfc.nasa.gov/CAMPAIGN_DOCS/hydrology/hd_gsstf2.0.html
Chou, 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 Goddard satellite retrievals, version 2 (GSSTF2). J. Climate, 16, 3256-3273.
Table 1. Characteristics of SSM/I on board DMSP satellites Center of freq ( GHZ ) 19.35
22.24 37.00 85.50
Center of channels (mm) 15.5
13.5 8.1 3.5
Polarization V, H V V, H V, H 3 dB footprint (km x km) 69x43 50x40 37x29 15x13 Swath width (km) 1394 1394 1394 1394 Spatial sampling (deg) 0.25
0.25 0.25 0.125
SSM/I --- Special Sensor Microwave/Imager DMSP --- Defense Meteorological Satellite Program
Table 2. Approximate local times (LT) of equatorial crossing and data records for each SSM/I of the DMSP satellites used in the derivation of GSSTF2.
–––––––––––––––––––––––––––––––––––––––––– Satellites Equatorial Data records __________ crossing (LT)__________________________ F08 F10 1815/0615 0945/2145 9 Jul 1987 – 1 Jan 1991 – 31 Dec 1991 14 Nov 1997 F11 F13 0600/1800 0600/1800 1 Jan 1992 – 3 May 1995 – 31 Dec 1996 31 Dec 2000 F14 0845/2045 descend /ascend 8 May 1997 – 31 Dec 2000 –––––––––––––––––––––––––––––––––––––––––––
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 model:
Z -- Reference height for wind, temperature, and humidity (can be different for different variables) U -- Surface wind speed at Z
q
s -- Sea surface temperature (SST) Qs – Sea surface saturation specific humidity (salinity, cool skin effect) Q -- Surface air specific humidity at Z
q
-- Surface air potential temperature at Z
r
-- Air density Cp -- Isobaric specific heat Lv -- Latent heat of vaporation C D , C H , C E – Bulk transfer coefficients for momentum, sensible and latent heat fluxes L -- Monin-Obukhov length { =
q
v k -- von Karmen constant ( =0.4)
u
- kinematic viscosity of air
u
* 2 /( g k
q
v * ) }
GSSTF2 BULK FLUX MODEL:
(Chou 1993; Chou et al. 2003)
Wind stress
t
Sensible heat flux F
SH
Latent heat flux F
LH
=
r
=
r
=
r
C
D
(U Cp C
H –
Us) (U
– 2
Us) (
q
s
–
q
) Lv C
E
(U
–
Us) (Qs
–
Q) Input parameters: U(Z),
q
s,
q(Z)
, Qs, Q(Z) and Z * C
D
, C
H
, and C
E
depend on U, (
q
s
–
q
), and (Qs (Monin-Obukhov similarity theory or surface layer similarity theory)
–
Q) Us = 0.55 u
*
GSSTF2 BULK FLUX MODEL: (Chou 1993; Chou et al. 2003) Wind Stress
t
=
r
Sensible Heat Flux F SH Latent Heat Flux F LH = – = –
r r
u
* 2 Cp Lv
u
*
q
*
u
* q * Flux – Profile Relationship in Atmospheric Surface Layer: ( (U
q
– – (Q – Us)/u *
q
s )/
q
* Qs)/q * = [ln(Z/Z o ) – = [ln(Z/Z oT ) – = [ln(Z/Z o q ) –
y
u (Z/L)]/k
y
T (Z/L)]/k
y
q (Z/L)]/k
y
=∫(1 –
f
) d ln(Z/L), L =
q
v u * 2 /(g k
q
v* )
F
u = (1 – 16 Z/L)
-
0.25
,
f
T =
f
q = (1 – 16 Z/L )
-
0.5
(unstable)
f
u =
f
T =
f
q = 1 + 7 Z/L (stable), k = 0.40
GSSTF2 BULK FLUX MODEL: (Chou 1993; Chou et al. 2003) * C D , C H , and C E depend on U, (
q
S –
q
), and (Q S – Q) (Monin-Obukhov similarity theory) C D C H C E = k = C 2 /[ln( D 1/2 Z / Z O k/[ln( ) Z – / Z
y
u ( Z/L )] 2 OT ) –
y
T ( Z/L )] = C D 1/2 k/[ln( Z / Z O q ) –
y
q ( Z/L )] Zo
=
0.0144
u
* 2
/
g
+
0.11
u
/u
* Zo T
=
u
/u
*
[a
1 ( Z O
u
*
/
u
) b1
]
Zoq
=
u
/u
*
[a
2 ( Z O
u
*
/
u
) b2
]
( momentum roughness length) ( temperature roughness length) ( humidity roughness length)
RETRIEVAL OF GSSTF2 FLUXES: (Chou et al. 2003) Wind Stress Latent Heat Flux F
t
Sensible Heat Flux F SH =
r
LH =
r
C D =
r
(U – U S ) 2 Cp C H Lv C E (U (U – – U U S S ) (
q
) (Q S S – –
q
) Q) • • • • • • • U -- daily SSM/I-v4 10-m wind (Wentz 1997)
q
S -- daily SST (NCEP reanalysis) Q S
q
-- 0.98 x 0.622 e S /p S (salinity, cool skin effect) Q -- daily SSM/I-v4 10-m specific humidity (Chou et al. 1995, 1997) -- daily 2-m potential temp (NCEP reanalysis) Stress direction -- SSM/I-v4 10-m wind direction (Atlas, et al. 1996) C D , C H , C E depend on U, (
q
S –
q
) & (Q S – Q) (Monin-Obukhov similarity or surface layer similarity theory) Chou, 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 Goddard satellite retrievals, version 2 (GSSTF2). J. Climate, 16, 3256-3273.
ASTEX: Atlantic Stratocumulus Transition Experiment COARE: Coupled Ocean-Atmosphere Response Experiment FASTEX: Fronts and Atlantic Storm Track Experiment JASMINE: Joint Air-Sea Monsoon Interaction Experiment KWAJEX: Kwajalein Experiment NAURU99: Nauru ’ 99 Experiment SCOPE: San Clemente Ocean Probing Experiment TIWE: Tropical Instability Wave Experiment PACSF99: Pan-American Climate Study in eastern Pacific during 1999 MOORINGS: Buoy service in the North Pacific
1913-hourly fluxes calculated from ship data using GSSTF2 bulk flux model vs observed (a) wind stresses determined by ID method, (b) latent and (c) sensible heat fluxes determined by covariance method of 10 field experiments. C: COARE F: FASTEX X: other experiments
GSSTF2 daily (a) wind speeds, (b) specific humidity, and (c) temperature of surface air vs those of nine field experiments.
C: COARE F: FASTEX X: other experiments
GSSTF2 daily flux retrievals vs observed (a) ID wind stresses, (b) covariance latent heat fluxes, and (c) covariance sensible heat fluxes of nine field experiments.
C: COARE F: FASTEX X: other experiments
1988-2000 Annual Average
1988-2000 Annual Average
1988-2000 Annual Average
Conclusion:
GSSTF2 is a 13.5-yr (July 1987-Dec 2000) global dataset of daily ocean surface turbulent fluxes of momentum, latent and sensible heat, with 1
o
resolution GSSTF2 bulk flux model validated well by comparing computed hourly fluxes from research ship data with those of 10 field experiments conducted over tropical and northern midlatitude oceans during 1991-99 GSSTF2 daily wind stress, LHF, wind speed, surface air humidity, and SST compare reasonably well with those of collocated nine field fields experiments during 1991-1999 Global distributions of GSSTF2 1988-2000 annual- and seasonal-mean turbulent fluxes show reasonable patterns related to atmospheric general circulation and seasonal variations GSSTF2 is useful for studying intra-seasonal to inter-annual variability, Asian monsoon, ENSO, water cycle, and surface heat 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.