GEWEX MOTIVATIONS FOR LANDFLUX ACTIVITY William B. Rossow Distinguished Professor CREST at The City College of New York May 2007.

GEWEX MOTIVATIONS FOR LANDFLUX ACTIVITY

William B. Rossow

Distinguished Professor

CREST at

The City College of New York

May 2007

(Chronological Order)

1) Cloud—Climate Feedback Problem Led toISCCP, SRB and GPCP

2) Important (leading) Sources of Uncertainty for SRBare Land Surface (Sea Ice) Properties =Temperature, Emissivity, Spectral Albedo

3) Completion of Global (Atmospheric) E&W Cycle Requires Land (Ice) Surface Turbulent Fluxes

4) Connection of Climate Change to Human InterestsRequires Land Hydrology Predictions =Water Storage (Lakes, Soil Moisture,

Snow/Ice, Acquifer) and Runoff (Discharge, Floods)

GLOBAL ENERGY BUDGET (Wm-2)

TOP: DWN-SW UP-SW UP-LW NET

+342 -106 -233 +3

ATM: NET SW NET LW NET

+71 -182 -111

SRF: DWN-SW UP-SW DWN-LW UP-LW

+189 -24 +345 -396

SRF: NET-SW NET-LW NET

+165 -51 +114

SRF: EVAP (=GPCP PRECIP) SENSIBLE NET

-85 -17 -102

SRF: EVAP (GSSTF2) SENSIBLE NET

-100 -12 -112

SOME EVIDENCE THAT NET-SW IS SMALLER BY 5

SOME EVIDENCE THAT PRECIP IS LARGER BY 10

Deseasonalized TOA Flux AnomaliesT

OA

Up

war

d F

lux

Des

easo

nal

ized

An

om

aly

Rel

ativ

e to

’85

–’8

8 (W

m-2)

Reflected SW

OLR

NORTHWARD ENERGY TRANSPORTREQUIRED TO BALANCE NET RADIATION

AT EACH LATITUDE

Zhang

Zhang

-90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90

-90

-80-70

-60

-50-40

-30

-20-10

010

20

3040

50

6070

8090

100

110

Tota

l Oce

an

ic S

urf

ace

Energ

y F

lux

(W/m

^2)

FD + GSSTFFD + HOAPSFD + WHOISRB + GSSTFSRB + HOAPSSRB + WHOI

Total Net Surface Flux Into Ocean

Zhang

-90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

No

rth

ward

Oce

anic

Ene

rgy

Tra

nsp

ort

(pW

)

88-00 Mean (W/ Min/Max) of FD/SRB+GSSTF/HOAPS/WHOI

Shortwave Downward Flux Validation

Stackhouse

Longwave Downward Flux Validation

WHAT’S MISSING?

THE LAND

PROPERTIES AND FLUXES

WATER STORAGE & RUNOFF

The NASA TRMM Multi-Satellite Precipitation Analysis

(TMPA or 3B42 [TRMM product number]) [Adler/Huffman]

Almost 9 years (‘98-06’)of 3-hr analysis available--produced at TSDIS.

3-hr window with passive microwave (gaps filled with Geo-IR) calibrated by TRMM

Research product uses PR information and monthly gauges

Partitioning the Precipitation

Model Estimates of Evaporation Over the GEWEX CSEs, Land, Ocean, Globe

Annual mean latent heat flux (W/m2) from R1, R2, ERA40, JRA, Noah, CLM, Mosaic and ensemble means for GHP CSE regions as well as for the Global Land (-60 to + 60), Ocean (-90 to 90), and the entire Globe. The areas are ordered from left to right by their annual mean surface air temperatures in the R1. Note the dry MDB and AMMA areas bracketing the wetter tropical areas.

Roads

Papa

Prigent

(%)

Case study: the large Siberian watersheds

Lena

Yenissey

Ob

Papa

Teodosio Lacava – IMAA-CNR

Projection: EASE Grid Global; Datum: WGS-84

0 5010 4020 30

Mean Soil Moisture (% volume): April 2003-2005 A

From Kerr

Output Evaluation: Global ObservationsOutput Evaluation: Global Observations

Terrestrial water storage from GRACE (top) and 2m column soil moisture plus snow water equivalent from Noah (bottom), April/May (left) and September (right), 2003 (1000 km smoothing) From Bosilovich

GRACE

Case study: The Rio Negro River (Amazon River basin)A combination with water level variations from altimetry (Topex-Poseidon)

Identification of floodplains using multi-satellite technique

Construction of water level time series

Estimation of water level maps

Computation of water level variation maps

Computation of surface water volume variations

GRACE

Integrated discharge (Jatuarana-Manacapuru)

Comparison with Grace and reconstructed in-situ water volume estimates

Grace(2003-2006)(ground water+soil moisture+surface water)

Multi-satelliteand altimeter(1993-2000)(surface water)

Papa

Potential and StatusDEM and Runoff models Y YAlbedo (spectral) Y RSkin Temperature (diurnal) Y RVegetation Properties P RSurface Meteorology Y Y-NPrecipitation Y YSnow Water Amount Y Y-NFlooding (standing water) Y RWater Levels (& discharge) P RSoil Moisture P RWater Storage Y R

BACKUP SLIDES

Energy Cycle of Atmosphere

Zonal MeanKinetic Energy

EddyAvailable

Potential Energy

EddyKinetic Energy

Zonal MeanAvailable

Potential Energy

Baroclinic Cycle

Gz

Ge

Dz

De

ZHANG AND ROSSOW 1997

Case study: the large Siberian watersheds

1. Evaluation with in-situ snowmelt date and snow depth over the southern Ob river

2. Evaluation with in-situ run-off and discharge at the Ob estuary

VARIATION OF CLIMATE FORCINGS

GLOBAL PRECIPITATION

EXTENDING THE RECORD

Annual Average Global Surface Annual Average Global Surface Fluxes Fluxes

(21-Year Average; Jan 1984 - Dec 2004)SW Downward Fluxes (SRB SW v2.7,W m-2)

LW Surface Fluxes (SRB LW v2.5, W m-2)

SRB: Stackhouse

Global Precipitation Climatology Project Global Precipitation Climatology Project (GPCP)(GPCP)

Robert Adler (GPCP Coordinator) NASA/GSFC Laboratory for Atmospheres-USA

http://lwf.ncdc.noaa.gov/oa/wmo/wdcamet-ncdc.htmlhttp://precip.gsfc.nasa.gov

GPCP: Adler

Climate’s Energy Cycle

Annual Mean Generation of APE

Sign of GE Confirms Lorenz estimateand Contradicts Peixoto & Oort

GZ

GE Romanski

First Determination of Gz and Ge from Observations

Cooling of Winter Poles

Winter Storms

SummerMonsoons

GZ

GE

Latent Heating

Romanski

Anomaly in Upper Ocean Heat Content from Ocean Measurements and Surface Fluxes

Zhang

NORTHWARD ENERGY TRANSPORTBY ATMOSPHERE

Zhang

NORTHWARD ENERGY TRANSPORTBY OCEANS

Zhang