James Dewar presenting liquid hydrogen: Physics Today, March 2008

James Dewar presenting liquid hydrogen: Physics Today, March 2008

Effects of Anomalies in Ancillary Data on Cloud and Radiation Products of the ISCCP

and SRB Projects?

(Seminar at CIRA, March, 11, 2008)

by

Ehrhard Raschke (Hamburg)

Stefan Kinne (Hamburg)

With contributions from Ely Duenas (GISS, NY)

Yuan-C. Zhang (GISS, NY) William B. Rossow (GISS, NY)

Planetary Albedo: 31, 31, 30 %

Surface temperature 15.2, 14, 14 K

1991 - 1995

surface albedo 13, 15,15%

We intend to demonstrate that the information by ancillary data has already introduced

errors into final products. We will also discuss briefly

differences of ISCCP to IPCC results.

Variables Data set of variables

Cloud Cover, Optical Thickness, Top Temperature by Type Cloud Particle Size Cloud Vertical Structure Atmospheric Temperature and Tropospheric Humidity Atmospheric Humidity (Upper Troposphere, Stratosphere) Atmospheric Composition Stratospheric Total Ozone Stratospheric Ozone Profiles Stratospheric Aerosols Tropospheric Aerosols Snow cover Sea Ice cover Diurnal Cycle of Air Temperature over Land Surface Skin Temperature and Visible Reflectance Surface Spectral Albedo and Emissivity by Type

ISCCP satellite radiances ISCCP-based Climatology Combined ISCCP-Rawinsonde Climatology TOVS, Oort Climatology for filling SAGE Climatology Actual record from Various Sources TOMS, TOVS for filling SAGE Climatology SAGE Baseline Current-day Climatology NOAA product NSIDC product Climatology based on surface weather reports and NCEP reanalysis From ISCCP retrievals GISS GCM reconstruction by surface type and season

Ancillary data for ISCCP radiation products

SOLAR RADIATIONPrimarily affected by

Insolation, clouds,

aerosols, surface reflectance +

“second order characteristics”

LONGWAVE RADIATION

primarily affected by

skin temperatureatmospheric temperature,

water vaporcloud cover and

cloud top and base heights +

“second order characteristics”

ISCCP: Surface temperature and reflectance; water vapor & air temperature are the most important ancillary data. http://ISCCP.giss.nasa.gov

ISCCP: All clouds: top pressure, optical thickness & amount

ISCCP: Cloud amounts: Total, low, middle & high

-7

-6

-5

-4

-3

-2

-1

0

1

2

1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

ISCCP SRB

ISCCP and SRB: Downward solar radiation at surface for clear skies, deseasonalized

vs. period July 85 to June 89

Deseasonalised monthly global averages of the clear sky downward solar radiation at the surface, of the projects ISCCP and SRB.

Downward solar at surface: left (monthly - deseasonalised vs. 1/85 to 12/88); right (annual anomalies with respect to 21 year average)

ISCCP

SRB

Anomalies of the effective surface albedo (ratios up-to-down)

ISCCP clear

SRB clear

Upward solar radiation at TOA: left (monthly - deseasonalised vs. 1/85 to 12/88); right (annual

averages)

ISCCP

SRB

From [email protected]

mailto:[email protected]

Longwave radiation: Skin temperature vs. emission, dw lw and its CE at surface

ISCCP

SRB

Upward (lem) and downward (lds) fluxes of longwave radiation at surface

Total net radiation at TOA

Total net radiation at surface

CE of DIV

DIV

solar infrared

A = Incident solar at TOAX = Effective surface albedoE = Emission from surfaceD = Outgoing solar at TOAF = Outgoing infrared at TOADd = CE on outgoing solar at TOABb = CE on downward solar at surfaceFf = CE on outgoing infrared at TOAHh = CE on downward infrared at surface

Annual averages of differences between CERES and ISCCP

2000 - 2003


Annual averages of differences between SRB and ISCCP

2000 - 2003

Conclusion and Recommendation

There is very strong evidence that natural and “artificial” anomalies in ancillary data cause

anomalies in cloud and radiation products, which may cause (and had already caused in the past)

false interpretations with respect to climate variations and their causes.

We, therefore, recommend that all such ancillary data must be quality-inspected with respect to

natural and “artificial” anomalies before their use in computations of cloud and radiation products.

(These conclusions need to be considered also in other GEWEX data assessments!

“Trends” in Model results: IPCC-4AR and MPI (only)

observedAnnual insolation

in IPCC-4AR models

-0,25

-0,2

-0,15

-0,1

-0,05

0

0,05

0,1

0,15

0,2

1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004

Global monthly insolation at TOA: ISCCP minus SRB: June 2007

Global averages (TSI/4) of monthly insolation at TOA: ISCCP minus SRB


Standard deviation of monthly radiation products of 22 IPCC-4AR models

Differences to ISCCP of MPI and all IPCC models: 12 year (1984-1995) averages


375

380

385

390

395

400

405

410

0 6 12 18 24 30 36

ISCCP SRB CERES

Clear sky emission from ground (Wm-2); global monthly averages Jan 2001 to Dec 2003

Clear sky emission from ground in ISCCP, SRB and CERES: global monthly averages from January 2001 to December 2003

Aerosol optical depth (global average over oceans) from ISCCP radiance data (Mishchenko et al. 2007, in 2

publications and at Gordon Conference)

Almost 25% reduction from 1995 to 2005 ?

Mishchenko et al., 2007, Science

The path to the „truth“ must be kept clean!

THANKS !

Annual average of total outgoing radiative fluxes to space for the 1984-1995 period (except for 2000-2003 for CERES) in W/m2. Data are displayed for three climatologies (ISC, CER, SRB), the IPCC-4AR model median and 20 IPCC-4AR models. The ISCCP here refers to the 4 year (2000-2003) CERES time-period.

Differences (1984 to 1995) of downward solar (left) and longwave (right) radiation at surface for cloudy (top) and clear skies (middle row) and of the cloud effect (bottom)

cloudy

clear

cloud effects

Documents

James Dewar presenting liquid hydrogen: Physics Today, March 2008