Page images

Roy W. Spencer

NASA/Marshall Space Flight Center
Global Hydrology and Climate Center
Huntsville, Alabama 35806

(205) 922-5960 (voice)

(205) 922-5788 (fax) (e-mail)


Satellite information retrieval techniques, passive microwave remote sensing, satellite precipitation retrieval, global temperature monitoring, space sensor definition, satellite meteorology.

[blocks in formation]

4/87 - present: Space Scientist

NASA/Marshall Space Flight Center

10/84-4/87: Visiting Scientist

USRA NASA/Marshall Space Flight Center

7/83 - 10/84: Assistant Scientist

Space Science and Engineering Center, Madison, Wisconsin

12/81-7/83: Research Associate

Space Science and Engineering Center, Madison, Wisconsin


U.S. Science Team Leader, Advanced Microwave Scanning Radiometer, 1996-present Principal Investigator, a Conically-Scanning Two-look Airborne Radiometer for ocean wind vector retrieval, 1995-present.



U.S. Science Team Leader, Multichannel Microwave Imaging Radiometer Team, 1992

Member, TOVS Pathfinder Working Group, 1991-1994.

Member, NASA HQ Earth Science and Applications Advisory Subcommittee, 1990-1992.
Expert Witness, U.S. Senate Committee on Commerce, Science, and Transportation,

Principal Investigator, High Resolution Microwave Spectrometer Sounder for the Polar

Principal Investigator, an Advanced Microwave Precipitation Radiometer for rainfall monitoring. 1987-present.

Principal Investigator, Global Precipitation Studies with the Nimbus-7 SMMR and DMSP SSM/L, 1984-present.

Principal Investigator, Space Shuttle Microwave Precipitation Radiometer, 1985. Member, Japanese Marine Observation Satellite (MOS-1) Validation Team, 1978-1990. Chairman, Hydrology Subgroup, Earth System Science Geostationary Platform Committee, 1978-1990.

Executive Committee Member, WetNet - An Earth Science and Applications and Data System Prototype, 1987-1992.

Member, Science Steering Group for the Tropical Rain Measuring Mission (TRMM),


Member, TRMM Space Station Accommodations Analysis Study Team, 1987-1991. Member, Earth System Science Committee (ESSC) Subcommittee on Precipitation and Winds, 1986.

Technical Advisor, World Meteorological Organization Global Precipitation Climatology Project, 1986-1992.


Spencer, R. W., and W.D. Braswell, 1997: How dry is the tropical free troposphere? Implications for global warming theory. Bull. Amer. Meteor. Soc., 78.

Spencer, R.W., J.R. Christy, and N.C. Grody, 1996: Analysis of "Examination of 'Global atmospheric temperature monitoring with satellite microwave measurements". Climatic Change, 33, 477-489.

Spencer, R.W., W. M. Lapenta, and F. R. Robertson, 1995: Vorticity and vertical motions diagnosed from satellite deep layer temperatures. Mon. Wea. Rev., 123, 1800-1810.

Spencer, R.W., R.E. Hood, F.J. LaFontaine, E.A. Smith, R. Platt, J. Galliano, V.L. Griffin, and E. Lobl, 1994: High-resolution imaging of rain systems with the Advanced Microwave Precipitation Radiometer. J. Atmos. Oceanic Tech., 11, 849-857.

Spencer, R. W., 1994: Oceanic rainfall monitoring with the microwave sounding units. Rem. Sens. Rev., 11, 153-162.

Spencer, R.W., 1994: Global temperature monitoring from space. Adv. Space Res., 14, (1)69(1)75.

Spencer, R.W., 1993: Monitoring of global tropospheric and stratospheric temperature trends. Atlas of Satellite Observations Related to Global Change, Cambridge University Press.

Spencer, R.W., 1993: Global oceanic precipitation from the MSU during 1979-92 and comparisons to other climatologies. J. Climate, 6, 1301-1326.

Spencer, R.W., and J.R. Christy, 1993: Precision lower stratospheric temperature monitoring with the MSU: Technique, validation, and results 1979-91. J. Climate, 6, 1301-1326.

Spencer, R.W., and J.R. Christy, 1992a: Precision and radiosonde validation of satellite gridpoint temperature anomalies, Part I: MSU channel 2. J. Climate, 5, 847-857.

Spencer, R.W., and J.R. Christy, 1992b: Precision and radiosonde validation of satellite gridpoint temperature anomalies, Part II: A tropospheric retrieval and trends during 1979-90. J. Climate, 5, 858-866.

Spencer, R.W., J.R. Christy, and N.C. Grody, 1990: Global atmospheric temperature monitoring with satellite microwave measurements: Method and results, 1979-84. J. Climate, 3, 1111-1128.

Spencer, R.W., and J.R. Christy, 1990: Precise monitoring of global temperature trends from satellites. Science, 247, 1558-1562.

Spencer, R.W., H.M. Goodman, and R.E. Hood, 1989: Precipitation retrieval over land and ocean with the SSM/I: identification and characteristics of the scattering signal. J. Atmos. Oceanic Tech., 6, 254-273.

Spencer, R.W., M.R. Howland, and D.A. Santek, 1986: Severe storm detection with satellite microwave radiometry: An initial analysis with Nimbus-7 SMMR data. J. Climate Appl. Meteor., 26, 749-754.

Spencer, R.W., 1986: A Satellite passive 37 GHz scattering based method for measuring oceanic rain rates. J. Climate Appl. Meteor., 25, 754-766.

Spencer, R.W., and D.A. Santek, 1985: Measuring the global distribution of intense convection over land with passive microwave radiometry. J. Climate Appl. Meteor., 24, 860-864.

Spencer, R.W., 1984: Satellite passive microwave rain rate measurement over croplands during spring, summer, and fall. J. Climate Appl. Meteor., 23, 1553-1562.

Spencer, R.W., B.B. Hinton, and W.S. Olson, 1983: Nimbus-7 37 GHz radiances correlated with radar rain rates over the Gulf of Mexico. J. Climate Appl. Meteor., 22, 2095-2099.

Spencer, R.W., D.W. Martin, B.B. Hinton, and J.A. Weinman, 1983: Satellite microwave radiances correlated with radar rain rates over land. Nature, 304, 141-143.

Spencer, R.W., W.S. Olson, W. Rongzhang, D.W. Martin, J.A. Weinman, and D.A. Santek, 1983: Heavy thunderstorms observed over land by the Nimbus-7 Scanning Multichannel Microwave Radiometer. J. Climate Appl. Meteor., 22, 1041-1046.

Christy, John R., R.W. Spencer, and W.D. Braswell, 1997: How accurate are satellite thermometers? Nature, 25 September.

McGaughey, G., E.J. Zipser, R.W. Spencer, and R.E. Hood, 1996: High-resolution passive microwave observations of convective systems over the tropical Pacific Ocean. J. Appl. Meteor., 35, 1921-1962.

Christy, J.R., R.W. Spencer, and R.T. McNider, 1995: Reducing noise in the MSU daily lowertropospheric temperature dataset. J. Climate, 8, 888-896.



1996: AMS Special Award "for developing a global, precise record of earth's temperature

operational polar-orbiting satellites, fundamentally advancing our ability to monitor climate."

1991: NASA Exceptional Scientific Achievement Medal

1990: Alabama House of Representatives Resolution #624
1989: MSFC Center Director's Commendation

Chairman CALVERT. Thank you, Doctor. Dr. Robock?


Mr. ROBOCK. Thank you. I agree with the IPCC report that says that, "The balance of evidence suggests there is a discernible human influence on climate," and as Mr. Roemer pointed out, this is the balance of evidence, it's not unambiguous proof; there are still a lot of things that we don't know for which we need more research, including, as they say in the IPCC report, "Our knowledge is currently limited because the expected signal is still emerging from the noise of natural variability and because there are uncertainties in key factors. These include the magnitude and patterns of long term variability." And I agree with this too.

However, I would just like to show a little bit of the evidence that supports the idea that there is a human impact on climate. The way we do these calculations are with these general circulation models, the global climate models that Dr. Spencer mentioned. They include they can take into account all the different things that cause climate to change, not just greenhouse gases, but everything else.

Recent calculations by NOAA's Geophysical Fluid Dynamics Laboratory at Princeton University have used the latest model which includes the atmosphere and the ocean to test these different theories. Figure 1, here, shows a calculation done where the black line is the observations of global average surface temperature taken from the middle of the last century till now, and the red line is the result of a climate model calculation if you just put in changing CO2 up to the present. And you see this model shows that the climate predicts that the climate-should be warmer than it is now, just taking into account the effects of CO2.

And this is an example of some of the earlier calculations that have been criticized because they show too much warming, and this argument has been used to show that there's something wrong with the models. But what was wrong with this calculation is that they only included one of the causes of climate change, that is CO2. It didn't include the other causes of climate change.

Then, they repeated this calculation putting in CO2 and aerosols. Aerosols are dust particles, pollutant particles in the troposphere that block out some of the sunlight, reflecting it back to space and cooling the surface. So this calculation, which includes the warming effect of CO2 and the cooling effect of aerosols, does an excellent job of reproducing the past climate.

After World War II, when there was rapid industrialization in the world, there was a tremendous output of CO2 and aerosols, and the CO2 effect takes a long time to be felt because it's a small change in the amount of CO2 in the atmosphere; but the aerosol effect was felt quite rapidly. And, therefore, this delayed the warming after World War II. So you can see that the claim that all the warming was at the beginning of the century is actually well reproduced by this model because the aerosols after World War II delayed the warming. They blocked out some of the sunlight counteracting the effect of the CO2. But today, the CO2 effect is much

« PreviousContinue »