Editorial Type:
Article
Article Type:
Research Article

The Earth’s Clear-Sky Radiation Budget and Water Vapor Absorption in the Far Infrared

Ashok Sinha Space and Atmospheric Physics Group, Blackett Laboratory, Imperial College of Science, Technologyand Medicine, London, United Kingdom

Search for other papers by Ashok Sinha in
Current site
Google Scholar
PubMed Close
and
John E. Harries Space and Atmospheric Physics Group, Blackett Laboratory, Imperial College of Science, Technologyand Medicine, London, United Kingdom

Search for other papers by John E. Harries in
Current site
Google Scholar
PubMed Close
Print Publication:
01 Jul 1997
DOI:
https://doi.org/10.1175/1520-0442(1997)010<1601:TESCSR>2.0.CO;2
Page(s):
1601–1614
Restricted access

Abstract

Detailed observational data are used to simulate the sensitivity of clear-sky outgoing longwave radiation (OLR) to water vapor perturbations in order to investigate the effect of uncertainties in water vapor measurements and spectroscopic parameters. Seasonal, geographical, and spectral variations in the clear-sky OLR, and of zonal mean clear-sky atmospheric cooling rate profiles are calculated for this purpose. Outside of deep convective regions, when only water vapor is varied, it is found that the 20–30-μm waveband of the far infrared (FIR) is the most substantial influence on the clear-sky OLR change. By contrast, the largest contribution to the clear-sky OLR variation in deep convective areas is from the continuum. Similarly, seasonal clear-sky infrared cooling rates are largely determined by contributions from the FIR and continuum, with a systematic variation in these contributions with latitude and altitude. The results presented reinforce the conclusions of recent studies that the lack of validation of FIR model line parameters under atmospheric conditions may have serious implications for the accuracy of simulations of clear-sky OLR variability. FIR parameterizations in climate models should be therefore validated by observational programs.

Corresponding author address: Dr. Ashok Sinha, Blackett Laboratory, Imperial College of Science, Technology and Medicine, London SW7 2BZ, United Kingdom.

Abstract

Detailed observational data are used to simulate the sensitivity of clear-sky outgoing longwave radiation (OLR) to water vapor perturbations in order to investigate the effect of uncertainties in water vapor measurements and spectroscopic parameters. Seasonal, geographical, and spectral variations in the clear-sky OLR, and of zonal mean clear-sky atmospheric cooling rate profiles are calculated for this purpose. Outside of deep convective regions, when only water vapor is varied, it is found that the 20–30-μm waveband of the far infrared (FIR) is the most substantial influence on the clear-sky OLR change. By contrast, the largest contribution to the clear-sky OLR variation in deep convective areas is from the continuum. Similarly, seasonal clear-sky infrared cooling rates are largely determined by contributions from the FIR and continuum, with a systematic variation in these contributions with latitude and altitude. The results presented reinforce the conclusions of recent studies that the lack of validation of FIR model line parameters under atmospheric conditions may have serious implications for the accuracy of simulations of clear-sky OLR variability. FIR parameterizations in climate models should be therefore validated by observational programs.

Corresponding author address: Dr. Ashok Sinha, Blackett Laboratory, Imperial College of Science, Technology and Medicine, London SW7 2BZ, United Kingdom.

Save
Cover Journal of Climate
Journal of Climate

  • Carli, B., and J. H. Park, 1988: Simultaneous measurements of minor stratospheric constituents with emission far infra-red spectroscopy. J. Geophys. Res.,93, 3851–3865.

  • Chahine, M. T., 1992: The hydrological cycle and its influence on climate. Nature,359, 373–379.

  • Chance, K. V., J. C. Brasunas, and W. A. Traub, 1980: Far infra-red measurements of stratospheric HCl. Geophys. Res. Lett.,9, 704–706.

  • Clough, S. A., F. X. Kneizys, and R. W. Davies, 1989: Line shape and the water vapor continuum. Atmos. Res.,23, 229–241.

  • ——, M. J. Iacono, and J.-L. Moncet, 1992: Line-by-line calculations of atmospheric fluxes and cooling rates: Application to water vapour. J. Geophys. Res.,97, 15 761–15 785.

  • Collins, W. D., and A. K. Inamdar, 1995: Validation of clear-sky fluxes for tropical oceans from the Earth Radiation Budget Experiment. J. Climate,8, 569–578.

  • Davies, G. R., 1993: The far infrared continuum absorption of water vapour. J. Quant. Spectrosc. Radiat. Transfer,50, 673–694.

  • Del Genio, D., W. Kovari, and M. S. Yao, 1994: Climatic implications of the seasonal variation of upper tropospheric water vapour. Geophys. Res. Lett.,21, 2701–2704.

  • Fortelius, C., 1995: Inferring the diabatic heat and moisture forcing of the atmosphere from assimilated data. J. Climate,8, 224–239.

  • Frey, R. A., S. A. Ackerman, and B. J. Soden, 1996: Climate parameters from satellite spectral measurements. Part I: Collocated AVHRR and HIRS/2 observations of spectral greenhouse parameter. J. Climate,9, 327–344.

  • Gaffen, D. J., and W. P. Elliot, 1993: Column water-vapor content in clear and cloudy skies. J. Climate, 6, 2278–2287.

  • Harries, J. E., 1977: Submillimeter wave spectroscopy of the atmosphere. J. Opt. Soc. Amer.,67, 880–893.

  • Harrison, E. F. D., P. Minnis, B. R. Barkstrom, V. Ramanathan, R. D. Cess, and G. G. Gibson, 1990: Seasonal variation of cloud radiative forcing derived from the Earth Radiation Budget Experiment. J. Geophys. Res.,95, 18 687–18 703.

  • Houghton, J. T., L. G. Meira Filho, J. Bruce, H. Lee, B. A. Callander, E. Haites, N. Harris, and K. Maskell, Eds., 1994: Climate Change 1994. Radiative Forcing of Climate Change and an Evaluation of the IPCC IS92 Emission Scenarios. Cambridge University Press, 339 pp.

  • Inamdar, A. K., and V. Ramanathan, 1994: Physics of greenhouse effect and convection in warm oceans. J. Climate,7, 715–731.

  • Kiehl, J. T., and B. P. Briegleb, 1992: Comparisons of the observed and calculated clear-sky greenhouse effect—Implications for climate studies. J. Geophys. Res.,97, 10 037–10 049.

  • Levitus, S., 1984: Annual cycle of temperature and heat storage in the world ocean. J. Phys. Oceanogr.,14, 727–746.

  • Murty, D. G. K., W. L. Smith, H. M. Wolf, and C. M. Hayden, 1993: Comparison of radiances observed from satellite and aircraft by using 2 atmospheric transmittance models. Appl. Opt.,9, 1620–1628.

  • NASA, 1992: World climate research programme. [Available from Distributed Archive Center, Goddard Space Flight Center, Greenbelt, MD 20771.].

  • Oort, A. H., 1983: Global atmospheric circulation statistics, 1958–1973. NOAA Professional Paper 14, U.S. Government Printing Office, 180 pp + 47 microfiches.

  • Peixoto, J. P., and A. H. Oort, 1992: Physics of Climate. American Institute of Physics, 520 pp.

  • Raval, A., and V. Ramanathan, 1989: Observational determination of the greenhouse effect. Nature,342, 758–761.

  • ——, A. H. Oort, and V. Ramaswamy, 1994: Observed dependence of outgoing longwave radiation on surface temperature and moisture. J. Climate,7, 807–821.

  • Rossow, W. B., and R. A. Schiffer, 1991: ISCCP cloud data products. Bull. Amer. Meteor. Soc.,72, 2–20.

  • ——, and L. C. Garder, 1993: Validation of ISCCP cloud detections. J. Climate,6, 2370–2393.

  • Salathe, E. P., and D. Chesters, 1995: Variability of moisture in the upper troposphere as inferred from TOVS. J. Climate,8, 120–132.

  • Shine, K. P., 1991: On the causes of the relative greenhouse strengths of gases such as halocarbons. J. Atmos. Sci.,48, 1513–1518.

  • Sinha, A., 1995: The relative influence of lapse rate and water vapour on the greenhouse effect. J. Geophys. Res.,100, 5095–5103.

  • ——, and M. R. Allen, 1994: Climate sensitivity and tropical moisture distribution. J. Geophys. Res.,99, 3707–3716.

  • ——, and J. E. Harries, 1995: Water vapour and greenhouse trapping: The role of far infra-red absorption. Geophys. Res. Lett.,22, 2147–2150.

  • ——, and K. P. Shine, 1995: Modelled sensitivity of the earth’s radiation budget to changes in cloud properties. Quart. J. Roy. Meteor. Soc.,121, 797–819.

  • Stephens, G. L., and T. J. Greenwald, 1991: The earth’s radiation budget and its relation to atmospheric hydrology: I. Observations of the clear-sky greenhouse effect. J. Geophys. Res.,96, 15 311–15 324.

  • ——, D. L. Jackson, and I. Wittmeyer, 1996: Global observations of upper tropospheric water vapor derived from TOVS radiance data. J. Climate,9, 305–326.

  • Sun, D.-Z., and R. S. Lindzen, 1993: Water vapour feedback and the ice age snowline record. Ann. Geophys.,11, 204–215.

  • ——, and ——, 1993: Distribution of tropical tropospheric water vapor. J. Atmos. Sci.,50, 1643–1660.

  • Susskind, J., 1993: Water vapour and temperature. Atlas of Satellite Observations Related to Global Change, R. J. Gurney, J. L. Foster, and C. L. Parkinson, Eds., Cambridge University Press, 89–128.

  • Traub, W. A., K. V. Chance, D. G. Johnson, and K. W. Jucks, 1991: Stratospheric spectroscopy with the far-infrared spectrometer (FIRS-2): Overview of recent results. J. Soc. Photo-Opt. Instrum. Eng.,1491, 298–307.

  • Weaver, C. P., W. D. Collins, and H. Grassl, 1994: Relationship between clear-sky atmospheric greenhouse effect and deep convection during the Central Equatorial Pacific Experiment: Model calculations and satellite observations. J. Geophys. Res.,99, 25 891–25 901.

  • Webb, M. J. A., A. Slingo, and G. L. Stephens, 1993: Seasonal variation of the clear-sky greenhouse effect: The role of changes in atmospheric temperatures and humidities. Climate Dyn.,9, 117–129.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 352 88 4
PDF Downloads 151 53 2