LOGIN TO YOUR ACCOUNT

Username
Password
Remember Me
Or use your Academic/Social account:

CREATE AN ACCOUNT

Or use your Academic/Social account:

Congratulations!

You have just completed your registration at OpenAire.

Before you can login to the site, you will need to activate your account. An e-mail will be sent to you with the proper instructions.

Important!

Please note that this site is currently undergoing Beta testing.
Any new content you create is not guaranteed to be present to the final version of the site upon release.

Thank you for your patience,
OpenAire Dev Team.

Close This Message

CREATE AN ACCOUNT

Name:
Username:
Password:
Verify Password:
E-mail:
Verify E-mail:
*All Fields Are Required.
Please Verify You Are Human:
fbtwitterlinkedinvimeoflicker grey 14rssslideshare1
Conant, William C.; Vogelmann, Andrew M.; Ramanathan, V. (2011)
Publisher: Co-Action Publishing
Journal: Tellus A
Languages: English
Types: Article
Subjects:
This paper is motivated by several recent studies that have shown that observations of atmosphericsolar absorption systematically and significantly exceed model estimates. This papertests whether uncertainties in the physics of water vapor absorption in clear skies are directlyresponsible for this unexplained excess absorption. Radiative transfer calculations of clear-skysolar fluxes are compared to measurements in the tropical Pacific at the surface and the tropopause.We find that the atmospheric absorption in excess of that predicted by radiative transfermodels, if it exists, is less than the experimental uncertainty of 7 W m<sup>−2</sup> (diurnally averaged).Furthermore, the difference between observed and modeled absorption is essentially independentof water vapor amounts between 35 and 51 kg m<sup>−2</sup>. A more direct test of the accuracy ofmodeled water vapor absorption is conducted with two independent multi-spectral radiometersat the Atmospheric Radiation Measurement site in Oklahoma, each providing over 16 000surface measurements of direct solar radiation in the 0.94 mm region. These spectral data confirmstate-of-the-art radiation model computations of water vapor line absorption to within 5% forthe wavelength region tested. The model-observation agreement for both tropical andOklahoma data strongly suggests that uncertainties in the physics of water vapor absorptionin clear skies are not a source for any significant excess solar absorption, thus narrowing thesearch to other atmospheric constituents or water vapor in cloudy skies.DOI: 10.1034/j.1600-0870.1998.t01-1-00010.x
  • The results below are discovered through our pilot algorithms. Let us know how we are doing!

    • Arking, A. 1996. Absorption of solar energy in the atmosphere. Discrepancy between model and observations. Science 273, 779-782.
    • Blanchet, J.-P. and List, R. 1983. Estimation of optical properties of arctic haze using a numerical model. Atmosphere-Ocean 21, 444-465.
    • Cess, R. D., Zhang, M. H., Minnis, P., Corsetti, L., Dutton, E. G., Forgan, B. W., Garber, D. P., Gates, W. L., Morcrette, J.-J., Potter, G. L., Ramanathan, V., Subasilar, B., Whitlock, C. H., Young, D. F. and Zhou, Y. 1995. Absorption of solar radiation by clouds: Observations Versus Models. Science 267, 496-499.
    • Charlock, T. P. and Alberta, T. L. 1996. The CERES/ ARM/GEWEX Experiment (CAGEX) for the retrieval of radiative fluxes with satellite data. Bull. Am. Met. Soc. 77, 2673-2683.
    • Chou, M.-D. and Zhao, W. 1997. Estimation and model validation of surface solar radiation and cloud radiative forcing using TOGA COARE measurements. J. Clim. 10, 610-620.
    • Conant, W. C. 1996. An examination of the solar absorption under clear skies for the central equatorial Pacific. Observations versus models. MS thesis, University of California, 50 pp.
    • Conant, W. C., Ramanathan, V., Valero, F. P. J. and Meywerk, J. 1997. An examination of the clear-sky solar absorption over the central equatorial pacific: observations versus models. J. Climate 10, 1874-1884.
    • Harrison, L. C. and Michalsky, J. J. 1994. Objective algorithms for the retrieval of optical depths from ground-based measurements. Appl. Optics 33, 5126-5132.
    • Harrison, L. C., Michalsky, J. J. and Berndt, J. 1994. Automated multifilter rotating shadow-band radiometer. An instrument for optical depth and radiation measurements. Appl. Optics 33, 5118-5125.
    • Kiehl, J. T. and Trenberth, K. E. 1997. Earth's annual global mean energy budget. Bull. Am. Meteorol. Soc. 78, 197-208.
    • Lacis, A. A. and Oinas, V. 1991. A description of the correlated-k distribution method for modeling nongray gaseous absorption, thermal emission, and multiple scattering in vertically inhomogeneous atmospheres. J. Geophys. Res. 96, 9027-9063.
    • Li, Z., Leighton, H. G., Masuda, K. and Takashima, T. 1993. Estimation of SW flux absorbed at the surface from TOA reflected flux. J. Clim. 6, 317-330.
    • Liljegren, J. C. 1994. Two-channel microwave radiometer for observations of total column precipitable water vapor and cloud liquid water path. 5th Symposium on Global Change Studies, 262-269.
    • Liou, K. N. 1992. Radiation and cloud processes in the atmosphere, Oxford Press.
    • Michalsky, J. J., Liljegren, J. C. and Harrison, L. C. 1995. A comparison of Sun photometer derivations of total column waver vapor and ozone to standard measures of same at the Southern Great Plains atmospheric radiation measurement site. J. Geophys. Res. 100, 25,995-26,003.
    • Ohmura, A. and Gilgen, H. 1993. Re-evaluation of the global energy balance. Geophys. Monogr. no. 75, IUGG, 93-110.
    • Pilewskie, P. and Valero, F. P. J. 1995. Direct observations of excess solar absorption by clouds. Science 267, 1626-1628.
    • Ramanathan, V., Subasilar, B., Zhang, G. J., Conant, W. C., Cess, R. D., Kiehl, J. T., Grassl, H. and Shi, L. 1995. Warm pool heat budget and shortwave cloud forcing: A missing physics? Science 267, 499-503.
    • Rothman, L. S., Gamache, R. R., Tipping, R. H., Rinsland, C. P., Smith, M. A. H., Benner, D. C., Devi, V. M., Flaud, J.-M., Camy-Peyret, C., Perrin, A., Goldman, A., Massie, S. T., Brown, L. R. and Toth, R. A. 1992. The HITRAN molecular database: Editions of 1991 and 1992. J. Quant. Spectrosc. Rad. T rans. 48, 469-507.
    • Stephens, G. L. 1996. How much solar radiation do clouds absorb? Science 271, 1131-1134.
    • Teillet, P. M. 1990. Rayleigh optical depth comparisons from various sources. Appl. Optics 29, 1897-1900.
    • Valero, F. P. J., Schwartz, S. E., Cess, R. D., Ramanathan, V., Minnis, P., Ackerman, T. P. and Tooman, T. P. 1995. ARESE (ARM Enhanced Shortwave Experiment) Science Plan. Available from the United States Department of Energy, 53 pp.
    • Vogelmann, A. M., Ramanathan, V., Conant, W. C. and Hunter, W. E. 1997. Observational constraints on the non-lorentzian continuum eVects in the near-infrared solar spectrum using ARM ARESE data. J. Quant. Spectrosc. Rad. T rans., in press.
    • Waliser, D. E., Collins, W. D. and Anderson, S. P. 1996. An estimate of the surface shortwave cloud forcing over the western Pacific during TOGA COARE. Geophys. Res. L ett. 23, 519-522.
    • Wild, M., Ohmura, A., Gilgen, H. and Roeckner, E. 1995. Validation of general circulation model radiative fluxes using surface observations. J. Clim. 8, 1309-1324.
  • No related research data.
  • No similar publications.

Share - Bookmark

Cite this article

Collected from