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2004 | 46 | 2 |
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Uncertainty in stratiform cloud optical thickness inferred from pyranometer measurements at the sea surface

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The relative ‘plane-parallel’ error in a mean cloud optical thickness retrieved from ground-based pyranometer measurements is estimated. The plane-parallel error is defined as the bias introduced by the assumption in the radiative transfer model used in cloud optical thickness retrievals that the atmosphere, including clouds, is horizontally homogeneous on the scale of an individual retrieval. The error is estimated for the optical thickness averaged over the whole domain, which simulates the mean cloud optical thickness obtained from a time series of irradiance measurements. The study is based on 3D Monte Carlo radiative transfer simulations for non-absorbing, all-liquid, layer clouds. Liquid water path distributions in the clouds are simulated by a bounded cascade fractal model. The sensitivity of the error is studied with respect to the following factors: averaging time of irradiance used in an individual retrieval, mean cloud optical thickness, cloud variability, cloud base height and solar zenith angle. In the simulations presented in this paper, the relative bias in the domain averaged cloud optical thickness retrieved from pyranometer measurements varies from +1% for optically thin clouds to nearly –20%. The highest absolute value of the relative bias is expected for thick and variable clouds with high bases (e.g. 1 km) and retrievals based on long-term mean irradiances (averaging time of the order of several tens of minutes or hours). The bias can be diminished by using short-term irradiance averages, e.g. of one minute, and by limiting retrievals to low-level clouds.
Opis fizyczny
  • Polish Academy of Sciences, Powstancow Warszawy 55, 81-712 Sopot, Poland
  • Barker H.W., Curtis T. J., Leontieva E., Stamnes K., 1998, Optical depth of overcast cloud across Canada: estimates based on surface pyranometer and satellite measurements, J. Clim., 11, 2980–2993.
  • Barker H.W., Marshak A., 2001, Inferring optical depth of broken clouds above green vegetation using surface solar radiometric measurements, J. Atmos. Sci., 58 (20), 2989–3006.
  • Boers R., van Lammeren A., Feijt A., 2000, Accuracy of cloud optical depth retrievals from ground-based pyranometers, J. Atmos. Ocean. Technol., 17 (7), 916–927.
  • Cahalan R. F., 1994, Bounded cascade clouds: albedo and effective thickness, Nonlinear Proc. Geophys., 1, 156–167.
  • Cahalan R. F., Ridgway W., Wiscombe W. J., Bell T. L., Snider J.B., 1994a, The albedo of fractal stratocumulus clouds, J. Atmos. Sci., 51 (16), 2434–2455.
  • Cahalan R. F., Ridgway W., Wiscombe W. J., Gollmer S., Harshvardhan, 1994b, Independent pixel and Monte Carlo estimates of stratocumulus albedo, J. Atmos. Sci., 51 (24), 3776–3790.
  • Cahalan R. F., Silberstein D., Snider J.B., 1995, Liquid water path and planeparallel albedo bias during ASTEX, J. Atmos. Sci., 52 (16), 3002–3012.
  • Cahalan R. F., Snider J.B., 1989, Marine stratocumulus structure, Remote Sens. Environ., 28, 95–107.
  • Davis A.B., Cahalan R. F., Spinhirne J.D., McGill M. J., Love S.P., 1999, Offbeam lidar: an emerging technique in cloud remote sensing based on radiative Green-function theory in the diffusion domain, Phys. Chem. Earth B, 24, 757–765.
  • Davis A., Marshak A., Cahalan R., Wiscombe W., 1997, The Landsat scale-break in stratocumulus as a three-dimensional radiative transfer effect, implications for cloud remote sensing, J. Atmos. Sci., 54 (2), 241–260.
  • Davis A., Marshak A., Wiscombe W. J., Cahalan R. F., 1996, Scale invariance of liquid water distributions in marine stratocumulus. Part I. Spectral properties and stationarity issues, J. Atmos. Sci., 53 (11), 1538–1558.
  • Ershov O.A., Lamden K. S., Levin I.M., Salganik I.N., Shifrin K. S., 1988, Determination of the cloud optical depth over sea by measurements of cloud brightness, Izv. Akad. Nauk SSSR, Ser. Fiz. Atmos. Okeana, 24 (5), 539–544, (in Russian).
  • Feigelson E.M. (ed.), 1981, Radiation in a cloudy atmosphere, Gidrometeoizdat, Leningrad, 280 pp., (in Russian).
  • Feijt A. J., 2000, Quantitative cloud analysis using meteorological satellites, Ph.D. thesis, Wageningen Univ., Wageningen, 186 pp.
  • Francis J.A., Ackerman T.P., Katsaros K. B., Lind R. J., Davidson K. L., 1991, A comparison of radiation budgets in the Fram Strait summer marginal ice zone, J. Clim., 4, 218–235.
  • Gage K. S., Nastrom G.D., 1986, Theoretical interpretation of atmospheric wave number spectra of wind and temperature observed by commercial aircraft during GASP, J. Atmos. Sci., 43 (7), 729–740.
  • Hayasaka T., Kuji M., Tanaka M., 1994, Air truth validation of cloud albedo estimated from NOAA advanced very high resolution radiometer data, J. Geophys. Res., 99, 18685–18693.
  • Kraichnan R.H., 1967, Inertial ranges in two-dimensional turbulence, Phys. Fluids, 10 (7), 1417–1423.
  • Kuji M., Hayasaka T., Kikuchi N., Nakajima T., Tanaka M., 2000, The retrieval of effective particle radius and liquid water path of low-level marine clouds from NOAA AVHRR data, J. Appl. Meteorol., 39, 999–1016.
  • Leontieva E., Stamnes K., Olseth J.A., 1994, Cloud optical properties at Bergen (Norway) based on the analysis of long-term solar irradiance records, Theor. Appl. Climatol., 50 (1)–(2), 73–82.
  • Leontyeva E., Stamnes K., 1994, Estimation of cloud optical thickness from groundbased measurements of incoming solar radiation in the Arctic, J. Clim., 7 (4), 566–578.
  • Lubin D., Simpson A. S., 1997, Measurement of surface radiation fluxes and cloud optical properties during the 1994 arctic ocean section, J. Geophys. Res., 102 (D4), 4275–4286.
  • Marchuk G., Mikhailov G., Nazaraliev M., Darbinjan R., Kargin B., Elepov B., 1980, The Monte Carlo methods in atmospheric optics, Springer-Verl., NewY ork, 208 pp.
  • Marshak A., Davis A., Cahalan R., Wiscombe W., 1994, Bounded cascade models as nonstationary multifractals, Phys. Rev. E, 49, 55–69.
  • Marshak A., Davis A., Wiscombe W., Titov G., 1995, The verisimilitude of the independent pixel approximation used in cloud remote sensing, Remote Sens. Environ., 52 (1), 71–78.
  • Marshak A., Knyazikhin Y., Davis A. B., Wiscombe W. J., Pilewskie P., 2000, Cloud-vegetation interaction: use of normalized difference cloud index for estimation of cloud optical thickness, Geophys. Res. Lett., 27 (12), 1695–1698.
  • Minnis P., Heck P.W., Young D. F., Fairall C.W., Snider J.B., 1992, Stratocumulus cloud properties derived from simultaneous satellite and island-based instrumentation during FIRE, J. Appl. Meteorol., 31 (4), 317–339.
  • Nakajima T.Y., King M.D., 1990, Determination of the optical thickness and effective particle radius of clouds from reflected solar radiation measurements. I. Theory, J. Atmos. Sci., 47 (15), 1878–1893.
  • Payne R.E., 1972, Albedo of the sea surface, J. Atmos. Sci., 29 (5), 959–970.
  • Pinto J.O., Curry J.A., Fairall C.W., 1997, Radiative characteristics of the Arctic atmosphere during spring as inferred from ground-based measurements, J. Geophys. Res., 102 (D6), 6941–6952.
  • Platnick S., Li J.Y., King M.D., Gerber H., Hobbs P.V., 2001, A solar reflectance method for retrieving the optical thickness and droplet size of liquid water clouds over snow and ice surfaces, J. Geophys. Res., 106 (D14), 15185–15200.
  • Raschke R.A., Cox S.K., 1983, Instrumentation and technique for deducing cloud optical thickness, J. Clim. Appl. Meteorol., 22, 1887–1893.
  • Rozwadowska A., Optical thickness of stratiform clouds over the Baltic inferred from on-board irradiance measurements, Atmos. Res., (in press).
  • Rozwadowska A., Cahalan R. F., 2002, Plane-parallel biases computed from inhomogeneous Arctic clouds and sea ice, J. Geophys. Res., 107 (D19), 4384, doi:10.1029/2002JD002092.
  • Stamnes K., Tsay S.-C., Laszlo I., WiscombeW., 2000, DISORT, a general-purpose Fortran program for discrete-ordinate method radiative transfer in scattering and emitting layered media: documentation and methodology, version 1.1., NASA/GSFC, Greenbelt.
  • Stamnes K., Tsay S.-C., Wiscombe W., Jayaweera K., 1988, Numerically stable algorithm for discrete-ordinate-method radiative transfer in multiple scattering and emitting layered media, Appl. Opt., 27, 2502–2509.
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