Atmosphere and Ocean Research Institute, University of Tokyo
Department of Atmospheric Science, Colorado States University
National Center for Atmospheric Research
Research and Information Center, Tokai University
Center for Environmental Remote Sensing, Chiba University
抄録
Comparisons of microphysical properties of low clouds (e.g. marine stratocumulus (Sc)) simulated by a spectral bin microphysics (SBM) model with those obtained from observations are conducted off the coast of California at DYCOMS-II (Second Dynamics and Chemistry of Marine Stratocumulus) period. We use various types of data (i.e. not only observation data from aircraft but also data retrieved from satellite) for the comparison. Three-dimensional one way nesting simulation with SBM model is conducted. Comprehensive Analysis Program for Cloud Optical Measurements (CAPCOM) retrieval algorithm is used to derive cloud microphysical and optical properties from GOES (Geostationary Operational Environment Satellite) satellite. Aircraft data obtained by C-130 aircraft during the period is also used. The comparisons show that the cloud optical thickness simulated by the SBM model is much smaller than that retrieved from satellite. The model also underestimates cloud droplet number concentration and liquid water content compared to aircraft observations. More detailed analysis shows that relative humidity (i.e. super saturations) are smaller in the model than those observed because of weaker updraft velocity in the model, which causes smaller number concentration through less active nucleation process. Sensitivity experiments of changing grid resolution show that lower resolution (dx=300m) causes the weaker updraft velocity, thus suggesting the necessity of higher resolution to reproduce the microphysical and optical properties of marine Sc.
内容記述
The XXV IUGG General Assembly : Earth on the Edge: Science for a Sustainable Planet, 28 June - 7 July 2011, Melbourne Convention & Exhibition Centre, Melbourne, Australia
Validation of JMANHM+HUCM through comparisons with satellite and aircraft observation in DYCOMS-II period
Sato_IUGG_2011.pdf
(3.88MB)
