We analyzed macrophysical characteristics of clouds and their radiative effects using COSMO mesoscale model and four German CLOUDNET sites. The study was performed for selected days with optically thick cloudiness, which relates to the period from April to October 2018. The short-term forecasts with only 3-hour time interval permit to evaluate only cloud microphysics effect on global irradiance at ground. The comparisons of liquid cloud water content (QC) and ice cloud content (QI) between measurements and modelling are discussed. We showed that the CLOUDRAD experimental cloud radiation interaction scheme provides a better agreement in global irradiance with observations than that from the default scheme.
An effect of the implementation of the new aerosol-cloud-radiation interaction scheme in the COSMO model is described. The results of simulations with the new scheme are given for various values of the aerosol concentration. The aerosol effect on the forecast of cloud microphysical characteristics and radiative fluxes was determined. The study conducted for Meteorological Observatory of Moscow State University for a warm period (April – October) 2018. Values of integral cloud water/ice content obtained in experiments with fixed cloud nuclei concentration were noticeably smaller than in experiment with aerosol climatological data. Simulations shown the decreasing of global radiation with increasing cloud particle number that is connected with increasing of the concentration of cloud nuclei. We obtain better results against observations when cloud nuclei concentration is set according to Tegen aerosol climatology compare to fixed concentration.
The radiation effects of aerosol in clear sky under continental aerosol (Meteorological Observatory of MSU (Russia), Lindenberg Observatory (Germany)), over semi-desert areas (Israel) and Arctic district at the Tiksi International Hydrometeorological (Russia) observatory were estimated using the mesoscale COSMO-Ru model. The effect of aerosol on the surface air temperature is also was investigated. For the present study we use the aerosol dataset from CIMEL (AERONET) sun photometer measurements and the data of shortwave radiation components based on reliable instruments Kipp&Zonen. The application of the new MACv2 climatology radiation model provides the annual average relative error of the total global radiation which does not exceed 25 W/m2. We suggest that in clear sky conditions the sensitivity of air temperature at 2 meters to aerosol in all considered geographical areas lie within 0.9°C per 100 W/m2 change in shortwave net radiation changes.
We analyzed clouds macrophysics and their radiative effects according to COSMO mesoscale atmospheric model and measurements at Lindenberg Observatory (Germany). Different cloud parameters simulated by the model and derived from measurements of ground-based remote sounding systems as well as by measurements of the BSRN station have been compared for snow-free conditions during March-October, 2016. We show that simulated water vapor content (QV) values were higher than the observed ones in the middle and upper troposphere. Furthermore, the modeled cloud ice water content (QI) is significantly higher at these altitudes and the ice cloud water path (TQI) is ten times higher than the observed value. Typical values of TQI and of TQC (liquid cloud water path) lie within 3*10-13-1.1 kg/m2 and 0.0017-2.9 kg/m2 , respectively with average values of 0.015 and 0.079 kg/m2 correspondingly. We also found a positive bias with the measurements for the TQC greater than 0.1 kg/m2 and a negative bias for other values. A clear nonlinear dependence of solar irradiance at ground against TQC values was obtained both from measurements and model experiments. We showed a significant (29%) underestimation of model solar irradiance for the same TQC values in overcast cloud conditions compared with the observations.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.