Open AccessCollocated measurements of boundary layer cloud microphysical and radiative properties: A feasibility study
Author(s) -
Henrich F.,
Siebert H.,
Jäkel E.,
Shaw R. A.,
Wendisch M.
Publication year - 2010
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2010jd013930
Subject(s) - radiative transfer , effective radius , remote sensing , spectroradiometer , environmental science , cloud computing , atmospheric radiative transfer codes , albedo (alchemy) , moderate resolution imaging spectroradiometer , cloud top , boundary layer , cloud albedo , meteorology , planetary boundary layer , atmospheric sciences , physics , turbulence , optics , reflectivity , geology , cloud cover , computer science , art , galaxy , operating system , satellite , quantum mechanics , thermodynamics , art history , astronomy , performance art
First data from collocated, helicopter‐based measurements of boundary layer cloud microphysical properties (effective droplet radius R eff , droplet number concentration N ) and spectral radiative quantities (cloud optical thickness τ , cloud top albedo ρ , reflectivity ) are presented. The in situ measurements of the microphysical cloud properties were collected by the Airborne Cloud Turbulence Observation System (ACTOS) attached to a helicopter by a 145 m long rope. Cloud spectral reflectivity was derived from radiances measured by grating spectrometers combined with downward looking optical inlets installed underneath the helicopter. Correlations between cloud microphysics and reflected radiation are presented for two cloud cases with different optical and geometrical thicknesses. On the basis of common retrieval techniques, τ and R eff are derived using a radiative transfer model. The results of the retrieval are compared to the collocated in situ measurements and data from the Moderate‐Resolution Imaging Spectroradiometer (MODIS). Within the limitations of the relatively small data set, the feasibility of closely collocated microphysics and radiation data and their benefits were demonstrated.