@Article{KrisnaWEJWWBMPAVM:2017:CoAiSa,
author = "Krisna, Trismono C. and Wendisch, Manfred and Ehrlich, Andr{\'e}
and J{\"a}kel, Evelyn and Werner, Frank and Weigel, Ralf and
Borrmann, Stephan and Mahnke, Christoph and P{\"o}schl, Ulrich
and Andreae, Meinrat O. and Voigt, Christiane and Machado, Luiz
Augusto Toledo",
affiliation = "{Universit{\"a}t Leipzig} and {Universit{\"a}t Leipzig} and
{Universit{\"a}t Leipzig} and {Universit{\"a}t Leipzig} and
{Universit{\"a}t Leipzig} and {Johannes
Gutenberg-Universit{\"a}t Mainz} and {Johannes
Gutenberg-Universit{\"a}t Mainz} and {Johannes
Gutenberg-Universit{\"a}t Mainz} and {Max Planck Institute for
Chemistry (MPIC)} and {Max Planck Institute for Chemistry (MPIC)}
and {Deutsches Zentrum f{\"u}r Luft und Raumfahrt (DLR)} and
{Instituto Nacional de Pesquisas Espaciais (INPE)}",
title = "Comparing airborne and satellite retrievals of optical and
microphysical properties of cirrus and deep convective clouds
using a radiance ratio technique",
journal = "Atmospheric Chemistry and Physics Discussion",
year = "2017",
volume = "758",
abstract = "t. Solar radiation reflected by cirrus and deep convective clouds
(DCCs) was measured by the Spectral Modular Airborne Radiation
Measurement System (SMART) installed on the German HALO (High
Altitude and Long Range Research Aircraft) during the ML-CIRRUS
and the ACRIDICON-CHUVA campaigns. In particular flights, HALO
performed closely collocated measurements with overpasses of the
Moderate Resolution Imaging Spectroradiometer (MODIS) on board of
Aqua 5 satellite. Based on the nadir upward radiance, the optical
thickness \τ and bulk particle effective radius reff of
cirrus and DCC are retrieved using a radiance ratio algorithm
which considers the cloud thermodynamic phase, the cloud vertical
profile, multi layer clouds, and heterogeneity of the surface
albedo. For the cirrus case, the comparison of \τci and
reff,ci retrieved on the basis of SMART and MODIS upward radiances
yields a normalized mean absolute deviation of 0.5% for \τci
and 2.5% for reff,ci. While for the DCC case, the respective
deviation is 5.9% for \τdcc and 13.2% for reff,dcc. The
larger deviations in case 10 of DCC are mainly attributed to the
fast cloud evolution and three-dimensional radiative effects.
Measurements of spectral radiance at near-infrared wavelengths
with different absorption by cloud particles are employed to
investigate the vertical profile of cirrus effective radius. The
retrieved values of cirrus effective radius are further compared
with corresponding in situ measurements using a vertical weighting
method. Compared to the MODIS observation, spectral measurements
of SMART provide an increased amount of information on the
vertical distribution of particle sizes at cloud top, and
therefore allow 15 to reconstruct the profile of effective radius
at cloud top. The retrieved effective radius differs to in situ
measurements with a normalized mean absolute deviation between 4
\− 19%, depending on the wavelength chosen in the retrieval
algorithm. While, the MODIS cloud product underestimates the in
situ measurements by 48%. The presence of liquid water clouds
below the cirrus, the variability of particle size distributions,
and the simplification in the retrieval algorithm assuming
vertically homogeneous cloud are identified as the potential error
contributors.",
doi = "10.5194/acp-2017-758",
url = "http://dx.doi.org/10.5194/acp-2017-758",
issn = "1680-7367",
language = "en",
targetfile = "krisna_comparing.pdf",
urlaccessdate = "27 abr. 2024"
}