@Article{KrisnaWEJWWBMPAVM:2018:TwCaSt,
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 = "{University of Leipzig} and {University of Leipzig} and
{University of Leipzig} and {University of Leipzig} and
{University of Leipzig} and {Johannes Gutenberg University} and
{Johannes Gutenberg University} and {Johannes Gutenberg
University} and {Max Planck Institute for Chemistry (MPIC)} and
{Max Planck Institute for Chemistry (MPIC)} and {German Aerospace
Center (DLR)} and {Instituto Nacional de Pesquisas Espaciais
(INPE)}",
title = "Comparing airborne and satellite retrievals of cloud optical
thickness and particle effective radius using a spectral radiance
ratio technique: two case studies for cirrus and deep convective
clouds",
journal = "Atmospheric Chemistry and Physics",
year = "2018",
volume = "18",
number = "7",
pages = "4439--4462",
month = "Apr.",
abstract = "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 High Altitude
and Long Range Research Aircraft (HALO) during the Mid-Latitude
Cirrus (ML-CIRRUS) and the Aerosol, Cloud, Precipitation, and
Radiation Interaction and Dynamic of Convective Clouds System -
Cloud Processes of the Main Precipitation Systems in Brazil: A
Contribution to Cloud Resolving Modelling and to the Global
Precipitation Measurement (ACRIDICON-CHUVA) campaigns. On
particular flights, HALO performed measurements closely collocated
with overpasses of the Moderate Resolution Imaging
Spectroradiometer (MODIS) aboard the Aqua satellite. A cirrus
cloud located above liquid water clouds and a DCC topped by an
anvil cirrus are analyzed in this paper. Based on the nadir
spectral upward radiance measured above the two clouds, the
optical thickness tau and particle effective radius r(eff) of the
cirrus and DCC are retrieved using a radiance ratio technique,
which considers the cloud thermodynamic phase, the vertical
profile of cloud microphysical properties, the presence of
multilayer clouds, and the heterogeneity of the surface albedo.
For the cirrus case, the comparison of tau and r(eff) retrieved on
the basis of SMART and MODIS measurements yields a normalized mean
absolute deviation of up to 1.2% for tau and 2.1% for r(eff). For
the DCC case, deviations of up to 3.6% for tau and 6.2% for r(eff)
are obtained. The larger deviations in the DCC case are mainly
attributed to the fast cloud evolution and three-dimensional (3-D)
radiative effects. Measurements of spectral upward radiance at
near-infrared wavelengths are employed to investigate the vertical
profile of r(eff) in the cirrus. The retrieved values of r(eff)
are compared with corresponding in situ measurements using a
vertical weighting method. Compared to the MODIS observations,
measurements of SMART provide more information on the vertical
distribution of particle sizes, which allow reconstructing the
profile of r(eff) close to the cloud top. The comparison between
retrieved and in situ r(eff) yields a normalized mean absolute
deviation, which ranges between 1.5 and 10.3 %, and a robust
correlation coefficient of 0.82.",
doi = "10.5194/acp-18-4439-2018",
url = "http://dx.doi.org/10.5194/acp-18-4439-2018",
issn = "1680-7316 and 1680-7324",
language = "en",
targetfile = "krisna_comparing.pdf",
urlaccessdate = "27 abr. 2024"
}