ACEPOL: Aerosol Characterization from Polarimeter and Lidar


To improve our understanding of the effect of aerosols on climate and air quality, measurements of
aerosol chemical compostion, size distribution, height profile, and optical properties (AOT, SSA) are of
crucial importance. From a remote sensing perspective, the most extensive set of aerosol properties can
be obtained by combining passive multi-angle, multi-spectral measurements of intensity and polarization
with active measurements performed by a High Spectral Resolution LIDAR (HSRL). In this proposal, we
will perform aerosol measurements over the USA from the NASA high altitude ER-2 aircraft using
measurements of 3 different spectro/photo polarimeters (RSP, airMSPI, and airSPEX), which differ in
terms of spectral, angular, and spatial sampling, with active measurements of the airborne HSRL-2. We
will compare the capabilities of the different polarimeters for retrieval of aerosol microphysical and
optical parameters, as well as their capabilities to derive aerosol layer height (near-UV polarimetry, O2
a-band). The retrieved aerosol properties and retrieved layer height are compared with HSRL-2. Finally,
we we develop an algorithm for a joint retrieval using polarimeter and HSRL measurements
simulataneously, making full use of the information in the remote sensing measurements, and apply the
algorithm to polarimeter / HSRL-2 measurements from the ER-2. This work provides insight into the
maximum amount of information on aerosol that can be obtained by satellite remote sensing and is
important in preparation of satellite missions like METOP-SG, Earthcare, PACE, and ACE.


Project number


Main applicant

Dr. O.P. Hasekamp

Affiliated with

SRON - Netherlands Institute for Space Research