In:
Atmospheric Chemistry and Physics, Copernicus GmbH, Vol. 18, No. 10 ( 2018-05-18), p. 7001-7017
Abstract:
Abstract. This study focuses on the analysis of aerosol hygroscopic growth during the
Sierra Nevada Lidar AerOsol Profiling Experiment (SLOPE I) campaign by using
the synergy of active and passive remote sensors at the ACTRIS Granada
station and in situ instrumentation at a mountain station (Sierra Nevada,
SNS). To this end, a methodology based on simultaneous measurements of
aerosol profiles from an EARLINET multi-wavelength Raman lidar (RL) and
relative humidity (RH) profiles obtained from a multi-instrumental approach
is used. This approach is based on the combination of calibrated water vapor
mixing ratio (r) profiles from RL and continuous temperature profiles from
a microwave radiometer (MWR) for obtaining RH profiles with a reasonable
vertical and temporal resolution. This methodology is validated against the
traditional one that uses RH from co-located radiosounding (RS) measurements,
obtaining differences in the hygroscopic growth parameter (γ) lower
than 5 % between the methodology based on RS and the one presented here.
Additionally, during the SLOPE I campaign the remote sensing methodology used
for aerosol hygroscopic growth studies has been checked against Mie
calculations of aerosol hygroscopic growth using in situ measurements of
particle number size distribution and submicron chemical composition measured
at SNS. The hygroscopic case observed during SLOPE I showed an increase in
the particle backscatter coefficient at 355 and 532 nm with relative
humidity (RH ranged between 78 and 98 %), but also a decrease in the
backscatter-related Ångström exponent (AE) and particle linear
depolarization ratio (PLDR), indicating that the particles became larger and
more spherical due to hygroscopic processes. Vertical and horizontal wind
analysis is performed by means of a co-located Doppler lidar system, in order
to evaluate the horizontal and vertical dynamics of the air masses. Finally,
the Hänel parameterization is applied to experimental data for both
stations, and we found good agreement on γ measured with remote
sensing (γ532=0.48±0.01 and γ355=0.40±0.01) with respect to the values calculated using Mie theory
(γ532=0.53±0.02 and γ355=0.45±0.02),
with relative differences between measurements and simulations lower than
9 % at 532 nm and 11 % at 355 nm.
Type of Medium:
Online Resource
ISSN:
1680-7324
DOI:
10.5194/acp-18-7001-2018
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2018
detail.hit.zdb_id:
2092549-9
detail.hit.zdb_id:
2069847-1
