Aerosol, Cloud, Precipitation, and Radiation
Interactions and Dynamics of Convective Cloud Systems
(ACRIDICON)
Project Outline for a HALO Demo Mission
DLR Oberpfaffenhofen (Atmospheric Physics, Flight Operations)
FU Berlin (Space Science)
HU Jerusalem (Atmospheric Physics)
IFM-GEOMAR at University of Kiel (Marine Meteorology)
IfT Leipzig (Physics)
MPIC Mainz (Air Chemistry, Biogeochemistry, Cloud Physics & Chemistry)
MPIM Hamburg (Climate Processes)
University of Mainz (Atmospheric Physics/Meteorology)
University of Frankfurt (Atmospheric Physics/Meteorology)
University of Darmstadt (Electron Microscopy)
University of Bonn (Meteorology)
University of Heidelberg (Environmental Physics)
University of München (Meteorology)
ACRIDICON
Motivation
General scientific questions to be addressed by ACRIDICON:
1)
Does interaction of aerosols with clouds
and precipitation influence the formation & dynamics of
convective cloud systems and influence the vigor of heavy weather
events?
2)
What are the effects of convective
cloud systems on the solar &
terrestrial radiation budget
and how important is the micro
structure of the clouds?
3)
Can these effects induce substantial
changes in the global circulation
of the atmosphere, the Earth’s
energy budget, and climate?
ACRIDICON
Objectives
Specific scientific questions to be answered by ACRIDICON:
1)
Can we achieve comprehensive in-situ characterization of the
microphysical & chemical properties of aerosol, cloud, and precipitation
particles in convective cloud systems with the deployed scientific
instrumentation?
2)
Do the deployed aircraft remote sensing instruments (radar & lidar)
allow to determine reliable microphysical profiles of convective clouds?
3)
What are characteristic particle properties in the convective cloud inflow,
updraft, and outflow, and how do they change in the course of cloud
evolution?
4)
Can we observe characteristic differences in the microphysical properties,
dynamics, and radiative effects of convective cloud systems in polluted &
unpolluted air?
ACRIDICON
Measurement Region & Time
¾
Measurements region, where intense convective activity can be expected
and where clean background air is polluted by regional sources.
¾
Example: Iberian Peninsula, which can be easily reached by HALO.
Alternative or complementary locations: Western Europe (France, British Isles)
and around the Alps.
¾
Flights probing the interior of
convective clouds as well as their
inflow and outflow regions
should be conducted in clean
and polluted air masses.
¾
The mission would be scheduled
for summer (maximum convection),
but the planned experiments should
also be feasible in late spring/early fall.
ACRIDICON
Flight Pattern
¾
For vertical documentation of the microphysical evolution of the
convective clouds, flights shall start by probing the aerosols below cloud base,
and then ascend through the young cloud in the growing stages of the
convective cloud, to the level of the anvil.
¾
The penetrations should be such
that ambient air and aerosols
will be sampled as well, including
air detrained from the cloud.
¾
The vertical cross
section should take an hour.
Several profiles shall be
taken with similar
thermodynamic conditions but
contrasting aerosol content.
ACRIDICON
Aircraft Measurements
¾
In-situ characterization & remote sensing of aerosol, cloud, and
precipitation particle properties, cloud dynamics, and radiative properties shall
be accompanied by trace gas measurements to identify the extent and
sources of air pollution influencing the investigated convective cloud systems.
¾
We distinguish between core aircraft instrumentation & measurement
parameters which appear to be most important for achievement of the aims,
and of optional instruments & parameters which would be desirable but less
important (subsequent Tables).
ACRIDICON
Core Instrumentation 1
Measurement Parameters
Instruments/Packages
Volume
(Racks)
Operating
Partners
updraft velocity, turbulence
& precipitation intensity
3-D wind sensors, p, T, RH, weather radar,
drop sondes
2
DLR
aerosol & cloud residual
number concentration, size
distribution, volatility,
absorption coefficient
aerosol inlets & counterflow virtual impactor 1-2
(CVI); condensation & optical particle
counters (CPC, OPC, PSAP),
thermodenuder, filter collection, Lyman-α
hygrometer, dewpoint mirror
IfT
aerosol & cloud particle
number concentration, size
distribution, shape, phase,
chemical composition
condensation & optical particle counters
(COPAS, CIP, FSSP, CIP), aerosol mass
spectrometer (Q/TOF-AMS, SPLAT),
holographic system (HALOHOLO)
2-3
MPIC-C,
Uni Mainz
aerosol particle number
concentration, size
distribution, volatility,
absorption coefficient
optical particle counters (OPC, PCASP,
FSSP); multi-channel condensation particle
counters (CPC); thermal denuder; mobility
analyzer (DMA); multi-angle absorption
photometer (MAAP)
1
DLR
cloud condensation nuclei
concentration, aerosol
absorption & scattering
coefficients
cloud condensation nuclei counter (CCNC),
optical analyzers (SP2, PAS, nephelometer);
particle collectors (filter/impactor)
1
MPIC-B
ACRIDICON
Core Instrumentation 2
Measurement Parameters
Instruments/Packages
Volume
(Racks)
Operating
Partners
ice nuclei concentration
ice nuclei counter (INC)
1
Uni
Frankfurt
CO, O3
optical spectrometer
0-1
DLR,
MPIC-A
liquid water path
microwave radiometer
1
Uni
München
cloud base and density
cloud radar
1
MPIM
aerosol particle vertical
distribution, cloud top
height
cloud lidar (POLIS)
1
Uni
München
irradiance, radiance, actinic
flux densities
spectral radiometer, imaging spectrometer
(polarization)
1-2
IfT
ACRIDICON
Optional Instrumentation
Measurement Parameters
Instruments/Packages
Volume
(Racks)
Operating
Partners
vertical distribution of
aerosol particles, water
vapor, and optically thin
clouds
cloud lidar
6
DLR
NO, NOy, O3
chemiluminescence, UV absorption
1
DLR
NO, NOx, O3
chemiluminescence
1
MPIC-A
CO, CO2, HCHO, H2O2
optical spectrometer
0-1
MPIC-A
carbon monoxide, volatile
organic compounds (VOC)
mass spectrometry (PTR-MS)
1
MPIC-A
O3, NO2, BrO, HCHO, IO,
OIO, OClO, H2O vapour,
O2, O4, UV/vis/near IR skylight radiances
DOAS
0-1
Uni
Heidelberg
ACRIDICON
Complementary Activities
¾
Satellite remote sensing: aerosol optical depth, Angstrom coefficient, particle
size & type (sulfates, dust, smoke, sea salt); cloud & precipitation effective
radii, phase, optical depth, liquid water path; trace gas distributions for CO,
CH4, O3, NOx, etc. (FU Berlin, HU Jerusalem, IFM-GEOMAR, Uni Heidelberg)
¾
Ground-based remote sensing: evolution of the various types of
hydrometeors in the clouds investigated by the aircraft (conventional and
polarimetric radars, DLR).
¾
Off-line particle analysis: aerosol and cloud residual particle composition &
structure (electron, atomic force, and optical microscopy; laser desorption
ionization and secondary ion and mass spectrometry; biochemical assays;
evolved gas analysis; Uni Frankfurt, Uni Darmstadt, MPIC-B).
¾
Data assimilation and numerical simulations: convective cloud properties,
processes, and effects at a hierarchy of scales, from the individual particle
through the individual cloud scale, the regional scale to the global circulation
and climate scales (HU Jerusalem, IFM-GEOMAR).
ACRIDICON
Status
¾
Many instruments for ACRIDICON are already operational and has been
applied successfully on the Falcon and other research aircrafts.
¾
Several new and improved instruments are currently under development.
¾
Depending on the progress of these developments, the actual volume of
individual instruments and instrumentation packages may still undergo some
change.