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| Titel |
Setup and first airborne application of an aerosol optical properties package for the In-service Aircraft Global Observing System IAGOS. |
| VerfasserIn |
Ulrich Bundke, Andrew Freedman, Andreas Herber, Ina Mattis, Marcel Berg, Julia De Faira, Andreas Petzold |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250124910
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| Publikation (Nr.) |
 EGU/EGU2016-4415.pdf |
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| Zusammenfassung |
| The atmospheric aerosol influences the climate twofold via the direct interaction with solar
radiation and indirectly effecting microphysical properties of clouds. The latter has the largest
uncertainty according to the last IPPC Report. A measured in situ climatology of the aerosol
microphysical and optical properties is needed to reduce the reported uncertainty of the
aerosol climate impact.
The European Research Infrastructure IAGOS (In-service Aircraft for a Global Observing
System; www.iagos.org) responds to the increasing requests for long-term, routine in situ
observational data by using commercial passenger aircraft as measurement platform.
However, scientific instrumentation for the measurement of atmospheric constituents
requires major modifications before being deployable aboard in-service passenger
aircraft.
The prototype of the IAGOS Aerosol Package (IAGOS-P2E) consists of two modified
CAPS (Cavity Attenuated Phase Shift) instruments from Aerodyne Research, Inc. and one
optical particle counter (Model Grimm Sky OPC 1.129). The CAPS PMex monitor
provides a measurement of the optical extinction (the sum of scattering and absorption)
of an ambient sample of particles. There is a choice of 5 different wavelengths -
blue (450 nm), green (530 nm), red (630 nm), far red (660 nm ) and near infrared
(780 nm) - which match the spectral bands of most other particle optical properties
measurement equipment. In our prototype setup we used the instrument operating
at 630nm wavelength (red). The second CAPS instrument we have chosen is the
CAPS NO2 monitor. This instrument provides a direct absorption measurement
of nitrogen dioxide in the blue region of the electromagnetic spectrum (450 nm).
Unlike standard chemiluminescence-based monitors, the instrument requires no
conversion of NO2 to another species and thus is not sensitive to other nitro-containing
species.
In the final IAGOS Setup, up to 4 CAPS might be used to get additional aerosol
properties using the different spectral information. The number of CAPS units to be used
will depend on the size of the final electronic boards which are currently under
development.
The Sky OPC measures the size distribution theoretically up to 32 μm covering the
relevant size information for calculation of aerosol optical properties. Because of the inlet cut
off diameter of D50 = 3μm we are using the 16 channel mode in the range of 250 nm - 2.5
μm at 1 Hz resolution.
In this presentation the setup of the IAGOS Aerosol package P2E is presented and
characterized for pressure levels relevant for the planned application, down to cruising
level of 150 hPa. In our aerosol lab we have tested the system against standard
instrumentation with different aerosol test substances. In addition first results for airborne
measurements are shown from a first airborne field campaign where in situ profiles are
compared to LIDAR measurements over Bornholm (Denmark) and Lindenberg
(Germany). |
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