Troposphere (IEK-8)

Nitrogen Oxides: Package2b (IAGOS-CORE)

The nitrogen oxide instrument Package2b (P2b), used for IAGOS-CORE on airplane type Airbus A340, is based on the principle of photoluminescence. Photons are detected which are released due to the chemical reaction between the atmospheric NO and the ozone added in the detector. The conversion from NO2 to NO is triggered by the photolytic conversion with the light of UV-LEDs. Turning those LEDs on an off allows a sequential measurement of NO and NOx. The measurement instrument is constructed to operate stable and autonomous in a time range of several months.

Aerosoles

For aerosol measurements, the Package2c is used in the IAGOS-CARIBIC Flying Laboratory, a modified cargo container on the Airbus A340-600 by Lufthansa. IAGOS-CORE will use the in 2022 new developed air quality instrument Package2e (P2e).

Package2c (IAGOS-CARIBIC)

The IAGOS Aerosol Package P2c measures the aerosol particle size distribution by means of an optical particle counter (OPC) and the integral number concentrations of aerosol particles and of non-volatile particle cores by means of two condensation particle counters (CPC). The aerosol size information for the so-called accumulation mode (particle diameter 0.1-1 µm) covers the range of particles available for the formation of liquid water and ice clouds. The total number concentration provides information on gas-to-particle conversion and particle nucleation at flight altitude level. The difference between the total and the non-volatile particle cores number concentration covers complementary information on the anthropogenic contribution to the atmospheric aerosol burden.

Package2e

The Package 2e Instrument is designed for the autonomous measurement of aerosol particle optical properties, size distribution and total-number concentration in the atmosphere in combination with the measurement of NO₂. This combination of measurements is a measure of the air quality.

The aerosol particle size distribution is measured by means of a Portable Optical Particle Spectrometer (POPS). This instrument is based initially and further developed for IAGOS deployment in close cooperation with NOAA Atmospheric Composition & Chemical Processes (ACCP) group.

Beside this, a condensation particle counter (CPC) is installed, which uses water as working liquid measuring the total particle number-concentration in close cooperation with Aerosol Dynamics and Aerosol Devices Inc.

The particle extinction coefficient at different wavelengths (450, 630 nm) is measured by means of three Cavity Phase Shift Particulate Matter extinction (CAPS PMex) tubes. The NO₂ concentration is measured by means of a fourth CAPS tube (CAPS NO₂). The functions of the instrument are controlled by a FPGA / and Realtime single board computer which also collects and records the relevant signals of the instruments.