Package2d (Greenhouse Gases)

Instrument PI:     Christoph Gerbig, MPI for Biogeochemistry, Jena (

Package2d (also denoted P2d) is designed for the autonomous measurement of greenhouse gases and measures simultaneously CO2, CH4, CO and water vapour (H2O) at high precision. It is based on a commercial analyser developed by Picarro Inc. (Model G2401-m), which was redesigned to meet the requirements of IAGOS operation. The measurement principle is based on wavelength-scanned cavity ring-down spectroscopy (CRDS) using absorption lines in the infrared (1603 nm for CO2, 1651 nm for CH4 and H2O and 1567 nm for CO. Three telecom‐grade distributed feedback (DFB) lasers provide light of the appropriate wavelengths. The instrument contains a cavity as sample cell for simultaneous measurement of all species.

Figure. 1: Schematics of the P2d sampling approach.


The P2d instrumentation consists of the instrument unit and two pressure cylinders, which provide compressed air with known concentrations of CO2, CH4 and CO for in-flight calibration. The instrument is connected with FEP tubing to the inlet (Rosemount TAT housing) at the fuselage. P2d is connected with Package1 via Ethernet for data transmission.

Time resolution:    4s
Precision (4s, 1 sigma):     CO2: ±0.04 ppm;  CH4: ±0.4 ppb;  CO: ±10 ppb
Accuracy (100s, 1 sigma): CO2: ±0.13 ppm;  CH4: ±1.3 ppb;  CO: ±4 ppb
Interferences:        none


The instrument is designed for autonomous deployment over periods of up to 6 months. The actual deployment can be shorter if, e.g., contamination or loss of sensitivity is encountered. The instrument operates fully automatically. It utilises the Weight on Wheels (WoW) signal of the aircraft to switch between standby (on ground) and normal operation (in air). In-flight calibration checks include determination of the sensitivity for CO2, CH4 and CC. Before and after each deployment, the instrument is shipped to the laboratory for detailed quality assurance. Details of operating procedures, data analysis and quality assurance are described in the SOP.


P2d has been approved for installation on IAGOS-CORE aircraft by EASA STC. The first P2d has been installed and activated aboard the IAGOS-CORE aircraft D-AIKO operated by Deutsche Lufthansa.


P2d was developed by Max-Planck-Institute for Biogeochemistry, Jena in cooperation with enviscope GmbH and is manufactured by enviscope GmbH. Responsible Design Organisation (DO, EASA Part 21J): Gomolzig Aircraft Services GmbH for P/N IAG0S-PIId-02 (EASA STC 10060508).