The IAGOS-CORE aerosol package: instrument design, operation and performance for continuous measurement aboard in-service aircraft

Ulrich Bundke,Marcel Berg,Norbert Houben,Amir Ibrahim,Markus Fiebig,Frank Tettich,Christoph Klaus,Harald Franke,Andreas Petzold

doi:10.3402/tellusb.v67.28339

Abstract

This work presents the characterisation of the Aerosol Package for the European Research Infrastructure IAGOS (In-service Aircraft for a Global Observing System). Condensation particle counter (CPC) are used to measure the aerosol number concentration of the total and the non-volatile particles. The size distribution is measured by means of an optical particle counter (OPC) in the diameter range of 0.25–3 µm. In particular the OPC is characterised for (1) leakage, (2) flow and calibration stability over the expected IAGOS pressure range of 170 hPa to 1013 hPa, (3) OPC accuracy test by comparing extinction measurements with calculated values from Mie theory using the OPC size distribution and (4) the inter-instrumental precision. The CPC is characterised in the same pressure range for (1) the lower cut-off diameter, (2) the instrument accuracy by comparing with a reference instrument (Faraday Cup Electrometer, FCE) and (3) the instrument precision. We conclude that the IAGOS Aerosol Package is a fully automated, robust, low-maintenance instrument providing high precision measurements with good accuracy.

Highlights

The natural variability of aerosol particles both in space and time is still one of the largest sources of uncertainty in global climate models (IPCC, 2013)
The atmospheric aerosol is included in the list of essential climate variables (ECV) of the atmosphere domain which has been defined in the framework of the Global Climate Observing System (GCOS, 2010)
Condensation particle counter (CPC) counting rates are converted to number concentrations and optical particle counter (OPC) as particle number concentrations per size bin by division by the volumetric flow rate

Summary

Introduction

The natural variability of aerosol particles both in space and time is still one of the largest sources of uncertainty in global climate models (IPCC, 2013). While ground-based networks for in-situ and remotesensing measurements of aerosol properties are well developed (Holben et al, 2001; Pappalardo et al, 2014), no comparable infrastructure is available for corresponding insitu measurements in the free troposphere, upper troposphere and lowermost stratosphere on a global scale. Vertically resolved in-situ data of aerosol properties are urgently needed for model validation and improvement (Aquila et al, 2011; Mann et al, 2014). 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 platforms. The infrastructure is built from two complementary approaches: the IAGOS-CORE component comprises the implementation and operation of autonomous instruments installed on up to 20 long-range aircraft of international airlines for continuous measurements of important reactive gases and greenhouse gases,

Methods

Results

Conclusion