Observations of trace gases in the lowermost stratosphere and upper troposphere from the SPURT aircraft measurement program

Introduction

SPURT (Spurenstofftransport in der Tropopausenregion, trace gas transport in the tropopause region) was an aircraft measurement program funded by the AFO 2000 programme of the German Ministry for Education and Research (BMBF). Eight campaigns (36 flights in total) were conducted between November 2001 and July 2003 to investigate trace gas transport in the extratropical upper troposphere and lowermost stratosphere in all seasons. A wide range of trace gases with different lifetimes and sink/source characteristics were measured in-situ from a Learjet 35A aircraft flying at altitudes up to 13.7 km. The data set is well suited for studies of atmospheric transport, for model validation, and for investigations of seasonal changes in the upper troposphere and lowermost stratosphere as demonstrated in numerous accompanying studies.

Dataset content

In-situ measurements of N2O, CH4, CO, CO2, CFC12, H2, SF6, NO, NOy, O3 and H2O along all flight tracks.

Position and meteorological quantities recorded by the aircraft along all flight tracks.

Meteorological data from ECMWF analysis fields and derived products such as potential vorticity and equivalent latitude interpolated to all flight tracks.

Merge files (extension .mrg) of all observations, aircraft positions and other data merged into one single file per flight at 5 sec temporal resolution. Due to different instrument response times or computer clocks, the individual measurements were typically shifted by several seconds relative to each other. These time shifts are corrected for in the merge files.

Ten day backward trajectories started every 12 minutes along the flight tracks computed with Lagranto (doi:10.5194/gmd-8-2569-2015) based on 3-hourly ECMWF IFS analysis/forecast fields.

Further information such as flight quicklooks, flight protocols, meteorological reports, etc.

All measurement data are provided in NASA/Ames format (https://espo.nasa.gov/content/Ames_Format_Specification_v20), which is a self-explaining ASCII format that can conveniently be read by many software packages, e.g. the nappy library for python.

Quick start guide

Download and unpack the gzip compressed tar file (unpacking generates the two directories images and data)

Change to the directory data and open the file index.html with a web browser. This will open a web page providing an overview of the eight campaigns and associated data.

For most purposes it will be sufficient to work with the merge files: Change to the data directory and list all merge files by typing "ls */*/*.mrg" (Linux)  or "dir *\*\*.mrg" (Windows).

References:

The  reference journal article for the SPURT project is

Engel, A., Bönisch, H., Brunner, D., Fischer, H., Franke, H., Günther, G., Gurk, C., Hegglin, M., Hoor, P., Königstedt, R., Krebsbach, M., Maser, R., Parchatka, U., Peter, T., Schell, D., Schiller, C., Schmidt, U., Spelten, N., Szabo, T., Weers, U., Wernli, H., Wetter, T., and Wirth, V.: Highly resolved observations of trace gases in the lowermost stratosphere and upper troposphere from the Spurt project: an overview, Atmos. Chem. Phys., 6, 283–301, https://doi.org/10.5194/acp-6-283-2006, 2006.

Many more scientific publications emerged from the project (see reference list and object identifiers).