Content - Trace Gas Climatologies

Trace Gas and Aerosol Climatologies - SPARC Data Initiative

Activity leaders

Michaela I. Hegglin
Department of Meteorology, University of Reading, UK 

Susann Tegtmeier
Helmholtz Centre for Ocean Research Kiel (GEOMAR), Germany 

Team members

Activity description

The SPARC initiative on Trace Gas Climatologies (or: SPARC Data Initiative) aims to compare vertically-resolved chemical trace gas climatologies derived from satellite measurements (extending from the upper troposphere to the lower mesosphere, but with a primary focus on the stratosphere).

Accurate knowledge of trace gas climatologies (including their variability) is crucial not only for their intrinsic value but also for validation of numerical model simulations; the SPARC CCMVal activity noted that for some species satellite products appear to contradict each other, and recommended an assessment of the various data products available to support future model evaluations. The SPARC Data Initiative aims to tackle this task and is analysing a variety of long- and short-lived trace gas species (O3, H2O, CH4, N2O, HNO3, NOx, HCl, ClO, OClO, HOCl, HF, BrO, SF6, CO, aerosols, and others). While the analysis of ozone, aerosol, and water vapour climatologies will support other ongoing SPARC activities focused on characterising long-term changes, this work will also provide valuable information on data quality to data merging activities currently being carried out by NASA and ESA. The outcome of the SPARC Data Initiative will be published in a peer-reviewed SPARC Report, which will constitute the first SPARC assessment of long- and short-lived trace gas species (apart from aerosol, ozone, and water vapour).

The Data Initiative has also been facilitated through an ISSI International Team activity, with the team consisting of both data analysts and experts from most of the major satellite instrument groups.

Published results

Journal publications:

Tegtmeier, S., M.I. Hegglin, J. Anderson, A. Bourassa, S. Brohede, D. Degenstein, L. Froidevaux, R. Fuller, B. Funke, J. Gille, A. Jones, Y. Kasai, K. Krüger, E. Kyrölä, G. Lingenfelser, J. Lumpe, B. Nardi, J. Neu, D. Pendlebury, E. Remsberg, A. Rozanov, L. Smith, M. Toohey, J. Urban, T. von Clarmann, K.A. Walker and H.J. Wang, 2013: The SPARC Data Initiative: A comparison of ozone climatologies from international satellite limb sounder. J. Geopyhs. Res., doi: 10.1002/2013JD019877.

Hegglin, M.I., S. Tegtmeier, J. Anderson, L. Froidevaux, R. Fuller, B. Funke, A. Jones, G. Lingenfelser, J. Lumpe, D. Pendlebury, E. Remsberg, A. Rozanov, M. Toohey, J. Urban, T. von Clarmann, K.A. Walker, R. Wang and K. Weigel, 2013: SPARC Data Initiative: Comparison of water vapor climatologies from international satellite limb sounders. J. Geopyhs. Res., doi: 10.1002/jgrd.50752.

SPARC Science Report:

SPARC, 2017: The SPARC Data Initiative: Assessment of stratospheric trace gas and aerosol climatologies from satellite limb sounders. By M. I. Hegglin and S. Tegtmeier (eds.), SPARC Report No. 8, WCRP-5/2017, available at

SPARC activity updates:

SPARC Newsletter No. 36 (2010), p.22: The SPARC Data Initiative, by M. I. Hegglin and S. Tegtmeier.

Website for further information (note: this website is no longer updated).