Sep 17 – 19, 2018
WMO, Geneva
Europe/Paris timezone

Observed composition trends and variability in the upper troposphere / lower stratosphere (OCTAV UTLS) – first results from airborne data

Sep 18, 2018, 2:20 PM
Salle B (WMO, Geneva)

Salle B

WMO, Geneva

Avenue de la Paix 7bis, Geneva, Switzerland


Dr Daniel Kunkel (Institute for Atmospheric Physics, JGU Mainz)


The upper troposphere / lower stratosphere (UTLS) is affected by the Brewer Dobson Circulation (BDC) as well as transport across the tropopause and the jets. The effect of changes in the dynamical properties on the distribution of tracers in the UTLS is therefore difficult to detect, since it involves the coupling of transport and mixing processes on very different temporal and spatial scales. Further complications arise from the short term variability of the tropopause and jet locations, which introduces variability in tracer distributions, particularly for those with strong gradients at the tropopause. It is therefore essential to account for the dynamically induced variability by, e.g. the tropopause location when looking at trends of trace gas distributions and long-term changes. The Stratosphere-troposphere Processes And their Role in Climate (SPARC) emerging activity OCTAV-UTLS (Observed Composition Trends and Variability in the UTLS) aims to reduce the uncertainties in trend estimates by accounting for these dynamically induced sources of variability. Achieving these goals by using existing UTLS trace gas observations from aircraft, ground-based, balloon and satellite platforms requires a consistent analysis of these different data with respect to the tropopause or the jets. Therefore, a central task for OCTAV-UTLS is the development of common metrics which are applicable to the different types of data sets to account for the dynamically induced tracer variability. In this presentation we will show results from an initial analysis of well characterized airborne in-situ data. We will present this data using varying geophysically-based coordinate systems including tropopause and upper tropospheric jet relative coordinates. These coordinates have been derived from the JETPAC tool (Jet and Tropopause Products for Analysis and Characterization) and MERRA-2 (Modern-Era Retrospective analysis for Research and Applications, Version 2) reanalysis data.

Primary authors

Dr Daniel Kunkel (Institute for Atmospheric Physics, JGU Mainz) Gloria Manney (NorthWest Research Associates & New Mexico Tech) Dr Luis Millan Valle (NASA Jet Propulsion Laboratory) Peter Hoor (Institute for Atmospheric Physics, Johannes Gutenberg University Mainz) Dr irina Petropavlovskikh (NOAA/CIRES)

Presentation materials

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