Observational data synthesis (TPChange Central Project Z01)

The UTLS (upper troposphere and lower stratosphere) is a region relevant for weather and climate forecasts as well as for chemical aspects in the troposphere and stratosphere. For these reasons many observations have been conducted in recent years. Comparing data of different measurement campaigns is sometimes a bit difficult, especially for the supporting model data. Often, different model types or grid widths are used or one variable is missing or calculated with different methods.

The main goal of this work is to create a dataset of multiple measurement campaigns with consistent meteorological parameters and supporting analysis.

In a first step, we use ERA5 (European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis v5) data with a horizontal grid width of 1° and a time resolution of 6 hours as well as CLaMS (Chemical Lagrangian Model of the Stratosphere) data. In a second step, we also use ERA5 data with a time resolution of 1 hour and a horizontal grid width of 0.3°.The dataset contains several native and derived meteorological (e.g., potential vorticity, equivalent latitude) variables and tropopause diagnostics (e.g., height of laps rate and several dynamical tropopauses) from ERA5. To include information on transport and time scales artificial regional tracers (e.g., O₃, CO) and age spectrum variables (e.g., E90 tracer, mean age) from CLaMS are used. The interpolation is carried out for multiple campaigns i.e., for several airborne and balloon campaigns on different platforms.

To introduce the dataset, we also present a few possible application examples in relation to the distribution of trace gases and other species. Furthermore, we present comparisons of different model data and measurement data.