During Phase I of SHARP intense interactions between the projects have successfully been establishes. This strategy will be pursued in Phase II.

SHARP-WV (with focus on stratospheric water vapour) and SHARP-OCF (with focus on stratospheric ozone) will primarily investigate the impact of increasing greenhouse gas concentrations and climate change on stratospheric composition (Theme 1). Likewise, SHARP-BDC will focus on the impact of climate change on changes in stratospheric dynamics, particularly the Brewer-Dobson circulation (Theme 1). At the same time, the results of these three projects will provide information on resulting stratospheric changes that are needed to study the feedback of stratospheric change on tropospheric climate and weather which is the main topic of SHARP-STC (Theme 2).  

The model simulations will be performed in three projects, SHARP-BDC, SHARP-OCF and SHARP-STC. The simulations will be jointly defined and coordinated in order to provide the best possible basis not only for a detailed investigation of the specific questions in each individual project but also for a common analysis of model data and respective observations in the other SHARP-projects. Model output data will also be provided to the satellite data groups in SHARP-OCF and -WV for comparison with the derived observational products.

The new SEN simulations performed in SHARP-BDC, -OCF and -STC have been designed to address specific science topics of the individual projects, e.g. the SEN-GW experiments of SHARP-BDC to study the influence of gravity waves on the BDC, or SEN-N2O und SEN-GHG the influence of increases in nitrous oxide and greenhouse gases on ozone, and SEN-STE to study stratosphere-troposphere mass exchange. However changes in ozone due N₂O will also be interesting to analyze in SHARP-STC or SHARP-BDC. A 150-year SEN simulation designed to study the (reference) internal variability of the coupled ocean-atmosphere system in SHARP-STC will also be of interest to SHARP-WV for studying water vapour variability. Therefore, data products established in SHARP, which are derived from model simulations and observations, will be available to all SHARP projects.

A major goal of SHARP-OCF and SHARP-WV is to combine long-term satellite observations of stratospheric ozone, water vapour, halogenated key substances and other relevant trace gases measured by European sensors, primarily from MIPAS and SCIAMACHY both aboard Envisat, with other past and current data available and to study atmospheric composition in a changing climate. Water vapour data from SHARP-WV and halogenated key substances from SHARP-OCF will be used to study convective processes in the tropics and transport across the tropical tropopause. The impact of stratospheric variability in dynamics, e.g., the BDC, on stratospheric ozone (SHARP-OCF) and water vapour (SHARP-WV) are a common activity of these two projects. Analyses of long-term trends in stratospheric water vapour and ozone are accompanied by similar analyses of model data from all projects in order to identify the strengths and weaknesses of the CCM simulations. The long-term observational data can be used to validate and assess the ability of current models to describe past changes and are therefore made available to all projects within SHARP. In particular, observational data of ozone from SHARP-OCF will be used within SHARP-STC for the analysis of the response of the stratospheric polar vortices to climate change, while SHARP-BDC will use measures of the variability of uplift velocities as derived from observational data of water vapour, ozone, and SF₆. SHARP-STC will provide CCM to compare tracer-tracer correlations with observations derived in SHARP-BDC.

Satellite and model data are made available on central databases to which the partners have access by ftp. A central storage device has been installed at FUB which can be used by all partners. A project webpage has been established providing information between the partners (password protected) and the public. Since the participating groups have long-term experience in joint projects, we expect that the cooperation and coordination of work will be successful. Joint publications on cross-cutting issues are expected to be published by the end of SHARP-I.