UTLS

Integrated Studies of Dynamics, Chemistry,
Clouds and Radiation of the
Upper Troposphere and
Lower Stratosphere

START08 & preHIPPO Field Campaign Workshop

8 - 9 January 2008

NCAR: Boulder, Colorado

Stratosphere-Troposphere Analyses of Regional Transport (START-08) and HIAPER Pole-to-Pole Observations (HIPPO) of Carbon Cycle and Greenhouse Gases experiment will have a joint payload and operation in Spring 2008. During this workshop, the investigators will provide an overview of the scientific issues the experiments planned to address. Related modeling and satellite data analyses will be discussed. Planning for forecast and flight operations will also be part of the workshop. We invite the community’s participation and scientific involvement in the project.

UTLS Science Mission Pages:

START-05: Stratosphere-Troposphere Analyses of Regional Transport 2005
START-08: Stratosphere-Troposphere Analyses of Regional Transport 2008
T-REX: Terrain-induced Rotor EXperiment
DC3: Deep Convective Clouds & Chemistry experiment

The UTLS is a highly coupled region: dynamics, chemistry, microphysics and radiation are fundamentally interconnected. Water vapor and ozone, perhaps the two most important greenhouse gases in the UTLS, are controlled by both transport processes, such as stratosphere-troposphere exchange, and chemical processes including multiphase chemistry, and cloud microphysics, which in turn are influenced by the temperature and aerosol distributions.

Goals

• To plan and to conduct integrated UTLS studies using the new HIAPER aircraft optimize integration with observations from the NASA A-train satellites and with NCAR multi-scale models.
• To facilitate crosscutting collaboration within NCAR and partnerships with the university community.
• To provide community service and help the build up of HIAPER capability (instrument development and campaign support).

This schematic figure (adapted from Stohl et al. 2003) highlights the important processes coupling dynamics, chemistry and cloud microphysics in the UTLS region. The green line denotes the time average tropopause. In the tropics, maximum outflow from deep convection occurs near ~12-14 km, while the cold point tropopause occurs near 17 km. The intervening region has characteristics intermediate between the troposphere and stratosphere, and is termed the tropical transition layer (TTL). Extratropical stratosphere-troposphere exchange occurs in tropopause folds and intrusions linked with synoptics weater systems; these events transport stratospheric ozone into the troposphere. In addition, convection brings near-surface pollutants (from boimass burning or anthropogenci emissions) into the upper troposphere, strongly influencing global-scale chemistry.