In connection with the American Geophysical Union's Chapman Conference, four scientists will brief science writers on recent discoveries and continuing issues regarding Atmospheric Science Across the Stratopause. The stratopause is the transitional region, around 50 kilometers (30 miles) altitude, between the stratosphere and mesosphere. The conference runs from April 19 to 22.

Date: Tuesday, April 20, 1999
Time: 10:00 AM to noon
Place: Governor Calvert House, State Circle (opposite the State Capitol), Annapolis, Maryland
Driving directions and press registration information will be found later in this advisory.

The briefing will consist of four 30-minute sessions, with time for questions, presented by scientists who are reporting newsworthy research at the conference. AGU Chapman Conferences are topical meetings designed to permit organized and in-depth exploration of specialized subjects in a manner not possible at large meetings. They encourage disciplinary and newly emerging research fields and problem areas, or for revisiting areas where recent developments warrant a new look.

Press Briefing Program

10:00 A.M.
Human and other influences on middle atmosphere climate
Briefer: Dr. Guy Brasseur, Senior Scientist,
Director of Atmospheric Chemistry Division National Center for Atmospheric Research, Boulder, Colorado

It is now accepted that manmade pollutants, released in the lower atmosphere, can cause depletion of the stratospheric ozone layer on a global scale. At the same time, other manmade effects are predicted to occur, and these are not as well established. For example, global warming of the lower atmosphere should lead to global cooling of the middle atmosphere. Our ability to observe this cooling is complicated by other perturbations, including solar activity and volcanic eruptions. Several papers presented at the conference will attempt to assess the impact of various contributors to middle atmosphere global change.

10:30 A.M.
The elusive hydroxyl radical: new observations and theories
Briefer: Dr. Robert Conway, Research Physicist
Naval Research Laboratory, Washington, D.C.

Hydroxide (OH) is one of the most important radicals in middle atmospheric chemistry, but one of the most difficult to measure. As a result, its vertical and global distribution is poorly understood. New space borne measurements of OH to be presented at this conference promise to revise accepted theories. They will also shed light on mysterious results obtained from a 20-year long effort to measure the OH column from a ground-based observatory.

11:00 A.M.
Space based monitoring of middle atmospheric chemistry and meteorology
Briefer: Prof. Dirk Offerman, Department of Physics
Wuppertal University, Wuppertal, Germany

The next generation of satellite experiments to monitor the middle atmosphere will combine high vertical and horizontal resolution to map the stratosphere and mesosphere in unprecedented detail. These experiments will fly aboard NASA's new EOS (Earth Observing System)satellites. A prototype of these experiments, the CRyogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA), has already flown on the space shuttle and is the subject of several presentations at this conference. They offer a first glimpse of the wealth of information that will become available from EOS.

11:30 A.M.
New perspectives on the coupling between the stratosphere and the magnetosphere
Briefer: Dr. David Siskind, Research Physicist
Naval Research Laboratory, Washington, D.C.

Various studies over the past two decades have suggested that nitrogen oxides in the stratosphere can be produced from energetic electrons associated with the aurora and the magnetosphere. Since nitrogen oxides react with stratospheric ozone, it implies a coupling between the stratosphere and the magnetosphere. New evidence confirms the existence of such coupling; however, controversy exists as to the global extent of this phenomenon. Papers presented at this conference will offer several perspectives on this topic.

Information on the conference

For further information on this conference, including abstracts of presentations, please consult the AGU web site:
http://www.agu.org/meetings/cc98hcall.html.

Driving directions to Governor Calvert House from Washington and Baltimore and from National (DCA) and Baltimore-Washington International (BWI) Airports will be found at:
http://www.agu.org/meetings/cc98hcall.html#progcom2.

Hotel information may be found at
http://www.agu.org/meetings/cc98hcall.html#CusI.

Press registration

Journalists and public information officers of scientific institutions may attend this briefing. Please bring identification, such as an ID card from your publication. Freelancers must provide evidence of published science writing during 1998 or 1999, or a current membership card in NASW or one of its regional affiliates, or a letter from a publication assigning you to cover this event.

To assist our planning, it would be helpful if you inform Harvey Leifert of your intention to attend this briefing, which can be done by return email. It is not necessary to do so, however.

There will be no press room or filing facilities at the conference.