Contents: conveners, program committee, sponsors, conference program, objectives, expected participation, field of interest, further information.

AGU Chapman Conference on Atmospheric Water
Vapor and Its Role in Climate

Kailua-Kona, Hawaii, USA 20–24 October 2008

Conveners

• Steven Sherwood, Yale University, New Haven, Connecticut, USA
• Natalia Andronova, University of Michigan, Ann Arbor, Michigan, USA
• Ray Pierrehumbert, University of Chicago, Chicago, Illinois, USA

Program Committee

• Dieter Kley, Forschungszentrum Juelich, Juelich, Germany
• Liz Moyer, University of Chicago, Chicago, Illinois, USA
• Joyce Penner, University of Michigan, Ann Arbor, Michigan, USA
• Rémy Roca, LMD/IPSL, Paris, France
• Karen Rosenlof, NOAA Aeronomy Laboratory, Boulder, Colorado, USA
• Masato Shiotani, Kyoto University, Kyoto, Japan
• Brian Soden, RSMAS/MPO, University of Miami, Coral Gables, Florida, USA
• Tammy Weckwerth, NCAR, Boulder, Colorado, USA

The conveners and planning committee wish to thank the European Geosciences Union for their cooperation in the planning of this conference.

Sponsors

Program Schedule

The conference will be held at the Sheraton Keauhou Bay Resort & Spa, 78-128 Ehukai Street. Kailua-Kona, and will span five days, with Wednesday off (see below for the planned field trip). The schedule is designed to maximize discussion and debate opportunities, and to make the meeting approachable to a broad audience. Each meeting day will consist of a morning and afternoon session, beginning with a keynote lecture, then continuing with two sessions on each of the three main focus areas:

1. Upper troposphere and lower stratosphere
2. Interaction of water vapor and convection
3. Climate, water vapor transport and the hydrological cycle

The meeting will finish with a closing session to sum up the meeting and consider future directions. Each session from 1–3 above will include two invited talks (speakers TBA) to introduce the key issues, followed by open discussions moderated by the program committee, and brief poster presentations. There will be one poster session per day for other attendees to present their work.

Please see the conference program for specific details.

Conference Objectives and General Description

The main objective of the proposed conference Atmospheric Water Vapor and Its Role in Climate is to bring together a diverse group to discuss recent advances in the understanding of processes related to, and new methods for observing, atmospheric water vapor. This constituent has attracted strong interest since the early 1970s for a number of reasons. First, water vapor is the most important greenhouse gas and is anticipated to provide the single largest feedback on climate change. It also plays a decisive role in controlling the development of atmospheric convection and cloud cover. Clouds exert additional feedbacks on climate, though of unknown strength, and polar stratospheric clouds enable ozone destruction through heterogeneous reactions involving chlorine compounds. Finally, water vapor is the source of the important hydroxyl radical which is responsible for removing many atmospheric pollutants.

A number of unanswered scientific questions surround atmospheric water vapor. These include:

• What allows such large vapor supersaturations to persist, as recently observed at low temperatures?
• What accounts for the reported decadal changes in stratospheric humidity, and what impact have these changes had on stratospheric chemistry or climate?
• Do we understand humidity well enough to predict it in different climates?
• How does atmospheric humidity regulate storm strength, mesoscale organization, and intraseasonal variability?
• What can we learn from isotopes of water in vapor or precipitation?
• Do paleoclimate proxies indicate surprises in past hydrological cycles, cloudiness, or poleward heat transport?
• Are recent proposals for the temperature-dependence of Earth's hydrological cycle and precipitation behavior adequate?
• Can attention to water vapor help us understand the still-mysterious role of clouds in different climates?

These questions involve a diverse array of disciplines and methods. The main purpose of this meeting is therefore to bring key groups together: those familiar with (or in the process of developing) new water vapor observing systems, those studying how atmospheric cloud, convective, and/or dynamical processes interact with water vapor, and those interested in the role of water vapor in climate change including paleoclimates, to discuss recent developments and future directions. A Chapman conference is uniquely suited to fruitful discussion of new observing system needs and possibilities, and of crosscutting science issues: a group of manageable size that includes experimental and theoretical expertise across disciplines rarely occurs in any other venue. Abstracts are solicited for new work on any topic relevant to the above, or other questions relating to water vapor and climate.

AGU is a worldwide scientific community that advances, through unselfish cooperation in research, the understanding of Earth and space for the benefit of humanity.

© 2009 American Geophysical Union

updated 17 September 2008