Director's Message

It has been a busy year for ACD scientists, who have led and supported several community field campaigns, developed breakthrough measurement technologies, and applied leading-edge measurements in pursuit of new scientific understanding in the field and in the laboratory. ACD staff has developed MOPITT data to “validated” status, analyzed MOPITT observations to provide new insights into the transport of pollutants in the atmosphere, integrated MOPITT observations with MOZART simulations to produce new, exciting information on emissions, atmospheric processes, and model descriptions. ACD remote-sensing staff have continued with preparations for HIRDLS and identified mission critical but recoverable problems before the imminent launch of the Aura spacecraft. Additionally, members of the Division have organized many workshops to bring together the best thinking on Megacity pollution, chemistry climate interactions, emission inventories, and the important influence of the upper troposphere/lower stratosphere (UTLS) region on climate and composition. ACD scientists have brought their expertise to national and international fora to inform the decisions that will determine the fate of the atmosphere, and have developed next generation chemical climate models of the stratosphere and troposphere and a regional air quality forecast model. ACD has also taken stock of its strengths and the demands of society and the scientific community that the Division serves and have developed a new science plan for ACD. Simultaneously, the Division is preparing for a new facility to house ACD that provides an opportunity to create new facilities to further serve the community.

Emissions to the atmosphere will continue to grow as world population grows in numbers. The mission of ACD is to understand the role of chemistry in the Earth system and how that role will be modified by increased emissions, to apply that understanding in the service of society by providing the fundamental scientific underpinnings in the decision support process, and by enabling others in our scientific community to contribute to this enterprise.

Particularly noteworthy among the many achievements recorded in this document are 1) the resolution of the Tropical ozone paradox by a careful integration of satellite observations of CO and other species with air trajectory calculations and chemical transport models; and 2) a new linear ion trap that will increase sensitivity, time frequency, and analytical capability, particularly for many complex, partially-oxygenated organic molecules that play key roles in the formation of organic aerosol. These two achievements bracket the scope of ACD activities from the development of new technologies in the laboratory that will propagate into the community through technology transfer, leading ultimately to the publication of new understanding of atmospheric processes based on an integration of observations from state-of-the-science instrumentation, advanced numerical modeling of chemical processes, and detailed meteorological analysis of atmospheric air motions. These particular achievements do not stand alone; perusal of this report will reveal many more scientific and technical accomplishments.

A Division such as ACD is only as good as its staff. To renew our staff and maintain the scientific vitality of the Division we have, over the past two years, hired six new scientists (three in 2003). It is noteworthy that these new hires have contributed both to the two accomplishments described above and to many of the numerous accomplishments described in this report.

Over the last year, ACD has been assessing its scientific directions and how that research plays into the broader relevance to society. We have chosen to align our research along two principal themes: “Regional and Global Scale Air Quality” and the “Role of Chemistry in the Climate System.” In line with the NCAR Strategic Plan, NCAR as an Integrator, these themes integrate much of the research in ACD in laboratory, field, and theoretical studies. ACD leads and contributes significantly to two NCAR Strategic Initiatives described in the NCAR Plan: Biogeosciences, and the Whole Atmosphere Community Climate Model (WACCM). Furthermore, ACD has several participants in an additional initiative on Wildfires.

To further align ACD research with the NCAR Strategic Plan and with the ACD Science Plan, ACD scientists are proposing several new strategic initiatives, including Megacity Impacts on Regional and Global Environments (MIRAGE), an Integrated study of dynamics, chemistry, clouds and radiation of the upper troposphere and lower stratosphere (UTLS), and a Chemistry-Climate Initiative. ACD scientists are also participating in several other proposals, including a paleo climate initiative, and an initiative to utilize GPS radio-occultation measurements. In addition to intrinsic scientific merit, these proposals, in common with the existing initiatives, align with the broader NCAR goals of supporting the community through the creation of cyber-infrastructure.

ACD scientists are focusing attention on three community modeling areas, and progress in each of these areas is described herein. Because chemistry is important to climate issues, middle atmosphere science, and regional air quality, ACD is unable to focus on one single community model but has adopted a strategy of collaborating on several NCAR community modeling activities. We lead the effort to incorporate the principal chemical influences into WACCM, to integrate chemistry into the Community Climate System Model, and to extend the Weather Research and Forecast model to predict air quality. Details of the progress being made in each of these areas are described in this report.

To capture the views of the community that we serve on these activities and to increase the involvement of that community in ACD activities, ACD has co-sponsored, with the NCAR Director, several community workshops, starting with a MIRAGE workshop at the end of 2002 and culminating in a UTLS workshop in October 2003. In addition, ACD has co-sponsored a chemistry climate workshop in Santa Fe (February 2003) and an emissions workshop in Boulder (August 2003) aimed at building a community to study chemistry climate issues and to improve chemistry-climate model simulations. This program will continue with a biogeoscience-sponsored workshop in November 2003.

In addition to the Division’s workshop visitors, over the past year we have had many longer-term visitors to ACD, some sponsored by ACD visitor programs. Some of the activities of these visitors are described here. These individuals have added to our scientific vitality and advanced our research agenda. In return, we have provided training opportunities, access to facilities not available at home institutions, and transferred technology. We thank our visitors for all that they have contributed and hope that they have benefited from their time with us. We are committed to maintaining our visitor programs and expanding them as opportunities arise.

I hope you will find much of interest in the ACD science described in this document. Please contact me if you would like to learn more on any topic in this report that interests you.

Yours sincerely,

Daniel McKenna
Division Director