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Researchers tackle clouds, rivers with NSF Career awards


October 23, 2009

Two ASU faculty members have earned Faculty Early Career Development (CAREER) awards from the National Science Foundation (NSF).

The CAREER program is NSF’s most prestigious, and supports the early career development activities of teacher-scholars who most effectively integrate research and education within the mission of their organization. It provides five-year research grants to each recipient.

The CAREER award winners are Pierre Herckes, assistant professor in the Department of Chemistry and Biochemistry; and Hilairy Hartnett an assistant professor in the Department of Chemistry and Biochemistry and the School of Earth and Space Exploration in the College of Liberal Arts and Sciences. ASU junior faculty were awarded six CAREER awards earlier this year.

Cloud chemistry; often the unexpected

Pierre Herckes will investigate the impact of clouds on atmospheric composition.

More specifically, he will study how cloud droplets act as miniscule chemical reactors that can transform atmospheric gases and particles into new and sometimes threatening chemical forms. This has a direct impact on atmospheric composition with implications for human health and global climate.

The health related aspect of his research stems from chemical reactions in clouds or fogs that might transform some relatively innocent chemicals into, for example, the potent carcinogen and mutagen, N-nitroso dimethylamine (NDMA). Herckes will tackle the problem through laboratory and observational field studies.

In the laboratory Herckes can simulate reactions occurring in cloud droplets under controlled conditions. This allows for identification of reaction products, the determination of reaction mechanisms and rates, which can later be used in complex atmospheric models.

“In the field, we will study clouds and fogs in a variety of environments,” Herckes says. “These will include highly polluted fogs in the Central Valley of California, more pristine mountain clouds in Arizona as well as marine clouds on the East Coast. This will yield novel insights into cloud chemistry, as observations of this type are quite rare.”

Herckes’s will use part of the grant (more than $560,000) to reach out to K–12 students through educational class modules that teach about the formation of clouds and their role in the water cycle, their impact on air pollution and their role in climate processes. A Web-interface will allow students and the general public to check on the latest status of field experiments, including real-time images from Web cameras, movies of cloud events and chemical composition data.

Organic carbon in the Colorado River system

Hilairy Hartnett’s research will develop a regional carbon budget for the Colorado River system using a combination of field measurements and laboratory manipulation experiments. Rivers are the dynamic link between terrestrial and aquatic ecosystems.

“Our basic understanding of river carbon cycling is based largely on data from pristine rivers,” Hartnett says. “Yet today virtually all rivers are managed to optimize water supply, flood control and hydropower. On the Colorado River, the system of dams and reservoirs has dramatically altered hydrodynamics and geomorphology, light conditions and sediment-water interactions.”

Hartnett wants to develop a broader understanding of the effects of these reservoirs on carbon biogeochemistry of the rivers. Organic carbon is the currency of ecosystems. Plants produce it and animals consume it. Understanding where the carbon in the Colorado River comes from and what happens to it along the way will tell Hartnett something about the role of the river with respect to regional carbon budgets and also, more generally, about how large managed rivers contribute to the transport of carbon to the sea..

The goal is to construct a carbon budget for each of the major reservoirs, to determine how much carbon comes in from upstream, how much is stored in sediments, how much is released as carbon dioxide and how much is transported downstream to the next reservoir. Hartnett also will investigate the composition of the organic carbon in each reservoir and assess how the composition changes downstream. The project requires both field sampling – to measure the amounts of carbon and nitrogen in sediments – and laboratory experiments. The latter are designed to show how reactive the carbon is to different processes like microbial degradation, photo-oxidation and sorption to mineral surfaces.

Hartnett’s project (award is more than $570,000) also will enhance learning outcomes for geoscience students through field-based teaching. The education component of the project will provide field science experiences for undergraduates and improve learning by giving them a real research project to participate in rather than a controlled laboratory experience.

CAREER awards provide an example of the economic benefit that a research university can bring to its state. Each year, Arizona universities pour nearly $1 billion into the Arizona economy from their research, most of which is funded by the U.S. government and entities from outside the state. Research money brought in by universities is restricted money that can be used only for the research activity it supports. It cannot be used to compensate for cuts in other parts of the university’s budget.