Seeds

This year the awarding of unsolicited seed grants was reinstated and four grants were awarded for the period 8/1/99-7/31/2000. Each of the four promises to provide preliminary results that will pull in major research funding for continued efforts.

Ray Arritt, a new CGRER member (see Faculty Focus), received $19,172 for examining the ability of global climate models (GCMs) to capture regional climatic fluctuations. Said another way, Ray wants to evaluate whether GCMs can reliably reproduce aspects of weather systems that are important to the shaping of regional climate. A positive answer to this question would suggest that we can use regional numerical climate models to focus on these systems in more detail.

More specifically, Ray will be extracting data from two of the better GCMs and determining their accuracy in representing two continental-scale circulation patterns, the Great Plains low level jet (LLJ) and the North American monsoon system (NAMS). These circulation patterns are important determinants of the quantity of Iowa's summertime precipitation. Since the NAMS has a sudden onset over only a few days and the LLJ almost always occurs at night, Ray is using six-hourly data from the models instead of the monthly average values used in most climate studies. If the GCMs perform well for the current climate, this fact would give us some confidence (but doesn't guarantee) that the models can be used to predict how the LLJ and NAMS will be altered by future changes in greenhouse gas concentrations.

Ray admits to letting his enthusiasm for the project carry him away. Hearing that the seed grant would be awarded, he performed some of the research before the money arrived and has already submitted a paper to Geophysical Research Letters.

CGRER's Luis Gonzalez and Greg Ludvigson received a $17,055 grant to stretch use of the new Paul H. Nelson Stable Isotope Laboratory into a new area. Researchers have known for years that sphaerosiderites could be used as indicators of environmental conditions of ancient times. These tiny nuggets of the iron carbonate mineral siderite up to a few millimeters in diameter are abundant in wetland soils of the distant past. However the formation of these ancient sphaerosiderites is not well understood, and thus their encoded messages about past temperatures, rainfall, and soil chemistry cannot be easily deciphered.

Luckily sphaerosiderites are still being formed. Luis and Greg will be using the Isotope Laboratory to determine the sphaerosiderite carbon and oxygen isotope chemistry in order to grasp how hydrology, climate, and vegetation affect sphaerosiderite growth in modern soils. Then they can apply their findings concerning modern sphaerosiderites to the formation of ancient sphaerosiderites, and extrapolate information about ancient environments in the process. In particular, they are striving to outline thoroughly the environmental parameters of the mid-Cretaceous, the most recent period that experienced both atmospheric CO2 concentrations and global mean temperatures similar to -- and even greater than -- those predicted for the near future. The sphaerosiderites that were deposited in the Midwest at that time will help us create scenarios of what Iowa's temperature and precipitation patterns may become in the future, if through global warming we return to temperatures and climates similar to those of the Cretaceous.

CGRER members Keri Hornbuckle (UI, Civil and Environmental Engineering) and Bill Eichinger (UI, Iowa Institute of Hydraulic Research and CEE) received $20,000 to establish the Iowa Atmospheric Measurement Station (IA-AMS). This permanent monitoring station, to be located near Iowa City, will allow the long-term measurement of a variety of very specific atmospheric and climatic traits. As one example, Keri's primary interest lies in the transport of persistent organic pollutants (POPs), which are air toxins such as dioxins, herbicides, and byproducts of combustion. Although these compounds continue to float around the globe, being deposited and then returning to the air time and time again, little is know about how climate, changing land use patterns, or changes in diurnal, seasonal, and global temperatures affect their movement or changing concentrations in the air or soil. Her collaboration with Bill (who can produce a planar picture of the atmosphere using optical radiometry) promises to produce a detailed picture of the fluxes and relative concentrations of such pollutants between air and terrestrial surfaces. Keri and Bill hope to be able to describe vertical transport of both particle bound and gaseous POPs.

The IA-AMS would have the potential of pulling together a diverse group of researchers from within and outside of the UI, all of whom observe and measure or numerically model atmospheric or climatic variables in different manners. It would provide an excellent resource for student training and research projects in chemistry or meteorology. It could provide the nucleus for an expanded research station in future years. And it could become part of an international web of sampling stations that are comparing atmospheric changes across the continent. In anticipation of this last goal, Keri has already submitted an NSF grant to establish similar stations in Mexico and Canada.

Mark Young (UI, Chemistry Department) received funding to perform a very different type of detailed atmospheric analysis. Mark's $19,856 grant will allow the completion of an atmospheric reaction chamber on the UI campus and the initiation of its experimental use. This chamber will be dedicated to analyses of the interactions between aerosolized mineral particles and atmospheric gases, interactions that have been recognized as potentially important to climate change. Researchers have determined that the chemistry of gas phase species, including the effects of pollutants, may be altered when they become adsorbed on mineral particles (such as iron or silicon oxides). Conversely the gases may alter the form or chemistry of the mineral particles. These complex interactions have been little investigated, in part because of the sophisticated equipment and interdisciplinary analysis required.

This CGRER grant will encourage multidisciplinary collaboration that will broaden and deepen our understanding of the gas-particle interplay in a very detailed manner, looking at the interaction gas by gas, mineral by mineral, always in a controlled environment. Mark and Paul Kleiber (UI, Physics and Astronomy) have designed the reaction chamber and its instrumentation and have outlined experimental protocols. CGRER member Vicki Grassian (UI, Chemistry) is an expert on the chemistry of such interactions, while CGRER's Greg Carmichael (UI, Chemical and Biochemical Engineering) will feed the resulting data into his numerical models of atmospheric chemistry and transport, which in turn will be fed into global models.

This unusual integration of disciplines and approaches, coupled with the difficulty and specificity of the measurements and the fine-tuned capabilities of the instrumentation and reaction chamber, will make the work done here globally unique. However it will remain relevant to Iowa because Iowa's environment abounds both in the emission of gaseous pollutants and in the aerosolization of mineral particles from agriculture and industry.