In 1999, CGRER awarded four seed grants totaling $76,083.
Evaluation of Climate Change Scenarios for the Central U.S.
Ray Arritt received $19,172 for examining the ability of global climate models (GCMs) to capture regional climatic fluctuations. He evaluated 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 extracted data from two of the better GCMs and determined 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. Were the GCMs to perform well, that would give us some confidence (but wouldn’t guarantee) that the models could be used to predict how future changes in greenhouse gas concentrations would alter the LLJ and NAMS.
Holocene Sphaerosiderites: Calibrating an Innovative Paleoclimate Proxy
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. Gonzalez and Ludvigson used 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. They then applied their findings to the formation of ancient sphaerosiderites, extrapolating information about ancient environments in the process. In particular, they strove to outline the environmental parameters of the mid-Cretaceous, the most recent period that experienced both atmospheric CO2concentrations and global mean temperatures similar to — and even greater than — those predicted for the near future.
Design and Installation of the Iowa Atmospheric Measurment Station (IA-AMS)
Keri Hornbuckle and Bill Eichinger received $20,000 to establish the Iowa Atmospheric Measurement Station (IA-AMS). This permanent monitoring station, located near Iowa City, allows 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 Eichinger produced a detailed picture of the fluxes and relative concentrations of such pollutants between air and terrestrial surfaces. The IA-AMS pulls 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 provides an excellent resource for student training and research projects in chemistry or meteorology. In anticipation of future projects, Hornbuckle submitted an NSF grant to establish similar stations in Mexico and Canada.
An Experimental Examination of the Role of Mineral Aerosols in the Greenhouse Gas Effect
Mark Young received funding to perform a very different type of detailed atmospheric analysis. Young’s $19,856 grant allowed the completion of an atmospheric reaction chamber on the UI campus and the initiation of its experimental use. This chamber is dedicated to analyses of the interactions between aerosolized mineral particles and atmospheric gases, interactions that have been recognized as potentially important to climate change. This CGRER grant encouraged multidisciplinary collaboration that broadened and deepened 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. Young and Paul Kleiber designed the reaction chamber and its instrumentation and outlined experimental protocols. Vicki Grassian analyzed chemistry of such interactions, while Greg Carmichael fed the resulting data into his numerical models of atmospheric chemistry and transport. This unusual integration of disciplines and approaches made this work globally unique.