Joan Blainey, co-sponsored by the University of Arizona Department of Hydrology and Water Resources

I believe the best way to create a greater public understanding of science is to engage the next generation of Americans at the primary and secondary school level in scientific exploration of the natural world. As a Space Grant Fellow, my goal is to improve scientific literacy in earth system science by developing soil moisture educational materials for the web, and by participating in GLOBE soil moisture data collection campaigns with southern Arizona students. GLOBE, a global science outreach program of cooperative schools, has so far linked soil moisture data collection campaigns for 200 K-12 schools. From January 1998 to the present, 12,000 schools around the world have been trained in GLOBE protocols which include data collection for air temperature, surface water quality, soil moisture, and/or soil temperature. GLOBE is a worldwide hands-on primary and secondary school-based science program that provides students the opportunity to take scientific measurements, report their data on the internet, and utilize the interactive website (www.globe.gov) to create maps and graphs of GLOBE data sets. As my primary contribution to educational outreach, I will develop and conduct classroom testing of age-appropriate GLOBE educational materials that help students and teachers understand scientific fundamentals such as hypothesis testing, data sampling, and data analysis in addition to a basic introduction to earth science via the hydrologic cycle.

Soil moisture is an important component of the hydrologic cycle. Only a very small portion of the earth’s fresh water is held in soil, but it is a critical resource for plant and animal life. The availability of soil moisture at any given time or place plays an important role in the exchange of moisture and energy between the atmosphere and the land surface. Soil moisture directly affects the partitioning of incoming solar radiation into sensible and latent heat fluxes, affects soil thermal properties as well as surface albedo, and is a controlling variable affecting the distribution of plant assemblages. Knowledge of soil moisture is essential for predicting climate on annual and seasonal time scales.

Many studies have demonstrated that passive microwave remote sensing has great potential for monitoring soil moisture on a large scale. In the upper 5 cm of the earth’s surface, microwave frequencies detect a large difference in the emission between water and dry soil due to the dielectric constant of water. Measurements obtained from passive microwave instruments are calibrated by comparison with ground-based measurements. Ground-based measurements are critical for verification and improved interpretation of measurements obtained by passive microwave sensors.

Gravimetric soil moisture measurements, the current scientific standard for measuring soil moisture, can be made simply and reliably with minimal equipment needs. By engaging K-12 students in soil moisture data collection and gravimetric soil moisture measurements throughout the United States, a scientific data set will be created that will provide researchers with much needed information about the spatial distribution of soil moisture. Because of the great cost and logistical challenges, few large-scale field experiments have been conducted in which soil moisture measurements have been made simultaneously or near-simultaneously over large areas. A goal of the GLOBE soil moisture program is to recruit as many students and schools as possible to provide such a dataset.

At the middle and high school level, student activities include collecting soil moisture samples and measuring soil moisture following GLOBE protocols. In accordance with these protocols, teams of students, parents, and local mentors select an open flat area of about 90 m by 90 m within 10 km of their school. Three samples of soil moisture are collected twice each year at depths of 0 to 5 cm and at 10 cm within a 10 m circle and are identified by GPS coordinates. Students at the high school level determine the mass of the soil samples both wet and after oven drying to determine gravimetric water content and bulk density.

In coordination with local educational outreach associated with these sampling activities, I propose to develop and conduct classroom testing of a series of age-appropriate lesson plans for K-12 teachers to help students make connections between point, local, and regional soil moisture measurements. These materials will be made available to teachers on the GLOBE web site (www.globe.gov).

By determining the months of the year during which the largest portion of the earth’s landmass has soil moisture values above a particular threshold, we can determine the best time for GLOBE students to engage in their data collection campaigns. Soil moisture measurements are typically within a small range of values; the timing of soil moisture campaigns is of primary importance in order to incorporate a range of values when sampling efforts occur only twice a year. The second valuable component of the students’ data will be an analysis of the spatial variability in measured soil moisture, which will be compared with existing predictions of spatially distributed soil moisture derived from land surface models and satellite-based remote sensing.

Engaging students with data collection, experimentation, and classroom activities related to the soil moisture component of the hydrologic cycle, an aspect of earth science with which they have some familiarity, will provide an exciting challenge. My contribution is to test and provide teachers with prepared materials and activities as a basis for their lesson plans and to make these materials available on the GLOBE website. During the fall, I have been contacting local teachers involved in previous years with the GLOBE soil moisture campaign to get their input on the educational materials I have been developing and to begin developing a connection with the Tucson teachers and schools I will collaborate with during the April soil moisture sampling campaign. I hope the impact of these activities will be to strengthen the basic understanding of an earth science topic in schools participating in GLOBE and to provide more Internet resources for teachers to present earth science curricula.