Education and Human Resourcese [ED]

ED13A MCC:level 2 Monday 1340h

Rates, Fluxes, and Cycling in the Earth System: What Do We Know, What Are We Teaching? Posters

Presiding:D W Mogk, Montana State University; R M MacKay, Physics and Meteorology, Clark College

ED13A-0714 1340h

Rates, Fluxes, and Cycling in the Earth System: What Do We Know, What Are We Teaching?

* Mogk, D W (mogk@montana.edu) , Dept. of Earth Sciences, Montana State University, Bozeman, MT 59717 United States
Manduca, C A (cmanduca@carleton.edu) , Science Education Resource Center, Carleton College, Northfield, MN 55057 United States

Earth system science provides exciting new insights into the dynamics of the Earth. This approach emphasizes a special focus on the processes, pathways, and interfaces across different subsystems; the transfer of mass and energy throughout the Earth system; and the influence of biota and humanity on Earth processes (AGU, 1997). Consequently, rates, fluxes and global cycling are all concepts that are essential to understanding the dynamic Earth system. Topics of interest range from mantle dynamics, rates of uplift and denudation, surficial processes, contaminant transport in water and air media, nutrient cycling, atmospheric chemistry, and the near space environment. New advances in research have provided an array of new "speedometers" that provide exciting new insights into the duration, frequency, and magnitude of processes that operate across the Earth system. As important as these concepts are for the geoscience curriculum, they are often difficult for students to comprehend. Dynamic processes typically occur on temporal and spatial scales that are beyond the human experience, complex interactions must be reconciled between competing processes, and both negative and positive feedback mechanisms need to be considered. It is also important to demonstrate to students not only what we know, but also how we observe, measure and interpret Earth phenomena. As Earth system science advances, there is a growing need to also develop effective instructional practices that support learning about rates, fluxes, and cycling (e.g. 3- and 4-dimensional thinking) by students at all levels. Collections and services at the Science Education Resource Center (http://serc.carleton.edu) begin to address these needs in areas such as research on learning in the geosciences, using data in the classroom, teaching with visualizations, and teaching biocomplexity in the geosciences.

http://serc.carleton.edu

ED13A-0715 1340h

Geochemical Cycles of the Major Elements in the Oceans: What do we Know and how do we Know it?

* Drever, J I (drever@uwyo.edu) , University of Wyoming, Dept. Geology & Geophysics, 1000 E. University Ave., Laramie, WY 82071 United States

In the context of the cycles of the major elements in the oceans, the emphasis forty years ago was on the relative constancy of the composition of the ocean and atmosphere over geologic time. More recently, the focus has been on variations in input and output fluxes, with corresponding variations in the composition of seawater and the atmosphere. The present-day riverine input (corrected for human activities) is fairly well constrained. Fluxes associated with reaction between seawater and the ocean floor (hydrothermal processes at spreading centers, low-temperature alteration of oceanic crust and detrital sediments) are not well constrained at the global scale: some of the data (particularly for potassium) are contradictory. We need to maintain a clear distinction between fluxes that are measured directly and fluxes that are computed on the basis of mass balance and the assumption of steady-state on some time scale. Modeling of past variations in seawater composition are based on assumptions regarding past weathering rates (which are not well constrained by direct observation, except to a limited extent by Sr isotopes and Ge/Si ratios), and past rates of hydrothermal circulation. Seafloor spreading rates are used as a proxy for hydrothermal circulation in the Cenozoic and Mesozoic: global sea level has been used as a proxy for hydrothermal circulation in the Paleozoic. The data that constrain past seawater compositions can be classified as direct (e.g. composition of ancient marine evaporite minerals and enclosed fluid inclusions; the composition of marine carbonate minerals) and indirect (e.g. S, C, Sr isotopic records). Although there are good geological records of these isotopic proxies, their interpretation in terms of past fluxes and the composition of the ocean and atmosphere is dependent on models that contain various assumptions. Despite a great deal of uncertainty, models based on relatively simple assumptions give results that seem reasonable and consistent with limited data.

ED13A-0716 1340h

Rate Processes in Ocean Climate, Volcanoes, Earthquakes, and Glaciers: Their role in Multiple equilibria and Oscillations

* Whitehead, J A (jwhitehead@whoi.edu) , Woods Hole Oceanographic Institution, MS21, Department of Physical Oceanography, Woods Hole, MA 02543 United States

Models of ocean circulation driven by temperature and salinity driving exhibit multiple equilibria. The temperature and salinity response times along with advection are factors in the simplest (classic) example of this. A laboratory model will be illustrated. Oscillations arise when a layer of fresh water is cooled faster than it can be replaced. Mixing of salty water is a factor. Laboratory examples and the simple mechanics of such a temperature to salinity oscillation will be showed. Volcanoes are unsteady because of many factors, but the simplest factor is probably that flow resistance increases as flow decreases due to cooling. This arises because the cooling time is smaller than the excursion time of a material parcel, so that magma stiffens before escaping. Oscillations arising from this feature are illustrated and a laboratory example described. Likewise, earthquakes and glacial surges exhibit such oscillations. Time scales are associated with temperature changes, grain size alterations, fluid migration etc. Again a simplified laboratory model will be described.

ED13A-0717 1340h

Mass Balance and Atmospheric Chlorofluorocarbon CFC-12: Using Interactive Online Models and Data in Introductory Atmospheric Science.

* MacKay, R M (rmackay@clark.edu) , Clark College Physics and Meteorology, 1800 E McLoughlin Blvd., Vancouver, WA 98663 United States
Manduca, C A (cmanduca@carleton.edu) , Science Education Resource Center, Carleton College, One North College St., Northfield, MN 55057 United States

We present an interactive online "Mass Balance Model" that is useful for introducing students to the connection between flow rates, total accumulation, and residence time in a generic system. This mass balance model has been modified for application to trace gases in the atmosphere. Students use the "Trace Gas Model" to: 1) simulate actual levels of chlorofluorocarbon (CFC-12) in the atmosphere for the recent past; 2) simulate future levels of CFC-12 for different assumed emission scenarios; 3) help them understand the connection between long CFC-12 residence time and viable emission reduction policies to help limit future CFC-12 buildup and stratospheric ozone loss. Student survey results suggest positive student attitudes towards the online learning environment and using it to explore a topic of current public interest. The activities are presently available online as examples on the NSDL Starting Point site. Starting Point is a compilation of resources for instructors of introductory geoscience courses. Examples of Starting Point modules on how to incorporate innovative teaching methods into your introductory geoscience courses include: Lecture Demonstrations, Teaching With Data, Teaching With Models, Role Playing, and Socratic Questioning.

http://serc.carleton.edu/introgeo/index.html

ED13A-0718 1340h

Earth System Data Microsets for Education From the Atmospheric Sciences Data Center

Phelps, C S (c.s.phelps@larc.nasa.gov) , Science Applications International Corporation, One Enterprise Parkway, Hampton, VA 23666 United States
Chambers, L H (l.h.chambers@larc.nasa.gov) , NASA Langley Research Center, MS 420, Hampton, VA 23681 United States
Oots, P C (p.c.oots@larc.nasa.gov) , Science Applications International Corporation, One Enterprise Parkway, Hampton, VA 23666 United States
Moore, S W (s.w.moore@larc.nasa.gov) , Science Applications International Corporation, One Enterprise Parkway, Hampton, VA 23666 United States
* Lorentz, K E (k.e.lorentz@larc.nasa.gov) , Science Applications International Corporation, One Enterprise Parkway, Hampton, VA 23666 United States
Dalton, A J (a.j.dalton@larc.nasa.gov) , NASA Langley Research Center, MS 420, Hampton, VA 23681 United States

The Atmospheric Sciences Data Center (ASDC) at NASA's Langley Research Center houses over 700 data sets related to Earth's radiation budget, clouds, aerosols and tropospheric chemistry. These data sets were produced to increase academic understanding of the natural and anthropogenic perturbations that influence global climate change. Scientists have been analyzing the extensive data to discover and quantify the complex interactions and feedbacks in the Earth system, communicating conclusions frequently with colleagues, policy makers and the general public. NASA's Science Mission Directorate aims to stimulate public interest in the understanding of these Earth system science findings and to encourage young scholars to consider careers in science, technology, engineering and mathematics. However, barriers still exist to the use of actual satellite observations in the classroom to energize the educational process. NASA is sponsoring the "Mentoring and inquirY using NASA Data on Atmospheric and earth science for Teachers and Amateurs" (MY NASA DATA) project to systematically support educational activities at all levels of formal and informal education by reducing the ASDC data holdings to `microsets' that will be easily accessible and explored by the K-12 and the citizen scientist communities. The microsets are available via Web site (http://mynasadata.larc.nasa.gov) with associated lesson plans, computer tools, data information pages, and a science glossary. Teacher workshops will be held each summer for five years to help teachers learn about incorporating the microsets in their curriculum. Additionally, a Live Access Server (LAS) has been populated with ASDC data holdings such that users can create custom microsets for desired time series, parameters and geographical regions. Currently, parameters from the Clouds and the Earth's Radiant Energy System (CERES), the Surface Radiation Budget (SRB), Tropospheric Ozone Residual (TOR) and the International Satellite Cloud Climatology Project (ISCCP) are available and provide important information on fluxes and cycles in the Earth system. The first MY NASA DATA teacher workshop was held at Langley Research Center August 4-11, 2004. Workshop participants will be submitting successful lesson plans that they have created to help their students understand Earth system concepts. Additionally, the project team will be reaching out to the professional and citizen scientist communities, both as data users and as additional sources for educational materials. Most importantly, this group can serve as mentors to teachers within their local community, assisting with any initial concern over scientific data use in the classroom.

http://mynasadata.larc.nasa.gov

ED13A-0719 1340h

Use of a Walk Through Time to Facilitate Student Understandings of the Geological Time Scale

* Shipman, H L (harrys@udel.edu) , U. of Delaware, Dept. of Physics and Astronomy, Newark, DE 19716-2570 United States

Students often have difficulties in appreciating just how old the earth and the universe are. While they can simply memorize a number, they really do not understand just how big that number really is, in comparison with other, more familiar student referents like the length of a human lifetime or how long it takes to eat a pizza. (See, e.g., R.D. Trend 2001, J. Research in Science Teaching 38(2): 191-221) Students, and members of the general public, also display such well-known misconceptions as the "Flintstone chronology" of believing that human beings and dinosaurs walked the earth at the same time. (In the classic American cartoon "The Flintstones," human beings used dinosaurs as draft animals. As scientists we know this is fiction, but not all members of the public understand that.) In an interdisciplinary undergraduate college class that dealt with astronomy, cosmology, and biological evolution, I used a familiar activity to try to improve student understanding of the concept of time's vastness. Students walked through a pre-determined 600-step path which provided a spatial analogy to the geological time scale. They stopped at various points and engaged in some pre-determined discussions and debates. This activity is as old as the hills, but reports of its effectiveness or lack thereof are quite scarce. This paper demonstrates that this activity was effective for a general-audience, college student population in the U.S. The growth of student understandings of the geological time scale was significant as a result of this activity. Students did develop an understanding of time's vastness and were able to articulate this understanding in various ways. This growth was monitored through keeping track of several exam questions and through pre- and post- analysis of student writings. In the pre-writings, students often stated that they had "no idea" about how to illustrate the size of the geological time scale to someone else. While some post-time walk responses simply restated what was done in the walk through time, some students were able to develop their own ways of conceptualizing the vastness of the geological time scale. A variety of findings from student understandings will be presented. This work has been supported in part by the Distinguished Scholars Program of the National Science Foundation (DUE-0308557).

ED13A-0720 1340h

Storytelling Through the Temporal Bands: Collapsing Time With the Power of Ten

* McCaffrey, M S (mark.mccaffrey@colorado.edu) , Cooperative Institute for Research in Environmental Sciences, 1540 30th Street, Boulder, CO 80309 United States

Framing the history of the universe with a logarithmic axis in time provides an opportunity to break the temporal continuum into specific segments within the continuum of time. In recent years, the log-ten approach to temporal scaling has been used as a scientific and educational scaffolding for a variety of cosmic and Earth system processes and events, such as in J.M. Mitchell's 1976 "An Overview of Climatic Variability and Its Causal Mechanisms," (Quaternary Research 6, 481-493) and the "temporal bands" presented in the 1986 Bretherton Report and follow-up "Earth System Science: A Closer View (1988, NASA). Other efforts, such as the NOAA Climate TimeLine Information Tool (http://www.ngdc.noaa.gov/paleo/ctl) have begun to further flesh out the "powers of ten" framework, which allows time to be effectively collapsed in order to focus on particular aspects of the evolution and existence of the universe. We will present an overview of past efforts to capture the breadth of the universe using log-ten temporal scaling. In addition, particular "stories" from each time scale will be proposed: from the first seconds of the Big Bang (+1010Yrs.) to the development of light, galaxies and solar systems and planet Earth (109Yrs.), from the tectonic processes, evolution of biologic life, and mass extinctions that have occurred at the scales of millions of years, to the orbital processes that serve as the primary trigger of Ice Ages over hundreds of thousands of years, then focusing on the emergence of Homo sapiens from Africa in the past 100,000 years, the development of agriculture and civilizations in the past 10,000 years or so during the Holocene, and then concentrating on shorter time-scales and the events and processes they span. Whether beginning at the beginning (The Big Bang) or beginning at the sub-annual scale in which our everyday lives are lived, the "powers of ten" provide a scientific framework that holds strong potential for communicating the history and nature of the universe.

ED13A-0721 1340h

Industrial Lead in the Global Environment

* Flegal, A R (flegal@etox.ucsc.edu) , A. Russell Flegal, Environmental Toxicology,WIGS,UC Santa Cruz, Santa Cruz, CA 95064 United States
Ericson, J E (jeericso@uci.edu) , Jonathon E. Ericson, Environmental Health, Science, and Policy, UC Irvine, Irvine, CA 92697-7070 United States

Although the rates of emission, fluxes and recycling of natural and industrial lead in biogeochemical systems are needed to quantify environmental lead pollution, those geochemical processes are rarely incorporated in either Earth Science or Environmental Health Science curriculum. The need for an understanding of the global lead cycle in those diverse fields is due to the omnipresence of industrial lead contamination that was initiated over five millennia ago, which has often exceeded natural emissions of lead by orders of magnitude. That contamination has been repeatedly demonstrated in environmental analyses ranging from the most remote polar regions and oceans of the Earth to urban and industrial regions. The latter include studies of soil lead in Baltimore, New Orleans, St. Paul-Minneapolis, Los Angeles, Tijuana, and Ottawa, which show that lead from past combustion of leaded gasoline remains in those cities and it is bioavailable. With the protracted residence time of that soil lead (10$^{2}$ - 10$^{3}$ years), it is estimated that generations of urban children will continue to be exposed to this toxicant, unless there is abatement. Moreover, many third world countries are still using leaded gasoline and other sources of industrial lead continue to be emitted into the environment, albeit at reduced levels. Consequently, the geochemical cycling of lead is and will continue to be a most appropriate and topical subject of study in the curriculum of earth science and environmental health science.

ED13A-0722 1340h

Incorporating Environmental Regulation and Litigation in Earth Science Curriculum

* Flegal, A R (flegal@etox.ucsc.edu) , University of California, Santa Cruz, Environmental Toxicology, WIGS UCSC, Santa Cruz, CA 95064 United States

Fundamental knowledge of geological processes is not only needed for effective environmental regulation and litigation, but Earth Science students find that relevance motivating in their studies of those processes. Crustal abundance and redox reactions suddenly become personally meaningful when they are used to account for the presence of high levels of carcinogenic Cr(VI) in the students' drinking water. Similarly, epithermal mercury deposits and the element's speciation gain new importance when they are related to the warning signs on the consumption of fish that the students catch and eat. And even those students that are not motivated by these, and many other, applications of geology find solace in learning that anthropogenic perturbations of the global lead cycle may partially account for their short attention span, lack of interest, and inability to learn the material. Consequently, a number of courses in environmental toxicology and ground water contamination have been developed that are based on (1) case studies in environmental regulation and litigation and (2) active student participation as "expert witnesses" opining on the scientific basis of environmental decisions.