Progress Report - Year One

During the first year of this proposal, two conference papers of the on-going remote sensing research and two radar proposals have been submitted for consideration. Remote sensing collaboration with Dr. Vern Vanderbilt at NASA Ames Research Center has been strengthened. The development of new ties with scientists at other NASA Centers is underway. Preliminary analyses of the radar data have led to significant developments in our understanding of the utility of SAR data for mapping wetlands and the accuracy of global wetland databases. This research directly supports NASA's ESE priority theme of global carbon cycle.

Analyses of RADARSAT ScanSAR data collected over the Kolyma River basin in northern Siberia indicates that multi-temporal SAR data can detect and monitor changes in the areal extent of methane source areas over a growing season. Specifically, RADARSAT appears to differentiate open water, inundated wetlands, and non-inundated areas - distinctions that are essential to the development of accurate regional to global methane budget estimates. Furthermore, our analyses show that there are substantial mapping errors in existing global databases with wetlands underrepresented by 2-10x. By implication, current atmospheric and carbon budget models using these same land surface parameterizations may also have significant errors. These results will be presented at the 6th International Wetland Symposium sponsored by the International Ecological Association (INTECOL) to be held in Quebec City, Canada (August 6-12, 2000).

An assessment of SAR polarization and incidence angle on wetland mapping is nearly complete. Research by Christopher Incardona, a SNR graduate student under the direction of Morrissey, indicates that HH and VV polarization have little impact on wetland differentiation but that shallow incidence angles have significant impact and future wetland mapping efforts should utilize shallow angle SAR data. Preparation of these results for publication is currently underway.

Two remote sensing proposals have been submitted to NASA and NASDA as part of this research effort. A proposal for access to ALOS SAR data that will be acquired by the Japanese National Space Development Agency (NASDA) was submitted in January 2000 in response to a Research Announcement. Acceptance of this proposal would provide no-cost access and preferential acquisition of ALOS SAR data. With the launch of ALOS SAR in 2003, a new generation of multi-polarization, multi-angle, high resolution SAR data will become available to support scientific studies of the Earth. Preferential access to this data at no cost would support the goals and objectives of the research proposed here and put the investigator in a very competitive position for securing follow-on funding. In response to a joint U.S. NASA and Canadian Space Agency announcement of opportunity (due February 28, 2000), the research team is preparing a proposal based on the analyses of RADARSAT II data. RADARSAT II is scheduled to be launched in 2002. Acceptance of this proposal would provide much needed funding to support graduate students and staff in these efforts.

Second Year Research Directions

The overall goal of this research is to quantify the contribution of northern ecosystems to the global methane budget as it relates to climate change. In this effort, she has examined the pivotal role of vegetation (at landscape, community, and stomatal scales) as conduits in the release of methane from the soil to the atmosphere. More recently, this research has focused on the role of satellite remote sensing for monitoring spatial variations in inundation that can lead to an improved understanding of the contributions of boreal wetlands to the global methane budget - an important contribution to NASA's Earth Science Enterprise.

The next step in this research will be to test the utility of recently and soon to be launched satellite sensors to map wetlands both seasonally and at local to circumpolar spatial scales. With the launch of NASA's Terra satellite in late 1999, multitemporal MODIS data will also soon be available. In addition, Landsat Enhanced Thematic Mapper (ETM) and IKONOS 1m high resolution satellites were launched in fall 1999 and data will soon be available. These and the upcoming international launches of ENVISAT, ALOS, and RADARSAT II synthetic aperture radar (SAR) will begin a new decade of remote sensing. These satellite instruments have spatial, radiometric, and spectral resolutions that far exceed existing sensors and thus represent the next generation of Earth observation. Mapping northern wetlands is a major challenge and critical to understanding the global carbon cycle. These new sensors offer great potential to meet this goal.

Visible-near infrared (VIS/IR) sensors such as ETM and MODIS can provide information on vegetative characteristics such as productivity, community type, and phenology under certain environmental conditions. These sensors offer substantial promise but are limited in their application in northern wetlands. Frequent cloud cover, shallow inundation depths, and selective absorption by surface waters pose significant challenges. In contrast, SAR can acquire data day or night and during most weather conditions. SAR is thus ideally suited for wetland mapping studies, particularly in northern regions. In addition, SAR can penetrate wetland vegetative canopies, allowing detection of underlying and often shallow (centimeters) inundation critical to methanogenesis. The fusion of VIS/IR and SAR data, however, may provide complementary and unique information regarding wetlands. One new area of research proposed here is sensor fusion, i.e., integration of VIS/IR and SAR data.

To fully assess the utility of the new sensors, local studies in St. Lawrence and Lake Champlain basins will be initiated to complement analyses of existing sites in the northern Alaska, Canada, and Siberia. The establishment of local sites is essential to develop the detailed understanding of sensor performance only possible through fieldwork coincident with satellite overpasses. In addition, graduate students will have access to local study sites to support their research as well as access to computational facilities and satellite data.

A third and entirely new direction for my research is in the area of water quality and human health. Specifically, fecal contamination of surface waters through agricultural runoff and its potential risk to human health. One of ESE's research themes (and a current AO) involves the environment and human health. Specifically, potential human health risks that result from the emergence diseases/illnesses that may be related to broad scale environmental changes. Surface water can carry infectious agents that can pose a serious risk to humans. In particular, this research would focus on integrating remote sensing, GIS, and environmental monitoring to develop predictive models of health risk. These models will be based on an understanding of the underlying tie between fecal contamination of surface waters and environmental determinants in rural environments.

NASA Center Collaboration

Collaboration with current global mapping efforts by researchers at the Goddard Institute for Space Science (GISS) would greatly enhance the direction and significance of my research, taking it to the next level. Working with world-class scientists like Drs. James Hansen and Elaine Matthews would provide much needed expertise for my research team, graduate students, and myself. In addition, collaboration with Dr. Vern Vanderbilt of NASA Ames Research Center will complement our on-going research with VIS/IR satellite data. In addition, I would seek to develop collaborative research on the human health initiative with the Center for Health Applications of Aerospace Related Technologies (CHAART) at NASA's Ames Research Center.

Dr. Leslie Morrissey is currently an Associate Professor in the School of Natural Resources (SNR) at the University of Vermont. She mergers her ecological background with an expertise in GIS and remote sensing to study northern wetlands for the purpose of understanding their role and response to global climate change. Dr. Morrissey's Vitae and publications can be accessed at

http://www.snr.uvm.edu/leslie/morrissey.html