Collaborators:
Don Davis - Prof. Statistical Hydrology
Lisa Graumlich - Dir. Inst. for the Study of Planet Earth
Mark Weltz - USDA-ARS Rangeland Scientist
The primary intent of this proposal is to develop data collection, data analysis, related curricula and a computer interface with pre-college educational programs within the U.S. and abroad in the area of soil moisture measurements. Several important scientific issues regarding the aggregation, representation and utility of direct soil moisture measurements for the purpose of improving and validating satellite-and model-derived soil moisture will be addressed with the data collected through this effort. A series of physical science and mathematical/statistical skills will be defined and integrated into this educational program. The appeal and relevance of these exercises will be improved by stressing their interdisciplinary nature and geographic setting. Soil moisture deserves special focus because: it represents the temporal and spatial variable state of the land-atmosphere interface, it is a critical factor in animal and plant productivity and because there is an overwhelming need for a widely distributed ground measurement network that only this kind of proposal can satisfy.
Every GLOBE program will be able to participate, to some degree, in this investigation of soil moisture and its relevance to the global climate system. Participants will be encouraged to locate soil moisture sites on local park land, preserves and wild areas with minimal man-made disturbance; to identify their site on soils and land cover maps of the region; and to correlate soil moisture measurements with concurrent meteorologic data. Additional participant responsibilities will be to: develop a sustainable sampling strategy; make regular gravimetric or automated soil moisture measurements; try to collect ancillary meteorologic data, particularly precipitation; maintain instrument calibration and personnel certification; analyze the precision and accuracy of each measurement; report acceptable data to a central, ftp-accessible computer data archive; seek out other local sources of soil moisture data; develop local networks that share equipment, expertise and educational resources; and, study satellite soil moisture data of select areas using a MOSAIC or Gopher internet connection. A preliminary version of a MOSAIC home page that will be used to interface with students can be found at:
http://www.hwr.arizona.edu/globe_home.html or http://128.196.72.61/globe_home.html
An extensive network of young Earth Scientists could double their scientific contribution by helping locate, digitize and archive historical and on-going soils and soil moisture measurements made by local government, utility, agricultural and educational organizations. Data quality and the spatial and temporal distribution of the available data constrains the scientific utility of this data set and will limit which data are accepted by the central data archive. Any data that is archived will be assimilated using spatially distributed hydrologic models and gridded over as large a region as possible.
A Project Summary
B Table of Contents
C Project Description
Introduction Research Issues Potential Local and Scientific Collaborations Overall Program Design Measurement Component C.1 - General Mission Requirements C.2 - General Instrument Specifications Education Component C.3 - Potential Education Modules UA Analysis Component C.4 - Program Development Timeline Type, distribution and density of measurement stations Quality Control and Quality Assurance (QC/QA) Management Plan
D Bibliography
E Bibliographic Sketches
Alfredo Huete James Washburne Don Davis Lisa Graumlich Mark Weltz
F Summary Proposal Budget
G Current and Pending Support
H Facilities, Equipment and other Resources
I Outside Collaborative Arrangements
Introduction
The primary intent of this proposal is to establish data collection, analysis and a computer interface with suitable pre- college educational programs through a coordinated series of measurements and analysis related to surface soil moisture. Soil moisture is a critical link between the Atmospheric, Hydrologic and Land Cover science components identified in the GLOBE Announcement of Opportunity (AO) and is necessary to under-stand the hydrologic, biochemical and energy cycles at the Earth's surface. Fortunately, gravimetric soil moisture is easy to measure. Thus soil moisture is an ideal educational candidate to study the interconnected Earth/Climate system. Scientifically, however, point measurements of gravimetric soil moisture are only relevant to large-scale climate change studies if they help explain and can be placed in a regional context. This requires an understanding and identification of local and regional soils, land cover and meteorology. Thus, a secondary component of the measurement program outlined below addresses the classification of soils and vegetation patterns. Basic meteorological measurements are also required to study atmosphere-surface interactions but are beyond the scope of this proposal.
A broad range of subjects are addressed by this and other GLOBE program components to complement and reinforce any pre- college curriculum. The goal of this proposal is to emphasize the related science and math skills but also to make use of several interdisciplinary connections outlined below in order to broaden the appeal and relevance of these exercises. Clearly, science and mathematical skills are developed from the collection and analysis of data. Environmental studies require an appreciation and application of geography at many scales and helps put local issues in a more global perspective. Analytical reading and writing skills are bolstered by studying and reporting on the scientific literature related to the student's investigations. The nested and distributed nature of the program allows local upper-grade students to mentor and help teach lower-grade students. Finally, the GLOBE program makes a nice case study of the role of science in a politically charged environment.
The reason why soil moisture deserves special focus by GLOBE is its importance: as a state variable at the Earth-Atmosphere interface, as a critical factor in animal and plant productivity, and because there is an overwhelming need for a widely distributed ground measurement network. As a state variable, soil moisture controls the partitioning of precipitation into infiltration and runoff. Soil thermal properties, largely a function of soil moisture, control the rate and magnitude of surface warming and cooling and thus help partition radiant energy at the Earth's surface into latent and sensible heat components. Soil hydrologic properties, largely a function of soil moisture, control a plants ability to grow and thus help determine the type and productivity of the surface cover. By influencing agricultural productivity, soil moisture can even be related to the pattern of settlement in arid and semiarid regions. The beauty of soil moisture is that most of us, particularly people whose well being is tied to agriculture, have a good intuitive understanding of soil moisture and its consequences. Thus, many complex issues associated with climate change, natural variability and Earth science are addressed and understandable by studying soil moisture. Another unlikely asset is that soil moisture is so very poorly studied in a regional or global context. Virtually any controlled, well distributed data set has the opportunity to significantly impact the current revolution in satellite technology, land-surface modeling and our ability to better understand the whole climate system. Potential satellite soil moisture sensors are sensitive to many characteristics of surface soils and vegetation canopies which are difficult to estimate without extensive ground measurements and thus remain largely experimental. The timing of this initiative is fortuitous in that science and technology are ripe to take advantage of a spatially distributed measure of soil moisture such as will be produced by this initiative.
The most basic challenge poised by soil moisture is how to adequately characterize its magnitude. As inherently understandable as dry and wet soils are at a point scale, our ability to quantify the average soil moisture over larger areas suffers many limitations (Nielsen et al., 1973, Keisling et al., 1977, Rao and Ulaby, 1977). The first issue that could be addressed by soil moisture measurements over a large area is just how representative these measurements are of mean conditions (ISLSCP, 1992). A closely related issue is how to aggregate or disaggregate measurements over a range of scales (BAHC, 1993). Possible questions that could be addressed by this data set include:
- What is the spatial and temporal variability of soil moisture across the land surface?
- What density of soil measurement stations are required to validate different satellite-derived soil moisture products?
- How should point gravimetric measurements be aggregated to larger scales?
- How well do various satellite-derived soil moisture products agree with gridded ground data?
- What is the correlation between standard soils and vegetation land cover maps and actual ground observations?
Most GCM's and mesoscale models now include simple biosphere- atmosphere transfer schemes (BATS) to define the influence of the land-surface on the more traditional atmospheric variables (Dickinson et al., 1993; Sellers et al., 1986). In general, soils are coarsely approximated by a series of buckets with prescribed capabilities to store, drain and evaporate water (Manabe et al., 1965). Several related issues confront the international climate modeling community, namely how to prescribe, quantify and validate different soil-related parameterizations (ISLSCP, 1993). Equally important and basic research is required to assimilate soil moisture into operational forecast models (Mitchell, 1994). Retrospective meteorological analysis of the summer of 1993 across the central U.S. was significantly improved using realistic soil moisture (Betts, 1994). Thus, the following questions are of great current interest:
- How well do various model-derived soil moisture products agree with gridded observations?
- How to best assimilate distributed soil moisture into large-scale models?
- How can the land-surface parameterization of existing climate and meso-scale models be improved either by a better observational understanding of soil moisture variability or by including these observations in model assimilation?
The cause and implications of annual and longer soil moisture variations to man and the environment is a final and very pertinent research issue from the perspective of climate change studies. Repeated cycles of aridity have ravaged Northern Africa and led to severe desertification (Nicholson and Lare, 1990). Extended periods of high soil moisture have been implicated in aggravating the Flood of 1993 across the Upper Mississippi (Betts, 1994).
- What are the ranges of soil moisture at select sites and what critical points exist for critical animal and plant systems?
Exactly how each of these issues will be addressed is best left until the extent and quality of the GLOBE soil moisture data base has been established. Additional collaborations will likely be required. A high quality data base will assure a favorable response to this need.
Advanced students will be encouraged to review/evaluate the results from younger students as well as to prepare demonstrations, literature reviews/summaries and other guidance/out-reach activities for local as well as regional GLOBE science groups.
An extensive network of young Earth Scientists could double their scientific contribution by helping locate, digitize and archive historical and on-going soils and soil moisture measurements made (but "lost") by local government, utility, agricultural and educational organizations. This data source has great potential because of the probable broader geographic and biome distribution of these stations and a stronger commitment to longer-term measurement time-series. Guidelines for locating, evaluating, retrieving, coding and archiving this type of data will be developed.
The University of Arizona (UA) soil moisture project will guide the collection of and assimilate soil moisture measurements made by local, regional and global GLOBE science groups to provide a readily accessible, visual display of current and past measurements made by this group and to form collaborations with other scientists to improve our understanding of land-surface processes and models. A preliminary version of a MOSAIC home page that will be used to interface with students can be found at:
http://www.hwr.arizona.edu/globe_home.html or http://128.196.72.61/globe_home.html
No specific collaborations with scientists involved with satellite soil moisture detection have been formed at this time. This is because no operational soil moisture sensor is currently in orbit and most researchers in this field are reluctant to furnish highly preliminary satellite data or to agree to assimilate a data set (produced by GLOBE) of unknown quality. Many of the questions regarding the quantity and quality of the GLOBE soil moisture data set and the analysis of satellite soil moisture sensors should be resolved in the coming year. The potential to significantly influence and participate in this rapidly evolving field is huge, given an effective soil moisture measurement campaign on the part of GLOBE schools. Among the potential scientific and educational collaborations that have been identified are:
- A regional focus group in Oklahoma and Kansas; to take advantage of ongoing collection networks associated with the Oklahoma and Kansas mesonets, the DOE Southern Great Plains Atmospheric Radiation Measurement (ARM) Program, the GEWEX Continental-scale International Project (GCIP) and the USDA Agricultural Research Service (ARS) Little Washita Experimental Watershed.
- A regional focus group in southern Arizona and Northern Mexico; to take advantage of ongoing and planned data collection in the Upper San Pedro Basin by a NASA EOS Interdisciplinary Science (IDS) investigation into aridland hydrology and the USDA-ARS Walnut Gulch Experimental Watershed.
- Validation of early satellite soil moisture products by NASA and the ARS Hydrology Laboratory using Meteorsat active radar data extracted over the previous two sites on a weekly basis.
- Develop tutorials related to satellite soil moisture detection research with the French National space agency (CNES) and an agricultural bureau (CEMAGREF) using passive microwave data from ERS-1.
- Analyze seasonal and regional patterns of soil moisture based on a retrospective study of global SMMR passive radar data currently being conducted by NASA's Jet Propulsion Laboratory (JPL).
- Study the correlation between soil moisture and satellite- derived vegetation indices conducted by the USGS EROS Data Center (EDC).
- Improvement/assessment of NOAA's National Meteorological Center (NMC) Eta model using observed verses estimated initial soil moisture conditions.
- Improvement/assessment of the European Community Medium- range Weather Forecasting (ECMWF) model using observed vs. estimated initial soil moisture conditions.
- Participation in ongoing ISLSCP and IGBP initiatives to better define the global distribution of soils and critical GCM initial/validation data sets.
Spatial sampling Study/Sample plot Gridded Plot Cross-country transect Soil pit
Temporal sampling Meteorologic 1 hr/day/IOP Soil moisture/temp./precip. 3 hr/day/IOP Vegetation weekly/mo
Supporting measurements - GPS location, precipitation, basin ID
Participants in this project will be asked to select an appropriate (preferably natural) study site; describe the soils, vegetation cover and regional significance; develop a substainable sampling strategy; make regular gravimetric or automated soil moisture measurements; try to collect ancillary meteorologic data, particularly precipitation; maintain instrument calibration and personnel certification; analyze the precision and accuracy of each measurement; report acceptable data to a central, ftp-accessible computer data archive; seek out other local sources of soil moisture data; develop local networks that share equipment, expertise and educational resources; and, study satellite soil moisture data of select areas using a MOSAIC or Gopher internet connection. The measurement and educational components of this program are discussed below and summarized in Tables C.1-3.
Measurement Component
Conceptual design - Gravimetric soil moisture is determined easily by calculating sample net weight loss after drying. Measurement errors are possible but largely controllable. More interesting is the high inherent spatial variability of soils and soil moisture which allows for a wide application of statistical and sampling techniques to analyze data from any given site. Data aggregation issues and understanding physical differences between ground and satellite data provide a range of Earth Studies and climate-related topics to be explored using data merged regionally from a network of GLOBE observers.
Experimental methodology - A nested scale approach is proposed for rapid implementation without severe logistical or conceptual breakdowns. An overall project goal is to establish a globally distributed set of primary soil moisture sites which are largely representative of local biomes/soils. Regional focus sites will be identified for more intensive measurements on a case-by-case basis. A limited number of continuous soil moisture sensors will be distributed as part of this intensive focus effort. The science director shall largely focus on assimilating these prime research sites. Alternative exercises will be defined to better understand soil moisture and its relation to climate change where geography/logistics makes it impossible to participate in the integrated investigation of natural soil moisture variability.
Experimental procedure - A classical scientific approach is recommended which consists of: preparation, sampling, analysis, synthesis and further study. Preparation must include placing the selected site into a regional context by classifying its vegetation/biome, soils and geography. The most basic sampling approach relies on the Rule of Three: 3 samples, from 3 locations, weighed 3 times. More involved sampling and quality assurance exercises will be developed for upper grade levels based on sample grids and transects. Forms will be developed to help standardize data collection. Additional procedures are outlined below.
Soil Moisture:
basic: trowel, plastic bags, ties or tape, site map, 1 gm scale, solar dryer
better: shovel, sealed can, .01 gm scale, 100 degC oven
automatic: gypsum, semiconductor, other
Conceptual design - A series of educational modules will be developed to guide students through site selection, soil moisture sampling and analysis, remote sensing applications and Earth systems relevance. To the greatest extent possible, data quality will be monitored locally and only general systematic/programmatic checks will be established by the central archive. Upper-level students will be asked to mentor lower-level students to better serve local soils interest groups. Students will interact with each other and the project by way of a computer internet connection.
Data Analysis - Statistics and logic are the primary mathematical skills that will be developed. Most data analysis will be able to be done using a simple hand calculator and graph paper. Applications based on computer spreadsheets will also be developed. Data precision will be determined by multiple measurements and error analysis that considers equipment calibration. Correlation or other analysis relative to ancillary data such as precipitation, plant growth and net solar radiation will be encouraged. Basic soil storage (bucket), energy balance and microwave models will be provided to explore first-order data modeling.
Communication and Computers - GLOBE member schools will be connected to the internet by NSF so standard group inter- communication will be maintained through the use of a MOSAIC home page and email. MOSAIC and the lower overhead (no graphics) UNIX browser called LYNX are freely distributed from:
ftp://ftp.ncsa.uiuc.edu/Mosaic/Unix/binaries/2.5 ftp://ftp2.cc.ukans.edu/pub/lynx
A central data archive will be maintained at the University of Arizona for any scientifically usable data that is collected by the project. Data exchange will be through an anonymous FTP server. All data exchange formats will be self describing and clearly indicate data quality. A SUN Sparc 5 workstation is requested is serve as this internet hub, data archive, MOSAIC server and to run data interpolation and modeling programs for gridding GLOBE data. A designated, locally isolated gateway machine is also warranted for system load and security considerations. A PC 486 is required to effectively simulate and demonstrate educational material and visualization on a machine identical to other GLOBE schools.
The UA GLOBE science team will concentrate on developing educational modules, managing the data archive and producing 1 and 2-d data visualization products. Several layers of appropriate GIS data sets will be made available to students, such as STATSGO's soils and Anderson land cover. Considerable effort will be required to aggregate widely scattered soil moisture data. Table C.4 lays out some product targets. As scientifically products become available, we will integrate these into our current research and publications.
Time after award Target
1 wk Basic home page and anonymous FTP archive accessible
1 mo Critical field procedures described
3 mo Critical data analysis described
6 mo Illustrative ground and satellite examples
for first 2 focus sites
12 mo Full suite of education modules; small-scale gridding
18 mo Large-scale gridding; Aggregation paper
24 mo Validation/model initialization paper
Every GLOBE program will be able to participate, to some degree, in this investigation of soil moisture and its relevance to the global climate system. However, data quality and the spatial and temporal distribution of the available data limits the scientific utility of this data set and will be used to limit the data that will be accepted by the central data archive. Soil moisture measurements will be classified as follows:
1) Technique, for educational purposes, no scientific value
2) Calibration, does not represent natural conditions
3) Point sample I-III,
4) Transect average I-III,
5) Grid average I-III,
6) Historical I-III,
Data quality levels (or synonymously one-three star data) for potentially archivable data are designated as follows: I) raw/field, II) acceptable based on all team, field, and precision standards, and III) acceptable based on local and regional data assimilation.
Any ground measurements of soil moisture can only hope to validate regional and satellite measures of soil moisture if they are representative of regionally prominent soil profile types. It is also important to understand that no realizable station density will adequately sample the high spatial variability of soil moisture such that a simple average will be acceptable as a regional average. Thus, the distribution and density of soil moisture measurements sites are only limited by our ability to assimilate these data in a regional context. Participants in this project are encouraged to locate soil moisture sites on local park land, preserves and wild areas with minimal man-made disturbance, to identify the classification and range of their site on soils and land cover maps of the region, to correlate soil moisture measurements with concurrent meteorologic data and to make measurements on a regular basis. Only sites which comply with most of these requirements are suitable for further scientific analysis at the archive center.
The timing of soil moisture measurements are dictated by natural and orbital considerations. Phenomalogically, the time it takes local soils to dry down or exhibit significant changes (usually on the order of a week) limits the maximum time step. At the other end, measurements more often than every three hours are rarely justified. When regular measurements are not possible, measurement timing is best coordinated with satellite orbital considerations so as both measurements are synchronous or nearly so. From a climate change perspective, any periodic measurement program would be valuable, with regular weekly and daily schedules of most use. Timing guidelines will be broadcast as part of the archive center's home page activities since large-scale synchronous observation goals will change with time.
The FAO soils map of the World and a preliminary version of STATSGO will be used to estimate hypothetical regional sampling densities based upon the diversity of regional soils. Thus, the number of classified soil groups within each 1ox1o area and also the percent area covered by the two dominant classes can be determined. These maps will assist GLOBE managers to allocate scarce grant resources where questions of regional sample density are at issue.
A seven step procedure will be implemented to promote data quality and adherence to scientific protocols. These steps are:
1) Instrument calibration
2) Technique qualification
3) Station rating
4) Paired and stratified sampling schemes
5) Acceptable precision levels
6) Consistency checks with related parameters
7) Selective archiving with station/operator/measurement quality codes
Thus, QC/QA will largely be the responsibility of the contributing station. This must be so because the main product, soil moisture, has an inherently high spatial and temporal variability. Any attempts to filter incoming data at the archive cannot properly account for this high natural variability. A related issue is to make the reporting requirements rigorous while maintaining student interest. Each of the seven steps above will hopefully be considered part of the logical requirements of scientific investigation and will be educational in and of themselves. There can be no sure monitoring of electronically-submitted data and so the seriousness of fraud must be considered one of the educational activities.
Instrument calibration - the inherent accuracy and repeatability of weighing scales will be assessed annually or as conditions warrant. Technique qualification - groups or individuals will perform a series of sampling, weighing and calculating exercises designed to flag potential problems due to operator carelessness or poor procedure. Qualification tracking is best done by qualified GLOBE instructors at a local scale. Certification will be required before data can be added to the central archive.
Station rating - the suitability of each measurement station will be rated depending upon its extent, regional importance, natural state, availability of supporting data (soils description, rainfall and meteorology), length of record, and general data quality.
Paired and stratified sampling schemes - multiple measurements are encouraged wherever possible to help assess data quality. Both spatial and temporal sampling schemes can be designed for this purpose. Grid, transect and treatment (natural-wetted, grazed- ungrazed) sampling strategies are particularly useful. The destructive nature of gravimetric sampling dictates that intensively sampled areas be left as training areas whereas carefully controlled grids are best for long-term monitoring.
Acceptable precision levels - repeat measurements of a given sample yield simple estimates of data precision and standards will be set for acceptable data. Samples collected from a given area within the same time period should be roughly comparable although high soil spatial variability somewhat limits easy application of this principle.
Consistency checks with related parameters - a locally derived antecedent rainfall index can be a useful independent indicator of soil moisture. Simple energy balance models can also be used to help understand soil moisture variability where micro-meteorologic data is available. Procedures for correlating two independent variables will be developed.
Selective archiving with station/operator/measurement quality codes - information about each of the foregoing topics will be included along with the archived data to help sort or filter the data depending upon various criteria.
Dr's Huete and Washburne will share equally primary responsibility for the proposed project. Together they will:
- coordinate the development of any required educational modules,
- develop procedures and standards for the collection of soil moisture measurements,
- enter collaborative research projects based on these data,
- establish a MOSAIC home page to facilitate educational outreach,
- manage an FTP accessible computer archive of GLOBE-related soil moisture data,
- participate in teacher training and other educational out-reach activities,
- maintain contacts with other GLOBE science management teams to
coordinate the exchange and quality of required ancillary data,
- maintain contacts with the general soils, soil moisture remote
sensing research communities,
- satisfy all NSF reporting requirements of this project.
The collaborating scientists (Dr's Davis, Graumlich and Weltz) will help develop educational support material for this effort and offer guidance and support at on-site meetings to occur at least twice a year. Specifically,
- Dr. Davis will assist in the development of statistical analysis
exercises,
- Dr. Graumlich will help integrate general global change issues
into educational modules and serve as an interface with
related projects on campus,
- Dr. Weltz will assist in the development of field procedures and
retrospective data exercises using the ARS Walnut Gulch data
base,
The Department of Soil & Water Science and the Department of Hydrology & Water Resources at the University of Arizona will jointly distribute project funds in accordance with general University Guidelines.
Betts, A.K., Ball, J.H. and Beljaars, A.C.M., 1993, Comparison between the land-surface response of the ECMWF model and the FIFE- 1987 data, Q.J.R. Meteor. Soc., 119, 975-1001. Biospheric Aspects of the Hydrologic Cycle (BAHC), 1994, Aggregation Workshop, Tucson, AZ (special issue reports in J. Hydrology, ~mid-1995). Chen, F., Mitchell, K. and Schaake, J., 1995, Impact of soil moisture and hydrologic processes on land-surface evaporation modeling, Proc. AMS Conf. on Hydrology, Dallas, TX Dickinson, R.E., Henderson-Sellers, A. and Kennedy, P.J., 1993, Biosphere-Atmosphere Transfer Schemes (BATS) Version 1e as coupled to the NCAR Community Climate Model (CCM), Climate & Global Dynamics Div., NCAR/TN-387+str, 72 p. International Satellite Land Surface Climatology Project (ISLSCP), 1992, Remote Sensing of the Land Surface for Studies of Global Change: Models - Algorithms - Experiments, Workshop Report, Columbia, MD. Loveland, T.R., Merchant, J.W., Ohlen, D.O. and Brown, J.F., 1991, Development of a land-cover characteristics database for the conterminous U.S., Photogram. Eng. Rem. Sens., 57(11), 1453-1463. Keisling, T.C., Davidson, J.M., Weeks, D.L. and Morrison, R.D., 1977, Precision with which soil physical parameters can be estimated, Soil Sci., 124(4), 241-248. Manabe, S., Smagorinsky, J. and Strickler, R.F., 1965, Simulated climatology of a general circulation model with a hydrologic cycle, Mon. Wea. Rev., 93, 769-798. Mitchell, K.E., 1994, GCIP initiatives in operational mesoscale modeling and data assimilation at NMC, Proc. AMS Conf. on Global Change Studies, Nashville, TN NATO Advanced Research Workshop (ARW), 1993, Global Environmental Change and Land Surface Processes in Hydrology: The Trials and Tribulations of Modeling and Measuring, Abstracts, Tucson, AZ. Nicholson S.E. and Lare, A.R., 1990, A climatonomic description of the surface energy balance in the Central Sahel: Part II: the evapoclimatonomy submodel, J. Appl. Meteor., 2:123-137. Nielsen, D.R., Bigger, J.W. and Erh, K.T., 1973, Spatial variability of field-measures soil-water properties, Hilgardia, 42(7), 215-257. Rao, R.G.S. and Ulaby, F.T., 1977, Optimal spatial sampling techniques for ground truth data in microwave remote sensing of soil moisture, Rem. Sens. Environ., 6, 289-301. Sellers, P.J.,, 1986, A simple biosphere model (SiB) for use within general circulation models, J. Atm. Sci., 43(6), 505-531. Vinnikov, K.Y. and Yeserkepova, I.B., 1991, Soil Moisture: Empirical data and model results, J. Climate, 4, 66-79.
Facilities
Office - ~144 ft2 space with existing furniture
Computers - high use, available for support/student activities
HWR: Eos Image Processing and Visualization Lab - 8 SUN workstations,
SUN 670 Server, 8mm,1/4",9 track tape drives,
BW and color PS & 600 bpi printers, Cannon color scanner
ERDAS Imagine and Arc-Info Software,
SWS: Modis Project Silicon Graphics lab
Network - Campus T1 (1.5 Mb/s) connection and campus fiber-optic inter-connect
Major Equipment
(see computers, above)
Other Resources
Secretarial, computer system management and advanced programming
support are available through the HWR-Eos Project Office.
Micrometeorological station expertise is available from J.
Shuttleworth (HWR) and P. Brown (AZ. Met. network).
Back to UA/GLOBE Soil Moisture home page
Last updated: 12/15/94
Comments? globe@hwr.arizona.edu
~