Sponsored by the USDA, Agricultural Research Service; Texas Tech University, Office of International Affairs, International Center for Arid and Semiarid Land Studies; the Soil and Water Conservation Society, Golden Spread Chapter; and United States Geological Survey
A joint meeting of the Fifth International Conference on Aeolian Research (ICAR-5) and the Global Change and Terrestrial Ecosystems- Soil Erosion Network (GCTE-SEN) attracted over 130 scientists from 18 nations to the campus of Texas Tech University in Lubbock, Texas on July 22- 25, 2002. Previous ICAR meetings were held in Aarhus, Denmark (1985): Sandbjerg, Denmark (1990): Zyzxx, California, USA (1994); and Oxford, England, UK (1998). The ICAR meetings bring together physical and environmental scientists interested in the latest challenges and discoveries in aeolian (wind as a geological process) research. The GCTE-SEN, a core project of the International Geosphere-Biosphere Programme (IGBP), has a dual thrust: (1) to design and undertake experimental and monitoring programs to provide a predictive understanding of the impacts of climate and land use on soil erosion, and (2) to refine and adapt current erosion models for use in global change studies from plot to regional scales. GCTE-SEN has sponsored meetings to evaluate, test and compare water erosion models, but little has been done in regards to wind erosion and aeolian processes. More information on the network is available at http://mwnta.nmw.ac.uk/GCTEFocus3/networks/erosion.htm .
ICAR-5 was co-sponsored by the U.S. Geological Survey (USGS), U.S. Department of Agriculture (USDA), Agricultural Research Service (ARS), the Soil and Water Conservation Society Golden Spread Chapter, and the International Center for Arid and Semiarid Land Studies (ICASALS). A pre-meeting field trip led by Drs. Warren Wood (USGS), Stephen Stokes (Oxford), John Stout (USDA- ARS), and B.L. Allen (Texas Tech) showed 40 participants a variety of aeolian landscapes and processes operating on the Southern High Plains of west Texas; the excursion inspired spirited discussions and a great technical interchange amongst the participants. A midweek break featured field trips to the Lubbock Lake Landmark geoarchaeological site and a unique exhibit of medieval Vatican art on display at the Texas Tech Museum. Evening cultural programs during the conference included performances of cowboy poetry and country and Western music by influential Texas artists, providing an opportunity for more lighthearted exchanges.
The ICAR-5/GCTE-SEN meeting was dedicated to the memory of Dr. Harold Dregne, an internationally renowned expert on desertification. Dregne, a distinguished professor at Texas Tech and ICASALS director emeritus, authored 10 books and more than 170 scientific publications during his career. Dregne traveled throughout the world consulting for United Nations agencies and performing research for over 25 years on the causes and environmental impacts of desertification, until his untimely death earlier in 2002.
The conference provided an opportunity for researchers focusing on both the theoretical-modeling and field-experimentation aspects of aeolian processes to interact and learn the research needs and findings of their counterparts. One modeler stated “the conference was very productive for me as I had a weak knowledge of aeolian field studies”: a field researcher stated that he was excited to learn how current knowledge of the geomorphology of terrestrial aeolian “hotspots” is used to improve models of global-scale mineral aerosol transport. Perhaps due to the meeting’s location in the heartland of the North American Great Plains, many presentations at ICAR-5 dealt with wind erosion of agricultural lands in the USA, Canada, and elsewhere.
ICAR-5/GCTE-SEN included 133 papers presented during seven theme sessions each focusing on a different area of aeolian research. Every session included one or two keynote presentations, about eight oral presentations, and a larger number of posters. This allowed the keynotes and oral presentations to be of sufficient length with posters providing an opportunity for a wide variety of topics and discussions. All presentations (poster and oral) were accompanied by short written papers in a proceedings volume distributed to all participants at the beginning of the conference and now available online to the research community at http://www.lbk.ars.usda.gov/wewc/icar5/abstracttableofcontents.html .
A session on “Fundamental Processes” was highlighted by a number of papers (by Alfaro and Rajot, Bullard et al., Gillette, and Li et al.) investigating the mechanisms by which sand motion at the earth’s surface results in the emission of fine mineral dusts. Alfaro and Rajot’s keynote summarizing uncertainties in estimating fine dust emission via wind erosion suggested that mineral aerosol emissions are more a function of surface roughness than sedimentary texture of the source area. Another theme of many papers presented in this session was the aerodynamics of the interaction between windflow and other environmental parameters at a variety of spatial scales (including presentations by Bauer et al., Garvey et al., Lee and Greeley, McKenna Neumann and Rice, Sterk et al., and Wiggs et al.).
The second theme session, “Instrumentation/Measurement in the Field and Lab,” included a keynote presentation by Mikami Masao with preliminary results of ADEC, the Sino-Japanese Aeolian Dust Experiment on Climate Impact (http://www.aeoliandust.com). Some of the papers in this session concerned improvements in wind tunnels (Leys et al.’s mini-wind tunnel used for field studies in Australia, and al-Nassar et al’s long atmospheric boundary layer wind tunnel in Kuwait) and remote sensing techniques for a landscape-based approach to wind erosion prediction (Chavez et al.’s work combining satellite and ground-based techniques in southwestern North America). A number of presentations (including those by Baas, Van Boxel et al., and the other keynote by McKenna-Neuman and Nickling) showed how new instruments now available make measurements of sand motion, dust emission, and meteorological variables possible with sensitivities that would have been unthinkable even a decade ago, allowing researchers to gather data that allows a critical re-evaluation of standard formulas of dust emission, many of which date back many decades. McKenna-Neuman and Nickling’s keynote pointed out that calibration of instruments and spatial and temporal scaling pose significant challenges, and standardization of instruments and techniques is needed to improve cross-study comparisons.
Field investigations of aeolian processes in almost all continents on earth including Australia (McTainsh et al.), Asia (Murao), North America (Arimoto et al.), Africa (Rajot et al.), Europe (Letic and Savic), Antarctica (Lancaster et al), and even simulations of Martian processes (Kinch et al.) were described at ICAR-5, many in the third theme session on “Field Studies.” Zobeck et al.’s keynote on measurement and data analysis methods for field-scale research pointed out that there are many methods but relatively few principles, describing important considerations for properly matching instrumentation and site. The other keynote presentation by Leys et al. described an Australian program for testing regional dust emission models for environmental auditing, and the challenges of matching the scale and temporal frequency of data collection to model requirements.
For the first time at ICAR, a session was held on the modeling of aeolian processes. Several presentations described new schemes for simulating the large-scale transport and distribution of mineral dust aerosols in operational short-term forecasting (Barnum et al. and Song Zhenxin) and in long-term models (Ginoux’s keynote). Zender and Newman described the important relationships between topographic depressions and global atmospheric dust distributions, and Shao and Li illustrated how computational fluid dynamics (CFD) algorithms not widely available at the time of previous ICAR conferences can be used in the numerical simulation of aeolian processes. Raupach and Lu’s keynote presentation overviewed how land-surface processes can be represented in numerical models of aeolian activity, while many other papers showed applications and testing of the WEPS and RWEQ models used for wind erosion prediction in a predominantly agricultural context.
The session on environmental impacts of aeolian processes and erosion control included presentations on dust produced by agricultural operations with regards to their effects (Zhao et al.) and control mechanisms (Hagen’s keynote), while the keynote presentation by Claiborn et al. considered to what extent wind-eroded dusts contribute to violations of particulate-matter air pollution standards. Global hot spots of aeolian dust emission caused by desiccation of playas such as the Aral Sea (Singer et al.) and Owens Lake (Winn et al.) were covered, as well as the effects of aeolian processes on sensitive marine (Garrison et al.) and terrestrial (Goldstein et al.) ecosystems.
The session on aeolian paleoenvironments included papers illustrating the use of geochemical, geophysical and stratigraphic methods in aeolian research- techniques utilized in many other presentations throughout the meeting. Muhs’s keynote showed how geochemical ratios of dune sands in western North America provide insights into the origin, evolution, and long-term history of aeolian sand bodies, while posters by Moreland et al. and Hoang et al. showed how grain-size trends in Paleozoic loessites documented wind-strength variations hundreds of millions of years in the past. The relationships of climate dynamics to aeolian processes were illustrated by Lancaster et al., who showed how dune forms in the western Sahara could be used to reconstruct Quaternary wind regimes, and by Knight et al. and Tsoar, whose presentations quantified how climate factors and changes affect the mobility of dunes. The final session, focusing on new approaches to the study of dunes and related landforms, included presentations by Walker (keynote) and Mulligan showing the ability of new computational techniques to simulate airflow processes and dune movement and morphology.
The ICAR-5/GCTE-SEN 2002 web page at http://www.lbk.ars.usda.gov/wewc/icarv.aspx contains an archive of the meeting, including downloadable copies of all papers presented (proceedings). Special issues of Earth Surface Processes and Landforms, Geomorphology, Environmental Modelling and Software, and Journal of Soil and Water Conservation will appear soon with peer-reviewed articles derived from many of the presentations.
- Thomas E. Gill (Texas Tech University, email@example.com) and Ted M. Zobeck (USDA Agricultural Research Service, firstname.lastname@example.org)