Introduction to special section on Aeolian Processes: Field Observations and Modeling

Abstract

[1] Aeolian processes, involving erosion, transportation, and deposition of sediment by the wind, occur in a variety of environments including coastal areas, semiarid, and arid regions (e.g., cold and hot deserts), agricultural fields, and some planetary bodies, notably Mars and possibly Venus and Titan. Aeolian processes are responsible for the emission, transport, and deposition of dust and formation of areas of sand dunes. [2] This special section contains 14 papers that recognize the distinguished career of Dr. Dale Gillette. The papers are based upon oral and poster presentations given at the Sixth International Conference on Aeolian Research (ICAR VI), which was held at the University of Guelph, Ontario, Canada, 23–28 July 2006 (for a summary of the conference see Lancaster et al. [2006]). A special aspect of ICAR VI was the recognition of the long, multifaceted, and distinguished career of Dale Gillette, known to many for his seminal work on mineral aerosols and wind erosion processes. ICAR VI was the latest in a series of conferences on aeolian processes, sediments, and landforms that started in 1986 in Aarhus, Denmark, followed by conferences in Sandberg, Denmark (1990); Zzyzx, California (1994); Oxford, UK (1998); and Lubbock, Texas (2002). The next ICAR will be held in Argentina in 2010. [3] The papers in this volume were chosen for their close relationships to aspects of Dale Gillette's career and his major scientific contributions, as well as being a reflection of some of the most innovative contemporary approaches to studies of aeolian processes, sediments, and landforms. Many of the papers cite Dale's work and are clearly inspired by the fundamental concepts and approaches that he articulated. Thus, there are papers on dust emissions from disturbed and undisturbed surfaces [e.g., Macpherson et al., 2008] that build on the work of Gillette et al. [1980] as well as field studies of dust events and processes [McGowan and Clark, 2008] that continue and build upon the methodology developed during collaborative work at Owens Lake, California, the major source of mineral dust in the western United States prior to mitigation measures designed to reduce dust emissions [Cahill et al., 1996; Gillette et al., 1997a, 1997b, 1997c]. Further papers document experiments on dust deposition processes [Goossens, 2008] and field studies of dust deposition to soils and ecosystems [Bowker et al., 2008; Goldstein et al., 2008]. [4] Dale Gillette was a pioneer in conceptualizing and quantifying the effects of roughness elements (rocks, vegetation) on wind erosion and sediment transport processes [Gillette and Stockton, 1989; Musick and Gillette, 1990; Raupach et al., 1993; Stockton and Gillette, 1990], and this volume contains a number of papers [e.g., Brown et al., 2008; King et al., 2008; Sutton and McKenna Neuman, 2008; Okin, 2008; Shao and Yang, 2008] that build on the fundamental concepts that Gillette and his colleagues developed. Dale Gillette also maintained a long-term interest in the fundamentals of sediment mobilization and transport by wind [e.g., Gillette and Stockton, 1986; Gillette et al., 1996]; papers in this special section by Rasmussen and Sorensen [Rasmussen and Sorensen, 2008] as well as McKenna Neuman and Sanderson [McKenna Neuman and Sanderson, 2008] provide further understanding of the controls of sediment transport and creative ways in which to model these complex nonlinear processes. Throughout his career, Dale Gillette maintained a strong interest in modeling of aeolian processes. Many of the papers in this volume develop models that can be used to assess aeolian processes and their effects on the environment as well as to understand fundamental controls of the processes [e.g., Okin, 2008]. Although Dale never worked on dunes, the approach of the paper on barchan dune corridors [Elbelrhiti et al., 2008] adopts the approach to modeling advocated by him, being firmly based upon fundamental physical principles. [5] The papers in this volume clearly indicate the diversity and healthy state of aeolian research today. Challenges for the immediate future include the issue of scaling of detailed process studies, such as those reported here, on small spatial and temporal scales to regional and global issues such as the global dynamics of aeolian systems, including for example the contribution of dust deposition to soil development, and the human dimensions of change in aeolian systems. Despite considerable progress in recent years, there still remains a significant gulf between the modeling community and those engaged in field and experimental studies. Dale Gillette provides a stellar example of a person who has been able to bridge this gap and thereby contribute in a unique way to scientific understanding of aeolian processes as well as its application to real-world problems of wind erosion and air quality.