Software simplifies air-sea data estimates

Eos, Vol. 82, No. 1, January 2, 2001 on Alaska's Aleutian islands may mean that disastrous aircraft encounters with volcanic ash "could happen pretty much any time." Another unknown is the potential for scien­ tific and technological progress in areas, including basic research, that explains why volcanoes—and magma and gas activity— behave the way they do. Progress also could b e made in understanding operational aspects of what volcanoes have done in the past and what that could teach scientists about future activity and in outreach to edu­ cate the general public, as well as civil defense officials, about volcano hazards. Already a number of tools, including GPS (global positioning system), InSAR (interferometric synthetic aperture radar),and sophisti­ cated modeling, are helping to increase knowledge and provide advance notice about volcanic eruptions. Prior to the June 1991 eruption of Mt. Pinatubo in The Philippines, for instance, advance information about eruptive possibilities provided the public with about

two months in which to make civil defense preparations. Howard Zebker, professor of geophysics at Stanford University in California, said there are currently 600 potentially active volcanoes on the Earth. He said it is financially and logistically difficult to provide instrumentation to monitor all of them b e c a u s e many are diffi­ cult to reach or can b e dangerous. However, Zebker said s o m e tools are useful for distance monitoring. InSAR, he said, can provide detailed measurements of deforma­ tion on the Earth, including motion resulting from volcanic activity He said that o n e place scientists are study­ ing deformation movement at the centimeter scale is on several islands in the Galapagos archipelago, off the coast of Ecuador. "Our hope is to study their motions and try to understand how close we are" to a volcanic event, he said. Peter Mouginis-Mark, chief scientist with the Pacific Disaster Center at the University of

Software Simplifies Air-Sea Data Estimates PAGE 2 The atmosphere and o c e a n s interact at the o c e a n surface through boundary layers that are millimeters to many tens of meters thick. Processes at work in this relatively thin region are crucial in controlling the coupling between air and o c e a n and, as such, are important both in studies of the o c e a n or atmosphere in isolation, and in studies of the coupled system that investigate—for example—interannual climatic variability However, as a practical matter, attempts to generate flux estimates from particular obser­ vational data sets often involve a great deal of effort, since the relevant parameterizations are scattered throughout the literature; may have only limited applicability to certain locations and regimes; and are found using algorithms that are often c o m p l e x and iterative. This can b e especially frustrating when boundary layer theory is only peripheral to the main scientific or educational interest.

To begin to simplify and standardize flux estimates, we have developed the AIR_SEA toolbox, a software package of subroutines with a consistent user interface that c a n b e used to estimate parameters important in atmosphere/ocean coupling using the best available theory We intend to update this col­ lection from time to time as new and better parameterizations emerge, and we hope that other workers will add to this collection to more widely disseminate their results. The toolbox consists of a collection of MATLAB m-files that are distributed as source code. MATLAB is available on a wide variety of operating systems and platforms and it is widely used in the oceanographic community In addition, the vectorized nature of MATLAB lends itself to a more transparent presentation of the underlying algorithms.The toolbox struc­ ture is designed to facilitate quality control checks at intermediate stages in the process­ ing of a particular data set. Different compo­ nents can b e c o m b i n e d as necessary

Hawaii and professor of geology at the Hawaii Institute of Geophysics and Planetology stressed the importance of volcanologists working with scientists in other fields, as well as with govern­ ment bodies such as the U.S. Federal Emergency Management Agency (FEMA), relief agencies, and others. "Providing disaster relief personnel with [information about volcanic activity] ahead of time is the number one challenge volcanolo­ gists are going to b e faced with"he said. Referring to the theme of the briefing, Mouginis-Mark said that s o m e volcano hazard products he hopes will b e available by the year 2010 include the ability to detect eruption onsets within about 10 minutes, more accurate models of eruption plumes and effu­ sion flow paths, and improved use of GPS and other tools, as well as providing information to the public and to disaster relief officials.

Randy

Showstack,

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depending on the specific measurements available and flux parameters desired. Litera­ ture references are provided in the documen­ tation so the user can evaluate the original work. The toolbox is available via the World Wide Web at the SEA-MAT site maintained by Rich Signell of the U.S. Geological Survey (http://crusty. er.usgs.gov/sea-mat/). An electronic supplement to this news item containing more details about the t o o l b o x structure and functionality may b e obtained at the Web site: http://www.agu.org/eos_elec/ 00179e.html.

Authors Rich Pawlowicz, Department of Earth and Ocean Sciences, University of British Columbia, Vancouver, Canada; Bob Beardsley and Steve Lentz, Woods Hole Oceanographic Institution, Woods Hole, Mass., USA; Ed Dever, Center for Coastal Studies, Scripps Institution of Oceanogra­ phy La Jolla, Calif., USA; and AyalAnis, Depart­ ment of Oceanography Texas A&M University at Galveston,Tex., USA