bluuebunny/crossref_metadata_2025 huggingface dataset:
Discussion on the Forum Article, “What is the aurora?”
Authors: Bhardwaj Anil
Published: October 2006

In a recent Forum article—“What is the Aurora?” (Eos Trans. AGU, 85(52), 567, 28 December 2004)—John Clarke has raised an important issue: how we define the aurora. I, too, was confronted by the same question when I was writing a review entitled “Auroral emissions of the giant planets” with Randy Gladstone [Bhardwaj and Gladstone, 2000]. I widely searched the literature then, to find how the aurora should be defined.

Finally we defined the aurora as “electromagnetic radiation emanating from the high latitudes of a planet (also called auroral or polar latitudes).” We also defined auroras as “(generally) high‐latitude atmospheric emissions that result from the precipitation of energetic charged particles from a planet's magnetosphere.”
[Comment on “Meeting the challenges of natural hazards in the wake of the tsunami disaster” by Soroosh Sorooshian] More on the challenges of natural hazards
Authors: Pierson Thomaas C.
Published: October 2006

In the 11 January 2005 issue of Eos, Soroosh Sorooshian offered cogent suggestions about how we, as professional scientists, might do more to make the world safer from natural hazards. Not explicitly mentioned was an additional important contribution we can make that requires no additional research. It is simply to more effectively apply what is already known by increasing public awareness of both the hazards themselves and the simple, life‐saving responses to hazards that people can take without outside warning, direction, or assistance from public officials.

For example, school children in many seismic areas are taught to duck immediately under desks or tables during earthquakes (“drop, cover, and hold on”). Similarly, people living in coastal areas along subduction zones can be taught that earthquakes may cause tsunamis and to respond to a felt earthquake by moving as quickly as possible to high ground or to inland areas and remaining there for a few hours.
C‐band radar observes water level change in swamp forests
Authors: Lu Zhong , Crane Mike , Kwoun Oh‐Ig , Wells Chris , Swarzenski Chris , Rykhus Russ
Published: October 2006

C‐band radar pulses backscatter from the upper canopy of swamp forests, and consequently interferometric synthetic aperture radar (InSAR) analysis of C‐band imagery has not been exploited to study water level changes in swamp forests. This article explores C‐band ERS‐1 (European Remote Sensing Satellite) and ERS‐2 InSAR data over swamp forests composed of moderately dense trees with a medium‐low canopy closure in southeastern Louisiana to measure water level changes beneath tree cover.

Wetlands cover more than 4% of the Earth's land surface and interact with hydrologic, biogeochemical, and sediment transport processes that are fundamental in understanding ecological and climatic changes [Alsdorf et al, 2003; Prigent et al., 2001 ; Melack and Forsberg, 2000; Dunne et al., 1998]. Measurement of water level changes in wetlands, and consequently of changes in water storage capacity, provides a required input for hydrologic models, and is required to comprehensively assess flood hazards [e.g., Coe, 1998].
AGU plans Congressional Visits for 10–11 May
Authors: Sorooshian Soroosh
Published: October 2006

A primary objective of the Committee on Public Affairs, which I chair, is to increase the number of AGU members who bring their knowledge to bear on matters of common concern at the national level. An excellent opportunity to do so is the upcoming Congressional Visits Day (CVD), slated to take place 10–11 May 2005 on Capitol Hill, in Washington, D.C.

Over 200 scientists from all disciplines will gather together for a half day of briefings from congressional and Administration leaders on the topic of science in the federal government. The next day, the scientists spend the full day visiting their congressional delegations and other members of Congress who shape the federal budget for geophysical research.
RADARSAT‐1 interferometric baseline catalog at the Alaska satellite facility
Authors: Gens Rudiger
Published: October 2006

Interferometric synthetic aperture radar (InSAR) techniques are used in numerous applications, especially in long‐term monitoring of surface deformations. For these studies, a large data volume is needed and the issue of careful data selection is critical. One of the main parameters to decide whether a particular data set is suitable for a certain application is the interferometric baseline. The knowledge of the baselines limits the extra processing efforts required to determine the usefulness of data sets for the application project.
Assembly focuses on volcanism and societal impacts
Authors: Grunder Anita , McNutt Steve
Published: October 2006

With a theme of “Volcanism and Its Impact on Society,” the November 2004 meeting of the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI) held in Pucón, Chile, brought together experts to discuss many aspects of volcanology

The five‐day IAVCEI meeting was the association's largest, attracting 940 participants from 44 countries. U.S. participants constituted one third. The meeting consisted of over 1100 abstracts presented in 12 theme sessions, and reflected a diversity of disciplines and techniques encompassed by volcanic studies.
Objectives for a cabled observatory in Alaska's Beaufort Sea
Authors: Coakley Bernard , Chayes Dale , Proshutinsky Andrey , Weingartner Tom
Published: October 2006

Study of the Arctic Ocean is limited by the sea ice and harsh weather that prevent access through much of the year. These constraints have restricted data acquisition in the past and obscured understanding of events, processes, and variability of the environment of the Arctic Ocean. Breaching this isolation can be achieved through the use of new technologies and the adaptation of existing instrumentation to monitor the shelf and basin independent of surface conditions.

Through much of its history, Arctic oceanography has been dedicated to the study of large‐scale seafloor structure, ocean circulation, and hydrographic structure. Recently, expedition‐based observations have been augmented by moored or ice‐tethered instruments that provide year‐round observations during the span of their deployment. With increased knowledge collected over an extended period, variability has become apparent but is not well understood. Permanent seafloor instrumentation is the only way to understand this variability (seasonal and annual) in the context of what may be rapid climate change (annual to decadal).
Tackling strategies for thriving geoscience departments
Authors: Wuebbles Donald J. , Takle Eugene S.
Published: October 2006

Special sessions on thriving geosciences departments and on cyberinfrastructure in the geosciences highlighted the recent 5th AGU Meeting of Heads and Chairs of Earth and Space Science Departments. The meeting was held in conjunction with the 14th meeting of the Heads and Chairs of Programs in Atmospheric, Oceanic, Hydrologic and Related Sciences, sponsored by the American Meteorological Society (AMS),and the University Corporation for Atmospheric Research (UCAR).

“From Surviving to Thriving: Strategies for Advancing University Geoscience Programs in Times of Change” was a topic that drew intense interest. This panel discussion, led by Don Wuebbles (University of Illinois), included panelists Eric Betterton (University of Arizona), Judy Curry (Georgia Institute of Technology), Heather MacDonald (College of William and Mary), and Jim Kirkpatrick (University of Illinois).
Paleoceanography and paleoclimatology of the Southern Ocean
Authors: Filippelli Gabriel , Warnke Detlef , Flores Jose Abel , Marchitto Thomas
Published: October 2006

Among the greatest successes of the Ocean Drilling Program were the concerted drilling efforts and exciting results recovered from the Southern Ocean (SO) surrounding Antarctica. Scientific drilling in the SO and on the Antarctic margin has recovered material from hundreds of sites for scientific analysis. The dynamic nature of ice sheet development and ice/margin interactions through time has been observed, as has the role that the SO plays in the development and persistence of Antarctic glaciation. The SO has been documented as a sensitive mixing pool of global water masses that is at times a locus of high biological sedimentation. Also, the SO has been found to contain high‐resolution records of climate forcing and response, and as such it may hold clues to future climate.
Earth system focus for Geosphere‐Biosphere Program
Authors: Brasseur Guy , Steffen Will , Noone Kevin
Published: October 2006

Global change is perhaps the greatest environmental issue facing humanity. The Earth's atmosphere and biosphere are undergoing profound change, due not simply to terrestrial or extraterrestrial geophysical forces, but to the numbers and activities of people.

Over the last 100 years the human population soared from little more than one billion to six billion, and over the last 50 years economic activity increased nearly tenfold. Half the Earth's land surface has been modified for direct human use, and nearly all is affected by humans in one way or another. Over two thirds of ocean fisheries are fully or overexploited, and scant pristine coastline exists outside of the high latitudes. The composition of the atmosphere—particularly greenhouse gases, reactive gases, and aerosol particles—is significantly different from a century ago.
The largest aftershock ever recorded?
Authors: Grasso J. R. , Voisin C.
Published: October 2006

The largest aftershock recorded so far of the Mw 9.3 Sumatra earthquake of 26 December 2004 might be assumed to be the 28 March off‐Sumatra event (Mw 8.7), which occurred three months later, 160 km away, and with a 0.6 magnitude deficit. Because the 28 March event reproduces in size and location the Mw 8.5 main shock of 1861, it could be argued that it should rank as among Earth's top 10 largest main shocks since 1900. Whether the 28 March event was an aftershock or compound earthquake, what does it imply for the occurrence of the next Indonesian “Big One”?

What is known about fault interactions and earthquake triggering primarily derives from shallow earthquakes in the brittle crust. This knowledge reduces to distribution laws in size and time: a power law for the frequency size distribution of earthquakes ‘Gutenberg and Richter, 1954’; a power law for the decay of seismicity rate after any earthquake [Omori, 1894; Utsu et al., 1995]; and the Båth law for the average size of the largest aftershock [Richter, 1958].
New tools for analyzing time series relationships and trends
Authors: Moore J. C. , Grinsted A. , Jevrejeva S.
Published: October 2006

Geophysical studies are plagued by short and noisy time series. These time series are typically nonstationary contain various long‐period quasi‐periodic components, and have rather low signal‐to‐noise ratios and/or poor spatial sampling. Classic examples of these time series are tide gauge records, which are influenced by ocean and atmospheric circulation patterns, twentieth‐century warming, and other long‐term variability.

Remarkable progress recently has been made in the statistical analysis of time series. Ghil et al. [2002] presented a general review of several advanced statistical methods with a solid theoretical foundation. This present article highlights several new approaches that are easy to use and that may be of general interest.
Hotspot ecosystem research on the margins of European Seas
Authors: Weaver Philip P. E.
Published: October 2006

The European Union has recently funded an integrated project called Hotspot Ecosystem Research on the Margins of European Seas, or HERMES, which began on 1 April 2005 and will run for four years. HERMES is designed to gain new insights into the biodiversity, structure, function, and dynamics of ecosystems along Europe's deep‐ocean margin.

It represents the first major attempt to understand European deepwater ecosystems and their environments in an integrated way, by bringing together expertise in biodiversity, geology, sedimentology physical oceanography, microbiology, and biogeochemistry so that the relationship between biodiversity and ecosystem functioning can be understood. The project extends beyond basic research, mapping, and habitat classification into ecosystem modeling and policy advice. The modeling is aimed at improving the ability to forecast the effect on ecosystems of natural and anthropogenic perturbations.
Does the core leak?
Authors: Walker Richard J. , Walker David
Published: October 2006

Appreciable geophysical evidence has accumulated to suggest that some slabs subduct into the Earth's deep mantle and that certain mantle plumes originate in the lower mantle. Despite this progress in understanding geophysical geodynamics, debate continues on corroborating geochemical evidence. If some plumes rise from the core‐mantle boundary and there is chemical interaction between the core and mantle, it is possible that such plumes could contain a unique fingerprint that is characteristic of the core.

Unequivocal identification of a core component in a plume‐derived rock could potentially settle major questions in geodynamics. This article reviews geochemical tools that would likely be sensitive to such interactions, and considers possible mechanistic causes for core‐mantle interaction.
Web site on marine connectivity around Australia
Authors: Condie Scott
Published: October 2006

The Commonwealth Scientific and Industrial Research Organisation (CSIRO), with support from the Western Australian Government, has developed an online tool for marine scientists and managers to investigate the largescale patterns of spatial connectivity around Australia that are associated with ocean current transport (Figure l). This tool, referred to as the Australian Connectivity Interface, or Aus‐Connle, is expected to find applications in areas such as tracer dispersion studies (see example by Ridgway and Condie [2004]), larval dispersion and recruitment, and the development of scenarios and preliminary risk assessments for contaminant dispersion in the marine environment.

After selecting a region of interest, users can investigate where material carried into that region comes from, or where material originating in that region goes to, over a range of timescales (weeks to months). These connectivity statistics are based on large numbers of particle trajectories (one million at any given time) estimated from satellite altimeter data, coastal tide‐gauge data, and winds from meteorological models ]Condie et al., 2005]. Users can save the results in a variety of formats (CSV, Excel, or XML) and, as an option, may save their sessions by first registering.
U.S. nitrogen science plan focuses collaborative efforts
Authors: Holland E. A. , Guenther A. , Lee‐Taylor J. , Bertman S. B. , Carroll M. A. , Shepson P. B. , Sparks J. P.
Published: October 2006

Nitrogen is a major nutrient in terrestrial ecosystems and an important catalyst in tropospheric photochemistry. Over the last century human activities have dramatically increased inputs of reactive nitrogen (Nr, the combination of oxidized, reduced, and organically bound nitrogen) to the Earth system (Figure 1). Nitrogen cycle perturbations have compromised air quality and human health, acidified ecosystems, and degraded and eutrophied lakes and coastal estuaries [Vitousek et al., 1997a, 1997b; Rabalais, 2002; Howarth et al., 2003; Townsend et al., 2003; Galloway et al., 2004].

Increased Nr affects global climate. Use of agricultural fertilizers such as ammonium nitrate leads to increased soil production of nitrous oxide (N2O), which has 320 times the global warming potential of carbon dioxide (CO2). Emission of nitrogen oxides (NOx = nitric oxide, NO + nitrogen dioxide, NO2) from fossil fuel burning leads to increases in tropospheric ozone, another greenhouse gas. Ozone is phytotoxic, and may reduce terrestrial CO2 sequestration. To predict the effects of nitrogen cycling changes under changing climatic conditions, there needs to be a better understanding of the global nitrogen budget.
The Langley‐Newcomb brouhaha over the flying machine
Authors: Carter W. E. , Carter M. S.
Published: October 2006

One century after the Wright brothers proved it was possible to build a piloted heavier‐than‐air “flying machine,” several airlines will soon, perhaps as early as October 2005, begin to operate the largest passenger aircraft ever built, the Airbus A380. The A380 is nearly half again as large, in terms of passenger floor space, as the Boeing 747‐400. It can be configured to hold as many as 840 passengers, and it has a takeoff weight of 550,000 kg, a maximum range of 15,000 km, and a cruising speed of Mach 0.85.

The remarkable advances in aeronautics realized during the past century make it difficult to understand how anyone, let alone Simon Newcomb, one of the most prominent U.S. scientists at the turn of the twentieth century, could have opposed efforts by Samuel Pierpont Langley to build a piloted winged aircraft for the military. Newcomb argued that Langley was doomed to failure because the technology required to build such an aircraft was not then available, and he bemoaned the “waste” of scarce government funds toward the effort.
Chesapeake Bay plankton and fish abundance enhanced by Hurricane Isabel
Authors: Roman M. R. , Boicourt W. C. , Kimmel D. G. , Miller W. D. , Adolf J. E. , Bichy J. , Harding L. W. , Houde E. D. , Jung S. , Zhang X.
Published: October 2006

Hurricane Isabel made landfall east of Cape Lookout, North Carolina, as a Category 2 (Safford‐Simpson scale) hurricane on 18 September 2003. The storm's center tracked to the northwest, passing west of Chesapeake Bay (Figure 1) in the early morning of 19 September. Hurricane Isabel brought the highest storm surge and winds to the region since the Chesapeake‐Potomac hurricane of 1933 and Hurricane Hazel in 1954 (http://www.erh. noaa.gov/er/akq/wx_events/hur/isabel_2003. htm). Storm surge was variable in the region, reaching a high of 2.7 m on the western side of the bay where the heaviest rainfall occurred. The highest sustained wind in the bay region reached 30.8 m s−1 at Gloucester Point,Virginia, with gusts to 40.7 m s−1.
Ethnic differences in geoscience attitudes of college students
Authors: Whitney David J. , Behl Richard J. , Ambos Elizabeth L. , Francis R. Daniel , Holk Gregory , Larson Daniel O. , Lee Christopher T. , Rodrique Christine M. , Wechsler Suzanne P.
Published: October 2006

While a gender balance remains elusive in the geosciences [de Wet et al., 2002], the underrepresentation of ethnic minorities in these fields is at least as great a concern.

A number of cultural and social factors have been proposed to explain the poor ethnic minority representation in the geosciences, including limited exposure to nature, deficient academic preparation, inadequate financial resources to pursue higher education, ignorance of career opportunities in the geosciences, insufficient family support, and misconceptions of the field.
U.S. climate variability and predictability program reorganizes
Authors: Legler David M.
Published: October 2006

Scientific advances, new ways of organizing research, and changes in the programmatic and budget landscapes have motivated an evaluation and reorganization of the U.S. Climate Variability and Predictability (U.S. CLIVAR) program (CLIVAR is part of the World Climate Research Programme (WCRP)). After considering a number of inputs and to ensure that U.S. CLIVAR is well structured to meet relevant objectives over the next decade, the program is changing its scientific committee infrastructure.
Experiment to characterize tropical cloud systems
Authors: May Peter T. , Mather James H. , Jakob Chriatian
Published: October 2006

A major experiment to study tropical convective cloud systems and their impacts will take place around Darwin, northern Australia, in January and February 2006. The Tropical Warm Pool International Cloud Experiment (TWP‐ICE) aims to study cloud systems and their radiative, chemical, and moisture budget impacts from the initial convection through to the decaying, convectively generated cirrus.

This broad aim is being addressed by a dense observational network that includes two sites equipped with cloud radar and lidar, a polarimetric (dual‐polarization) weather radar and another operational Doppler radar in the area, wind profilers, infrared interferometers, flux stations, lightning interferometers, and oceanographic measurements. Also, an array of five radiosonde sites arranged in a ring with a diameter of about 250 km around Darwin will conduct soundings every three hours for a period of 24 days.
Water supply planning in the Lake Michigan region
Authors: Walker Doug , Wickenkamp Jeff
Published: October 2006

Standing in Chicago, Illinois, and gazing across the vastness of Lake Michigan, it is hard to imagine that communities in the surrounding region could be concerned about running short of water. However, international treaties, U.S. Supreme Court decrees, and interstate agreements restrict diversions of water from the Great Lakes in an effort to maintain lake levels. This forces the region to use alternative sources of water to serve the rapidly growing population.

Local governments in the southern Lake Michigan region, and likely elsewhere in the Lake Michigan region, need to acquire and integrate data and information regarding the region's water supply into planning processes.
Earth and Space Science Ph.D. Class of 2003 Report released
Authors: Keelor Brad
Published: October 2006

AGU and the American Geological Institute (AGI) released on 26 July an employment study of 180 Earth and space science Ph.D. recipients who received degrees from U.S. universities in 2003. The AGU/AGI survey asked graduates about their education and employment, efforts to find their first job after graduation, and experiences in graduate school. Key results from the study include: The vast majority (87%) of 2003 graduates found work in the Earth and space sciences, earning salaries commensurate with or slightly higher than 2001 and 2002 salary averages. Most (64%) graduates were employed within academia (including postdoctoral appointments), with the remainder in government (19%), industry (10%), and other (7%) sectors. Most graduates were positive about their employment situation and found that their work was challenging, relevant, and appropriate for someone with a Ph.D. The percentage of Ph.D. recipients accepting postdoctoral positions (58%) increased slightly from 2002. In contrast, the fields of physics and chemistry showed significant increases in postdoctoral appointments for Ph.D.s during the same time period. As in previous years, recipients of Ph.D.s in the Earth, atmospheric, and ocean sciences (median age of 32.7 years) are slightly older than Ph.D. recipients in most other natural sciences (except computer sciences), which is attributed to time taken off between undergraduate and graduate studies. Women in the Earth, atmospheric,and ocean sciences earned 33% of Ph.D.s in the class of 2003, surpassing the percentage of Ph.D.s earned by women in chemistry (32%) and well ahead of the percentage in computer sciences (20%), physics (19%), and engineering (17%). Participation of other underrepresented groups in the Earth, atmospheric, and ocean sciences remained extremely low.
Antarctic science
Authors: Summerhayes Colin
Published: October 2006

Once upon a time, dinosaurs roamed Antarctica and swam in its seas. Since then, life evolved as the climate cooled into the ice ages. Life will no doubt continue to evolve there as the globe now warms. But nowadays, humans are having a profound and direct effect on life in Antarctica, the sub‐Antarctic islands, and the surrounding Southern Ocean, which are being invaded by a wide range of alien species including microbes, algae, fungi, bryophytes, land plants, invertebrates, fish, birds, and mammals.
[Comment on “Raising the ante on the climate debate”] Wasting public money?
Authors: Parrish Judith Totman
Published: October 2006

The letters written by U.S. Rep. Joe Barton and his committee (Forum, Eos, 12 July 2005, p. 262) asking for data from Michael Mann and other scientists are certainly chilling because of the time it would take to meet the requests, but Rep. Barton has every right to make such requests.

Thomas Crowley asked,“At some point, one must ask why should a member of the U.S. Congress get involved in this matter which may have been raised by a Canadian?” He opines that the reason was to intimidate and foment uncertainty. The real answer is, Barton is making the request because he can and is doing what, in his mind, is his job. That the issues were raised by a Canadian is immaterial; plenty of Americans are also skeptical of global change research. Moreover, the argument that “there is more agreement than disagreement” among the various paleoclimate reconstructions would not resonate with a layperson; even laypeople know that the history of science is fraught with examples of consensuses that proved wrong.
2004 Editors' Citation for excellence in refereeing
Authors: Anonymous
Published: October 2006

The reviewers whose photographs appear below have been cited by Editors of AGU journals for excellence in refereeing. The Editor's citation recognizes this special service to the Union, and the individuals listed below are to be commended for consistently providing constructive and thoughtful reviews.
Arctic system on trajectory to new, seasonally ice‐free state
Authors: Overpeck Jonathan T. , Sturm Matthew , Francis Jennifer A. , Perovich Donald K. , Serreze Mark C. , Benner Ronald , Carmack Eddy C. , Chapin F. Stuart , Gerlach S. Craig , Hamilton Lawrence C. , Hinzman Larry D. , Holland Marika , Huntington Henry P. , Key Jeffrey R. , Lloyd Andrea H. , McDonald Glen M. , McFadden Joe , Noone David , Prowse Terry D. , Schlosser Peter , Vörösmarty Charles
Published: October 2006

The Arctic system is moving toward a new state that falls outside the envelope of glacial‐interglacial fluctuations that prevailed during recent Earth history. This future Arctic is likely to have dramatically less permanent ice than exists at present. At the present rate of change, a summer ice‐free Arctic Ocean within a century is a real possibility, a state not witnessed for at least a million years. The change appears to be driven largely by feedback‐enhanced global climate warming, and there seem to be few, if any processes or feedbacks within the Arctic system that are capable of altering the trajectory toward this “super interglacial” state.
Cheaper electronic journals for libraries
Authors: Tullis Terry E. , Holoviak Judy C.
Published: October 2006

Production of the print version of journals adds substantially to the expense of publication. Since 2002 the institutional subscribers to AGU journals have shared equally these extra fixed costs no matter which format they purchased. Fixed costs are the expenses incurred regardless of number of copies produced. The fixed cost for print includes creating the printing plates from electronic files and setting up the presses and the bindery and mailing equipment.

For equity among all subscribers, rates for 2006 have been set to better reflect the cost of the service being provided. Only the institutions subscribing to the print version will be charged for its printing, paper, and mailing.
Dissolved Organic Carbon Reference Material Program
Authors: Hansell Dennis A.
Published: October 2006

Analytical chemistry benefits from uniformly applied and readily accessible reference materials to assess the accuracy of experimental results. Without assessment, experimental findings are best considered with a healthy dose of skepticism. For several chemical analyses, reference materials are available commercially Amino acids, for example, are biochemical analytes for which standard materials are readily available from commercial vendors. There are many environmental analyses, however, for which reference materials are not available. One such measurement had been that of organic carbon dissolved in natural waters.
Ecological modeling for applied science
Authors: Melton Forrest , Lobitz Brad , Turner Woody , Sheffner Edwin , Haynes John
Published: October 2006

Ecological modeling is becoming an increasingly important tool for uniting biological observations with remote sensing and ground‐based data networks to develop predictive tools for resource management and human health.

The availability of over three petabytes of data from the NASA Earth Observing System Data and Information System (EOSDIS) alone provides an unprecedented opportunity to develop Earth science applications for decision support. In combination with data networks such as the U.S. National Oceanic and Atmospheric Administration's National Climate Data Center, the nonprofit NatureServe's network of biological inventories, the National Environmental Public Health Tracking Network of the U.S. Centers for Disease Control and Prevention, and many others, there is a vast wealth of Earth observation data on parameters as diverse as land cover, sea surface temperature, precipitation, species distribution, and disease occurrence.
On books that popularize science
Authors: McBirney Alexander
Published: October 2006

I found David Stern's review of Bill Brysonapos;s book, A Short History of Nearly Everything (Eos, 86(20), 198, 17 May 2005), rather disturbing, for it raised a question that has been bothering me for some time. Stern has high praise for the book but comments that “in the few instances where this reviewer knew the facts, they did not always jibe with the text.” He goes on to point out factual errors regarding rather basic information that anyone should be able to obtain from standard references.
Reductions in Arctic sea ice cover no longer limited to summer
Authors: Meier Walter , Stroeve Julienne , Fetterer Florence , Knowles Ken
Published: October 2006

Summer sea ice in the Arctic has shown a significant downward trend of 8% per decade since the late 1970s, leading to a reduction of approximately 20% in sea ice extent in September (when the annual minimum occurs) (Stroeve et al., 2005). The past three summers (2002–2004) have been among the lowest on record, and 2002 was the extreme minimum. Despite decreasing summer extents, the sea ice extent has typically rebounded to near‐normal levels during the winter season, yielding an annual average trend of only −3%. This is not surprising since as temperatures drop below freezing, sea ice quickly forms.
Ecohydrology of Water‐Controlled Ecosystems: Soil Moisture and Plant Dynamics
Authors: Williams David G.
Published: October 2006

Ecohydrology is an emerging and synthetic discipline in the biogeosciences aimed at understanding connections between the ecological dynamics of vegetation and the hydrological cycle, and how vegetation‐water interactions influence elemental cycling and energy exchange. An ecohydrology perspective is especially relevant and important for understanding dynamics of arid and semiarid ecosystems and landscapes.

In these water‐limited ecosystems, highly variable patterns of precipitation, geomorphology and soils strongly influence vegetation structure, dynamics, and function. These systems are “pulse‐driven”; bursts of biological activity commence with discreet inputs of precipitation. These short‐lived and highly active periods are separated by periods of extreme water limitation and vegetation stress. The duration and spatiotemporal dynamics of precipitation pulses and plant‐available soil moisture are key features in these ecosystems, controlling vegetation composition, nutrient biogeochemistry and energy exchange.
Congressional Science Fellow
Authors: O'Riordan Catherine
Published: October 2006

Josh Trapani has been selected to serve as AGU's 2005–2006 Congressional Science Fellow. Trapani is a paleontologist who most recently studied the genetic basis of tooth development in fish as a postdoctoral fellow in the Ecology and Evolutionary Biology Department at the University of Colorado, in Boulder.

“By studying the complexity of genetic differences between species of fish with different dentition patterns, we are able to begin to determine the evolutionary processes—chiefly selection and constraint—responsible for the evolution and maintenance of these differences over geologic time,” he noted.
Comment on “The need for better contacts between hydrologists in the two Americas”
Authors: Dias Nelson Luís
Published: October 2006

Robin Clarke's article in Eos (“The Need for Better Contacts between Hydrologists in the Two Americas,” 86(23), 7 June 2005) touches on an important issue for the development of hydrology in South America. Having been authored by an eminent hydrologist from an important Brazilian hydrology research center only strengthens its significance.

Clarke states a few reasons for weak South American participation in AGU's activities: the language barrier, scarce funds, and conditions for conducting research, plus a lack of a clear scientific agenda. In this comment, I argue that many mechanisms that would lead to more South American participation in AGU already exist, and only need to be improved.
[Reply to “Wasting public money?” by Judith Totman] Politically motivated request?
Authors: Bradley Raymond S.
Published: October 2006

Judith Totman Parrish (Forum,Eos, 86(32), 9 August 2005, p. 294) asks Thomas Crowley to provide evidence that the U.S. Rep. Joe Barton's (R.‐N.Y) request for information from me, and from my colleagues Michael Mann and Malcolm Hughes, was politically motivated.

Among a host of items, here are some of the things Barton specifically asked for: “…all financial support you have received related to your research, including, but not limited to, all private, state, and federal assistance, grants, contracts (including subgrants or subcontracts), or other financial awards or honoraria…the location of all data archives relating to each published study for which you were an author or co‐author… [a list of all] requests…you or your co‐authors [have] received for data relating to the climate change studies, what was your response, and why?”
Major earthquake shakes northern Pakistan
Authors: Kumar Mohi
Published: October 2006

A magnitude 7.6 earthquake that shook the western Himalayas on 8 October killed at least 23,000 in Pakistan and 1,400 in India, injured more than 50,000 people, and left more 2.5 million people homeless across the Kashmir region. The official death toll could exceed 30,000, placing this among most deadly earthquakes to have ever occurred on the Indian subcontinent.

Scientists warn that, given the lack of development and poor construction in the area, future earthquakes in more densely populated areas could be devastating. David Simpson, president of the Incorporated Research Institutes for Seismology, said the 8 October quake ‘was a terrible disaster, but not to the level of what could happen in the future. This is yet again another warning message of things to come.”
A “river summer” on the Hudson
Authors: Pfirman Stephanie L. L. , Kenna Timohy , Cronin John , Son Lisa , Land Michelle
Published: October 2006

Faculty from regional colleges, universities, and research institutes gathered this past summer to teach each other about the Hudson River in New York through a three‐and‐a‐half week field trip called “River Summer.”

A pilot field course sponsored by the newly‐established Environmental Consortium of Hudson Valley Colleges and Universities, the program aims to help educators transform the Hudson watershed into an extended laboratory and classroom for multi‐institutional field programs, interdisciplinary research collaborations, and cooperative regional studies. Experiences from this excursion will be used as the foundation for a summer field course for undergraduates.
Winter convection continues in the warming southern Adriatic
Authors: Civitarese Giuseppe , Gačić Miroslav , Cardin Vanessa , Ibello Valeria
Published: October 2006

During winters in the eastern Mediterranean, cold winds blow over the waters of the southern portion of the Adriatic Sea, resulting in heat loss of the ocean. This cold surface water becomes denser than surrounding waters and sinks into the deep reaches of the Mediterranean Sea. This forms ‘deep water,’ or water once at the ocean's surface that now has sunk to depths of 1500 meters and more. The Southern Adriatic Pit (SAP) is the convection site and source for the Eastern Mediterranean Deep Water (EMDW). Since the late 1980s, the SAP has been monitored almost every year because of its importance in driving the eastern Mediterranean deep circulation convection cell.
Radiated energy and the physics of earthquake faulting
Authors: McGarr A. , Abercrombie R. E. , Kanamori H.
Published: October 2006

On the third day of a recent AGU Chapman Conference, held in Portland, Maine, near the Two Lights fault zones and the Fort Foster brittle zone, conference participants spent the gray June day scrambling over rocky ledges above the crashing surf along the coast of the Atlantic Ocean.

With field trip leader Mark Swanson, who with his students has studied the area in detail over the past 20 years, participants examined evidence of ancient earthquakes from about 300 million years ago when these rocks were 8 to 10 kilometers deep. This evidence included pseudotachylytes—glass generated by heating during fault slip at midcrustal depths.
Meet the Editor: Tectonics
Authors: Kumar Mohi
Published: October 2006

Kip Hodges was named the chief editor of AGU's journal, Tectonics, in 2004. He joined Onno Oncken,the European editor of the journal.

Hodges, a professor of Earth, atmospheric, and planetary sciences at the Massachusetts Institute of Technology (MIT), in Cambridge, said he plans to expand the journal's focus to include the capacity to cover breaking research in the field of tectonics.
Celebrating the physics in geophysics
Authors: Davis Anthony B. , Sornette Didier
Published: October 2006

The United Nations' Educational, Scientific and Cultural Organization (UNESCO) declared 2005 the “World Year of Physics” in celebration of the centennial of Einstein's annus mirabilis when, as junior clerk at the Swiss Patent Office in Berne, he published three papers that changed physics forever by (1) introducing Special Relativity and demonstrating the equivalence of mass and energy (E = mc2), (2) explaining the photoelectric effect with Planck's then‐still‐new‐and‐controversial concept of light quanta (E = hv), and (3) investigating the macroscopic phenomenon of Brownian motion using Boltzmann's molecular dynamics (E = kT), still far from fully accepted at the time.

The celebration of Einstein's work in physics inspires the reflection on the status of geophysics and its relationship with physics, in particular with respect to great discoveries.
Candidates for office 2006–2008
Authors: Anonymous
Published: October 2006

Timothy L. Grove. Member of AGU since 1973. Professor of Geology at the Massachusetts Institute of Technology. Major interest is understanding the chemical differentiation processes that have led to the formation of the crust and mantle of the Earth and similar processes in other planets, including the Moon, Mars, and meteorite parent bodies.
Meeting updates progress of U.S. Climate Change Program
Authors: Zielinski Sarah
Published: October 2006

The U.S. Climate Change Science Program (CCSP) has released its first, and overdue, assessment product—on temperature trends in the lower atmosphere—for public comment. A recent workshop called for greater involvement from a wider range of scientists and more support at the regional level to improve the effectiveness of the CCSP

The workshop “Climate Science in Support of Decision Making”, held in Arlington, Va., 14–16 November, brought together scientists, policymakers, government workers, and educators to provide an update on the assessment process and develop future priorities for the program. CCSP is a collaboration of 13 government agencies and departments that coordinates and directs federal research on climate and global change.
Global impacts of Arctic climate processes
Authors: Dethloff Klaus , Rinke Annette , Morrison Hugh , Dorn Wolfgang , Gerdes Ruediger , Maslowski Wieslaw , Kattsov Vladimir , Lange Manfred A. , Görgen Klaus , Lynch Amanda
Published: October 2006

The polar regions are experiencing major climate and environmental changes due to the combined effects of natural variability and global warming. To address regional Arctic climate processes and their global feedbacks, 53 experts from the United States, Canada, Europe, and Russia gathered for a recent workshop at the Alfred Wegener Institute for Polar and Marine Research, in Potsdam, Germany.

The workshop, which was organized by Klaus Dethloff and Annette Rinke, focused on the use of regional models of the Arctic, global coupled climate models, and Arctic impact studies. This article summarizes the main advances and outstanding issues in Arctic modeling that were presented and discussed during the workshop.
Quantifying freshwater sustainability through multiscale mapping
Authors: Kanivetsky Roman , Shmagin Boris
Published: October 2006

The issue of freshwater availability and sustainability within U.S. federal and state governments. For example, a recent report by the U.S. National Science and Technology Council (NSTC) urges the federal government to take new steps to understand freshwater sustainability in the United States [NSTC, 2004]. Although the report refers to ‘availability’—a concept that in the past has applied only to human needs and that implies that a resource may decline or be liquidated—the focus of the report is on ‘sustainability’ as commonly defined in the literature today. Sustainability requires that consumption will not cause a decline or liquidation of freshwater resources.
Sea salt shifts the range sizes of Asian dust
Authors: Zhang Daizhou , Iwasaka Yasunobu , Shi Guangyu
Published: October 2006

A noticeable phenomenon of Asian dust particles during their trans‐Pacific transport is that in cases where there is no precipitation, the mode diameters at different surface sites are approximately the same, about 3–4 microns for number distributions (particle number via particle size in per cubic unit of air) or a little larger for mass and volume distributions. This can be confirmed by comparing published data obtained in coastal areas of China, the Korean peninsula, Japanese islands, and the west coast of the United States.

While significant progress in the study of mineral dust particles in the atmosphere has been made, this phenomenon is not yet understood. Recent studies [e.g.,Zhang and Iwasaka, 2004] suggest that the interaction between dust particles and sea salt is a significant process involved in the changes of dust particles in size and composition in the marine boundary layer. This process can lead to the growth of dust particles and is likely responsible for the consistency of the mode diameters at different sites.
Icebreaker expedition collects key Arctic seafloor and ice data
Authors: Darby Dennis A. , Jakobsson Martin , Polyak Leonid
Published: October 2006

The recently completed Healy‐Oden Trans‐Arctic Expedition 2005 (HOTRAX′05) retrieved 29 piston cores averaging nearly 12 meters in length from a complete transect across the central Arctic Ocean (Figure 1). These cores provide a critically‐needed sample cache for both a pan‐Arctic stratigraphy and a long‐awaited paleoclimate record that it is hoped will greatly improve the understanding of how deepwater is exchanged between Arctic basins, how the climate system in the Arctic works over longer time intervals, and how the Arctic system interacts with global systems. The coring was done from the U.S. Coast Guard Cutter (USCGC) Healy, while oceanographic measurements were made from the Swedish icebreaker Oden.

In addition to coring and oceanography, HOTRAX mapped the seafloor with multibeam bathymetry and collected chirp sonar profiles that not only mapped the strata to a sub‐bottom depth of 50–100 meters, but also provided detailed information on the geologic context of the core sites.
Seismic and acoustic detection of a bolide airburst in the Gulf of Naples (southern Italy)
Authors: D'Auria Luca , Marotta Enrica , Martini Marcello , Ricciolino Patrizia
Published: October 2006

On 10 September 2005 at 1711 LT (1511 UT) a loud boom was heard on the Ischia island. A clear seismic signal was also recorded by the seismic monitoring network of the Neapolitan volcanic areas (Ischia, Campi Flegrei, and Mount Vesuvius) and on a regional station (Mount Massico). On the basis of the seismic recordings and on acoustic phenomena reports, we relate this event to the atmospheric explosion (airburst) of a bolide about 15 km SW of Ischia at an elevation of about 11.5 km. The location has been obtained through nonlinear traveltime inversion in a realistic atmospheric model including wind effects. We show, using statistical estimators, how the traveltime pattern is due to both atmospheric winds and the bolide trajectory. Using the same reasoning we discard a human origin (supersonic jet or sea‐air missile). In addition, we also propose a new algorithm for fast acoustic traveltime computation for a supersonic moving source.
Failure envelope of first‐year Arctic sea ice: The role of friction in compressive fracture
Authors: Schulson E. M. , Fortt A. L. , Iliescu D. , Renshaw C. E.
Published: October 2006

New experiments have been performed on the brittle compressive failure of columnar‐grained, first‐year sea ice with the S2 growth texture, harvested from the floating cover on the Arctic Ocean. The ice was proportionally loaded biaxially across the columns at –10°C at 1.5 × 10−2 s−1; i.e., within the regime of brittle behavior. The results, when combined with earlier measurements of tensile strength by Richter‐Menge and Jones (1993), allow the complete brittle failure envelope to be constructed. The envelope is symmetric about the loading path R = σ2/σ1 = 1, owing to the isotropic character of the material within the horizontal plane of the ice sheet, but is asymmetric with respect to the compressive‐compressive and tensile‐tensile quadrants, owing to the relative weakness of the material under tension. The compressive strength reaches a maximum along the loading path R ∼ 0.5. Terminal failure occurs through either splitting (unconfined loading), Coulombic shear faulting under lower confinement (R < 0.2) or spalling under higher confinement (0.2 < R ≤ 1). An integral component of compressive failure under low confinement is the internal friction coefficient: its value under the conditions of the experiments (μi = 0.92 ± 0.09) is deduced from the failure envelope. The internal friction coefficient is shown through postterminal failure measurements to be closely similar to the coefficient of friction at the onset of sliding along the Coulombic faults. Granite exhibits similar behavior. Modeling reveals that the terminal failure stress under low confinement can be reasonably well described in terms of the comb‐crack mechanism (Schulson et al., 1999; Renshaw and Schulson, 2001) of brittle compressive failure. Comparison with observations and measurements in the field indicate that the failure processes that operate on the smaller scale are similar to at least some of those that operate on the larger scale, implying that the physics of failure may be scale‐independent.
Three‐dimensional finite difference time domain modeling of the diurnal and seasonal variations in Schumann resonance parameters
Authors: Yang Heng , Pasko Victor P.
Published: October 2006

The diurnal and seasonal variations of Schumann resonances (SR) have been reported in a number of experiments. In this paper, a three‐dimensional FDTD model of the Earth‐ionosphere cavity with a day‐night asymmetric conductivity profile is employed to study the diurnal and seasonal variability of the power and frequency of the first Schumann resonance (SR) mode. Comparison of the FDTD results and recent experimental measurements shows a clear modulation in the SR power related to the local ionospheric height and global lightning activity. It is found that SR frequencies are not only a function of the local time but also are controlled by the global lightning activity changing with universal time.