bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface and lightning sources of nitrogen oxides over the United States: Magnitudes, chemical evolution, and outflow
Authors: Hudman R. C. , Jacob D. J. , Turquety S. , Leibensperger E. M. , Murray L. T. , Wu S. , Gilliland A. B. , Avery M. , Bertram T. H. , Brune W. , Cohen R. C. , Dibb J. E. , Flocke F. M. , Fried A. , Holloway J. , Neuman J. A. , Orville R. , Perring A. , Ren X. , Sachse G. W. , Singh H. B. , Swanson A. , Wooldridge P. J.
Published: April 2007

We use observations from two aircraft during the ICARTT campaign over the eastern United States and North Atlantic during summer 2004, interpreted with a global 3‐D model of tropospheric chemistry (GEOS‐Chem) to test current understanding of regional sources, chemical evolution, and export of NOx. The boundary layer NOx data provide top‐down verification of a 50% decrease in power plant and industry NOx emissions over the eastern United States between 1999 and 2004. Observed NOx concentrations at 8–12 km altitude were 0.55 ± 0.36 ppbv, much larger than in previous U.S. aircraft campaigns (ELCHEM, SUCCESS, SONEX) though consistent with data from the NOXAR program aboard commercial aircraft. We show that regional lightning is the dominant source of this upper tropospheric NOx and increases upper tropospheric ozone by 10 ppbv. Simulating ICARTT upper tropospheric NOx observations with GEOS‐Chem requires a factor of 4 increase in modeled NOx yield per flash (to 500 mol/flash). Observed OH concentrations were a factor of 2 lower than can be explained from current photochemical models, for reasons that are unclear. A NOy‐CO correlation analysis of the fraction f of North American NOx emissions vented to the free troposphere as NOy (sum of NOx and its oxidation products) shows observed f = 16 ± 10% and modeled f = 14 ± 9%, consistent with previous studies. Export to the lower free troposphere is mostly HNO3 but at higher altitudes is mostly PAN. The model successfully simulates NOy export efficiency and speciation, supporting previous model estimates of a large U.S. anthropogenic contribution to global tropospheric ozone through PAN export.
Near‐terminator Venus ionosphere: How Chapman‐esque?
Authors: Fox J. L.
Published: April 2007

We have modeled the near‐terminator ionosphere of Venus for solar zenith angles χ between 60 and 85° in 5° increments, and from 86 to 90° in 1° increments. The most important neutral densities of the background thermospheres have been adopted from the VTS3 model of Hedin et al. (1983), which is based on densities from the Pioneer Venus (PV) Orbiter Neutral Mass Spectrometer (e.g., Niemann et al., 1980) that are normalized to the PV Orbiter Atmospheric Drag data (e.g., Keating et al., 1980). We compare the ion density profiles to those of a Chapman layer and to those obtained from radio occultation data. We determine the best fit values of nmax,0i and k in the Chapman expression nmax,χi = nmax,0i cos(χ)k for each solar zenith angle interval; using a linear least squares regression for log nmax,χi as a function of log cos(χ) we also derive the best fit values for the group of ten models for solar zenith angles from 60 to 89°. For a theoretical Chapman layer with plane parallel geometry, k = 0.5, and nmax,0i is the peak electron density at the subsolar point. In the near‐terminator region, the production rates and densities must be computed using spherical geometry, and this alone will cause the derived value of k to be reduced below the theoretical factor of 0.5. For the solar zenith angle models in the range 60–85°, we find that the magnitudes of the both the main (F1) and lower (E) peaks decrease as the solar zenith angle increases in a somewhat Chapman‐like manner, but the altitudes of the F1 and E peaks increase only slowly from 140 to 144 km and from 125 to 129.5 km, respectively. The nearly constant altitude of the F1 peaks has been attributed to the collapse of the thermosphere as it merges into the nighttime cryosphere (Cravens et al., 1981). This behavior is quite different from that of Mars, where the electron density peak altitudes have been observed to rise monotonically as the solar zenith angle increases. The predicted behavior for the Venus ionosphere is in general agreement with radio occultation data, but some differences also are observed. We discuss the differences between the modeled and observed peak altitudes and we attribute the differences partly to deficiencies in the VTS3 models and partly to uncertainties in the electron temperatures. There also may be some errors introduced into the radio occultation profiles in the very near‐terminator region due to deviations from spherical symmetry. In addition, differences exist between the measured and model peak magnitudes at solar zenith angles near 60° that we ascribe partly to the use of the S2K v2.22 solar flux model of Tobiska (2004), for which the EUV and soft X‐ray photon fluxes are significantly smaller than those of the S2K v1.24 or the Hinteregger solar flux models.
Tub toys orbit the Pacific subarctic gyre
Authors: Ebbesmeyer Curtis C. , Ingraham W. James , Royer Thomas C. , Grosch Chester E.
Published: April 2007

In 1992, a cargo container of children's bath toys fell overboard in the middle North Pacific Ocean. Subsequently, 29,000 toys were tracked 4,000 kilometers to southeastern Alaska [Ebbesmeyer and Ingraham, 1994]. The spill's upcoming fifteenth anniversary has prompted an examination of the reports of toys stranded on shorelines around the Subarctic Gyre, a planetary vortex the size of the United States.

Previous articles have reported the drift of sneakers and toys for a year or so only along the southern edge of the Pacific Subarctic Gyre [Ebbesmeyer and Ingraham, 1992, 1994]. However, continuing reports of stranded toys have stimulated curiosity about how long it would take the currents that link the Gyre's perimeter between Asia and America to transfer flotsam around the Gyre, that is, its orbital period. These currents (Figure 1) are the North Pacific Drift Current, Alaska Current/ Alaska Coastal Current, Alaskan Stream, Bering Slope Current and East Kamchatka Current, Oyashio Current, and Kuroshio. In the Bering Sea, the North Aleutian Current recurves north from Attu Island eastward along the north side of the Aleutians to merge with the Bering Slope Current.
Scientific integrity discussed
Authors: Zielinski Sarah
Published: April 2007

Scientists need to be more aware of how their science is used and misused, and they need to speak out more often, advised several speakers at a 12 December 2006 session at the AGU Fall Meeting in San Francisco, Calif.

Peter Gleick, co‐founder and president of the Pacific Institute for Studies in Development, Environment, and Security, said, “Increasingly, we live in a world in which science and policy are very intertwined, where the outcomes of science affect the outcomes of policy Policy is beginning to influence science.” Gleick discussed various challenges to the integrity of science, including logical fallacies, direct abuse of the scientific process, and a lack of independence in funding. Uncertainty, a natural part of all of science, can also be abused, he said. Gleick noted that in policy making, deciding when something is certain enough can be difficult.
Looking below the Moon's surface with radar
Authors: Campbell Bruce A. , Campbell Donald B. , Margot Jean‐Luc , Ghent Rebecca R. , Nolan Michael , Carter Lynn M. , Stacy Nicholas J. S.
Published: April 2007

Giovanni, the Goddard Earth Sciences Data and Information Services Center (GES DISC) Interactive Online Visualization and Analysis Infrastructure, has provided researchers with advanced capabilities to perform data exploration and analysis with observational data from NASA Earth observation satellites. In the past 5–10 years, examining geophysical events and processes with remote‐sensing data required a multistep process of data discovery, data acquisition, data management, and ultimately data analysis. Giovanni accelerates this process by enabling basic visualization and analysis directly on the World Wide Web. In the last two years, Giovanni has added new data acquisition functions and expanded analysis options to increase its usefulness to the Earth science research community.
Mount St. Helens petrology workshop
Authors: Rowe Michael C. , Pallister John S. , Grunder Anita
Published: April 2007

Following seismic activity in late September 2004, the current eruption of Mount St. Helens began with an explosive steam and ash emission on 1 October 2004, with hot dacite emerging from the crater floor on 11 October 2004. Nearly two years later, with more than 80 million cubic meters of erupted dacite, accompanied by rare explosions and predominantly shallow seismicity questions still remain about what initiated and what is sustaining the eruption.

The U.S. Geological Survey's (USGS) Cascade Volcano Observatory (CVO) hosted the 2006 Mount St. Helens Petrology Workshop in Vancouver, Wash., on 27–30 August 2006. With many of the more than 40 workshop participants finalizing contributions to a USGS Professional Paper on the current Mount St. Helens eruption, the workshop was a timely opportunity to share results, reconcile interpretations, and plan future research.
Uncertainty analysis in environmental modeling made easy
Authors: Pappenberger Florian , Harvey Hamish , Beven Keith , Hall Jim
Published: April 2007

Uncertainty analysis assesses the uncertainty in numerical model outputs that arises from ambiguity in model structures, parameters, boundary conditions, and evaluation data. An analysis of the impact of uncertainties should be undertaken in every environmental modeling exercise. Many techniques exist, however, and each requires an investment of time and resources to learn. The potential analyst is faced with the difficult question of which technique is best to use and which may be put off.
Your role in formulating public policy
Authors: O'Riordan Catherine
Published: April 2007

One goal of AGU is to assure that the results of our research are made available for the benefit of humanity. To achieve this goal takes the commitment of many members. There are numerous ways that you can contribute to the development of public policy that is based on sound science.

How do you get started? As Soroosh Soroosian states in his editorial in this issue of Eos, a first step may be to look for opportunities to talk to people in your local community about science and how our science can be used to benefit society. Talk to school teachers and students, business organizations, the media, and elected and appointed representatives and other officials of government such as school boards and planning commissions.
The physics of fluid oscillations in volcanic systems
Authors: Lane Stephen , Gilbert Jennie
Published: April 2007

Advances in technology and increases in the geophysical instrumentation of volcanoes now allow the surface effects of subterranean volcanic processes to be measured in unprecedented detail. Parameters such as ground motion and atmospheric disturbance are continuously monitored at some volcanoes, with high‐sensitivity instruments covering wide frequency ranges. The wealth and accuracy of the resulting data have permitted the identification of oscillatory behaviors within magmatic systems, and have further indicated that these behaviors are common. One of the challenges for volcanology is to fully utilize the diverse information recorded at the surface to understand more of the underground source processes, ultimately applying this understanding to improving eruption forecasts.
Connecting the Sun to the heliosphere
Authors: Zurbuchen Thomas H.
Published: April 2007

To better understand the processes that connect the Earth environment to the Sun, NASA's Living With a Star program must address questions that cut across traditional science disciplines. To meet this challenge, the Targeted Research and Technology component of Living With a Star has developed an innovative strategy to focus research on the most complex science targets. The targets are drawn up each year by a panel of senior scientists. These targets are then publicized, and individual researchers can propose solutions. NASA then selects teams of researchers through a peer‐review process for each targeted effort. This contrasts with other NASA programs in which individual and independent programs are selected for study.
Frost, Goldstein, and Korenaga awarded 2006 James B. Macelwane Medal
Authors: Burch James L. , Goldstein Jerry , Rubie David , Frost Daniel J. , Jordan Thomas H. , Korenaga Jun
Published: April 2007

Daniel J. Frost, Jerry Goldstein, and Jun Korenaga received the James B. Macelwane Medal at the AGU Fall Meeting honors ceremony, which was held on 13 December 2006 in San Francisco, Calif. The medal is given for significant contributions to the geophysical sciences by an outstanding young scientist.

Jerry Goldstein is one of the most exciting young researchers in space physics today, and his work has significantly advanced understanding of the Earth's magnetosphere. In particular, Jerry is widely recognized as the leading authority on the structure and dynamics of the Earth's plasmasphere, the region of cold plasma of ionospheric origin that is trapped in the inner portion of the magnetosphere.
Purdy awarded 2006 Maurice Ewing medal
Authors: Detrick Robert S. , Purdy G. Michael
Published: April 2007

G. Michael Purdy was awarded the Maurice Ewing Medal at the AGU Fall Meeting honors ceremony, which was held on 13 December 2006 in San Francisco, Calif. The medal recognizes significant original contributions to the scientific understanding of the processes in the ocean; for the advancement of oceanographic engineering technology and instrumentation; or outstanding service to marine science.

It is an honor for me to deliver the citation for G. Michael Purdy, the 2006 recipient of AGU's Maurice Ewing Medal. Mike Purdy has made significant and original contributions to our understanding of ocean crustal structure, been an innovative developer of marine seismic instrumentation, and served for over two decades as an important leader of the oceanographic community.
Landslide hazards after the 2005 Kashmir earthquake
Authors: Bulmer Mark , Farquhar Tony , Roshan Masud , Akhtar Sadar Saeed , Wahla Sajjad Karamat
Published: April 2007

The 8 October 2005 Kashmir earthquake killed 87,300 people and disrupted the lives of several million more. By current estimates, 30,000 still live in camps sited more in accordance with short term expedience than with freedom from risk of natural hazards. In December 2006, the international aid community expressed fears that 50,000 people in Northwest Frontier Province may leave their mountain homes this winter as landslides and avalanches block access roads. As the focus of humanitarian assistance shifts toward restoration of Kashmir's infrastructure, it is important that the persistent hazard of landslides within the earthquake affected region be understood and recognized [Bulmer, 2006].
New Arctic sea ice draft data from submarines
Authors: Wensnahan Mark , Rothrock David , Hezel Paul
Published: April 2007

Arctic sea ice thickness data from 17 newly processed submarine cruises covering over 49,000 kilometers of cruise track have now been added to the archive at the National Snow and Ice Data Center (NSIDC). This addition increases the archive by 68%, to a total of over 120,000 kilometers of track from 37 U.S. Navy and 2 Royal Navy submarine cruises. The data are actually of ice draft, the submerged portion of floating sea ice, which is about 89% of ice thickness.

Declines in Arctic sea ice extent and thickness in recent decades make this an invaluable data set for research into Arctic climate variations [e.g., Tucker et al., 2001], for testing sea ice models [e.g., Rothrock et al., 2003; Miller et al., 2005], and for intercomparison with measurements of thickness by other methods [e.g., Laxon et al., 2003].
New Madrid GPS: Much ado about nothing?
Authors: Stein Seth
Published: April 2007

Two articles in this issue address the surprising and intriguing negative result that high‐precision geodetic measurements find no compelling evidence for crustal motions in the New Madrid Seismic Zone of the central Unites States.

The geodetic measurements have drawn great interest because they add another puzzle to the many surrounding New Madrid. This area is the best known case of large earthquakes within the interior of the plates, in continental lithosphere. Such earthquakes are much rarer and release much less seismic energy than those at plate boundaries. Because idealized plates are perfectly rigid, these earthquakes demonstrate that deformation occurs within plates and provide a lower bound on their rigidity. Moreover, precisely because such earthquakes are rare, they pose a hazard to areas that are less well prepared for earthquakes than areas with more active ones. Assessing the hazard is further complicated by a growing sense that earthquakes within plates migrate among seismic zones that ‘turn on,’ remain active for some time, and then ‘turn off.’
Earthquake risk from strain rates on slipping faults
Authors: Newman Andrew
Published: April 2007

Discrete geodetic measurements made near active faults may capture only small bits of a relatively complex field of deformation surrounding a fault, making it difficult to accurately describe the nature of ongoing activity along the fault. This difficulty is compounded when geodetic measurements are reported as strain rates, which involve differences in the displacement between two or more sites over time. As a result, very low displacement rates can be quoted as very high strain rates, which may lead to incorrectly inferring high seismic risk. As an example, I look at a recent deformation study across the New Madrid Seismic Zone (NMSZ). The NMSZ, located in east central United States and away from rapidly deforming plate boundaries, is best known for its series of three large earthquakes (M>7) in the early 1800s, and continues today with numerous small earthquakes (Figure 1).
Recent observations and simulations of the Sun‐Earth system, Grand Hotel Varna, Bulgaria, 17–22 September 2006
Authors: Jordanova Vania , Roussev Ilia
Published: April 2007

ISROSES: International Symposium on Recent Observations and Simulations of the Sun‐Earth System.

Important challenges for solar‐terrestrial physics research are to advance our understanding of the Sun‐Earth system (SES) and to develop models to the level where timely and accurate predictions of space weather can be made that result in benefits to society. As more advanced technologies are placed into the space environment, our need to forecast space weather becomes more urgent. To achieve such a goal, an integrated understanding of the physical processes of the coupled Sun‐Earth system must be developed.
Surveying flash flood response in mountain streams
Authors: Carpenter Theresa M. , Taylor Stephen V. , Georgakakos Konstantine P. , Wang Jianzhong , Shamir Eylon , Sperfslage Jason A.
Published: April 2007

During the winter season of 2005, Southern California was besieged by a series of heavy precipitation events that caused widespread flash flooding, mud slides, debris flows, and significant damage. The first event began in December (28 December 2004 to 4 January 2005), triggered mudflows and flooding in the San Bernardino Mountains, and produced a record daily rainfall total for the city of Los Angeles.

The second period of heavy rainfall occurred in January (7–12 January 2005) and was widespread, extending from west of Santa Barbara to the San Bernardino Mountains in San Bernardino County and to the south including San Diego County. The peak rainfall total during the January 2005 event exceeded 700 millimeters (30 inches) over the six‐day period. Impacts included the disastrous La Conchita landslide in Ventura County, which killed 10 people and destroyed or damaged over 35 homes.
Humans “very likely” responsible for warming, Report concludes
Authors: Zielinski Sarah
Published: April 2007

Working Group I of the Intergovernmental Panel on Climate Change (IPCC) upgraded its assessment of the probability that humans are responsible for the warming of the planet in the last 50 years from ‘likely’ to ‘very likely,’ in a report on the state of the science released 2 February.

The language change indicates that the likelihood that humans are responsible for the warming increased from 66% in the last assessment, which was released in 2001, to 90%. Human influences on climate can now be seen in warming of the oceans and land, temperature extremes, and changes in wind patterns, according to the report.
New funding for ocean research proposed for 2008
Authors: Zielinski Sarah
Published: April 2007

The Bush Administration will request an additional US$143 million for coastal and marine research and conservation for Fiscal Year (FY) 2008, officials announced on 26 January.

“It is clear that good stewardship of the oceans, coasts, and Great Lakes must be a national priority,” said John H. Marburger III, director of the U.S. Office of Science and Technology Policy.
Climate change report adds to evolving debate
Authors: Zielinski Sarah
Published: April 2007

Working Group I of the Intergovernmental Panel on Climate Change (IPCC) released the summary of its report on the physical basis of climate change on 2 February. The report arrives at a time when the debate in U.S. political circles has shifted from the existence of climate change to methods of mitigation and adaptation.

Much of the past debate among U.S. politicians had focused on whether climate change exists and whether humans are responsible. But even some politicians who once were skeptical now find themselves believers. “It is hard not to be persuaded by the evidence,” said Rep. Bob Inglis (R‐S.C), who credited his change of heart on the growing body of scientific evidence and a recent trip to Antarctica. Inglis spoke at an 8 February hearing of the U.S. House of Representatives Committee on Science and Technology.
Broecker to receive Crafoord Prize
Authors: Anonymous
Published: April 2007

The Royal Swedish Academy of Sciences has selected AGU Fellow Wallace S. Broecker to receive the 1996 Crafoord Prize in Geosciences for 2006.

Broecker, Newberry Professor of Earth and Environmental Sciences at the Lamont‐Doherty Earth Observatory of Columbia University, in Palisades, N.Y., received the Maurice Ewing Medal in 1979 and the Roger Revelle Medal in 1995.
Isotopes in Palaeoenvironmental Research
Authors: Fischer Matt
Published: April 2007

The editor of this volume notes that the intention of this book is to “show how isotopes can be applied to understanding the paleoenvironment.” With that intention, several key issues should be addressed in each chapter.

These issues include: how isotopes vary on temporal and spatial scales (e.g., the timewise amplitude variation of the isotopes at different latitudes over different timescales), and statistical issues (are the statistical methods applied to the data sufficient for investigating isotope data?).
Technical problems develop in Mars satellite instruments
Authors: Zielinski Sarah
Published: April 2007

The Mars Reconnaissance Orbiter (MRO) has developed technical problems in two of its six science instruments, NASA announced on 7 February. The Mars Climate Sounder, which maps the distribution of temperature, ice clouds, and dust in the planet's atmosphere, has been temporarily stowed while scientists investigate why the instrument occasionally skips steps and puts the field of view slightly out of position. The problem first appeared in December and a fix seemed to work, but the problem reappeared in mid‐January.

Scientists are also investigating a problem with the High Resolution Imaging Science Experiment camera, MRO's main imager. In late November, noise in the form of bad pixels developed in one of the camera's 14 detector pairs, and six other detectors have since developed the problem. Though the effect on overall image quality is small, scientists are worried that the problem could worsen.
Energy transfer in the Earth‐Sun System
Authors: Lui A. T. Y. , Kamide Y.
Published: April 2007

The goal of this conference, which was supported by several agencies and organizations, was to provide a forum for physicists engaged in the Earth‐Sun system as well as in laboratory experiments to discuss and exchange knowledge and ideas on physical processes involving energy transfer. The motivation of the conference stemmed from the following realization: Space assets form an important fabric of our society, performing functions such as television broadcasting, cell‐phone communication, navigation, and remote monitoring of tropospheric weather. There is increasing awareness of how much our daily activities can be adversely affected by space disturbances stretching all the way back to the Sun. In some of these energetic phenomena, energy in various forms can propagate long distances from the solar surface to the interplanetary medium and eventually to the Earth's immediate space environment, namely, its magnetosphere, ionosphere, and thermosphere. In addition, transformation of energy can take place in these space disturbances, allowing chargedparticle energy to be transformed to electromagnetic energy or vice versa. In‐depth understanding of energy transformation and transmission in the Earth‐Sun system will foster the identification of physical processes responsible for space disturbances and the prediction of their occurrences and effects. Participants came from 15 countries.
Rudnick receives 2006 N. L. Bowen award
Authors: Lee Cin‐Ty A. , Rudnick Roberta
Published: April 2007

Roberta Rudnick received the N.L. Bowen Award at the 2006 AGU Fall Meeting. The award recognizes outstanding contributions to volcanology, geochemistry, or petrology.

One sign of a great scientist is that he or she uses fundamental observations in nature or experiments to drive questions and hypotheses on how natural processes work. Roberta satisfies all of these criteria, and more.
Managing drought in the United States: A roadmap for science and public policy
Authors: Diodato David M. , Wilhite Donald A. , Nelson Deborah I.
Published: April 2007

By 2050, the average moisture conditions in the southwestern United States will rival the worst conditions observed in the 1953–1956 and 2000–2003 droughts. These changes will be a consequence of increased temperatures and will occur even if precipitation levels remain fairly constant. As a result, all predicted scenarios of Colorado River flow at Lees Ferry, Ariz, indicate that within 20 years, discharge there will be insufficient to meet current consumptive water resource demands.

This sobering analysis was presented by Martin Hoerling and Jon Eischeid of the U.S. National Oceanic and Atmospheric Administration at the meeting Managing Drought and Water Scarcity in Vulnerable Environments—Creating a Roadmap for Change in the United States, presented by the Geological Society of America (GSA) in partnership with 20 other scientific organizations. Participants, including physical scientists, life scientists, social scientists, policy makers, Native Americans, water managers, and water users, represented a broad and diverse range of interests. Some preliminary findings are as follows.
Satellites to study geomagnetic storms
Authors: Kumar Mohi
Published: April 2007

NASA's Time History of Events and Macroscale Interactions during Substorms (THEMIS) mission to study geomagnetic substorms over the next two years launched on 17 February from Cape Canaveral Air Force Station, Fla. Substorms are visible in the atmosphere as a sudden brightening of polar auroral ribbons as they split and reorganize, and are thought to form when solar wind overloads the magnetosphere with too much energy. Substorms are closely related to space storms that can disable spacecraft, communications and navigation systems, and power grids and that can expose astronauts to high energy free electrons.

Launched from a single rocket, THEMIS's five satellites will align themselves between the Sun and the Earth to view substorms; simultaneously, ground stations in Alaska and Canada will monitor auroral dynamics.
Diffenbaugh receives 2006 James R. Holton Junior Scientist Award
Authors: Harshvardhan G. , Diffenbaugh Noah
Published: April 2007

Noah Diffenbaugh is a truly interdisciplinary geoscientist who has already made significant contributions to the field of high‐resolution climate modeling. His interests are varied and include climate/carbon dioxide/vegetation interactions, the response of extreme temperatures and precipitation events as well as the response of easternboundary current regions to anthropogenic radiative forcing, mechanisms of Holocene climate variability, and the potential impacts of future climate on human systems. An outcome of his climate studies is the discouraging prognosis for U.S., especially California, viticulture and enology in light of anticipated global warming. Noah is at the forefront of computational high‐resolution climate modeling, which will become an essential tool for policy planners by providing details that cannot be simulated by global models.
International Polar Year kicks off
Authors: Zielinski Sarah
Published: April 2007

The International Polar Year officially began on 1 March with an opening ceremony in Paris, France, and with local celebrations held throughout the week. The festivities marked the start of the two‐year international effort to understand ongoing change in the polar regions.

Previous IPYs (1882–1883 and 1932–1933) and the International Geophysical Year (1957–1958) resulted in a legacy that included the creation of maps of the polar regions, the establishment of permanent Antarctic research stations, the launch of the first satellites, and ratification of the Antarctic Treaty in 1961. Organizers of the current IPY hope that it will leave its own legacy of research, data, observation systems, and the inspiration of future scientists, said Robin Bell, chair of the U.S. National Committee for IPY and a geophysicist at Lamont‐Doherty Earth Observatory, Palisades, N.Y.
[Comment on “On award to Crichton”] On the validity climate models
Authors: Phillips Thomas , AchutaRao Krishna , Bader David , Covey Curtis , Gleckler Peter , Sperber Kenneth , Taylor Karl
Published: April 2007

We object to contributor Kevin Corbett's assertions, in his article “On award to Crichton” (Eos, 87(43), 464, 2006), that “Too often now, models are taken as data and their results taken as fact, when the accuracy of the models in predicting even short‐term effects is poor and the fundamental validity for most climate models is opaque…” Corbett cites (among other references) our Eos article “Coupled climate model appraisal: A benchmark for future studies” [Phillips et al, 2006], implying that our findings support his remarks. In fact, our evaluation of model simulations relative to observational data leads us to very different conclusions.
The Mayans: Climate determinism or geomagnetic determinism?
Authors: Gallet Yves , Genevey Agnès
Published: April 2007

Climatic variations since the end of the last ice age have been large enough to influence the fate of ancient civilizations, and deciphering the exact role of climate in the history of old societies is an active and challenging domain of research [e.g., deMenocal, 2001]. This potential influence, which serves as the foundation of ‘climate determinism,’ can be viewed as the response of natural‐resource‐dependent, agriculture‐based communities to climatically driven environmental changes. In some cases, these could have provoked major damage in economic and social organization of the societies, thus paving the way for political disintegration.

Could this climate variability be connected with the Earth's magnetic field? If so, a link might be found between the past geomagnetic field behavior and the history of humanity. This article explores that potential link, using a case study of the Classic Maya civilization.
Mars and Venus missions extended
Authors: Zielinski Sarah
Published: April 2007

The European Space Agency will continue to operate the Mars Express and Venus Express missions through early‐May 2009, the ESA announced on 27 February. Mars Express had been scheduled to end in October 2007 and Venus Express in June. The extension of the two missions will allow both satellites to continue mapping their respective planets as well as allow the scientists involved to conduct comparative planetology. These new studies could provide insight into how the planets formed and how life first emerged within the Solar System. Additional information about Mars Express can be found at http://www.esa.int/SPECIALS/Mars_Express/ and Venus Express at http://www.esa.int/ SPECIALS/Venus.Express/
Wikipedia's role in science education and outreach
Authors: Moldwin Mark B. , Gross N. , Miller T.
Published: April 2007

Where do most students get information about space science topics? An informal survey of 300 University of California, Los Angeles freshmen indicates that Wikipedia is their first stop when researching essentially any topic. One third of student pre‐service science teachers in a Boston University natural sciences course cited Wikipedia as a reference in their class reports on planetary exploration. A survey of Google® Web‐page rankings of 20 major topics in space physics (including aurora, space weather, solar wind, etc.) found that the Wikipedia entry was on the first page for 16, was in the top three for 11, and was the highest‐ranked site for six topics (magnetic reconnection, solar variation, Van Allen Radiation Belts, ionosphere, sudden ionospheric disturbance, and magnetometer).

The purpose of this note is to inform the community of the popularity of Wikipedia for introducing our field to students and the general public and to urge you to take a look at the Wikipedia entry for your area of expertise. Wikipedia articles are by nature encyclopedic and so provide students with an apparently complete source of material for use in reports and research projects. The question is, How good is the Wikipedia article compared with other top Google sites with regard to completeness and accuracy? We found that for many of the space physics key terms and concepts, Wikipedia was the most complete source of information. For many of the other top sites, basic information such as definition of the phenomena and fundamental properties (for example, average properties of the solar wind such as composition, speed, density, etc.), as well as science history and relevance of the topic to broader concepts, were either missing or difficult to find. Often the other top links focus so closely on details of a scientific study that the novice reader may not be able to understand much about the topic or concept they were originally searching for from that Web site. Thus, compared with many of the top Google hits, Wikipedia will appear to students to be an excellent reference for space science topics.
Achieving satellite instrument calibration for climate change
Authors: Ohring George , Tansock Joe , Emery William , Butler James , Flynn Lawrence , Weng Fuzhong , Germain Karen St. , Wielicki Bruce , Cao Changyong , Goldberg Mitchell , Xiong Jack , Fraser Gerald , Kunkee David , Winker David , Miller Laury , Ungar Stephen , Tobin David , Anderson James G. , Pollock David , Shipley Scott , Thurgood Alan , Kopp Greg , Ardanuy Philip , Stone Tom
Published: April 2007

For the most part, satellite observations of climate are not presently sufficiently accurate to establish a climate record that is indisputable and hence capable of determining whether and at what rate the climate is changing. Furthermore, they are insufficient for establishing a baseline for testing long‐term trend predictions of climate models. Satellite observations do provide a clear picture of the relatively large signals associated with interannual climate variations such as El Niño‐Southern Oscillation (ENSO), and they have also been used to diagnose gross inadequacies of climate models, such as their cloud generation schemes. However, satellite contributions to measuring long‐term change have been limited and, at times, controversial, as in the case of differing atmospheric temperature trends derived from the U.S. National Oceanic and Atmospheric Administration's (NOAA) microwave radiometers.
Amateur observations of atmospheric phenomena during the IGY
Authors: Schröder Wilfried
Published: April 2007

The fiftieth anniversary of the International Geophysical Year (IGY) provides an opportunity to look back at a scientific program which is now almost forgotten. Many of the research fields of the IGY required large numbers of observers around the world, far more than could be provided by the staffs of established institutions and university research groups. It became necessary to recruit men and women from outside the normal scientific net, but with an interest inastronomy and the physics of the planet.

Sydney Chapman, L.V. Berkner, M. Nicolet, V.V. Beloussov, J. Coulomb, E. Larsen, and others took a leading role in the planning of the IGY. Chapman had a personal interest in luminous phenomena of the upper atmosphere. One focus of Chapman's research had been collecting historical observations of auroras at low and middle latitude areas such as the Indian subcontinent, Greece, and the Pacific Ocean. He therefore consulted specialists such as C.W. Gartlein (Cornell University), James Paton (Edinburgh), Cuno Hoffmeister (Sonneberg), and N. Grisin, V.V. Sharonov, I.A. Khvostikov, earlier from the USSR, and others to plan and coordinate an international program of observations of auroras and other luminous phenomena of the upper atmosphere. At about this time his interest in noctilucent clouds (NLCs) was also suddenly aroused by a review containing photographs by George Witt (Sweden) that appeared in the journal Tellus.
Kamchatka volcano warnings for aviation discontinued
Authors: Zielinski Sarah
Published: April 2007

The program that provides warnings to the international aviation community when volcanoes on Russia's Kamchatka Peninsula erupt stopped providing these notices on 1 March due to a loss of funding.

As of 1 January 2007, the Federal Unitary Enterprise State Air Traffic Management Corporation of Russia halted its funding for the Kamchatka Volcanic Eruption Response Team. KVERT is a collaborative project of scientists from the Russian Institute of Volcanology and Seismology, the Kamchatka Experimental and Methodical Seismological Department, and the Alaska Volcano Observatory (AVO). AVO is a cooperative program of the U.S. Geological Survey, the University of Alaska Fairbanks Geophysical Institute, and the Alaska Division of Geological and Geophysical Surveys.
Outstanding student paper awards
Authors: Anonymous
Published: April 2007

The following members received Outstanding Student Paper Awards at the 2006 Fall Meeting in San Francisco, Calif. Winners in other sections and focus groups will be announced in subsequent issues of Eos.

Ting Chen, California Institute of Technology, Pasadena, Scaling of seismic moment with recurrence interval for small repeating earthquakes simulated on rate‐and‐state faults.
Biogeochemical and ecological research in the Indian Ocean
Authors: Hood Raleigh R. , Wajih S. , Naqvi A. , Wiggert Jerry D. , Subramaniam Ajit
Published: April 2007

The Indian Ocean has many unique characteristics that give rise to a variety of physical, biogeochemical, and ecological responses that are not observed in other ocean basins. For instance, atmospheric circulation over the ocean is seasonally influenced by the presence of the Asian landmass. The monsoonal forcing results in seasonally reversing surface oceanic circulations throughout the northern Indian Ocean, which are particularly energetic in the Arabian Sea. Unlike the Pacific and Atlantic oceans, there is no strong equatorial upwelling or biological response in the east. Furthermore, the Indian Ocean contains one of the most intense oxygen minimum zones (OMZs) in the world oceans, but unlike the Atlantic and Pacific, its OMZ is located in the north rather than along the eastern boundary.
Microsatellite to study plasma bubbles in ionosphere
Authors: Zielinski Sarah
Published: April 2007

An experimental instrument called the Flat Plasma Spectrometer, which was launched onboard a U.S. Air Force Academy microsatellite on 8 March, will study depletions in the ionosphere known as plasma bubbles that can disrupt satellite communications. The six‐month mission will demonstrate the effectiveness of the new instrument, which has been reduced to the size of a teacup. Reducing the size, weight, and power consumption of satellite instruments, such as this one, is expected to lower the cost of construction and launch and allow more of them to be flown simultaneously
North Korean nuclear test: Seismic discrimination low yield
Authors: Kim Won‐Young , Richards Paul G.
Published: April 2007

North Korea carried out a widely reported nuclear explosion on 9 October 2006 at 0135 UTC at a location about 40 kilometers northwest of the city of Kilju (Figure 1). The location of the test determined from seismic signals recorded at 31 stations around the world was given as 41.294°N, 129.094°E in Quick Determination of Epicenters (QED) by the U.S. Geological Survey's National Earthquake Information Center (NEIC), very close to Mantap‐san (Mount Mantap, 2205 meters, see Figure lc). Further, since the late 1990s, surveillance satellites have detected tunneling activity in this area suspected to be indicative of North Korea preparing to conduct nuclear tests at this site [Broad et al, 2005].
New detailed images of the Sun
Authors: Kumar Mohi
Published: April 2007

Newly released images of small‐scale solar structures indicate that the Sun is much more turbulent that previously known. The images, produced by the satellite Hinode (formerly known as Solar‐B), were released by NASA and the Japan Aerospace Exploration Agency (JAXA) on 21 March.

Many of the recently released images focused on a large sunspot identified by scientists in December 2006. The sunspot, which was anomalous because it occurred in the declining phase of the 11‐year sunspot cycle, ejected a flare of white light and protons.
Emergence of complex societies after sea level stabilized
Authors: Day John W. , Gunn Joel D. , Folan William J. , Yáñez‐Arancibia Alejandro , Horton Benjamin P.
Published: April 2007

Sea level rose rapidly from the Last Glacial Maximum (LGM, ∼18,000 years ago) until it stabilized about 7000 years ago. A millennium later, the rudiments of early civilizations appeared. However, the factors that might have spurred the first civilizations are a subject of debate, with proposals ranging across many possibilities from drought to the influence of individual rulers.

We hypothesize that sea level stabilization contributed significantly to the rapid advent of civilizations. Evidence from regions around the world shows that societies with class distinctions first emerged near coastal margins [e.g., Day et al., 2004; Kennett and Kennett, 2006], but there is little understanding of this process on a global scale. We show that the stabilization of sea level and the consequent dramatic increase in coastal margin productivity (CMP)—which resulted in increased availability of the high‐quality food necessary for the development of urban lifestyles—provide an explanation for the timing and location of emerging civilizations, and their varying regional characters. The coastal margin includes the continental shelf, nearshore upwelling zones, estuaries, and lower river floodplains affected by coastal water levels.
Report on Mississippi‐Atchafalaya streamflow
Authors: Zielinski Sarah
Published: April 2007

A new report from the U.S. Geological Survey presents streamflow and nutrient flux data from 1960–2005 for the Atchafalaya River, the main stem of the Mississippi River, 9 major subbasins of the Mississippi, and 21 additional selected subbasins. Nutrient flux estimates are provided for 6 water‐quality constituents: dissolved nitrite plus nitrate, total organic nitrogen plus ammonia nitrogen, dissolved ammonia, total phosphorous, dissolved orthophosphate, and dissolved silica. The report, “Streamflow and Nutrient Fluxes of the Mississippi‐Atchafalaya River Basin and Subbasins for the Period of Record Through 2005,” is available at http://toxics.usgs.gov/pubs/of‐2007‐1080/
Improved modeling of permafrost dynamics in a GCM land‐surface scheme
Authors: Nicolsky D. J. , Romanovsky V. E. , Alexeev V. A. , Lawrence D. M.
Published: April 2007

Global climate models (GCM) are frequently used to understand and predict future climate change, but most GCMs do not attempt to represent permafrost dynamics and its potentially critical feedbacks on climate. In this paper, we evaluate the Community Land Model (CLM3), which is a land‐surface scheme, against observations and identify potential modifications to this model that improve fidelity of permafrost and soil temperature simulations. These modifications include increasing the total soil depth by adding new layers, incorporating a surface organic layer, and modifying the numerical scheme to include unfrozen water dynamics and more realistic phase change representation.
Medroxyprogesterone and conjugated oestrogen are equivalent for hot flushes: a 1-year randomized double-blind trial following premenopausal ovariectomy
Authors: Prior Jerilynn C. , Nielsen Jason D. , Hitchcock Christine L. , Williams Lucy A. , Vigna Yvette M. , Dean Charmaine B.
Published: April 2007

Oestrogen therapy is the gold standard treatment for hot flushes/night sweats, but it and oestrogen/progestin are not suitable for all women. MPA (medroxyprogesterone acetate) reduces hot flushes, but its effectiveness compared with oestrogen is unknown. In the present study, oral oestrogen [CEE (conjugated equine oestrogen)] and MPA were compared for their effects on hot flushes in a planned analysis of a secondary outcome for a 1-year randomized double-blind parallel group controlled trial in an urban academic medical centre. Participants were healthy menstruating women prior to hysterectomy/ovariectomy for benign disease. A total of 41 women {age, 45 (5) years [value is mean (S.D.)]} were enrolled; 38 women were included in this analysis of daily identical capsules containing CEE (0.6 mg/day) or MPA (10 mg/day). Demographic variables did not differ at baseline. Daily data provided the number of night and day flushes compared by group. The vasomotor symptom day-to-day intensity change was assessed by therapy assignment. Hot flushes/night sweats were well controlled in both groups, one occurred on average every third day and every fourth night. Mean/day daytime occurrences were 0.363 and 0.187 with CEE and MPA respectively, but were not significantly different (P=0.156). Night sweats also did not differ significantly (P=0.766). Therapies were statistically equivalent (within one event/24 h) in the control of vasomotor symptoms. Day-to-day hot flush intensity decreased with MPA and tended to remain stable with CEE (P<0.001). In conclusion, this analysis demonstrates that MPA and CEE are equivalent and effective in the control of the number of hot flushes/night sweats immediately following premenopausal ovariectomy.
Exploring Pompeii: Discovering Hospitality through Research Synergy
Authors: O'Gorman Kevin D. , Baxter Ian , Scott Bernadette
Published: April 2007

Hospitality research continues to broaden through an ever-increasing dialogue and alignment with a greater number of academic disciplines. This paper demonstrates how an enhanced understanding of hospitality can be achieved through synergy between archaeology, the classics and sociology. It focuses on classical Roman life, in particular Pompeii, to illustrate the potential for research synergy and collaboration, to advance the debate on hospitality research and to encourage divergence in research approaches. It demonstrates evidence of commercial hospitality activities through the excavation hotels, bars and taverns, restaurants and fast food sites. The paper also provides an example of the benefits to be gained from multi-disciplinary analysis of hospitality and tourism.