March 2007


Research aircrafts observe further decline of ice cover

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Central Europe is not the only place where the past, warm winter has caused record temperatures. Unusually mild temperatures also prevented ice formation in the Arctic, specifically in the region around Spitsbergen. This is the conclusion drawn by scientists of the Alfred Wegener Institute for Polar and Marine Research and the German Aerospace Centre (DLR). Both institutes are members of the Helmholtz Association of German research centres. They aim to span the Helmholtz-network to observe environmental changes. Measurement activities of the recent expedition were part of the project ICESAR, and accomplished in collaboration with the European Space Agency (ESA).

Arctic sea ice plays an important role in climate change. The decline of average sea ice cover, observed over the past years, means that sea ice reflects progressively less solar energy back into space, causing temperatures in the Arctic to rise further. Usually, large areas of Spitsbergen are surrounded by ice at the end of the winter, and the fjords are frozen. “This year, our aircraft had to fly all the way to the limits of their range in order to collect sufficient data above the sea ice”, explains Dr Jörg Hartmann, climate scientist at the Alfred Wegener Institute. The recently published UN climate report highlights warming of the Arctic as one of the four key issues in relation to global climate change.

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The goals of ICESAR include improvements of sea ice observations facilitated by satellite radar, as well as better predictions for weather and climate models. The research campaign provided data for the technical alignment of ESA satellite Sentinel 1, because one of its radar systems will take up observation of Arctic ice cover in 2011. The research aircraft Polar 2, operated by the Alfred Wegener Institute, is equipped with various meteorological instruments and camera systems. During a recording flight, Polar 2 travels at low altitude while, simultaneously, another research aircraft of the DLR covers the same trajectory three kilometres higher, surveying the ice with an imaging radar system. The data collected by this method will provide the basis for a procedure using satellite images for ice data assembly.

SPH will host symposium with nationally recognized experts

By Greg Rienzi
The Gazette

Climate change has been a front-page staple for months, afforded former Vice President Al Gore rock star status, united and divided scientists worldwide and made governments at the very least sit up and take notice.

Due to this convergence of factors and the magnitude of climate change’s implications on humankind, the Johns Hopkins Bloomberg School of Public Health will place the subject front and center for The Heat Is Rising, a full-day symposium to be held on Friday, April 6, in the school’s Sheldon Hall. The event, subtitled “What you need to know about climate change and public health,” will bring together Johns Hopkins researchers and nationally recognized experts on the topic.

Brian Schwartz, professor in the Division of Occupational and Environmental Health and one of the event’s speakers and organizers, said that, without doubt, the time is right for an event like this. The challenges associated with climate change have existed for decades, Schwartz said, but what is different now is that people are paying attention.

He pointed to the success, both critical and commercial, of the Oscar-winning documentary on global warming, An Inconvenient Truth, and the findings of the Intergovernmental Panel on Climate Change, which released a summary report in January that notably reported that human activities are very likely (greater than 90 percent) causing global warming and that average temperatures would probably rise between 3.2 and 7.2 degrees Fahrenheit by the end of the century. The IPCC was formed by the World Meteorological Organization and the United Nations Environment Program in 1988 to assess the risk of human-induced climate change, its potential impacts and options for adaptation and mitigation.

“The concerns have always been there, but there is an increasing priority given to them now,” Schwartz said. “People in general seem willing to do something about it. As political leadership is lagging, we hope that individual and grass-roots efforts will take the lead and motivate politicians to actions.”

Climate change refers to any significant change in measures of climate — such as temperature, precipitation or wind — lasting for an extended period, meaning decades or longer. Changes may result from natural factors (such as variation in the sun’s intensity), natural processes within the climate system (changes in ocean circulation) or human activities that change the atmosphere’s composition (by burning fossil fuels) or the land’s surface (deforestation).

Since late in the 18th century, scientists say, human activities associated with the Industrial Revolution have changed the composition of the atmosphere and influenced the Earth’s climate in significant and negative ways. According to National Oceanic and Atmospheric Administration and NASA data, the Earth’s average surface temperature has increased since 1900 by about 1.2 to 1.4 degrees Fahrenheit.

The symposium’s main goal is to shine some light on the relationships between climate change and health, and the science supporting those relationships. Specific topics to be addressed include how air pollution plus heat impacts respiratory and cardiovascular health outcomes, the escalation in the number of heat-stress cases and how climate change affects the spread of vector-borne diseases, such as malaria and Lyme disease.

The speakers will also discuss the potential catastrophic events associated with climate change, including the rising of sea levels, mass extinction of animal species and regional climate change. Some scientists predict that sea levels could rise by as much as 20 to 30 feet in the not-so-distant future, an occurrence that would result in the displacement of millions of coastal inhabitants, leading to social upheaval and the spread of disease.

The symposium also will provide a range of solutions, from individual behavior changes to global policies, to stabilize the climate. The solutions will focus primarily on how to decrease carbon emissions, which have been linked to the “greenhouse effect.”

“The challenges we face are really quite huge. One change is not going to solve our problems,” said Schwartz, who co-authored a paper, published in the December 2006 edition of the journal Environmental Health Perspectives, on the needed public health response to global environmental change. “We need to take many steps at the same time. Individuals need to do their part and examine behaviors that result in large carbon emissions, whether it be buying a hybrid car or purchasing wind-generated energy from local utilities, and national and local governments need to pursue policy changes, which will likely require a new infrastructure for energy production and supply.”

The symposium is co-sponsored by the Johns Hopkins Center for Public Health Preparedness, the Center for a Livable Future and the National Institute of Environmental Health Sciences’ Center in Urban Environmental Health.

Jim Hansen, director of NASA’s Goddard Institute for Space Studies since 1981, will deliver the keynote address. Hansen, widely regarded as the government’s top climate change scientist, has spent the past two decades, sometimes in the face of great resistance, trying to educate the public about the consequences of unchecked global warming.

The event will be broken into six sessions: “The Basics of Climate Change,” “Health Impacts of Climate Change,” “Infectious Disease Risk,” “Adaptation vs. Mitigation,” “Solutions for Adaptation and Mitigation” and a panel discussion moderated by WYPR founder and on-air personality Marc Steiner. The panel discussion will tackle such questions as, How can a community or region be better prepared for climate change and climate-related disasters?

In addition to Hansen and Schwartz, the list of presenters includes Jonathan Patz, former School of Public Health faculty member, now with the University of Wisconsin, Madison; Kent Bransford, president of Physicians for Social Responsibility; and current School of Public Health faculty members Cindy Parker and John Balbus. Balbus is also the director of the Environmental Health Program for Environmental Defense.

For more information and to register for the event, go to: www.jhsph.edu/preparedness. The symposium is free for Johns Hopkins students with valid ID; $15 for all others.

AUSTIN, Texas—Polar ice experts from Europe and the United States, meeting to pursue greater scientific consensus over the fate of the world’s largest fresh water reservoir, the West Antarctic Ice Sheet, conclude their three-day meeting at The University of Texas at Austin’s Jackson School of Geosciences with the following statement:

Surprisingly rapid changes are occurring in the Amundsen Sea Embayment, a Texas-size region of the Antarctic Ice Sheet facing the southern Pacific Ocean. Experts across a wide range of scientific disciplines from the United States and United Kingdom met in Austin, Texas, to identify barriers to improved predictions of future sea-level rise resulting from these changes.

The United Nations Intergovernmental Panel on Climate Change (IPCC) reported in February that the scientific community could not provide a best estimate or an upper limit on the rate of sea-level rise in coming centuries because of a lack of understanding of the flow of the large ice sheets.

All of the ice on Earth contains enough water to raise sea level over 200 feet, with about 20 feet from Greenland and almost all of the rest from Antarctica. Although complete loss of the Antarctic Ice Sheet is not expected, even a small change would matter to coastal populations.

Background:

The two-mile thick pile of ice and snow that is the Antarctic Ice Sheet spreads under its own weight, flowing down to the sea where the ice begins to float as ice shelves, with icebergs breaking off from the edges of the ice shelves. The ice shelves often run aground on islands, providing friction that slows the flow of the ice behind.

The consensus view of the workshop:

  • Satellite observations show that both the grounded ice sheet and the floating ice shelves of the Amundsen Sea Embayment have thinned over the last decades.
  • Ongoing thinning in the grounded ice sheet is already contributing to sea-level rise.
  • The thinning of the ice has occurred because melting beneath the ice shelves has increased, reducing the friction holding back the grounded ice sheet and causing faster flow.
  • Oceanic changes have caused the increased ice-shelf melting. The observed average warming of the global ocean has not yet notably affected the waters reaching the base of the ice shelves. However, recent changes in winds around Antarctica caused by human influence and/or natural variability may be changing ocean currents, moving warmer waters under the ice shelves.
  • Our understanding of ice-sheet flow suggests the possibility that too much melting beneath ice shelves will lead to “runaway” thinning of the grounded ice sheet. Current understanding is too limited to know whether, when, or how rapidly this might happen, but discussions at the meeting included the possibility of several feet of sea-level rise over a few centuries from changes in this region.
  • The experts agreed that to reduce the very large uncertainties concerning the behavior of the Antarctic ice in the Amundsen Sea Embayment will require new satellite, ground, and ship-based observations coupled to improved models of the ice-ocean-atmosphere system. Issues include:
    • The recent changes were discovered by satellite observations; however, continued monitoring of some of these changes is not possible because of a loss of capability in current and funded satellite missions.
    • The remoteness of this part of Antarctica from existing stations continues to limit the availability of ground observations essential to predicting the future of the ice sheet.
    • No oceanographic observations exist beneath the ice shelves, and other oceanographic sampling is too infrequent and sparse to constrain critical processes.
    • Current continental-scale ice sheet models are inadequate for predicting future sea level rise because they omit important physical processes.
    • Current global climate models do not provide information essential for predicting ice sheet and oceanic changes in the Amundsen Sea Embayment; for example, ice shelves are not included.

Resolving these issues will substantially improve our ability to predict the future sea level contribution from the Amundsen Sea Embayment of the Antarctic Ice Sheet.

Signed

Richard Alley, Pennsylvania State University
Sridhar Anandakrishnan, Pennsylvania State University
John Anderson, Rice University
Robert Arthern, British Antarctic Survey
Robert Bindschadler, NASA Goddard Space Flight Center
Donald Blankenship, University of Texas Institute for Geophysics
David Bromwich, The Ohio State University
Ginny Catania, University of Texas Institute for Geophysics
Beata Csatho, University at Buffalo, the State University of New York
Ian Dalziel, University of Texas Institute for Geophysics
Theresa Diehl, University of Texas Institute for Geophysics
Fausto Ferraccioli, British Antarctic Survey
John Holt, University of Texas Institute for Geophysics
Erik Ivins, Jet Propulsion Laboratory
Charles Jackson, University of Texas Institute for Geophysics
Adrian Jenkins, British Antarctic Survey
Ian Joughin, University of Washington
Robert Larter, British Antarctic Survey
Alejandro Orsi, Texas A&M University
Byron Parizek, The College of New Jersey
Tony Payne, University of Bristol
Jeff Ridley, Hadley Center for Climate Prediction, Met Office
John Stone, University of Washington
David Vaughan, British Antarctic Survey
Duncan Young, University of Texas at Austin

For background information on the meeting and the situation of the West Antarctic Ice Sheet, see the WALSE meeting site at http://www.jsg.utexas.edu/walse/.

For more information about the Jackson School, contact J.B. Bird at jbird@jsg.utexas.edu, 512-232-9623.

A recent NASA study suggests that tiny dust particles may have foiled forecasts that the 2006 hurricane season would be another active one.

In June and July 2006, there were several significant dust storms over the Sahara Desert in Africa. As this dust traveled westward into the Atlantic, satellite data show that the particles blocked sunlight from reaching the ocean surface, causing ocean waters to cool. These cooler waters may have impeded some storminess since hurricanes rely on warm waters to form.

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The 2006 Atlantic hurricane season wrapped up on Nov. 30 with just four tropical storms and five hurricanes, relatively calm compared to the record number of 12 tropical storms and 15 hurricanes in 2005.

While several factors likely contributed to the sharp decrease in the number of storms, “this research is the first to show that dust does have a major effect on seasonal hurricane activity,” said lead author William Lau, chief of the Laboratory for Atmospheres at NASA’s Goddard Space Flight Center, Greenbelt, Md. “Dust concentrations may play as big a role as other atmospheric conditions, like El Niño, and offer some predictive value, so they should be closely monitored to improve hurricane forecasts.”

Other researchers, however, say that atmospheric dust may have had relatively little influence on the 2006 hurricane season compared to the effects of underlying El Niño conditions.

Sea surface temperatures in 2006 across the prime hurricane-breeding regions of the Atlantic and Caribbean were found to be as much as 1 degree Celsius (1.8 degrees Fahrenheit) cooler than in 2005. Most striking was how quickly sea surface temperatures responded to variations in the amount of Saharan dust, Lau said. Following the most significant dust outbreak, which occurred in June and July, ocean waters cooled abruptly in just two weeks, suggesting that the dust had an almost immediate effect.

The dust worked to cool the ocean, but it also warmed the atmosphere by absorbing more of the sun’s energy. This temperature difference resulted in a shift in the large-scale atmospheric circulation. As air rose over West Africa and the tropical Atlantic, it sank and became less moist over the western Atlantic and Caribbean. This pattern helped to increase surface winds that enhanced ocean evaporation and churned deeper, colder waters, causing the area of cool seas to expand.

Lau and co-author Kyu-Myong Kim of Goddard analyzed data on ocean temperatures, clouds, and water vapor from NASA’s Tropical Rainfall Measuring Mission satellite and atmospheric dust levels from the Ozone Monitoring Instrument on NASA’s Aura satellite. The study was published in the Feb. 27 issue of the American Geophysical Union’s Eos.

The research also considered the role of El Niño by examining historical data on the intensity and development of tropical storms and hurricanes across the Atlantic basin. “We found that Saharan dust may have a stronger influence than El Niño on hurricane formation in the subtropical western Atlantic and Caribbean, but that El Niño has a greater impact in the tropical eastern Atlantic, where many storms are generated,” said Lau.

El Niño is the periodic warming of the ocean waters in the central and eastern equatorial Pacific, which in turn can influence pressure and wind patterns across the tropical Atlantic.

“In 2006, it is quite possible that the Saharan dust may have amplified or even initiated pre-existing atmosphere-ocean conditions due to El Niño,” said Lau. But other researchers say that while the amount of atmospheric dust in 2006 was greater than in 2005, the increase may have been too insignificant to be influential on the season. Instead, they believe the atmospheric effects from the underlying El Niño pattern in 2006 likely played a greater role.

Scott Braun, a hurricane specialist at NASA’s Goddard Space Flight Center, said that in 2006, El Niño brought about broad changes to atmospheric conditions that likely had at least some influence on hurricane formation across much of the Atlantic.

Braun noted that during most of the hurricane season a large area of high pressure was located across the eastern Atlantic. This steered disturbances away from the warmest waters, so that they were less able to mature into tropical storms and hurricanes. At the same time, sinking motion – an atmospheric air mass that has cooled and is falling – combined with enhanced winds in the middle and upper atmosphere to minimize development in the Caribbean and western Atlantic and keep storms away from the U.S. These strong upper-level winds would contribute to a drastic change of winds with height, known as “shear” that can rip storms apart.

“This large-scale pattern has been associated with the effects of El Niño, suggesting it may have played a role in the seasonal activity,” said Braun. “In fact, the last time the Atlantic produced so few storms was in 1997, when an El Niño pattern was also in place.”

Braun and another hurricane researcher, Bowen Shen at NASA’s Goddard Space Flight Center, agree that factors other than increased atmospheric dust may have contributed to cooler ocean waters in 2006.

“It is arguable that stronger surface winds over the tropical Atlantic may have cooled sea surface temperatures,” said Shen. These winds likely helped to keep waters cooler by mixing the upper layers of the ocean and sweeping warmer waters westward. And although the waters were certainly cooler in 2006 than in 2005, they were still at or slightly above normal, suggesting other conditions helped to shape the season.

Current and future research efforts that examine how the ocean responds to surface winds and dust should help clarify their role in hurricane development. Although seasonal atmospheric patterns may increase the amount of dust across the Atlantic, the same atmospheric patterns may also be responsible for creating stronger winds at the ocean surface. By modeling the oceans, winds, and dust, researchers will generate a clearer picture of how these conditions vary from season to season.

“Although we continue to make significant strides in forecasting hurricanes and understanding their development, it is important to remember that the atmosphere is a chaotic system and numerous meteorological variables influence individual storms and activity throughout the season. NASA’s constellation of several Earth-observing satellites, including Aura, is designed to provide coordinated measurements of these many variables for future research,” said Lau.

Mike Tidwell comments -Article like this give me pause to think. Imagine what this level of change means for our planet. When I read this article my heart is heavy. I don’t think I will ever understand why it is not a national emergency to reduce our emissions.

Many of the world’s climate zones will vanish entirely by 2100, or be replaced by new, previously unseen ones, if global warming continues as expected, a study released Monday said. sge.jpg

Rising temperatures will force existing climate zones toward higher latitudes and higher elevations, squeezing out climates at the colder extremes, and leaving room for unfamiliar climes around the equator, the study predicted.

The sweeping climatic changes will likely affect huge swaths of land from the Indonesian rainforest to the Peruvian Andes, including many known hotspots of diversity, disrupting local ecological systems and populations.

“Our findings are a logical outcome of global warming scenarios that are driven by continued emissions of carbon dioxide and other greenhouse gases,” said Jack Williams, a professor of geography at the University of Wisconsin-Madison, and author of the paper.

“The warmest areas get warmer and move outside our current range of experience and the colder areas also get warmer and so those climates disappear.”

Williams and colleagues from the University of Wyoming based their predictions on computer models that translate carbon dioxide and greenhouse gas emissions into climate change. The emissions’ estimates were taken from a report issued by the UN’s Intergovernmental Panel on Climate Change in February.

The models suggest that the climate zones covering as much as 48 percent of the earth’s landmass could disappear by 2100.

By that point, close to 40 percent of the world’s land surface area would also have a “novel” or new climate, according to the climate models.

Even if emission rates slowed due to mitigation strategies, the changes would still affect up to 20 percent of the earth’s landmass in each scenario, the authors said.

As a geographic phenomenon, the disappearing climates would likely affect tropical highlands and regions near the poles including the Colombian and Peruvian Andes, Central America, African Rift Mountains, the Zambian and Angolan Highlands.

The trend poses the greatest threat to areas of rich, but threatened, animal and plant life, in regions such as the Himalayas, the Philippines and African and South American mountain ranges. The changes could threaten some species with extinction and also displace or fragment local human populations.

As for new or novel climate zones, the phenomenon will largely affect the tropics or sub-tropics, such as the Amazonian and Indonesian rainforests, where even subtle temperature variations can have far-reaching effects, Williams said.

The study is published in the Proceedings of the National Academy of Sciences.

Lake Superior summer temperatures rising faster than regional air temperatures_lake_superior_waves.jpg

 

A new analysis of data from buoys, weather stations, and historical ice records indicates that summer surface temperatures of Lake Superior have increased approximately 2.5°C since 1979, roughly twice the rate of regional atmospheric warming. Austin and Colman hypothesize that declining winter ice cover is causing the lake to absorb more solar radiation than it did in past years. The increased absorption, in turn, causes earlier stratification of the lake at a rate of roughly half a day per year. Large mid-latitude lakes often freeze over in winter, mix thoroughly during spring and fall, and stratify in summer due to solar heating. The earlier start to Lake Superior’s stratified season significantly increases the period over which the lake warms during the summer months, resulting in higher summer temperatures. Though little-studied, the response of large lakes to climate change will likely have an important regional effect.

Title: Lake Superior summer water temperatures are increasing more rapidly than regional air temperatures: a positive ice-albedo feedback

Authors: Jay A. Austin: Large Lakes Observatory and Department of Physics, University of Minnesota, Duluth;

 POWERFUL NEW TOOL TO TRACK ATMOSPHERIC CARBON DIOXIDE BY SOURCE

Scientists from NOAA’s Earth System Research Laboratory announced today a new tool to monitor changes in atmospheric carbon dioxide and other greenhouse gases by region and source. The tool, called CarbonTracker, will enable its users to evaluate the effectiveness of their efforts to reduce or store carbon emissions.
The online data framework distinguishes between changes in the natural carbon cycle and those occurring in human-produced fossil fuel emissions. It also provides verification for scientists using computer models to project future climate change. Potential users include corporations, cities, states and nations assessing their efforts to reduce or store fossil fuel emissions around the world.
“NOAA encourages science that adds benefit to society and the environment. CarbonTracker does both,” said retired Navy Vice Admiral Conrad Lautenbacher <http://www.noaa.gov/lautenbacher.html&gt;, Ph.D., undersecretary of commerce for oceans and atmosphere and NOAA administrator. “Increasingly, observations of the Earth are demonstrating a remarkable impact on our understanding of human and natural systems. We are transitioning this understanding gained from intensive research into operations that benefit the environment and the economy.”
CarbonTracker distills an accurate assessment of greenhouse-gas increases or decreases. The resolution will increase to observe differences in concentration on finer geographical scales over time as data become available. Using the limited data that currently exist, the model can characterize emissions each month among U.S. regions, such as the West or the Southeast. As the observation network becomes denser, however, policymakers will be able to check the CarbonTracker Web site to compare emissions from urban centers. For instance, the resolution will be fine enough to determine the difference in net emissions from Sacramento as compared to San Francisco.
CarbonTracker’s initial applications are primarily for scientists, and to attract new partners in NOAA’s efforts to expand greenhouse gas observations in the United States and globally. NOAA and its partners are encouraging the addition of new monitoring sites around the United States and around the world to increase the resolution of point sources. Ultimately the site will provide easy-to-use information on local scales for policymakers, business leaders, teachers, and the public.
“CarbonTracker’s potential is enormous,” said Pieter Tans, head of NOAA/ESRL’s Carbon Cycle Greenhouse Gases group, who developed the tool. “We are moving into an era where emissions could have a price tag. If carbon trading, emissions reduction and sequestration schemes become more common around the globe, society will need the ability to compare their relative value. Accurate and objective information on changing atmospheric concentrations will be essential for both research and impact assessments.”
Until now, scientists have relied on limited direct records of atmospheric carbon dioxide, mainly from remote locations. Also, previously available computer models could not maximize the utility of the information derived. Only analyses of very broad global patterns of carbon dioxide emissions and uptake were possible. Estimates of local carbon emissions have used proxy data, such as reported point-source inventories, gasoline sales records, and other tallies from energy organizations and nations monitoring greenhouse gases, but there has been no way to verify what was actually released into the atmosphere.
CarbonTracker uses many more continuous observations than previously taken. The largest concentration of observations for now is from within North America. The data are fed into a sophisticated computer model with 135 ecosystems and 11 ocean basins worldwide. The model calculates carbon release or uptake by oceans, wildfires, fossil fuel combustion, and the biosphere and transforms the data into a color-coded map of sources and storage “sinks.” One of the system’s most powerful assets is its ability to detect natural variations in carbon uptake and release by oceans and vegetation, which could either aid or counteract societies’ efforts to curb fossil fuel emissions on a seasonal basis.
“Only the atmosphere itself can give us the real answer on all sources and sinks,” said Wouter Peters, who led the development of CarbonTracker at NOAA/ESRL and also is affiliated with the Cooperative Institute for Research in the Environmental Sciences. “This information will be critical. How atmospheric concentrations of greenhouse gases change in the future is one of the key uncertainties in the global climate models and the biggest driver behind climate change.”
NOAA collaborates with partners in France, Australia, Brazil and other nations to measure greenhouse gases globally. Through a longstanding collaboration, Environment Canada has provided a quarter of the data for North America. However, the global network is still sparse. Using today’s data, the system can distinguish surface emissions on a broad scale, but plans are underway to refine observations and modeling of carbon sources on much smaller scales.
NOAA’s Earth System Research Lab is the only institution measuring atmospheric greenhouse gases globally and provides more than half of the world’s data. The network includes individuals gathering air samples in flasks that are then shipped to the Boulder lab for analysis, aircraft carrying automated samplers to grab air from higher altitudes, and sensors atop tall towers transmitting data via telephone.
CarbonTracker is a NOAA contribution to the North American Carbon Program <http://www.nacarbon.org/nacp/&gt;, a multi-agency effort to quantify, understand, and predict the continent’s carbon cycle. CIRES <http://cires.colorado.edu/&gt; is a partnership between NOAA and the University of Colorado.

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