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Showing posts with label CLIMATE CHANGE. Show all posts
Showing posts with label CLIMATE CHANGE. Show all posts

Satellite Animation Shows February Return of the Pineapple Express

Written By Unknown on Saturday, February 7, 2015 | 12:51 AM

An animation of satellite imagery from NOAA's GOES-West satellite from Feb. 1 to Feb. 4, 2015 captured the movement of a stream of clouds associated with moisture called "The Pineapple Express." Image Credit: NASA/NOAA GOES Project, Dennis Chesters
An animation of satellite imagery from NOAA's GOES-West satellite from Feb. 1 to Feb. 4, 2015 captured the movement of a stream of clouds associated with moisture called "The Pineapple Express." Image Credit: NASA/NOAA GOES Project, Dennis Chesters

The "Pineapple Express" has set up again and is bringing wet weather to the U.S. Pacific Northwest. An animation of satellite imagery from NOAA's GOES-West satellite from Feb. 1 to Feb. 4, 2015 captured the movement of a stream of clouds associated with moisture that is expected to bring rain and snow to the region over the next several days.

The ‘‘Pineapple Express’’ occurs when warm air and lots of moisture are transported from the Central Pacific, near Hawaii, to the Eastern Pacific Ocean.

A wide-field movie by NOAA's GOES-West satellite shows the Pineapple Express' stream of clouds and moisture moving into the Pacific Northwest. The video was created by NASA/NOAA's GOES Project at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

“Good news for Northern California and the Pacific Northwest," said Bill Patzert, climatologist for NASA's Jet Propulsion Laboratory in Pasadena, California. "Beginning Wednesday, a series of storms pumped up by a moisture-laden ‘Pineapple Express’ system surging out of the warm tropical Pacific will deliver some small relief to rain and snow starved California. Though not a drought buster, we Californians are hoping this might be a preview of coming attractions for February and March. We are in the fourth quarter of our winter rain season and need a ‘hail mary’ to beat this drought down,” Patzert said.

On Feb.4 NOAA's National Weather Service Weather Prediction Center (NPC) in College Park, Maryland issued a short range forecast discussion about the Pineapple Express. NPC noted: A weather system that's tapping into abundant moisture in the Pacific will bring moderate to heavy rainfall to the Pacific Northwest beginning Wednesday. The rain will spread into northern California on Thursday and is expected to continue through the weekend. Some areas could see in excess of 10 inches of rain through early Saturday.

WATCH VIDEO

The Pineapple Express is expected to affect areas from northwest California into coastal Oregon and Washington State. NPC noted that the "Express" is expected to produce mostly light to moderate rainfall totals for the coastal Pacific Northwest on Feb. 4, with much heavier totals expected the following two days.

GOES satellites provide the kind of continuous monitoring necessary for intensive data analysis. Geostationary describes an orbit in which a satellite is always in the same position with respect to the rotating Earth. This allows GOES to hover continuously over one position on Earth's surface, appearing stationary. As a result, GOES provide a constant vigil for the atmospheric "triggers" for severe weather conditions such as tornadoes, flash floods, hail storms and hurricanes.

Source: Nasa

Climate change accelerates maturing of grape in wine production

Written By Unknown on Thursday, February 5, 2015 | 8:53 PM

Johann Martรญnez-Lรผscher , Nafarroako Unibertsitatea
                             Johann Martรญnez-Lรผscher , Nafarroako Unibertsitatea

The increase in temperatures and of CO2 levels – the consequences of climate change – accelerates the maturing of grapes in wine production, affecting colour and possibly aromas”. This was the conclusion of the PhD thesis defended by Johann Martรญnez-Lรผscher, undertaken jointly by the University of Navarra and the University of Bordeaux.

The biologist explained that if the forecasts by the Intergovernmental Panel on Climate Change of a level of 700ppm of carbon dioxide and a temperature increase of 4ยบC are proved correct, “the accumulation of sugars could be so rapid that the rest of these processes that depend on this will not be capable of keeping up. This will mean that, on comparing grapes with the same concentration of sugars or degree of alcohol, the crops under climate change conditions will have poorer colouration and this will be noticed in the wine”.

In fact, “it is increasingly more frequent to find wines with a higher alcoholic degree due to the over maturing of the grape”. Nonetheless, in the framework of climate change, the consequences can vary. “For example, the changes in levels of ultraviolet radiation or the decrease in rainfall may have antagonistic effects to those caused by an increase in temperature or CO2 levels. Thus, there are many unknowns about what the future holds”, he added.

Wine in a new scenario

In this way wine production will have to find solutions in order to confront environmental challenges. “The use of slower maturing ‘clones’ (sub-varieties) could be one of the possible strategies. It would also be very tempting to substitute the varieties planted in each location by others better adapted to warmer climates, but this would to a great extent mean giving up the typical characteristics of each variety of our wines – something unthinkable to date”.

Nevertheless, as this expert pointed out, climate change can provide new opportunities: for example, the production of a type of wine in cooler climes where it was not possible before. “This is the case of the incipient wine industry in the United Kingdom where I intend to continue working”, stated the researcher.

Mr. Martรญnez-Lรผscher’s research has been financed by the University of Navarra, the Navarre-Aquitane Cross-Border Cooperation Programme, the Spanish Ministry of Science and Innovation, and the 7th European Union Framework Programme.

Source: Elhuyar Fundazioa

NOAA joins with Princeton and other institutions in six-year study to help public better understand Southern Ocean

Written By Unknown on Monday, February 2, 2015 | 8:49 PM

NOAA is one of 10 institutions working together on the Southern Ocean Carbon and Climate Observations and Modeling program, or SOCCOM, a six-year, $21 million initiative to improve our understanding of the importance and health of the Southern Ocean encircling Antarctica. (Image by Oscar Schofield, Rutgers University)

The Southern Ocean that encircles Antarctica lends a considerable hand in keeping Earth's temperature hospitable by soaking up half of the human-made carbon in the atmosphere and a majority of the planet's excess heat. Yet, the inner workings — and global importance — of this ocean that accounts for 30 percent of the world's ocean area remains relatively unknown to scientists, as observations remain hindered by dangerous seas.

NOAA is one of 10 institutions working together on the Southern Ocean Carbon and Climate Observations and Modeling program, or SOCCOM, a six-year, $21 million initiative to improve our understanding of the importance and health of the Southern Ocean encircling Antarctica. (Image by Oscar Schofield, Rutgers University)

Princeton University, NOAA and eight other partner institutions now seek to make the Southern Ocean better known scientifically and publicly through a $21 million program that will create a biogeochemical and physical portrait of the ocean using hundreds of robotic floats deployed around Antarctica and an expanded computational capacity. The Southern Ocean Carbon and Climate Observations and Modeling program, or SOCCOM, is a six-year initiative headquartered at Princeton and funded by the National Science Foundation’s Division of Polar Programs, with additional support from the NOAA and NASA. The U.S. Argo program, led by CPO's Steven Piotrowicz, will play a major role in the project. 

"The scarcity of observations in the Southern Ocean and inadequacy of earlier models, combined with its importance to the Earth's carbon and climate systems, means there is tremendous potential for groundbreaking research in this region," Sarmiento said.
Central to the program are roughly 200 floats outfitted with biogeochemical sensors that will provide almost continuous information related to the ocean's carbon, nutrient (nitrate, in particular) and oxygen content, both at and deep beneath the surface. The floats are augmented biogeochemical versions of the nearly 4,000 Argo floats deployed worldwide to measure ocean salinity and temperature. SOCCOM marks the first large-scale deployment of these biogeochemical floats.

"These floats are revolutionary and this major new observational initiative will give us unprecedented year-round coverage of biogeochemistry in the Southern Ocean," Sarmiento said.
The Southern Ocean research will involve using Argo type floats equipped with new sensors that measure pH, nitrates in addition to temperature and salinity. (NOAA)

The floats will increase the monthly data currently coming out of the Southern Ocean by 10 to 30 times, Sarmiento said. That data will be used to improve recently developed high-resolution earth-system models, which will allow for a better understanding of the Southern Ocean and for better projections of Earth’s climate and biogeochemical trajectory. In keeping with SOCCOM's knowledge sharing, or "broader impacts," component, all the information collected will be freely available to the public, researchers and industry.

SOCCOM will provide direct observations to further understand the importance of the Southern Ocean as suggested by models and ocean studies. Aside from carbon and heat uptake, models have indicated that the Southern Ocean delivers nutrients to lower-latitude surface waters that are critical to ocean ecosystems around the world. In addition, the impacts of ocean acidification as levels of carbon dioxide in atmosphere increase are projected to be most severe in the Southern Ocean.

Other than administering the project, Sarmiento and other Princeton researchers will co-lead the modeling and broader impacts components, as well as coordinated data management. Researchers from NOAA's Geophysical Fluid Dynamics Laboratory housed on Princeton's Forrestal Campus will carry out high-resolution earth-system simulations in support of the modeling effort, which is led by the University of Arizona and includes collaborators from the University of Miami.

The floats will be constructed at the University of Washington with sensors from the Monterey Bay Aquarium Research Institute; NOAA’s Climate Program Office will provide half of the basic Argo floats. Float deployment, observation analysis and data assimilation will be led by the Scripps Institution of Oceanography at the University of California-San Diego. Climate Central, a non-profit science and journalism organization based in Princeton, will oversee the broader-impacts component. Researchers from Oregon State University and NOAA will develop the floats’ carbon algorithms.

“The SOCCOM effort is the first systematic expansion of the US Argo program into biogeochemistry. The unique subsurface ocean observations from SOCCOM will contribute towards our efforts to observe the global oceans,” said David Legler, director of NOAA’s Climate Observations Division.

In addition, NASA will support a complementary project involving researchers at the University of Maine and Rutgers University that will equip the floats with bio-optical sensors intended to gather data about biological processes in the water column.

This web story was written by Morgan Kelly, science writer for Princeton University, and includes an additional quote from NOAA's David Legler

Source: NOAA

Putting the Blizzard of 2015 into Historical Context

                    January-25-28-2015-Snowfall-Totals-Map Credit: NOAA

The recent “Blizzard of 2015” shutdown several major metropolitan areas in the Northeast and left several locations across Connecticut, Maine, Massachusetts, New Hampshire, and New York covered in over two feet of snow. But, how did this snowstorm compare to the region’s most historic storms? To place this storm and its societal impacts into historical context, NCDC used the Regional Snowfall Index or RSI to rank it on a scale from 1 to 5—similar to the Fujita scale for tornadoes or the Saffir-Simpson scale for hurricanes. These ranks are based on the snowfall amount within the region’s borders, the spatial extent of the storm, and the relationship of these elements to the area’s population.

The RSI value for January 25­–28, 2015, snowstorm is 6.16, which makes it a Category 3 or major event for the Northeast. With that RSI value, the snowstorm ranks 26th out of the 423 northeastern snowstorms NCDC has analyzed since 1900. The area of snowfall and population affected by 20 inches of snow or more were the primary drivers for this storm’s raw RSI score. Almost 5 million people experienced over 20 inches of snow and 15 million experienced over 10 inches of new snow. While these are significant impacts, the footprint of the heavy snow was relatively small compared to RSI Category 5 storms. These rare events typically have over 45 million people experiencing over 10 inches of snow. Nonetheless, this storm is well within the top 10% of storms analyzed for the Northeast.

The late February snowstorm of 1969 remains the strongest storm to hit the Northeast, with an RSI value of 34.03 making it a Category 5 or extreme event. The March 1993 “Storm of the Century” remains the second strongest snowstorm to hit the Northeast, with an RSI value of 22.12 also making it a Category 5 event.

Learn more about the Regional Snowfall Index and use our interactive mapping tool to see RSI rankings for almost 600 snowstorms since 1900.

Source: NOAA

Satellites for peat sake - Peatlands play vital role in curbing climate change

                         Peatlands play vital role in curbing climate change Credit: JHU
Peatlands make up just 3% of land but capture twice as much carbon as all forests combined.

They are also an important source of drinking water and provide a home to many rare and threatened animals and plants.

Ecosystems work best when left intact but these wetland areas are being threatened by human exploitation, resulting in vast carbon emissions, frequent and uncontrollable fires and loss of valuable landscapes.
                                            Handheld devices for collecting ground data

Rezatec in Oxfordshire, UK, supported by ESA’s Integrated Applications Promotions programme, in the Peat spotter project will give landowners an easier and cheaper way of calculating the potential economic value of conserving or restoring their peatlands and monitoring the results of their investment.

“Peat spotter helps landowners to manage their peat resource more sustainably through mapping the area, measuring the carbon it contains and monitoring how its integrity is changing over time,” says Patrick Newton, CEO of Rezatec.

To do this, satellite imagery is used to locate and create initial mappings of peatlands. This information is enriched with ground data collected by field agents using handheld devices.

An app prompts users in the field for measurements, satnav adds location information, and the data are then sent directly to a centralised office via satcom for analysis.

The new approach is a cost-effective way of measuring peat extent and how intact it is over wide and potentially remote areas that are otherwise expensive to measure or inaccessible from the ground.

Rezatec expects water companies, conservation groups and those using typically state-owned land for uses such as plantations to sign up for this service.

Peatlands are an important source of drinking water. Water companies using these resources can significantly reduce the water treatment necessary to meet drinking water standards if they are able to identify areas of degraded peatland and make restoration efforts at source.

Water derived from degraded peatlands can contain raised levels of dissolved organic carbon causing significant discolouration.

On land that is typically used for plantations, peat assets are included in the measurement of the greenhouse gas balance, but only through a rough calculation.

                                                     Deforestation damages peatlands

Making it cheaper and easier to locate and monitor peatlands will make it simpler to calculate the economic value of conserving and restoring these areas and, in turn, this can be positive for society, the economy and the environment.

Within the mobile device apps Rezatec includes: guides to help identify flora and fauna, videocam monitoring of borders, photo uploading, alerts when levels are breached, and fire mapping.

“This innovative use of satellite data has far-reaching benefits for the space industry and the wider UK economy,” notes Alan Brunstrom, head of the Service Business Office in ESA’s Integrated Applications Promotion programme.

“Perhaps more importantly, it demonstrates how the scientific analysis of ‘big data’ can benefit the environment and, in this particular scenario, provide valuable information to allow sustainable peatland management practices on a global scale.”

Source: JHU

Atmospheric warming heats the bottom of ice sheets, as well as the top

Written By Unknown on Saturday, January 31, 2015 | 4:27 PM

A 70-meter-deep basin formed near the summit of Greenland’s Flade Isblink Ice Cap in the fall of 2012 when a lake 540 meters beneath the ice surface suddenly emptied. Summer meltwater streams on the ice cap surface (blue) enter crevasses near the bottom of the image. Photo Credit: WorldView-2 Imagery (c) 2014, DigitalGlobe, Inc.
University of Minnesota researchers are part of a national team of scientists that has published a new paper showing for the first time that meltwater from the surface of an ice cap in northeastern Greenland can make its way beneath the ice and become trapped, refilling a subglacial lake. This meltwater provides heat to the bottom of the ice sheet.

These groundbreaking findings provide new information about atmospheric warming and its affect on the critical zone at the base of the ice. The warmth provided by the water could make the ice sheet move faster and alter how it responds to the changing climate.

The research is detailed in a new paper published today online by the journal Nature. The research was led by Cornell University Earth and Atmospheric Sciences researcher Michael Willis, who is also an adjunct faculty member in the geological sciences department at UNC-Chapel Hill's College of Arts and Sciences. The research study’s co-authors are Bradley Herried, University of Minnesota School of Earth Science’s Polar Geospatial Center; Michael Bevis, Ohio State University School of Earth Sciences; and Robin Bell, Columbia University Lamont Doherty Earth Observatory.

“We’re seeing surface meltwater make its way to the base of the ice where it can get trapped and stored at the boundary between the bedrock beneath the ice sheet and the ice itself,” Willis said. “As the lake beneath the ice fills with surface meltwater, the heat released by this trapped meltwater can soften surrounding ice, which may eventually cause an increase in ice flow.”

The researchers were able to pinpoint when the subglacial lake refilled using data collected from high-resolution satellite images from the University of Minnesota’s Polar Geospatial Center, as well as data from NASA’s operation IceBridge for calibration and verification.

The direct link between the surface meltwater and the filling of a lake at the base of the ice has never been seen before. Over the last few years the number of lakes on the surface of the Greenland ice sheet has greatly increased. Surface lakes are also occurring much farther inland at higher altitudes than in the past. If this mechanism of transferring water and warmth from the surface lakes to the bottom of the ice sheet is common then the Greenland Ice Sheet is likely to respond more rapidly to climate change than is currently predicted.

The Greenland ice sheet comprises about 80 percent of the land mass of Greenland and previous studies have documented that the ice sheet is melting at a faster rate due to climate change. The movement of meltwater beneath the ice sheet, from the interior to the ocean, is the topic of many investigations as it can control the speed at which the ice sheet moves. This is the first study to document that surface water can penetrate to the bottom of an ice cap and be trapped in place. Researchers say this process could also occur at other large bodies of ice.

The study was sparked in 2012 when Willis was mapping ice changes around the edge of the Greenland Ice Sheet as part of a study funded by U.S. National Science Foundation (NSF) to understand how much of the accelerating ice loss in Greenland is caused by melting and how much is caused by the increase of ice moving into the ocean.

During his research, Willis spotted a 70-meter-deep hole (the equivalent of a 10-story building) that had formed when a subglacial lake, far beneath the ice surface, emptied in the late fall of 2011. Subglacial lakes are rare in Greenland, and the presence of such a lake in the far northeast came as a surprise. The ice in this region is much too slow, too cold and too thin to allow melting beneath the ice cap, which is how a subglacial lake usually forms. 

Between 2012 and 2014, Willis watched as summer meltwater on the surface of the ice made its way down cracks around the hole and refilled the empty lake basin at the base of the ice cap. When water was flowing on the surface, the subglacial lake filled. When water stopped flowing on the surface, the subglacial lake stopped refilling.

Each summer scientists see bright blue streams form on the surface of Greenland as warm air melts the ice sheet. What happens to this water when it disappears into cracks in the ice has remained a mystery.

“This discovery that water can be stored in lakes beneath the ice shows how the plumbing on the surface is linked to the plumbing at the base," said co-author Bell.

The Cornell-led team calculated that the lake beneath the ice has filled about half way since its 2011 blowout that originally drove water from the lake at a volume of 215 cubic meters per second (nearly 57,000 gallons—close to the volume of a 30-foot-by-50-foot backyard swimming pool every second.)  As the lake refills, the surface meltwater carries stored heat, called latent heat, along with it from the relatively warm atmosphere to the icy depths. This latent heat reduces the stiffness of the surrounding ice and makes the ice more likely to flow out to sea.

Even though researchers have long known of the existence of subglacial lakes, never before have they witnessed any refilling from the surface. The refilling signals to researchers that Greenland’s ice loss has likely reached a milestone.

"We can actually see the meltwater pour down into these holes and then watch these subglacial lakes drain out and fill up again in real time,” said study co-author Bevis. “With melting like that, even the deep interior of the ice sheet is going to change. If enough water is pouring down into the Greenland Ice Sheet for us to see the same subglacial lake empty and refill itself over and over, then there must be so much latent heat being released under the ice that we’d have to expect it to change the large-scale behavior of the ice sheet.”

Source: University of Minnesota

Building a Better Weather Forecast? SMAP May Help

SMAP's soil moisture measurements will help with forecasts of precipitation and temperature. Image credit: UCAR
If you were trying to forecast tomorrow's weather, you would probably look up at the sky rather than down at the ground. But if you live in the U.S. Midwest or someplace with a similar climate, one key to a better weather forecast may lie beneath your feet.

Precipitation and temperature are part of every weather forecast. Precipitation comes from clouds, clouds are formed of airborne water vapor, and vapor comes from evaporating soil moisture -- so soil moisture governs precipitation. Evaporating soil moisture also makes air cooler, so it affects temperature. In certain kinds of climate, scientists believe, soil moisture is so influential that better observations of it might improve weather forecasts. These climates are transitional: not too humid and not too dry. For example, the agriculturally productive states of the U.S. Midwest fall into that category.

"Better soil moisture observations lead to better land-atmosphere interaction in weather forecasting models and ultimately to a better prediction of temperature and precipitation," said Michael Ek, leader of the Land Hydrology Team at the Environmental Monitoring Center of the National Oceanic and Atmospheric Administration (NOAA). "Weather models need good initial observations of the land surface, or you're starting from the wrong place."

Better soil moisture observations are just what the Soil Moisture Active Passive (SMAP) mission will provide. Scheduled for launch on Jan. 29, SMAP will collect the most accurate and highest-resolution soil moisture measurements ever made from a satellite SMAP will cover the entire globe in two to three days. Ek is a member of one of five groups in SMAP's Early Adopter program that have been working for several years on the question of how best to incorporate the new data into national weather forecasting models.

Forecasts will not improve, however, the moment SMAP starts collecting data. U.S. Department of Agriculture research scientist Wade Crow, a member of SMAP's science team, explained that, since closely spaced global soil moisture measurements have never existed before, the mathematical models used in weather forecasting are not configured to include them directly. Getting the best use out of the new observations has been a subject of active research for several years and will require some significant changes in how soil moisture data are assimilated into the models.

Data assimilation is necessary because weather forecasting models all drift a bit, like cars. If you're driving on a perfectly straight road, you still need to keep a hand on the steering wheel or you'll run off the edge sooner or later. Data assimilation in a model serves the same purpose as the slight movements of your hands that keep your car on course.

Drift is not a fatal flaw for a weather forecasting model any more than it is for a car. It is simply a sign that the Earth system is too vast and complicated to model perfectly with the resources available today. To steer forecasts toward greater realism, models ingest, or assimilate, real-world data and use them in sophisticated mathematical techniques. Each time updated observations become available, they are assimilated to improve the starting point for the next forecast.

Closely spaced and highly accurate global measurements are an important part of the process. For soil moisture, however, current observations are not on a fine enough scale to meet the needs of weather forecasting models directly. "Modelers compensate for the lack of direct observations of soil moisture by using more indirect measures, such as estimating it from observations of temperature and precipitation," Crow explained. "As a consequence, modeled soil moisture tends to diverge from reality. SMAP will be directly observing the state that they want, so they won't have to back it out from proxy measurements."

JPL scientist Eni Njoku is working with researchers at another forecasting center, the European Centre for Medium-Range Weather Forecasts (ECMWF) in Reading, England. Njoku said, "SMAP will provide benefits of higher soil moisture accuracy and spatial resolution than have previously been available from satellites. This could lead potentially to improved regional and global weather forecasts by ECMWF." Environment Canada, the branch of the Canadian government responsible for weather forecasting in that nation, is also working on assimilating SMAP data into its models.

"The numerical weather prediction centers are adapting to the new availability of soil moisture information and thinking of ways they can exploit it," Crow summarized. "It will be really exciting to see what they find."

SMAP is managed for NASA's Science Mission Directorate in Washington by the agency's Jet Propulsion Laboratory in Pasadena, California, with instrument hardware and science contributions made by NASA's Goddard Space Flight Center in Greenbelt, Maryland. JPL is responsible for project management, system engineering, radar instrumentation, mission operations and the ground data system. Goddard is responsible for the radiometer instrument. Both centers collaborate on science data processing and delivery to the Alaska Satellite Facility, in Fairbanks, and the National Snow and Ice Data Center, at the University of Colorado in Boulder, for public distribution and archiving. NASA's Launch Services Program at the agency's Kennedy Space Center in Florida is responsible for launch management. JPL is managed for NASA by the California Institute of Technology in Pasadena.

Source: Nasa

NASA Study Finds Earth’s Ocean Abyss Has Not Warmed

While the upper part of the world’s oceans continue to absorb heat from global warming, ocean depths have not warmed measurably in the last decade. This image shows heat radiating from the Pacific Ocean as imaged by the NASA’s Clouds and the Earth's Radiant Energy System instrument on the Terra satellite. (Blue regions indicate thick cloud cover.) Image Credit: NASA
The cold waters of Earth’s deep ocean have not warmed measurably since 2005, according to a new NASA study, leaving unsolved the mystery of why global warming appears to have slowed in recent years.

Scientists at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, analyzed satellite and direct ocean temperature data from 2005 to 2013 and found the ocean abyss below 1.24 miles (1,995 meters) has not warmed measurably. Study coauthor Josh Willis of JPL said these findings do not throw suspicion on climate change itself.

"The sea level is still rising," Willis noted. "We're just trying to understand the nitty-gritty details."

In the 21st century, greenhouse gases have continued to accumulate in the atmosphere, just as they did in the 20th century, but global average surface air temperatures have stopped rising in tandem with the gases. The temperature of the top half of the world's oceans -- above the 1.24-mile mark -- is still climbing, but not fast enough to account for the stalled air temperatures.

Many processes on land, air and sea have been invoked to explain what is happening to the "missing" heat. One of the most prominent ideas is that the bottom half of the ocean is taking up the slack, but supporting evidence is slim. This latest study is the first to test the idea using satellite observations, as well as direct temperature measurements of the upper ocean. Scientists have been taking the temperature of the top half of the ocean directly since 2005, using a network of 3,000 floating temperature probes called the Argo array.

"The deep parts of the ocean are harder to measure," said JPL's William Llovel, lead author of the study published Sunday in the journal Nature Climate Change. "The combination of satellite and direct temperature data gives us a glimpse of how much sea level rise is due to deep warming. The answer is -- not much."
Deep sea creatures, like these anemones at a hydrothermal vent, are not yet feeling the heat from global climate change. Although the top half of the ocean continues to warm, the bottom half has not increased measurably in temperature in the last decade. Image Credit: NERC
The study took advantage of the fact that water expands as it gets warmer. The sea level is rising because of this expansion and the water added by glacier and ice sheet melt.
To arrive at their conclusion, the JPL scientists did a straightforward subtraction calculation, using data for 2005-2013 from the Argo buoys, NASA's Jason-1 and Jason-2 satellites, and the agency’s Gravity Recovery and Climate Experiment (GRACE) satellites. 
From the total amount of sea level rise, they subtracted the amount of rise from the expansion in the upper ocean, and the amount of rise that came from added meltwater. The remainder represented the amount of sea level rise caused by warming in the deep ocean.
The remainder was essentially zero. Deep ocean warming contributed virtually nothing to sea level rise during this period.

Coauthor Felix Landerer of JPL noted that during the same period warming in the top half of the ocean continued unabated, an unequivocal sign that our planet is heating up. Some recent studies reporting deep-ocean warming were, in fact, referring to the warming in the upper half of the ocean but below the topmost layer, which ends about 0.4 mile (700 meters) down.

Landerer also is a coauthor of another paper in the same journal issue on 1970-2005 ocean warming in the Southern Hemisphere. Before Argo floats were deployed, temperature measurements in the Southern Ocean were spotty, at best. Using satellite measurements and climate simulations of sea level changes around the world, the new study found the global ocean absorbed far more heat in those 35 years than previously thought -- a whopping 24 to 58 percent more than early estimates.

Both papers result from the work of the newly formed NASA Sea Level Change Team, an interdisciplinary group tasked with using NASA satellite data to improve the accuracy and scale of current and future estimates of sea level change. The Southern Hemisphere paper was led by three scientists at Lawrence Livermore National Laboratory in Livermore, California.

NASA monitors Earth's vital signs from land, air and space with a fleet of satellites and ambitious airborne and ground-based observation campaigns. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records and computer analysis tools to better see how our planet is changing. The agency shares this unique knowledge with the global community and works with institutions in the United States and around the world that contribute to understanding and protecting our home planet.

Source: Nasa

Researcher uncovers surprising cause of the demise of Easter Island indigenous population

Written By Unknown on Friday, January 30, 2015 | 3:26 AM

Easter Island Credit: Yale
A new paper by a team of researchers including a Virginia Commonwealth University anthropology professor sheds new light on what led to the downfall of the indigenous population of Easter Island — also known as Rapa Nui — prior to European contact in 1722.

The study, "Variation in Rapa Nui (Easter Island) Land Use Indicates Production and Population Peaks Prior to European Contact," published in the Proceedings of the National Academy of Sciences, found that the population's demise likely had more to do with pre-existing environmental conditions than with environmental degradation by the indigenous people.

Christopher Stevenson, Ph.D., an assistant professor of anthropology in the School of World Studies in the College of Humanities and Sciences, recently discussed his team's findings with VCU News.

Your paper explores what led to the collapse of the prehistoric population of Rapa Nui. What did you conclude?

Our paper evaluates a longstanding debate and examines whether the prehistoric population of Rapa Nui experienced a significant islandwide demographic collapse prior to European contact in A.D. 1722. We have used dates from hydrated obsidian artifacts recovered from habitation sites as a proxy for land use over time. The analysis suggests region-specific dynamics that include abandonment of western coast and interior locations. These temporal land-use patterns correlate with rainfall variation and soil quality. The environmental stresses are regionally specific rather than islandwide. Significant erosion around the entire island generated by deforestation has been hypothesized by other researchers as a cause for economic failure. This does not hold up to scrutiny.

How would you characterize the significance of your findings?

This analysis demonstrates that the concept of a sudden "collapse" is a misleading characterization of prehistoric human population dynamics. As a result, we see our approach as useful in the study of other prehistoric societies for which a very rapid demographic collapse has been proposed in prehistory.

Although small, islands can be complex ecosystems that are structured by climatic variation and underlying geology. Human activities are constrained by these parameters and can even cause the ecosystem conditions to change appreciably through their manipulation of the landscape.

Were you surprised by what you found? In what ways?

The results of our research were really quite surprising to our team. Indeed, in the past we’ve published articles about how there was little evidence for pre-European contact societal collapse. When we proposed the [National Science Foundation-funded] project we were expecting that we would gather data supporting the notion that change did not occur until after European contact. In contrast our research suggests that significant changes in land use occurred prior to European contact. The connection between those changes in land use and notions of environmental degradation and subsequent societal collapse are limited.

There is no evidence that massive physical erosion took place on Rapa Nui before European contact and it is unlikely that physical erosion caused productivity decline and societal collapse. While we do not have direct population data, it is clear that people were reacting to regional environmental variation on the island before they were devastated by the introduction of European diseases and other historic processes. In short, our research does not support the suggestion that societal collapse occurred prior to European contact due to physical erosion and productivity decline, but it does indicate that use of less optimal environmental regions changed prior to European contact.

What did your research methodology entail?

We used a method called obsidian hydration dating to date the human creation of volcanic glass tools found at habitation sites. These dates were a proxy for the relative number of people on the island throughout prehistory. We also used an analysis of soil nutrients to look at the fertility of various landforms (e.g., coastal vs. upland) at different elevations up to 500 meters above sea level.

You've written several books on Rapa Nui. What led to your interest in this topic?

This is a continuation of my interest in looking at the development of agricultural systems in small island societies and how that impacts social and economic decisions made in prehistory.

What will you be working on next?

We will be applying some of the same concepts to the Canary Island agricultural systems which have a much higher diversity of geological ages and climatic conditions.

Source: Vcu

Mass animal die-offs may be increasing, new research shows

Large numbers of dead sunfish and largemouth bass in April 2014 following a severe winter on Wintergreen Lake, Kalamazoo County, Michigan. (Photo courtesy of G. Mittelbach)
Mass die-offs of animals may be increasing in frequency and — for birds, fishes, and marine invertebrates — in severity as well, according to a study of 727 mass mortality events since 1940.

Despite the ecological importance of individual mass mortality events, in which a larger than normal number of individuals die within a population, little research has been conducted on patterns across mass mortality events. The new study will help researchers better assess trends in mass mortality events and their causes, according to the authors of the paper in the Jan. 12 issue of the Proceedings of the National Academy of Sciences.

“The initial patterns are surprising, in terms of the documented changes to frequencies of occurrences, magnitudes of each event, and the causes of mass mortality,” said Samuel Fey, a postdoctoral fellow in the Department of Ecology and Evolutionary Biology at Yale and co-lead author of the paper. “These data also show that we have a lot of room to improve how we document and study these types of rare events.”

Fey, along with fellow researchers at the University of San Diego and University of California-Berkeley, report that the magnitude of the die-offs has increased in birds, fishes, and marine invertebrates, held steady among mammals, and decreased in frogs and amphibians. The authors recognized that more scientific research has been done on mass mortality events in the last few decades but said even accounting for this “discovery bias” does not explain all of the increase in such events. The increase in mass mortality events appears to be associated with a rise in disease emergence, biotoxicity, and multiple interacting stressors, they note.

Overall, disease was the primary culprit, accounting for 26% of the mass die-offs. The impacts of direct human activity, primarily from environmental contamination, caused 19% of such events. Another major cause was biotoxicity triggered by events such as algae blooms, rapid increases of algae in water systems. Processes directly influenced by climate — such as weather extremes, thermal stress, oxygen stress, or starvation — also contributed accounted collectively for about 25% of mass mortality events.

The most severe events were those with multiple causes, the paper shows.

“This study should improve our understanding of the continuum of mortality patterns and processes that exist between background mortality levels and species-level extinctions,” Fey said.

Adam M. Siepielski of the University of San Diego was co-lead author of the paper. Stephanie M. Carlson of the University of California-Berkeley was senior author. Fey began working on this research while a graduate student at Dartmouth College.

Source: Yale University

New Online Course Explores Social and Ecological Diversity of Himalayan Region

The conversion of forests into cropland worldwide has triggered an atmospheric change that, while seldom considered in climate models, has had a net cooling effect on global temperatures, according to a new Yale study.

Writing in the journal Nature Climate Change, Professor Nadine Unger of the Yale School of Forestry & Environmental Studies (F&ES) reports that large-scale forest losses during the last 150 years have reduced global emissions of biogenic volatile organic compounds (BVOCs), which control the atmospheric distribution of many short-lived climate pollutants, such as tropospheric ozone, methane, and aerosol particles.

Using sophisticated climate modeling, Unger calculated that a 30-percent decline in BVOC emissions between 1850 and 2000, largely through the conversion of forests to cropland, produced a net global cooling of about 0.1 degrees Celsius. During the same period, the global climate warmed by about 0.6 degrees Celsius, mostly due to increases in fossil fuel carbon dioxide emissions.

According to her findings, the climate impact of declining BVOC emissions is on the same magnitude as two other consequences of deforestation long known to affect global temperatures, although in opposing ways: carbon storage and the albedo effect. The lost carbon storage capacity caused by forest conversion has exacerbated global warming. 
Meanwhile, the disappearance of dark-colored forests has also helped offset temperature increases through the so-called albedo effect. (The albedo effect refers to the amount of radiation reflected by the surface of the planet. Light-colored fields, for instance, reflect more light and heat back into space than darker forests.)
“Without doing an earth-system model simulation that includes these factors, we can’t really know the net effect on the global climate.”— Nadine Unger
Unger says the combined effects of reduced BVOC emissions and increased albedo may have entirely offset the warming caused by the loss of forest-based carbon storage capacity.

“Land cover changes caused by humans since the industrial and agricultural revolutions have removed natural forests and grasslands and replaced them with croplands,” said Unger, an assistant professor of atmospheric chemistry at F&ES. “And croplands are not strong emitters of these BVOCs — often they don’t emit any BVOCs.”

“Without doing an earth-system model simulation that includes these factors, we can’t really know the net effect on the global climate. Because changes in these emissions affect both warming and cooling pollutants,” she noted.

Unger said the findings do not suggest that increased forest loss provides climate change benefits, but rather underscore the complexity of climate change and the importance of better assessing which parts of the world would benefit from greater forest conservation.

Since the mid-19th century, the percentage of the planet covered by cropland has more than doubled, from 14 percent to 37 percent. Since forests are far greater contributors of BVOC emissions than crops and grasslands, this shift in land use has removed about 30 percent of Earth’s BVOC sources, Unger said.

Not all of these compounds affect atmospheric chemistry in the same way. Aerosols, for instance, contribute to global “cooling” since they generally reflect solar radiation back into space. Therefore, a 50 percent reduction in forest aerosols has actually spurred greater warming since the pre-industrial era.
“[These emissions] don’t get as much attention as human-generated emissions... but if we change how much forest cover exists, then there is a human influence on these emissions.”— Nadine Unger
However, reductions in the potent greenhouse gases methane and ozone — which contribute to global warming — have helped deliver a net cooling effect.

These emissions are often ignored in climate modeling because they are perceived as a “natural” part of the earth system, explained Unger. “So they don’t get as much attention as human-generated emissions, such as fossil fuel VOCs,” she said. “But if we change how much forest cover exists, then there is a human influence on these emissions.”

These impacts have also been ignored in previous climate modeling, she said, because scientists believed that BVOC emissions had barely changed between the pre-industrial era and today. But a study published last year by Unger  showed that emissions of these volatile compounds have indeed decreased. Studies by European scientists have produced similar results.

The impact of changes to ozone and organic aerosols are particularly strong in temperate zones, she said, while methane impacts are more globally distributed.

The sensitivity of the global climate system to BVOC emissions suggests the importance of establishing a global-scale long-term monitoring program for BVOC emissions, Unger noted.

– Kevin Dennehy    kevin.dennehy@yale.edu    203 436-4842

Source: Yale University

Using Technology to Help Wild Cats and People Coexist

Written By Unknown on Thursday, January 29, 2015 | 9:22 PM

In Central India, F&ES doctoral student Jennie Miller is helping develop strategies to limit the increasingly frequent interactions between humans and wild cats that have triggered massive declines in populations of tigers and leopards.
 leopard Jennie Miller
Photo courtesy of Jennie Miller
For centuries, populations of tigers and leopards in central India have plummeted in the face of habitat degradation, the loss of prey, and a rise in sport hunting. Over the last few decades, however, it has been the increases in poaching and “retaliation killings” by livestock owners that have become the greatest threats facing these big cats.
 
Jennie Miller, a doctoral student at the Yale School of Forestry & Environmental Studies, says the best strategy to stem these losses is to limit the interactions between these rare cats and livestock animals. And she’s developing strategies that use spatial technology to achieve this goal.
 
In an interview, Miller describes the relationship between wild cats and humans in this part of the world, how simple technologies can reduce conflicts, and the risks of working so close to these predators.
 
Can you describe the research you’re doing in India? 

In a nutshell, I’m creating geospatial tools to help people and big cats sustainably coexist. In many parts of Asia, people graze their livestock in landscapes shared with tigers and leopards. Big cats regularly kill domesticated livestock since they are easy prey, causing profound livelihood loses for livestock owners. For example, in the Kanha Tiger Reserve in central India where I work, more than 400 cattle, buffalo, goats, and pigs are killed each year. Though this is less than 0.5 percent of the 85,000 livestock in the area, even a small number of attacks can create a sense of insecurity and frustration for livestock owners. To reduce attacks, owners sometimes lace livestock carcasses with pesticides to poison the cats when they return to feed. Since only about 3,500 tigers remain in the wild, every cat counts for the survival of the species.
jennie miller goat Photo courtesy of Jennie Miller

My research aims to help reduce this human-carnivore conflict by minimizing carnivore attacks on livestock. I’m building spatial models to understand where tigers and leopards are most likely to attack livestock. These models also generate “risk maps” to predict where future attacks may occur to assist the Forest Department and villagers when managing and grazing livestock. If livestock can be grazed in habitats where carnivores are less likely to attack — for example, away from dense forests where tigers hunt — then coexistence between people and tigers and leopards may be more feasible.
 
What are the threats facing these animals? And, for that matter, the people who live in these communities?

Over the past few centuries, habitat degradation, prey loss, and uncontrolled sport hunting have caused massive declines in tiger and leopard populations. However, in the past few decades, poaching and retaliation killing have emerged as the two greatest immediate threats for these big cats. Recent surges in the value of tiger and leopard body parts in international markets in southeast and east Asia — where they are sold for traditional medicine — are motivating a spree of illegal poaching, especially within India, which supports half the world’s wild tigers.
 
Retaliation killing — when villagers poison carnivores after losing livestock — also contributes to species declines, particularly since these incidences often kill young dispersing tigers and leopards as they move through agricultural fields to colonize or join other populations in nearby protected areas. And poaching and retaliation killing can be closely linked, since poachers may capitalize on a livestock owner’s desire to remove a troublesome tiger.
Photo courtesy of Jennie Miller Jennie Miller interviews a forest guard
Attacks on humans are rare — far less frequent than deaths due to car accidents or even snake bites. Perhaps due to their rarity and primal essence, the media often sensationalizes these “man-eater” attacks, which can further instigate anger, fear, and retaliations from people. Nonetheless, attacks do occasionally happen. People who share forests with tigers and leopards are very aware of these risks and take precautions to avoid chances of attack, such as staying indoors at night, traveling in groups and regularly protecting small children. There is a great amount of respect — driven by a mixture of fear, appreciation and reverence — for large cats in India.
 
What does the mapping technology you’re using reveal? 

We’re at an exciting point in time where spatial technology like GPS units and satellite data are enabling the development of simple tools for management and conservation. One example is “spatial risk mapping,” which I use for my research. Basically, I recorded the GPS coordinates of hundreds of dead livestock in my study site as well as random sites to measure variation across the landscape. I combine these with information about the location of other environmental and human features, such as roads, villages, forests, and shrubs. I then build statistical models to predict the probability of a tiger or leopard attack on livestock across the landscape.
 
The end result is a map that can help visually identify where attacks might occur in the future. These maps can serve as powerful tools because they transcend language and education barriers by visually representing risk and so could be useful to help villagers in remote areas protect their livestock.
 
What have you learned so far?

Since tigers and leopards both use stalking hunting tactics to attack prey, I expected them to show similar hunting patterns. However, I found that tigers and leopards differ greatly in where they tend to kill livestock: Tigers attack most often in dense forests away from human infrastructure like roads and villages, whereas leopards kill in more open vegetation and aren’t as deterred by human presence. In fact, on several occasions, leopards boldly strolled into villages at night and killed livestock in bamboo enclosures adjacent to people’s mud huts while they slept inside!

“People generally know how to avoid tiger attacks but could perhaps benefit from more conservation support for actively protecting livestock from leopard attacks.”— Jennie Miller

I also expected livestock owners to have a strong sense of where both tigers and leopards kill. Yet when I interviewed owners and compared their perceptions about where these two cats tend to kill, I found that owners have a very accurate sense of where tigers attack but a poorer understanding of where leopards attack. I suspect this disparity occurs because tigers are constrained to hunting in dense forests but leopards can kill in a broader diversity of habitats, making it generally harder to predict where a leopard will attack. This means that people generally know how to avoid tiger attacks but could perhaps benefit from more conservation support for actively protecting livestock from leopard attacks, such as by strengthening night enclosures or hiring livestock herders. 
 
What do you hope will come out of your research?

These results provide valuable insights into how big cats, livestock, and people interact which I hope will help strengthen animal husbandry and livestock management to better protect livestock and reduce human-carnivore conflict. I’m working with the Forest Department of Kanha Tiger Reserve to integrate these spatial risk models into management to help guide their conservation efforts. For example, risk maps can be used to understand carnivore hunting behavior and patterns, especially the distinction between tigers and leopards, for developing strategies for protecting livestock. In considering the risk of an attack alongside other grazing considerations — such as browse quality and access from villages — livestock owners may also be able to make grazing decisions in a more informed way.
Photo courtesy of Jennie Miller Miller inspects the remains of a cow killed by a wild cat.
What other skills have you had to develop to conduct this research? 

Learning Hindi has enabled me to more personally relate with villagers in India to understand the ramifications of livestock losses, as well as to understand the jokes made by my field assistants. Since I surveyed dead livestock and collected tiger and leopard scat for a year, I quickly developed a tolerance for bad smells, maggots, blood, and feces. I realized this a few months into fieldwork when I found myself elbow-deep in a bucket of water and tiger feces, separating the hair from particulate matter in order to identify prey contents. And to this day, I still reach for my GPS when I smell road kill. But more seriously, I also acquired a deep respect for the villagers and forest guards who literally risk their lives daily to live alongside tigers and leopards.
 
Have you ever felt unsafe doing this work, walking in places where these animals lurk?
Definitely! Though tigers and leopards rarely attack people, one or two people — usually solitary livestock herders or forest guards — are attacked in Kanha Tiger Reserve every year. These big cats don’t usually approach groups of people, so I always took a team of three to 10 people with me when surveying livestock carcasses. We also tried to avoid visiting fresh kills to reduce the chance that the cats would still be feeding when we approached. But sometimes this couldn’t be avoided and I can recall several cases when we knew a cat was lingering nearby.
 
Once, when my team and I were walking through a dense forest towards three cow carcasses killed the night before, the villagers in front of me said they could hear the tigress walking. When we reached the carcasses a few moments later, there was fresh blood on the carcass, indicating that she had been feeding a few minutes before we arrived. That day I truly began to understand the risks that villages take in living with these cats.
 
What made you want to focus your research in India? 

In January 2005 when I was a sophomore in college, I accompanied my father, a yoga and meditation teacher, on a visit to India to meet his guru. During our trip I saw first-hand the sudden tragedy of the tsunami in coastal Chennai and also heard stories while on safari about man-eating tigers in the dense jungles of Corbett Tiger Reserve. I was mesmerized by the people’s vibrancy and resiliency despite these unpredictable hardships, and greatly impressed by the extent to which Indians are economically and spiritually connected to nature. The trip helped inspire me to major in ecology and take classes in South Asian religion, art and language, and to later return to India as a Fulbright Scholar to study bird conservation in the western Himalayas. After a year of research in India I was hooked. I hope that I can continue working in India for the rest of my life.

NASA: Subglacial Lakes Seen Refilling in Greenland

Written By Unknown on Wednesday, January 28, 2015 | 4:44 PM

Refrozen meltwater ponds in northeast Greenland seen during an April 2013 IceBridge flight. Image Credit: NASA/Michael Studinger
Scientists using satellite images and data from NASA’s Operation IceBridge have found evidence of a drained and refilled subglacial lake beneath northeastern Greenland’s Flade Ice Cap. This sub-ice body of water is only one of a handful that have been detected in Greenland and its presence sheds new light on how the Greenland Ice Sheet reacts to warming temperatures.

Subglacial lakes are relatively common in Antarctica, and although recent studies have mathematically predicted possible locations for hundreds of such features in Greenland, few have actually been found. Bodies of water beneath the ice are normally detected either with ice-penetrating radar or by observing rapid changes in ice surface elevation such as bulges or basins.

In a new study funded by the National Science Foundation and published in the Jan. 21 issue of the journal Nature, a research team led by Michael Willis, a glaciologist at Cornell University in Ithaca, New York, found a large basin that formed over a 21-day period in the summer of 2011 using satellite images. The size and rapid formation of this basin was consistent with a drained subglacial lake, but its location raised a question. Where did the water in the lake come from?

Subglacial lakes typically form at the base of an ice sheet or glacier because of either friction or trapped heat from bedrock below. In order for this to happen, ice needs to move quickly or be thick enough to protect the ice sheet base from cold air at the surface and trap heat coming from the bedrock below. But something else had to be at work here. The research team used weather data and ice thickness measurements from IceBridge flights to calculate the temperature beneath the ice and found that it was well below what’s needed for normal basal melt.

Continued observation showed that the basin floor rose significantly during the next summer at the same time that nearby surface meltwater drained into cracks along the basin’s edge. This led the team to hypothesize that water from surface melting was refilling a lake beneath the ice. Snow accumulation and ice movement accounted for a portion of the basin’s rise, with meltwater runoff estimates filling in the rest of the increase, supporting the hypothesis.

This finding points to the possibility of similar meltwater-filled subglacial lakes in other parts of Greenland. Existing research has shown an extensive network of sub-ice drainage channels in Greenland that are thought to quickly move surface melt along the bed and to the ocean. The presence of subglacial lakes in Greenland could affect how parts of the ice sheet move by adding heat to ice at the base and softening. Further research on subglacial lakes in Greenland will likely help researchers improve projections of how the ice sheet will change in response to future warming.

Source: Nasa
 
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