Groundwater resources draining fast, NASA data show

Timothy Cama in the Hill: Humans are depleting a large portion of the world’s groundwater resources, and they are not being naturally refilled, researchers said. The scientists at the University of California Irvine used data from National Aeronautics and Space Administration (NASA) satellites to determine drainage of the world’s largest groundwater aquifers in recent years.

They found that a third of the 37 major aquifers were either worse off in 2013 than in 2003 or were highly stressed. “Available physical and chemical measurements are simply insufficient,” Jay Famiglietti, the principal researcher on the project, said in a Tuesday statement. Famiglietti is both a UC Irvine professor and the top water scientist at NASA’s Jet Propulsion Laboratory.

“Given how quickly we are consuming the world’s groundwater reserves, we need a coordinated global effort to determine how much is left,” he said.

The paper was published Tuesday in the journal Water Resources Research. It is the first to use data from NASA’s Gravity Recovery and Climate Experiment, or GRACE, satellite system, which detects changes in Earth’s gravity that can show groundwater levels.

It found that the most stressed aquifers were in extreme dry areas, whose residents and businesses have leaned most heavily on groundwater....

A bore well pump in India, shot by ABHIJEET, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Satellite eyes on threat to US freshwater

A press release from NASA: NASA has joined forces with the U.S. Environmental Protection Agency, National Oceanic and Atmospheric Administration, and U.S. Geological Survey to transform satellite data designed to probe ocean biology into information that will help protect the American public from harmful freshwater algal blooms.

Algal blooms are a worldwide environmental problem causing human and animal health risks, fish kills, and taste and odor in drinking water. In the United States, the cost of freshwater degraded by harmful algal blooms is estimated at $64 million annually. In August 2014, officials in Toledo, Ohio, banned the use of drinking water supplied to more than 400,000 residents after it was contaminated by an algal bloom in Lake Erie.

The new $3.6 million, multi-agency effort will use ocean color satellite data to develop an early warning indicator for toxic and nuisance algal blooms in freshwater systems a
nd an information distribution system to aid expedient public health advisories.

“The vantage point of space not only contributes to a better understanding of our home planet, it helps improve lives around the world,” said NASA Administrator Charles Bolden. “We’re excited to be putting NASA’s expertise in space and scientific exploration to work protecting public health and safety.”

Ocean color satellite data from NASA’s Aqua, the USGS-NASA Landsat, and the European Space Agency’s Sentinel-2 and -3 are currently available to scientists, but are not routinely processed and produced in formats that help state and local environmental and water quality managers. Through this project, satellite data on harmful algal blooms developed by the partner agencies will be converted to a format that stakeholders can use through mobile devices and web portals.

“Observations from space-based instruments are an ideal way to tackle this type of public health hazard because of their global coverage and ability to provide detailed information on material in the water, including algal blooms,” said Paula Bontempi of the Earth Science Division at NASA Headquarters in Washington....

A toxic algae bloom in Lake Erie in 2011, viewed by a NASA satellite

Bangladesh announces nationwide use of SERVIR satellite-based flood forecasting and warning system

A press release from NASA: Bangladesh officials have announced plans to expand a satellite-based flood forecasting and warning system developed by SERVIR to aid an area where floodwaters inundate from 1/3 to 2/3 of the country annually, killing hundreds of people and affecting millions. The system, which relies on river level data provided by the Jason-2 satellite, last year provided the longest lead time for flood warnings ever produced in Bangladesh.

SERVIR is a joint development initiative of NASA and USAID, working in partnership with leading regional organizations around the globe to help developing countries use information provided by Earth Observing satellites and geospatial technologies for managing climate risks and land use. SERVIR and the International Centre for Integrated Mountain Development based in Kathmandu, Nepal, developed the Jason-2 based flood forecasting and warning solution.

"Forecasters have the dream to extend lead time for flood warnings," said Amirul Hossain, executive engineer for the Bangladesh Water Development Board. "By using Jason-2 near real-time data, we made a real step forward in the flood forecasting system in Bangladesh."

About 80 million people depend on the BWDB Flood Forecasting and Warning Center flood warnings. This organization has progressively built and expanded its flood forecasting system. However, without data from Jason-2, warnings were issued just three to five days in advance of flooding. During the 2014 monsoon season, the FFWC used the new Jason-2 solution experimentally and was able to forecast flooding eight days in advance at nine locations of the Ganges and Brahmaputra River Basins in the north, northwest, and central part of the country.

..."We hope this is the beginning of a new journey, a new era for further development of the flood early warning system using space data or space technology,” said Hossain. “In the coming year, with support provided by the NASA SERVIR team, we would like to expand the system to many other locations where possible, to enable more people to benefit from this system by receiving more extended lead time for flood forecasts."...

Upper row: The Ganges Brahmaputra Meghna (GBM) river basins and the Ganges-Brahmaputra (GB) delta. Bottom row: The many river deltas (shown as a triangle in each region) located in large remote river basins that lack information for modeling rivers and water management. Image Credit: NASA SERVIR

NASA launches groundbreaking soil moisture Mapper

A press release from NASA: The Soil Moisture Active Passive (SMAP) observatory, a mission with broad applications for science and society, lifted off at 6:22 a.m. PST (9:22 a.m. EST) Saturday from Vandenberg Air Force Base, California, on a United Launch Alliance Delta II rocket. NASA's Jet Propulsion Laboratory in Pasadena, California, manages SMAP for NASA's Science Mission Directorate in Washington, with instrument hardware and science contributions made by NASA's Goddard Space Flight Center in Greenbelt, Maryland.

...SMAP now begins a three-year mission that will figuratively scratch below Earth's surface to expand our understanding of a key component of the Earth system that links the water, energy and carbon cycles driving our living planet. SMAP's combined radar and radiometer instruments will peer into the top 2 inches (5 centimeters) of soil, through clouds and moderate vegetation cover, day and night, to produce the highest-resolution, most accurate soil moisture maps ever obtained from space.

The mission will help improve climate and weather forecasts and allow scientists to monitor droughts and better predict flooding caused by severe rainfall or snowmelt -- information that can save lives and property. In addition, since plant growth depends on the amount of water in the soil, SMAP data will allow nations to better forecast crop yields and assist in global famine early-warning systems.

"The launch of SMAP completes an ambitious 11-month period for NASA that has seen the launch of five new Earth-observing space missions to help us better understand our changing planet," said NASA Administrator Charles Bolden. "Scientists and policymakers will use SMAP data to track water movement around our planet and make more informed decisions in critical areas like agriculture and water resources."....

NASA's Soil Moisture Active Passive (SMAP) observatory lifts off from Space Launch Complex 2 West at California's Vandenberg Air Force Base, beginning a three-year mission to map Earth's vital moisture hidden in the soils beneath our feet. Image credit: NASA/Bill Ingalls 

Good news on forests and carbon dioxide

NASA: A new NASA-led study shows that tropical forests may be absorbing far more carbon dioxide than many scientists thought, in response to rising atmospheric levels of the greenhouse gas. The study estimates that tropical forests absorb 1.4 billion metric tons of carbon dioxide out of a total global absorption of 2.5 billion -- more than is absorbed by forests in Canada, Siberia and other northern regions, called boreal forests.

"This is good news, because uptake in boreal forests is already slowing, while tropical forests may continue to take up carbon for many years," said David Schimel of NASA's Jet Propulsion Laboratory, Pasadena, California. Schimel is lead author of a paper on the new research, appearing online today in the Proceedings of National Academy of Sciences.

Forests and other land vegetation currently remove up to 30 percent of human carbon dioxide emissions from the atmosphere during photosynthesis. If the rate of absorption were to slow down, the rate of global warming would speed up in return.

The new study is the first to devise a way to make apples-to-apples comparisons of carbon dioxide estimates from many sources at different scales: computer models of ecosystem processes, atmospheric models run backward in time to deduce the sources of today's concentrations (called inverse models), satellite images, data from experimental forest plots and more. The researchers reconciled all types of analyses and assessed the accuracy of the results based on how well they reproduced independent, ground-based measurements. They obtained their new estimate of the tropical carbon absorption from the models they determined to be the most trusted and verified.

...The question of which type of forest is the bigger carbon absorber "is not just an accounting curiosity," said co-author Britton Stephens of the National Center for Atmospheric Research, Boulder, Colorado. "It has big implications for our understanding of whether global terrestrial ecosystems might continue to offset our carbon dioxide emissions or might begin to exacerbate climate change."

As human-caused emissions add more carbon dioxide to the atmosphere, forests worldwide are using it to grow faster, reducing the amount that stays airborne. This effect is called carbon fertilization. "All else being equal, the effect is stronger at higher temperatures, meaning it will be higher in the tropics than in the boreal forests," Schimel said....

Deep forest in Malaysia, shot by Ksmuthukrishnan, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 4.0 International license

NASA to study how African fires affect climate

Jan Piotrowski in SciDev.net: Climate scientists have received a boost of up to US$150 million from US space agency NASA for a five year campaign to probe how air pollution, manmade fires across Africa and warming oceans may affect our climate.

The money will be split equally among five projects under the umbrella of the agency’s Earth Venture initiative, which is designed to fill major knowledge gaps in earth sciences. A mixture of plane flights and surface measurements will shed light on processes that NASA’s satellite missions cannot pick up.

The projects are: Atmospheric chemistry and air pollution, Ecosystem chan
ges in a warming ocean, Greenhouse gas sources, African fires and Atlantic clouds, and Melting Greenland glaciers....  This is NASA’s second series of Earth Venture suborbital projects, recommended by the National Research Council in 2007. In 2010, the first series of five projects was selected.

"These new investigations address a variety of key scientific questions critical to advancing our understanding of how Earth works," said Jack Kaye, associate director for research in NASA's Earth Science Division in Washington in a NASA press release. “These innovative airborne experiments will let us probe inside processes and locations in unprecedented detail that complements what we can do with our fleet of Earth-observing satellites.”

Collecting hard data is the goal, but NASA scientist Hal Maring says that it is much more than an academic exercise — all projects were selected with a “heavy bias” towards their relevance for policy. “Our mission is to push the boundaries of field science to address weaknesses in our knowledge of Earth systems,” he says. “But behind these words is the assumption that the science better make a difference.”...

NASA image of fires in the Gambia in 2002

NASA study shows 13-year record of drying Amazon caused vegetation declines

A press release from NASA:With global climate models projecting further drying over the Amazon in the future, the potential loss of vegetation and the associated loss of carbon storage may speed up global climate change.

The study was based on a new way to measure the “greenness” of plants and trees using satellites. While one NASA satellite measured up to 25 percent decline in rainfall across two thirds of the Amazon from 2000 to 2012, a set of different satellite instruments observed a 0.8 percent decline in greenness over the Amazon. The study was published on Nov. 11 in Proceedings of the National Academy of Sciences.

While the decline of green vegetation was small, the area affected was not: 2.1 million square miles (5.4 million square kilometers), equivalent to over half the area of the continental United States. The Amazon's tropical forests are one of the largest sinks for atmospheric carbon dioxide on the planet.

"In other words, if greenness declines, this is an indication that less carbon will be removed from the atmosphere. The carbon storage of the Amazon basin is huge, and losing the ability to take up as much carbon could have global implications for climate change," said lead author Thomas Hilker, remote sensing specialist at Oregon State University in Corvallis, Oregon. Plants absorb carbon dioxide as part of photosynthesis, the process by which green plants harvest sunlight. The healthier the plants, the greener the forest.

The Amazon basin stores an estimated 120 billion tons of Earth's carbon – that's about 3 times more carbon than humans release into the atmosphere each year. If vegetation becomes less green, it would absorb less of that carbon dioxide. As a result, more of human emissions would remain in the atmosphere, increasing the greenhouse effect that contributes to global warming and alters Earth's climate...

Popcorn clouds above the Amazon rainforest, August 19, 2009. This type of cloud forms during the dry season, likely from water vapor released by plants during transpiration. Image Credit: NASA's Earth Observatory

NASA scientists watching, studying Arctic changes this summer

A press release from NASA: As we near the final month of summer in the Northern Hemisphere, NASA scientists are watching the annual seasonal melting of the Arctic sea ice cover. The floating, frozen cap that stretches across the Arctic Ocean shrinks throughout summer until beginning to regrow, typically around mid-September.

As of Aug. 19, Arctic sea ice covered about 2.31 million square miles. While this is on track to be larger than the record-breaking low year in 2012, the sea ice extent is still well below average for the past 30 years, and continues a trend of sea ice loss in the Arctic. From 1981 to 2010, the average sea ice extent on Aug. 19 was 2.72 million square miles – 18 percent larger than on that same date this year.

"While this year is not heading toward a record low minimum extent in the Arctic, sea ice is well below normal and continues an overall pattern of decreasing sea ice during summer in the Arctic,” said sea ice scientist Walt Meier, based at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

With the launch of five Earth-observing missions in 2014, NASA will be able to deliver even more crucial data to scientists trying to understand our changing planet.

While NASA scientists have used satellites to document sea ice changes for more than 40 years, this summer the agency is also flying three airborne research campaigns to observe different aspects of climate-driven change in the Arctic.

The ARISE (Arctic Radiation-IceBridge Sea and Ice Experiment) campaign will begin flights later this week from Greenland to measure how changing land and sea ice conditions in the region are affecting the formation of clouds and the exchange of heat from Earth’s surface to space.

For some time scientists at NASA and elsewhere have been concerned about how the retreat of sea ice in summer could affect the climate of the Arctic. This campaign is one of the first to study the interaction between sea ice loss and the Arctic atmosphere....

Arctic ice, shot by Pink floyd88 a, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

NASA's HS3 mission spotlight: The HIRAD instrument

NASA: The Hurricane Imaging Radiometer, known as HIRAD, will fly aboard one of two unmanned Global Hawk aircraft during NASA's Hurricane Severe Storm Sentinel or HS3 mission from Wallops beginning August 26 through September 29.

One of the NASA Global Hawks will cover the storm environment and the other will analyze inner-storm conditions. HIRAD will fly aboard the inner-storm Global Hawk and will be positioned at the bottom, rear section of the aircraft.

“HIRAD’s purpose is to map out where the strongest winds are in a hurricane. During its first deployment in 2010 for the GRIP airborne campaign, HIRAD had two interesting hurricane cases, Earl and Karl," said Daniel J. Cecil, the principal investigator for the HIRAD instrument at NASA's Marshall Space Flight Center, Huntsville, Alabama. "We have made improvements to the instrument since then, and are looking forward to the next good case - out over water, avoiding land of course!”

HIRAD is a passive microwave radiometer that was developed at NASA Marshall. A radiometer is an instrument used to measure the power of electromagnetic radiation. Because HIRAD is a passive microwave radiometer it detects microwave radiation naturally emitted by Earth. The radiation HIRAD detects is then used to infer wind speed at the surface of an ocean.

The antenna on HIRAD makes measurements of microwaves emitted by the ocean surface that are increased by the storm. As winds move across the surface of the sea they generate white, frothy foam. This sea foam causes the ocean surface to emit increasingly large amounts of microwave radiation, similar in frequency or wavelength, but much lower intensity, to that generated within a typical home microwave oven. HIRAD measures that microwave energy and, in doing so, allows scientists to deduce how powerfully the wind is blowing. With HIRAD’s unique capabilities, the two-dimensional structure of the surface wind speed field can be much more accurately determined than current operational capabilities allow....

A NASA artist's conception of HIRAD imaging

OCO-2 Lifts off on carbon-counting mission

Steven Siceloff at NASA: A Delta II rocket blazed off the launch pad at Vandenberg Air Force Base in California early Wednesday morning to begin a landmark mission to survey carbon dioxide gas in Earth's atmosphere.

NASA's Orbiting Carbon Observatory-2, or OCO-2, is expected to provide insight into how the planet adjusts to the increased production of carbon dioxide from a vantage point in orbit that will allow it to take readings on a scale never achieved before.

While ground stations have been monitoring carbon dioxide concentrations, OCO-2 will be the first spacecraft to conduct a global-scale reading over several seasons. The spacecraft is expected to produce detailed readings to provide regional sources of carbon dioxide as well as sinks for the greenhouse gas.

"There's quite a lot of urgency to see what we can get from a satellite like OCO-2," said David Crisp, the science team lead for the mission.

...The mission is the first of its kind in the agency's extensive history of Earth-observing spacecraft. The spacecraft was launched to replace the first OCO that did not make it into orbit due to an anomaly in February 2009. The spacecraft carries one instrument and its sole focus is detecting carbon dioxide and watching from space as the Earth "breathes" to see what becomes of the gas.

The instrument is precise enough that researchers will be able to count the number of carbon dioxide molecules in the layers of the atmosphere and use the data to draw conclusions about how the increasing amount of gas will affect things like the global temperature. OCO-2's mission is to last at least two years....

OCO-2's liftoff from Vandenberg Air Force Base, image by NASA

NASA widens 2014 hurricane research mission

A press release from NASA: During this year's Atlantic hurricane season, NASA is redoubling its efforts to probe the inner workings of hurricanes and tropical storms with two unmanned Global Hawk aircraft flying over storms and two new space-based missions.

NASA's airborne Hurricane and Severe Storm Sentinel or HS3 mission, will revisit the Atlantic Ocean for the third year in a row. HS3 is a collaborative effort that brings together several NASA centers with federal and university partners to investigate the processes that underlie hurricane formation and intensity change in the Atlantic Ocean basin. The flights from Wallops Flight Facility in Virginia take place between Aug. 26 and Sept. 29 during the peak of the Atlantic hurricane season that runs from June 1 to Nov. 30.

"This year we're going full-force into tropical cyclone research," said Scott Braun, HS3 mission principal investigator and research meteorologist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "We'll have two Global Hawks equipped with six instruments. The new NASA-JAXA Global Precipitation Measurement (GPM) Core Observatory will be providing much higher quality data than previously available on rain structure in tropical cyclones in all ocean basins. The surface-wind monitoring ISS-RapidScat instrument to be launched to the International Space Station t
his season will provide valuable information on surface winds in storms."

One of the remaining mysteries that HS3 is attempting to solve is the effect of the hot, dry and dusty Saharan Air Layer (SAL) in tropical storm formation and intensification. Some research points to SAL contributing to storm formation, while other research indicates SAL suppresses it. HS3 also will investigate the role of strong thunderstorms near the core of the storms as a possible driver of intensity change.  

This year NOAA, in addition to managing all of the dropsondes during the HS3 mission, will enable the mission to fly another week to better study tropical cyclones. A dropsonde is a device that measures winds, temperature and humidity, dropped from an aircraft.

The NASA Global Hawks are unmanned aircraft that will be piloted remotely from the HS3 mission control at NASA's Wallops Flight Facility. Global Hawk aircraft are well-suited for hurricane investigations because they can fly for as long as 26 hours and fly above hurricanes at altitudes greater than 55,000 feet...

Artist's rendering of NASA's ISS-RapidScat instrument (inset), which will launch to the ISS in 2014 to measure ocean surface wind speed and direction and help improve weather forecasts, including hurricane monitoring. It will be installed on the end of the station's Columbus laboratory. Image Credit: NASA/JPL-Caltech/JSC

Hidden Greenland canyons mean more sea level rise

NASA: Scientists at NASA and the University of California, Irvine (UCI), have found that canyons under Greenland's ocean-feeding glaciers are deeper and longer than previously thought, increasing the amount of Greenland's estimated contribution to future sea level rise.

"The glaciers of Greenland are likely to retreat faster and farther inland than anticipated, and for much longer, according to this very different topography we have discovered,” said Mathieu Morlighem, a UCI associate project scientist who is lead author of the new research paper. The results were published Sunday in the journal Nature Geoscience.

Ice loss from Greenland has accelerated during the last few decades. However, older ice sheet models predicted the speedup would be temporary because the glaciers would soon melt back onto higher ground and stabilize. The models projected that Greenland's contribution to global sea level rise would therefore be limited.

Morlighem's new topography shows southern Greenland's ragged, crumbling coastline is scored by more than 100 canyons beneath glaciers that empty into the ocean. Many canyons are well below sea level as far as 60 miles (100 kilometers) inland. Higher ground, where glaciers could stabilize, is much farther from the coastline than previously thought. The finding calls into question the idea that the recent accelerated ice loss will be short lived.

..."We have been able to make a quantum leap in our knowledge of bed topography beneath ice sheets in the last decade, thanks to the advent of missions like NASA's Operation IceBridge in combination with satellite data on the speed these ice sheets are flowing," said coauthor Eric Rignot of UCI and NASA's Jet Propulsion Laboratory (JPL), Pasadena, California.

The same research team reported new findings on glacial melt in West Antarctica last week. "Together the papers illustrate clearly the globe’s ice sheets will contribute far more to sea level rise than current projections show,” said Rignot...

Kejser Franz Josef Fjord near Stensjö Bjerg, Greenland Nationalpark. Shot by Erik Christensen, Wikimedia Commons, under Creative Commons 3.0 license

NASA Goddard to bring satellite data to African agriculture

NASA: From hundreds of miles in orbit, NASA satellites can measure how much rain falls in Niger or detect plant health in Mali. But on the ground, many African farmers and food distributors don't have good information about the growing conditions a few dozen miles down the road.

..."Putting the information in the hands of the agriculture users is one of the many ways that we can show that the satellite data has benefits to society," said Molly Brown, a research scientist with Goddard's Biospheric Sciences Laboratory.

Brown and her colleagues have already developed a 30-year dataset of satellite information on African precipitation rates, vegetation health, soil moisture and evapotranspiration – all indicators of crop health in a given area. With researchers from Columbia University, N.Y. she is developing a system that can improve the way insurance companies set rates for drought protection.

That data, however, would also be key information for local farmers and food distributors who have to determine which regions have a surplus of maize, millet, rice and more – and therefore which regions they should focus on to purchase excess food to sell at central markets. When distributors can buy excess food, it can encourage farmers to grow more in good years, knowing that there is a market. More food production, and more efficient distribution, could improve food security for the region.

...After a chance meeting with a representative of the African-based organization AGRA, or the Alliance for a Green Revolution in Africa, Brown started looking for ways to get satellite data to farmers and distributors through the mFarms platform. mFarms provides agricultural information via cell phones to their network – 80,000 farmers and thousands of other distributors, warehouses and more in 17 African countries....

Scarecrows at a South Africa farm, shot by Hein waschefort, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license 

NASA satellites show drought may take toll on Congo rainforest

NASA: A new analysis of NASA satellite data shows Africa's Congo rainforest, the second-largest tropical rainforest in the world, has undergone a large-scale decline in greenness over the past decade. The study, led by Liming Zhou of University at Albany, State University of New York, shows between 2000 and 2012 the decline affected an increasing amount of forest area and intensified. The research, published Wednesday in Nature, is one of the most comprehensive observational studies to explore the effects of long-term drought on the Congo rainforest using several independent satellite sensors.

"It's important to understand these changes because most climate models predict tropical forests may be under stress due to increasing severe water shortages in a warmer and drier 21st century climate," Zhou said.

Scientists use the satellite-derived "greenness" of forest regions as one indicator of a forest's health. While this study looks specifically at the impact of a persistent drought in the Congo region since 2000, researchers say that a continued drying trend might alter the composition and structure of the Congo rainforest, affecting its biodiversity and carbon storage.

Previous research used satellite-based measurements of vegetation greenness to investigate changes in the Amazon rainforest, notably the effects of severe short-term droughts in 2005 and 2010. Until now, little attention has been paid to African rainforests, where ground measurements are even sparser than in the Amazon and where droughts are less severe but last longer.

To clarify the impact of long-term drought on the Congo rainforest, Zhou and colleagues set out to see whether they could detect a trend in a satellite measure of vegetation greenness called the Enhanced Vegetation Index. This measure is developed from data produced by the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA's Terra satellite. The scientists focused their analysis on intact, forested regions in the Congo basin during the months of April, May and June each year – the first of the area's two peak rainy and growing seasons each year.

The study found a gradually decreasing trend in Congo rainforest greenness, sometimes referred to as "browning," suggesting a slow adjustment to the long-term drying trend. This is in contrast to the more immediate response seen in the Amazon, such as large-scale tree mortality, brought about by more episodic drought events...

In the Congo rainforest, a browning trend (brown) dominates smaller areas that show a greening trend (green) during April, May and June each year from 2000 to 2012. Image Credit: NASA Goddard's Scientific Visualization Studio

When waters rise: NASA improves flood safety

NASA: Flooding is the most frequent and widespread weather-related natural disaster, taking a huge toll in lives and property each year. NASA Earth-observing satellites and airborne missions provide vital information to emergency planners, relief organizations and weather forecasters, helping to improve flood monitoring and forecasting, as well as providing a more comprehensive understanding of one of Mother Nature's most damaging hazards.

NASA's Earth-observing satellites provide detailed images of flood-affected areas, which are vital for mapping flood extent. For i
nstance, the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on NASA's Terra and Aqua satellites monitor a broad area of our planet, providing visible-light imagery, infrared information and other types of data on a daily basis to scientists and emergency managers. The Landsat satellites in partnership with the U.S. Geological Survey provide even higher-resolution imagery, which can be used to map Earth's land surfaces before and after disasters. Landsat serves as an essential tool for assessing flood risk and mapping the extent of damage for post-disaster recovery. Earth Observing-1 (EO-1) is an advanced land-imaging mission that includes three advanced land imaging instruments and five revolutionary cross cutting spacecraft technologies.

The United Nations World Food Programme, which delivers food relief to inundated areas, uses NASA Earth science satellite-based flood maps to locate floods and map delivery routes to affected areas. Contractors with the U.S. Federal Emergency Management Agency (FEMA) also use Landsat imagery to track urban development, which can affect an area's flood risk....

In the spring of 2011, heavy rains and snow pack resulted in record releases from dams in Montana and the Dakotas, and near-record flooding along parts of the Missouri River. One especially hard-hit community was Hamburg, Iowa, where levee failure in early June caused extensive flooding and the evacuation of many homes. By late June, the U.S. Army Corps of Engineers had rebuilt the levees and Hamburg was protected from additional flooding. The left image, acquired on Sept. 24, 2010, was taken by the Thematic Mapper sensor aboard Landsat 5. The right image, acquired on Aug. 2, 2011, was taken by the Enhanced Thematic Mapper Plus on Landsat 7.

Amazon inhales more carbon than it emits

NASA: A new NASA-led study seven years in the making has confirmed that natural forests in the Amazon remove more carbon dioxide from the atmosphere than they emit, therefore reducing global warming. This finding resolves a long-standing debate about a key component of the overall carbon balance of the Amazon basin.

The Amazon's carbon balance is a matter of life and death: living trees take carbon dioxide out of the air as they grow, and dead trees put the greenhouse gas back into the air as they decompose. The new study, published in Nature Communications on March 18, is the first to measure tree deaths caused by natural processes throughout the Amazon forest, even in remote areas where no data have been collected at ground level.

Fernando Espírito-Santo of NASA's Jet Propulsion Laboratory, Pasadena, Calif., lead author of the study, created new techniques to analyze satellite and other data. He found that each year, dead Amazonian trees emit an estimated 1.9 billion tons (1.7 billion metric tons) of carbon to the atmosphere. To compare this with Amazon carbon absorption, the researchers used censuses of forest growth and different modeling scenarios that accounted for uncertainties. In every scenario, carbon absorption by living trees outweighed emissions from the dead ones, indicating that the prevailing effect in natural forests of the Amazon is absorption.

Until now, scientists had only been able to estimate the Amazon's carbon balance from limited observations in small forest areas called plots. On these plots, the forest removes more carbon than it emits, but the scientific community has been vigorously debating how well the plots represent all the natural processes in the huge Amazon region. That debate began with the discovery in the 1990s that large areas of the forest can be killed off by intense storms in events called blowdowns...

An aerial view of the Amazon rain forest, shot by lubasi, Wikimedia Commons,  under the Creative Commons Attribution-Share Alike 2.0 Generic license

Long-term warming likely to be significant despite recent slowdown

NASA-Goddard Space Center: A new NASA study shows Earth's climate likely will continue to warm during this century on track with previous estimates, despite the recent slowdown in the rate of global warming.

This research hinges on a new and more detailed calculation of the sensitivity of Earth's climate to the factors that cause it to change, such as greenhouse gas emissions. Drew Shindell, a climatologist at NASA's Goddard Institute for Space Studies in New York, found Earth is likely to experience roughly 20 percent more warming than estimates that were largely based on surface temperature observations during the past 150 years. Shindell's paper on this research was published March 9 in the journal Nature Climate Change.

Global temperatures have increased at a rate of 0.22 Fahrenheit (0.12 Celsius) per decade since 1951. But since 1998, the rate of warming has been only 0.09 F (0.05 C) per decade -- even as atmospheric carbon dioxide continues to rise at a rate similar to previous decades. Carbon dioxide is the most significant greenhouse gas generated by humans.

Some recent research, aimed at fine-tuning long-term warming projections by taking this slowdown into account, suggested Earth may be less sensitive to greenhouse gas increases than previously thought. The Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), which was issued in 2013 and was the consensus report on the state of climate change science, also reduced the lower range of Earth's potential for global warming.

...Shindell's paper further focuses on improving our understanding of how airborne particles, called aerosols, drive climate change in the Northern Hemisphere. Aerosols are produced by both natural sources – such as volcanoes, wildfire and sea spray – and sources such as manufacturing activities, automobiles and energy production. Depending on their make-up, some aerosols cause warming, while others create a cooling effect. In order to understand the role played by carbon dioxide emissions in global warming, it is necessary to account for the effects of atmospheric aerosols.

While multiple studies have shown the Northern Hemisphere plays a stronger role than the Southern Hemisphere in transient climate change, this had not been included in calculations of the effect of atmospheric aerosols on climate sensitivity. Prior to Shindell's work, such calculations had assumed aerosol impacts were uniform around the globe....

A new NASA study suggests that projections of Earth's future warming should be more in line with previous estimates that indicated a higher sensitivity to increasing greenhouse gas emissions. Image Credit: NASA SVS/NASA Center for Climate Simulation

NASA satellites see Arctic surface darkening faster

NASA: The retreat of sea ice in the Arctic Ocean is diminishing Earth's albedo, or reflectivity, by an amount considerably larger than previously estimated, according to a new study that uses data from instruments that fly aboard several NASA satellites.

The study, conducted by researchers at Scripps Institution of Oceanography, at the University of California, San Diego, uses data from the Clouds and Earth's Radiant Energy System, or CERES, instrument. There are CERES instruments aboard NASA's Tropical Rainfall Measurement Mission, or TRMM, satellite, Terra, Aqua and NASA-NOAA's Suomi National Polar-orbiting Partnership (Suomi NPP) satellites. The first CERES instrument was launched in December of 1997 aboard TRMM.

As the sea ice melts, its white reflective surface is replaced by a relatively dark ocean surface. This diminishes the amount of sunlight being reflected back to space, causing Earth to abso
rb an increasing amount of solar energy.

The Arctic has warmed by 3.6 F (2 C) since the 1970s. The summer minimum Arctic sea ice extent has decreased by 40 percent during the same time period. These factors have decreased the region's albedo, or the fraction of incoming light that Earth reflects back into space – a change that the CERES instruments are able to measure.

..."Scientists have talked about Arctic melting and albedo decrease for nearly 50 years," said Ramanathan, a distinguished professor of climate and atmospheric sciences at Scripps who has previously conducted similar research on the global dimming effects of aerosols. "This is the first time this darkening effect has been documented on the scale of the entire Arctic."

Eisenman, an assistant professor of climate dynamics, said that the results of the study show that the heating resulting from albedo changes caused by Arctic sea ice retreat is "quite large." Averaged over the entire globe, it's one-fourth as large as the heating caused by increasing atmospheric CO2 concentrations during the same period....

This image shows a visualization of Arctic sea ice cover on Sept. 12, 2013, with a yellow line showing the 30-year average minimum extent. A new study shows that the magnitude of surface darkening in the Arctic (due to the retreat of sea ice) is twice as large as that found in previous studies. Image Credit: NASA Goddard's Scientific Visualization Studio/Cindy Starr

New NASA laser technology reveals how ice measures up

Science Daily: New results from NASA's MABEL campaign demonstrated that a photon-counting technique will allow researchers to track the melt or growth of Earth's frozen regions. When a high-altitude aircraft flew over the icy Arctic Ocean and the snow-covered terrain of Greenland in April 2012, it was the first polar test of a new laser-based technology to measure the height of Earth from space.

NASA's Multiple Altimeter Beam Experimental Lidar flew over Southwest Greenland's glaciers and sea ice to test a new method of measuring the height of Earth from space.

Aboard that aircraft flew the Multiple Altimeter Beam Experimental Lidar, or MABEL, which is an airborne test bed instrument for NASA's ICESat-2 satellite mission slated to launch in 2017. Both MABEL and ICESat-2's ATLAS instrument are photon counters -- they send out pulses of green laser light and time how long it takes individual light photons to bounce off Earth's surface and return. That time, along with ATLAS' exact position from an onboard GPS, will be plugged into computer programs to tell researchers the elevation of Earth's surface -- measuring change to as little as the width of a pencil.

This kind of photon-counting technology is novel for satellites; from 2003 to 2009, ICESat-1's instrument looked at the intensity of a returned laser signal, which included many photons. So getting individual photon data from MABEL helps scientists prepare for the vast amounts of elevation data they'll get from ICESat-2.

"Using the individual photons to measure surface elevation is a really new thing," said Ron Kwok, a senior research scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "It's never been done from orbiting satellites, and it hasn't really been done much with airborne instruments, either."...

I can see my house from here. Actually, it's an aerial shot of Greenland, shot by Túrelio, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 2.5 Generic license

California water planners hear NASA long-term forecast

Terra Daily via JPL: Recent NASA research tying California weather to large-scale atmospheric patterns contributed to the newly issued experimental Winter Outlook Forecast for Water Year 2014 by the California Department of Water Resources (DWR). That forecast, calling for continued dry conditions for the third year in a row, was the first to include discussion of climate research from NASA's Jet Propulsion Laboratory, Pasadena, Calif.

JPL researchers have found a correlation between variations in California winter precipitation and a large-scale tropical weather pattern called the Madden-Julian Oscillation (MJO). Each oscillation event consists of recurring periods of storminess on a very large scale, 3,000 to 6,000 miles (5,000 to 10,000 kilometers), which travel eastward from the Indian Ocean across the Pacific. These events last about 50 days but do not recur regularly.

"When an MJO happens, California rainfall and snowfall increase and decrease during specific parts of its life cycle," said Duane Waliser, chief scientist of JPL's Earth Science and Technology Directorate. Waliser presented the research findings at the workshop where the DWR's water forecast was prepared.

"The MJO gives us a window of opportunity to forecast tendencies for more rain or dry weather three or four weeks in advance -- much longer than a standard weather forecast," Waliser said....

An aerial view of the coast in Santa Barbara, showing the western tip of Douglas Family Preserve's mesa on the right, and a portion of Arroyo Burro County Beach on the left. Shot by John Wiley User:Jw4nvc - Santa Barbara, California, Wikimedia Commons, under the Creative Commons Attribution 3.0 Unported license