New Technique Quickly Predicts Salt Marsh Vulnerability: Scientists working on a rapid assessment technique for determining which US coastal salt marshes are most imperiled by erosion were surprised to find that all eight of the Atlantic and Pacific Coast marshes where they field-tested their method are losing ground, and half of them will be gone in 350 years’ time if they don’t recapture some lost terrain.  USGS scientist Zafer Defne measures water and sediment movement at Forsythe National Wildlife Refuge, New Jersey. Photo: Sandra Brosnahan, USGS The US Geological Survey-led research team developed a simple method that land managers can use to assess a coastal salt marsh’s potential to survive environmental challenges. The method, already in use at two national wildlife refuges, uses any one of several remote sensing techniques, such as aerial photography, to gauge how much of an individual marsh is open water and how much of it is covered by marsh plants. By comparing the ratio of ponds, channels and tidal flats to marsh vegetation, land managers can determine which marshes stand the best chance of persisting in the face of changing conditions. This ratio, called the Unvegetated-Vegetated Marsh Ratio or UVVR, is a good surrogate for much more labor-intensive field studies, said oceanographer Neil Ganju of the USGS Woods Hole Coastal and Marine Science Center. Ganju is the lead author of the study, which was published Jan. 23 in Nature Communications. “Our method does a good job of tracking the main destructive processes in marshes -  the conversion of vegetated areas to open water, and the loss of sediment,” Ganju said. “Together these changes control the long-term fate of the marsh.” Salt marshes worldwide are being lost to sea-level rise, erosion, and land use changes. These marshes protect the coast against storms and erosion, filter pollution, and provide habitat for fish and shellfish. Land managers nationwide want to know which marshes stand the best chance of enduring, so they can concentrate marsh conservation and restoration work where it will be most effective. But making that assessment is normally difficult and costly, the researchers said. To find out whether the UVVR is a good predictor of coastal salt marshes’ fates, the researchers applied it to eight marshes that had already been studied. The sites were portions of Seal Beach National Wildlife Refuge and Point Mugu Naval Air Station in California; Rachel Carson National Wildlife Refuge in Maine; Fishing Bay Wildlife Management Area and Blackwater National Wildlife Refuge in Maryland; Reedy Creek and Dinner Creek at New Jersey’s Edwin B. Forsythe National Wildlife Refuge, and Schooner Creek in New Jersey. The researchers wanted to include marshes that seemed fairly stable and ones that seemed unstable. And to test their method, they needed sites where scientists had already done the field studies necessary to develop a detailed local “sediment budget.” “Think of a marsh as similar to a savings account, with sediment as the principal,” Ganju said. “Every new deposit of sediment is like interest added to the principal, and every sediment loss is like money spent. If a marsh is gaining sediment, it can tolerate some withdrawals, and the budget will still be in the black. If it’s losing sediment, that marsh is in the red. Its sediment either gets replenished by natural processes or human intervention, or eventually the principal will all be spent.” All eight marshes’ sediment budgets were “in the red.” And in each case that UVVR result correlated with the sediment budget, confirming that each of those marshes is losing ground. The researchers calculated the likely life spans of all eight marshes. The shortest, at Maryland’s Blackwater National Wildlife Refuge, was approximately 83 years, and the New Jersey marshes had life spans ranging from 170 to 350 years. The researchers stressed that these figures are estimates with large margins of error, and don’t necessarily mean that these marshes are doomed – only that they will need infusions of sediment to last longer. “Our results can be used to distinguish marshes that are struggling to survive from more resilient ones,” said co-author Matthew Kirwan, an assistant professor at the Virginia Institute of Marine Science. “That’s important because it will help prioritize restoration work.” Staffers at Massachusetts’ Parker River National Wildlife Refuge are working with members of the research team to identify which marsh units are losing sediment, and at what rates. "This will help us figure out where we can make a difference with restoration techniques. It will also help us determine which areas are beyond restoration," said Refuge Manager Bill Peterson. "This ensures that we're using our limited resources effectively to strengthen and enhance these valuable natural areas." The research paper, “Spatially integrative metrics reveal hidden vulnerability of microtidal salt marshes,” is online at http://dx.doi.org/10.1038/NCOMMS14156. An example of the UVVR mapped over a coastal wetland is at https://www.sciencebase.gov/catalog/item/57fe81fbe4b0824b2d148389 A graphic that includes maps of the eight marshes studied and their projected lifespans is available from study author Neil Ganju or public affairs specialist Heather Dewar. (See contact information, above right.)     #climatechange

New England’s 1816 “Mackerel Year,” Volcanoes and Climate Change Today: Hundreds of articles have been written about the largest volcanic eruption in recorded history, at Indonesia’s Mt. Tambora just over 200 years ago. But for a small group of New England-based researchers, one more Tambora story needed to be told, one related to its catastrophic effects in the Gulf of Maine that may carry lessons for intertwined human-natural systems facing climate change around the world today. In the latest issue of Science Advances, first author research fellow Karen Alexander at the University of Massachusetts Amherst and 11 others including aquatic ecologists, climate scientists and environmental historians recount their many-layered, multi-disciplinary investigation into the effects of Tambora’s volcanic winter on coastal fish and commercial fisheries. Alexander says, “We approached our study as a forensic examination. We knew that Tambora’s extreme cold had afflicted New England, Europe, China and other places for as long as 17 months. But no one we knew of had investigated coastal ecosystems and fisheries. So, we looked for evidence close to home.” In work that integrates the social and natural sciences, they used historical fish export data, weather readings, dam construction and town growth chronologies and narrative sources, among others, to discover Tambora’s effects on the Gulf of Maine’s complex human and natural system. Penobscot Bay fishermen cleaning mackerel near their saltwater farm. The shore mackerel fishery documented in Alexander and colleagues’ paper lasted for over 100 years. Photo courtesy of NOAA.  The 1815 eruption caused a long lasting, extreme climate event in 1816 known as the “year without a summer.” As volcanic winter settled on much of the Northern Hemisphere, crops failed, livestock died and famine swept over many lands. In New England, crop yields may have fallen by 90 percent. Alexander and colleagues found that 1816 was also called “the mackerel year,” a clue to what they would find regarding fisheries. Besides Tambora’s climate effects, the authors examined other system-wide influences to explain observed trends. These included historical events such as the War of 1812, human population growth, fish habitat obstruction due to dam building and changes in fishing gear that might have affected fisheries at the time. Employing historical methods within a Complex Adaptive Systems approach allowed them to group and order data at different scales of organization and to identify statistically significant processes that corresponded to known outcomes, Alexander explains. For instance, temperature fluctuations influenced the entire Gulf of Maine for short periods of time, while dam construction affected individual watersheds through the life of the dams. Space and time scales differ in each case, but both temperature fluctuations and habitat obstructions affect fish, and thus fisheries, at the same time. Such interactions are characteristic of complex systems, she notes. Establishing timing was key to solving the mystery, says Alexander. Major export species, including freshwater-spawning alewives and shad and marine-spawning mackerel and herring, have different temperature tolerances and seasonal migration patterns and timing, or phenology. Alewives and mackerel arrived earlier when water was colder, shad and herring arrive later after water had warmed up. Because of their phenology and vulnerability in rivers and streams during spawning, alewives suffered the most from the extreme climate event. In Massachusetts, where streams had been dammed for a long time, its effects were compounded, the researchers found. Fishermen tending a brush weir near the St. Croix around 1900. Weir fishing had changed little over the past 100 years. These men still used local available materials to construct the weir and harvested herring in row boats. Photo courtesy of NOAA.  In the early 1800s alewives were a “utility fish,” an important commercial export but also used locally as chicken feed, garden fertilizer and human food during the winter. The winter of 1816 was so cold, Alexander says that “Penobscot Bay froze solid from Belfast to Castine.” When alewives arrived at their seasonal spawning time, adverse conditions likely disrupted spawning runs, increased natural mortality and, critically for the people depending on them, decreased catch. She adds, “During this climate crisis, people couldn’t catch enough alewives to meet their needs, so they quickly turned to mackerel, the next abundant species to arrive along the coast. Pursuing mackerel and rapidly distributing it to communities with no other sources of food fundamentally altered the infrastructure of coastal fisheries.” Although records suggest that alewife populations apparently recovered within 25 years, “people responded rapidly and effectively to Tambora in only five years and never looked back when the crisis passed.” Rates of human and alewife response became uncoupled and the quick fixes, become permanent, later achieved an air of inevitability, the authors suggest. "Alewives and other fishes that inhabit both rivers and oceans are highly vulnerable to climate change,” said Michelle Staudinger, a USGS scientist with the Northeast Climate Science Center at UMass. “The lessons learned from this study will help us better anticipate, prepare and cope for additional future impacts on their populations as well as the human communities that depend on them." The authors added that “complex solutions elude simple explanations.” They point out the “many and obvious,” parallels between that sudden extreme event and current occurrences of drought, flood, storm devastation, food disruption and famine attributed to climate change. “The past can be a laboratory,” Alexander and colleagues write. Employing historical methods within a Complex Adaptive Systems approach may offer a simple way to examine complex systems where scale, rate and phenology enmesh interconnect human and natural processes, and help to “advance human resilience by strengthening resilience in the natural world.” Support for this work was provided by the Department of the Interior Northeast Climate Science Center, UMass Amherst’s Department of Environmental Conservation, the University of New Hampshire Institute of Earth, Oceans and Space, the U.S. Geological Survey, the Lenfest Ocean Program and New Hampshire Sea Grant. #climatechange

New Tool Shows Historic and Simulated Future Water Conditions in the U.S.: Water users around the country can now view the past and simulated future of hydrologic processes. The Hydrology Futures Portal, released today by the U.S. Geological Survey, provides a user-friendly interface summarizing monthly historic (1952 through 2005) and simulated future conditions (2020 through 2099) for various meteorological and hydrological variables at locations across the conterminous United States. The features on this new application include seven searchable meteorological and hydrological variables: actual evapotranspiration, atmospheric temperature, potential evapotranspiration and precipitation, runoff, snow water equivalent (the volume of water stored in the snowpack/depth of water if the snow melted), and streamflow. “The creation of the portal involved the expertise and skills of individuals from all over the U.S. in a number of different sciences and technological fields such hydrological modeling, climate science, geographic information systems, Web development and data science,” said Andrew Bock, lead USGS scientist for the project. “In 2017, the team plans to follow up the platform release with a number of informational products to help users better understand more advanced capabilities this system has to offer.” This collaborative effort is a product of a multi-year partnership between the USGS, the Department of Interior North Central and South Central Climate Science Centers and the Environmental Protection Agency. #climatechange

EarthView–Rare Snow Falls at the Edge of Sahara Desert: EarthViews is a continuing series in which we share a USGS Image of the Week featuring the USGS/NASA Landsat program. From the artistry of Earth imagery to natural and human-caused land change over time, check back every Friday to finish your week with a visual flourish! This Landsat 7 image shows an area on the edge of the Sahara Desert in northwestern Africa after significant snow fell. Credit: USGS/NASA Landsat program.(Public domain.) The EarthView: Rare Snow Falls at the Edge of Sahara Desert Description: In mid-December 2016, a rarity occurred on the edge of the Sahara Desert in northwest Africa. It snowed. Landsat 7’s Enhanced Thematic Mapper Plus (ETM+) sensor captured the image that shows the white covering on the caramel-colored landscape southwest of the Algerian community of Ain Sefra, a town sometimes referred to as “the gateway to the desert.” All the snow except that at the highest elevations melted soon after, a fact Landsat 8 confirmed when it passed overhead on December 27. This Landsat 8 image shows the same area a few days later after most of the snow has melted. Credit: USGS/NASA Landsat program.(Public domain.) Ain Sefra’s last snowfall occurred on February 18, 1979. While snow does collect in Africa at higher elevations—Mount Kilimanjaro in Tanzania has long been crowned by a cap of snow and ice—snow on the edge of the Sahara Desert seldom falls. The average summertime temperature at Ain Sefra is 99 degrees Fahrenheit. Though winter temperatures are known to drop into the 30s, snow is as rare as the cool temperatures given that just a few centimeters of precipitation fall there annually. Hungry for some science, but you don’t have time for a full-course research plate? Then check out USGS Science Snippets, our snack-sized science series that focuses on the fun, weird, and fascinating stories of USGS science. #climatechange

The Other 364 Days of the Year: The Real Lives of Wild Reindeer: Caribou, North America’s wild reindeer, have lives apart from their famous role on Christmas Eve. Reindeer and caribou (Rangifer tarandus) are large, cold-adapted, herding herbivores related to deer, elk and moose. To learn more about the biology behind these arctic antler-bearers, we turn to our colleagues at the USGS Alaska Science Center, who conduct a wide variety of earth science and ecological science surveys throughout our northernmost state. We asked USGS caribou (and large mammal) expert Layne Adams, Ph.D., about the lives of caribou for those other 364 days of the year. Adams has studied caribou and their predators in Denali National Park and elsewhere in Alaska for more than 30 years, helping land managers understand the best ways to manage these important species. Adams, a wildlife biologist at the Alaska Science Center, did an online chat with the Washington Post a few years ago: Don't worry, this large bull caribou is only resting! USGS scientist Layne Adams places a radiocollar on a sedated caribou in Denali National Park, Alaska. (USGS photo, public domain.) Read the transcript of the Washington Post live chat: “Reindeer: What do they do the other 364 days of the year?” Here are other Qs and As about reindeer that Dr. Adams answered: A mother caribou and her offspring, east of Chicken, Alaska (on the Yukon-Alaska border).  (Credit: Jamey Jones, USGS. Public domain.) Why are reindeer sometimes called caribou and caribou sometimes called reindeer? “Reindeer” and “caribou” are two common names for the same species (Rangifer tarandus), which occurs throughout the circumpolar North. “Reindeer” is the common name for Rangifer in Europe and Asia, whereas “caribou” is the North American name. The name “caribou” is a French derivative of a Native American word that means snow shoveler, which is a reference to the fact that caribou are often pawing through the snow to find food underneath. What are reindeer or caribou? Caribou and reindeer are part of the deer family — related to deer, moose and elk. They are the only deer species where males and females both grow antlers. Females and young males have antlers that are similar in size, but males older than 2 or 3 years have much larger antlers. Caribou and reindeer have been around for over a half-million years; their ancestors lived at the same time as now-extinct woolly mammoths and saber-toothed cats. Caribou are widely distributed across northern North America ranging from the Canadian High Arctic islands to the mountains and boreal forests of the Canadian southern provinces.  A small, endangered population in northern Idaho and adjacent northeastern Washington are the southernmost group in North America. The most numerous are those in the large migratory populations that occur from Alaska throughout much of northern Canada. What are “domestic reindeer”? Reindeer were domesticated across northern Europe and Asia several thousand years ago and are the basis of herding cultures in those regions. Domestic reindeer also occur in Alaska and Canada.  A little more than a century ago, 1300 reindeer were imported from Siberia to northwest Alaska in an attempt to establish a herding economy among the Native people in the region. At the time, caribou were scarce along the northwest coast of Alaska. Reindeer herding expanded widely across the west and north coasts of Alaska, as well as into northern Canada, such that around 600,000 domestic reindeer occurred throughout Alaska by the 1930s. During the Great Depression, the reindeer industry in Alaska collapsed and retracted to the Seward Peninsula of northwest Alaska where it continues today. While the main goal for domestic reindeer has been to provide meat and hides to local people, reindeer have been trained to pull sleds as a mode of transportation. White caribou hair stands out in contrast from the bright-colored tunda crowded with lichen and fall cranberry leaves.(Public domain.) What do they eat? Caribou forage on a variety of plants throughout the year. During winter, lichens are their most frequent food, with shrubs and grass or sedges making up the rest. Lichens are a combination of fungus and algae that grow together. On alpine and arctic tundra ranges, caribou primarily feed on terrestrial lichens, sometimes called reindeer moss, that occur within the low-growing grasses and shrubs that make up the tundra vegetation. In southern or boreal forest ranges, where caribou winter in deep snow, arboreal lichens that grow on trees are the predominant caribou forage. During summer, caribou shift to eating a wide variety of green plants including grasses or sedges, growing shrubs, and a variety of small forbs or flowering plants. In some regions, mushrooms abundant in late summer are an important food for caribou.   A bull caribou grazes in autumn at the Lake Clark National Park and Preserve in Alaska. (Public domain.) What do caribou do in the fall and winter? In the fall, some caribou herds start migrating — when they migrate is dictated by cues in changing day length in combination with the onset of snowfall as the long winter begins. Fall is also the breeding season when mature bulls compete with each other for opportunities to breed with females as the females become receptive. In winter, Arctic caribou generally migrate south into the northern fringe of the boreal forest or onto tundra winter ranges where terrestrial lichens are abundant. Some larger caribou herds migrate long distances, 300-400 miles, between their winter ranges and their calving and summer ranges. Smaller mountain populations migrate out of the higher mountains onto the tundra and forest ranges adjacent to their mountainous summer ranges, while small boreal forest populations are generally sedentary throughout the year. Once on their winter range, caribou remain there throughout the winter, from about early October to late April. How do they thrive in such cold temperatures? Caribou are well adapted to living in cold regions and thrive in areas where winter temperatures can reach 70 or 80 degrees below zero. These animals have a very dense haircoat, made up of wooly underfur and hollow guardhair, over their entire body (except the very tip of their nose) that provides superior insulation. They also have relatively large, wide hooves for walking and digging through snow. What do caribou do in the summer? After the females calve, caribou generally gather together in large groups to help them better avoid predators and to escape incredibly bothersome mosquitoes and parasitic flies. The different herds of caribou stay together in the high mountains and along the Alaskan seacoasts where the winds and cooler temperatures help protect them from summer heat and those pesky insects. After the number of insects decline in late July, the caribou herds scatter into smaller groups. This is an important time for caribou — they use the time before winter arrives to feed as much as possible on remaining green grasses and sedges, willow leaves, and even mushrooms to regain their body weight. USGS biologist Gretchen Roffler weighs a newborn caribou calf in Denali National Park, Alaska. (Public domain.) How big are calves? We’ve weighed quite a few newborn calves in Denali and on average they weigh about 17 pounds. Calves are born in May and early June throughout Alaska, with most calves being born in any herd within about a 10-day period. Caribou cows produce one calf each year and generally begin producing calves when they are 2 to 4 years old depending on the nutritional status of a given population. In small herds, such as the Denali Caribou Herd, calves are subject to intense predation primarily by wolves and grizzly bears — fewer than half survive beyond 2 weeks of age. In the large, migratory populations, early calf survival is markedly higher because the huge number of calves born over a brief interval can greatly swamp the ability of local predators to kill them. How big are adult caribou? In Denali National Park, where I currently study caribou, mature adult males average about 500 pounds but can weigh more than 600 pounds. Adult females are about half as big, averaging about 240 pounds (225- to 320-pound range). In the large, migratory herds, caribou are smaller with adult males and females averaging about 400 pounds for males and 200 pounds for females. How many herds are in Alaska? Simulation domain and winter ranges of the Central Arctic and Porcupine caribou herds, Alaska and Yukon.(Public domain.) There are 31 caribou herds recognized in Alaska, with 7 large migratory populations numbering 30,000 to 206,000 animals. These herds currently total just under 600,000 animals and account for about 97 percent of the caribou in the State. The remaining 24 herds are much smaller ranging from about 30 to 3000 animals each. Overall, Alaska’s caribou population was relatively low in the mid 1970’s, numbering around 250,000 statewide.  Caribou numbers increased to about 950,000 by the mid-1990s, as a couple of the large herds grew to historic high numbers.  Since then, caribou numbers have declined to around 620,000 today. Such wide fluctuations in caribou numbers over the time scale of decades are not unusual. Can you talk a little more about predators — what eats caribou? In general, the primary predators of caribou in Alaska are grizzly bears and wolves. Grizzly bears are very effective at killing young caribou calves less than a couple weeks old, although they also kill older caribou on occasion. Wolves are important predators of both young calves and older caribou. Other predators on caribou include black bears, golden eagles, wolverine, and coyotes. Humans are also important predators of caribou. Caribou are a mainstay of local subsistence in Bush Alaska, and a sought-after quarry for other Alaskan residents, as well as sport hunters from all over the world. On average, people harvest about 22,000 caribou a year in Alaska. Predation affects the number of caribou, particularly in the smaller, more sedentary populations. The large, migratory herds are able to reduce the negative effects of predation to some degree just due to their sheer numbers; the tradeoff is that they are more likely to be affected by the nutritional limitations of their ranges compounded by competition with their herd mates. Caribou are more vulnerable in deep snow Layne with caribou.(USGS photo, public domain.) A main goal of my research has been to understand the interrelationships of caribou and wolves in Denali National Park. For caribou, an important factor that affects how many are killed by wolves is the amount of snow during winter. In years with less snow, caribou have large expanses of wind-blown, snow-free land to seek their food, and they commonly make it through the winter in good shape. They can also more easily evade wolves because they can run unimpeded across the bare, frozen tundra. During such times, wolves are primarily able to kill those caribou that are old, injured, not in good shape, or just plain unlucky. We’ve found that when it is harder for wolves to catch caribou, the wolf packs tend to be smaller. But the balance shifts in favor of wolves when there is a lot of snow. Caribou then have a harder time finding enough to eat because they have to dig through deep or crusted snow or must seek food on high mountain ridges where there is little snow, but also little food. The caribou also have a harder time escaping from wolves in deep snow. In fact, wolves will sometimes chase caribou into areas with deep snow where the caribou are very vulnerable, even if they are in good shape. In those years, wolf packs tend to be bigger and some packs produce more pups. In contrast, our research shows that after severe winters, not only is a cow less likely to breed, but calves that are born are lighter, grow more slowly, and are more likely to be killed by predators in the weeks after they are born. Is climate change affecting caribou? We know, from our studies, that weather may be the most important factor affecting the yearly cycles of large hoofed mammals (such as caribou, moose and muskox) and their predators. However, the longer-term effects of climate change are much more complex. Unlike polar bears, which are highly dependent on sea ice that is declining due to warming temperatures, caribou are likely influenced by a wide variety of factors that will be affected by a warming climate, and some effects will be positive and some negative. For example, with a warming climate, we expect the growing season to be longer and provide caribou with green, nutritious forage earlier and for a longer period of time for a positive effect.  Our recent studies on Alaska’s Arctic Coastal Plain have been geared toward understanding how a warming climate is affecting the plants that caribou eat during summer; this information will help managers forecast how future habitat condition might affect the well-being of these large herbivores. However, we have also done research that indicates that with increasing temperatures we can expect more fires on boreal forest winter ranges for caribou that will likely result in reduced availability of lichen, their primary winter forage, which tends to not grow back for about 70 to 80 years after a fire. The overall effect of a warming climate on caribou will be dependent on how these and many other climate-related effects interact and that is very difficult to predict. Further, responses to climate change are likely to differ among the various caribou populations across North America. What does some of your research focus on? Currently, I am continuing long-term studies of the population dynamics of the Denali Caribou Herd and overseeing research on the summer habitat selection of caribou relative to forage quality and weather on Alaska’s Arctic Coastal Plain. Read More: Resilience of Caribou to Climatic Shifts in the Arctic USGS Alaska Science Center Large Mammal Ecology webpages Battling Flies and Fog in Search of Reindeer Poop The Changing Arctic Initiative (including caribou) #climatechange

Warmer Ocean Waters Seen to Spur Drought in Africa: Really?” and “Strange, but true” might be popular reactions to the idea that periodic El Niño events in the Pacific Ocean could have a long distance influence on drought conditions in Africa, almost half-a-world away. Unlikely as it may seem, these connections are widely accepted by climate scientists and weather experts across the globe. Strange, but true, indeed. El Niño and its counterpart, La Niña, are the warm and cool phases of a recurring climate pattern across the tropical Pacific — the El Niño-Southern Oscillation – that shifts back and forth irregularly every two to seven years. By disrupting large-scale air movements in the tropics and thus affecting temperature, precipitation, and winds, these changes in the Pacific Ocean set off a cascade of global side effects with each oscillation. Drought comes to Africa In the northern hemisphere’s winter and fall of 2015, El Niño reached a record high temperature in December-January-February and triggered historic levels of famine far away in east Africa. A related drought across southern Africa affected 30 million people. In November of 2016 Zimbabwe still faced severe water shortages. Observed Niño 3.4 sea surface temperature (SST) anomalies (vertical bars) and estimates of El Niño SST anomalies. Compared to an ensemble of climate change simulations (red line).  USGS image produced by Chris Funk. Public domain. Scientists from the U.S. Geological Survey, the University of California Santa Barbara, and the National Oceanic and Atmospheric Administration (NOAA) tracked the severe droughts in eastern and southern Africa. This science team has recently published a paper in the Bulletin of the American Meteorological Society (chapter 15) that assesses the extent that warmer ocean waters resulting from human-caused climate change likely intensified the impacts of the drought. The authors of the study evaluated the impacts of the rainfall reductions and air temperature increases in Africa during this period by means of a contra-positive experiment, in which a “world without climate change” was simulated in complex hydrologic models. These experiments revealed that the warming of El Niño beyond its historical averages during 1946-1975 likely helped produce a very large reduction in streamflow: 35% for Ethiopia and 48% for Southern Africa. Both regions experienced severe water shortages, as illustrated by estimates of per capita water availability. “In summary, what we seem to be seeing,” said Chris Funk, a USGS scientist and lead author of the study, “is that, as the oceans warm due to climate change, pockets of very warm sea surface temperatures develop that often act to increase the impact of natural climate variations such as El Niño and La Niña. These extreme sea surface temperatures can intensify droughts over food insecure areas, contributing to water stress and disrupting economic growth.” The data and scientific reasoning for these findings are detailed in the publicly available professional paper. Weakened livestock in Arsi Negele, south-central Ethiopia, Sept. 2, 2015.  Photo cedit: Getachew Abate (FEWS NET) and Kelbessa Beyene (World Food Programme), public domain. Monitoring drought to get ahead of famine Ethiopia suffered drought conditions in 2015 that were comparable to the severe drought and ensuing famine of 1984, during which hundreds of thousands of people perished. Like the case in the 1980s, the 2015 Ethiopian drought was related to a strong El Niño. Unlike that terrible episode, widespread acute food insecurity was avoided in 2015-2016 due to effective climate services, early warning of potential food insecurity, and social safety nets, particularly through the Famine Early Warning Systems Network (FEWS NET). USGS Water Hole Status map, early December 2016. Information source: earlywarning.usgs.gov Created by USAID in 1985 to help decision-makers plan for humanitarian crises, FEWS NET provides evidence-based analysis of food insecurity in some 35 countries. Implementing team members include the government agencies of NASA, NOAA, U.S. Department of Agriculture, and USGS, along with the commercial entities, Chemonics International Inc. and Kimetrica. Scientists at USGS, University of California Santa Barbara, NASA, and NOAA monitored the severe droughts associated with the extreme 2015-16 El Niño event in partnership with FEWS NET specialists in Africa and Washington, helping the U.S. Agency for International Development provide early and effective humanitarian assistance. The combined information derived from U.S. satellite remote sensing, climate forecasting, and land surface modeling capabilities provided the agro-climatic evidence needed by FEWS NET food security analysts to project livelihood impacts many months in advance. The resulting early warning of potential acute food insecurity was instrumental in mobilizing the resources needed to prevent a humanitarian catastrophe. Learn more Funk, C. and L. Harrison, S. Shukla, A. Hoell, D. Korecha, T. Magadzire, G. Husak, G. Gideon. “Assessing the Contributions of Local and East Pacific Warming to the 2015 Droughts in Ethiopia and Southern Africa” in “Explaining Extremes of 2015 from a Climate Perspective,” Bull. Amer. Meteor. Soc., 97 (12), S14–S18, doi:10.1175/BAMS-D-16-0149. USGS Earth Resources Observation and Science Center (EROS) University of California Santa Barbara Climate Hazards Group NOAA Earth System Research Laboratory, Physical Sciences Division USGS FEWS NET #climatechange

EarthView–Wildfires Scorch Pampas Region of Argentina: EarthViews is a continuing series in which we share a USGS Image of the Week featuring the USGS/NASA Landsat program. From the artistry of Earth imagery to natural and human-caused land change over time, check back every Friday to finish your week with a visual flourish! This Landsat 8 view of the Pampas region of Argentina, taken on December 22, 2016, shows initial fire scars. Credit: USGS/NASA Landsat Program. (Public domain.) The EarthView: Wildfires Scorch Pampas Region of Argentina Description: Since mid-December 2016, roughly two dozen wildfires in the Pampas region of Argentina have consumed almost 2.5 million acres while unleashing giant plumes of dense smoke above the rural landscapes. Likely caused by thunderstorms that followed a stretch of severe drought in the winter and spring of 2016, the first fires started southwest of the city of Bahía Blanca. A scene from Landsat 8’s Operational Land Imager (OLI) on December 22, 2016, shows smaller red burn scars from those initial blazes—an area of approximately 100,000 acres. This followup Landsat 8 view of the Pampas region of Argentina, taken on January 7, 2017, shows significantly increased fire scars. Credit: USGS/NASA Landsat Program. (Public domain.) Despite rain in the final days of December, a handful of hot spots persisted, and the fires spread. When it passed overhead on January 7, 2017, OLI captured dramatic imagery of large red burn scars across the landscape of Argentina’s central province of La Pampa, and its southern province of Rio Negro. On January 5, 2017, the International Charter “Space and Major Disasters,” of which USGS is a member, granted Argentina’s request for Charter members’ available satellite data to help in rapidly assessing the extent of damage and determining a disaster response. Hungry for some science, but you don’t have time for a full-course research plate? Then check out USGS Science Snippets, our snack-sized science series that focuses on the fun, weird, and fascinating stories of USGS science. #climatechange

Turning the Tide on the Chesapeake Bay: “I had the impression of an extremely productive and beautiful system,” said Batiuk, the U.S. Environmental Protection Agency’s (EPA) Associate Director for Science, Analysis, and Implementation with the Chesapeake Bay Program. “I didn’t see what was under the surface.” By the mid-1980s, when Batiuk relocated to the bay, its troubles had surfaced. Increased nutrients caused low oxygen (hypoxia) in the bay, suffocating fish and other aquatic species. “The Chesapeake hit its low point when I first became professionally involved,” Batiuk said. “Widespread losses of underwater grasses, low dissolved oxygen, reduced water clarity, and Hurricane Agnes had pushed the bay over the edge. Development, fertilizer, millions of people moving in, and limited waste-water treatment technology caused the ecosystem to bottom out.”   The French RV Marion Dufresne visits Baltimore, Maryland. The vessel was well suited to extract long marine sediment cores needed in climate change studies. Photograph Credit: Debra Willard, USGS. The Chesapeake Bay is extraordinary; its watershed includes more than 3,600 species of fish, wildlife, and plants. The bay produces an annual seafood harvest of about 500 million pounds, according to the Chesapeake Bay Foundation, making it third in the Nation, behind only the Atlantic and Pacific Oceans. In 1983, the Chesapeake Bay Program was formed to improve water quality. The program is a partnership between university, State, and Federal experts, including the U.S. Geological Survey (USGS). Despite strict standards for protecting living resources and extensive efforts in the decades that followed, hypoxia persisted. Scientific research was needed to understand natural versus human-induced changes and develop a sustainable resource-management plan. The USGS has a unique capability that allows them to reconstruct past environments and water quality by using paleoclimate science. European settlement dates back 400 years, so the USGS—working with partners—examined the thick sediments beneath the surface to construct climate records. To carry out this research, USGS scientists boarded the French national research vessel Marion Dufresne as part of a mission to extract long sediment cores from the bay. The USGS found that during the last 5,000 years, parts of the bay were hypoxic during wet years, and hypoxia increased after the 18th century because of human influences. The bay’s natural vulnerability and growing human imprint underscored the need to reset standards and refocus efforts to minimize hypoxia. “[The] USGS provided a scientific basis to define natural conditions and not make standards under- or over-protective but ensure they were realistic to achieve,” said Batiuk. “Based on USGS coring work, we could say that the strict water-quality standards were unattainable in the deepest parts of the bay, even well before [English explorer] John Smith first came,” he said. “The system naturally has lots of nutrients and even low dissolved oxygen in the deeper waters, but all [are] part of a very productive estuary.”     The USGS’s paleoclimate science, combined with other research, helped set the bay’s “pollution diet”—its Total Maximum Daily Load (TMDL). The Chesapeake Bay Watershed Agreement, signed in 2014, outlines acceptable dissolved oxygen levels and sets TMDLs for nitrogen, phosphorus, and sediment. In September 2016, the EPA and the USGS revealed new scientific evidence that actions taken across six States and the District of Columbia were making a difference. These actions included upgrading wastewater treatment, reducing farmland runoff, and lowering emissions. “It has been a struggle over three decades [with] the human population that increased 50 percent from 12 million to 18 million,” said Batiuk. “But we just released information with USGS showing about a dozen indicators have taken a turn for the better over the long term. [With] that human tide, we’re making a difference in a system that needs a big wallop of nutrient and sediment reductions to see a response.”   Map of the Chesapeake Bay and tributaries showing where sediment cores were collected from 1995-2006 to study how the modern Chesapeake Bay formed. Credit: Tom Cronin, USGS. Read more stories about USGS science in action. Click here for the print version. #climatechange

EarthView–Marree Man Geoglyph in Australia Does Reappearing Act: EarthViews is a continuing series in which we share a USGS Image of the Week featuring the USGS/NASA Landsat program. From the artistry of Earth imagery to natural and human-caused land change over time, check back every Friday to finish your week with a visual flourish! This Landsat 8 image, taken in November of 2016, shows the Australian outback after the Marree Man was re-etched. Credit: USGS/NASA Landsat Program. (Public domain.) The EarthView: Marree Man Geoglyph in Australia Does Reappearing Act Description: In June 1998, a pilot discovered a strange sight in the Australian outback that wasn’t there before—a huge outline of what appeared to be an Aboriginal man throwing either a boomerang or a stick. It turned out to be a geoglyph, which is a design on the ground typically made of natural elements and best viewed from above. This geoglyph was distinctive and large enough to be clearly visible in Landsat images. This Landsat 5 image, taken in May of 1998, shows the Australian outback before the Marree Man was created. Credit: USGS/NASA Landsat Program. (Public domain.) Its origin remains a mystery, as no credible source has claimed responsibility. Over the years, the “Marree Man” faded because of rain and wind. In July 2000, Landsat 7 shows an outline with far fewer details. This Landsat 5 image, taken in June of 1998, shows the Australian outback with the Marree Man. Credit: USGS/NASA Landsat Program. (Public domain.) In August 2016, the Marree Man was re-etched. A grader and GPS were used to re-create the outline, and this time the geoglyph is expected to last longer. The lines created are wind grooves that will trap water, so over time the outline should turn green. This Landsat 7 image, taken in July of 2000, shows the Marree Man faded from weathering. Credit: USGS/NASA Landsat Program. (Public domain.) Now clearly visible again in the November 2016 Landsat 8 image, Marree Man is among the biggest geoglyphs on Earth. It stretches 3.5 kilometers from the tip of his stick to his toes. From an airplane, a person would need to be at around 3,000 feet to view it in its entirety. Hungry for some science, but you don’t have time for a full-course research plate? Then check out USGS Science Snippets, our snack-sized science series that focuses on the fun, weird, and fascinating stories of USGS science. #climatechange

EarthView–Expansion at the Port of Rotterdam: EarthViews is a continuing series in which we share a USGS Image of the Week featuring the USGS/NASA Landsat program. From the artistry of Earth imagery to natural and human-caused land change over time, check back every Friday to finish your week with a visual flourish! This Landsat 7 view of Rotterdam harbor, taken on September 28, 2001, predates the beginning of the Maasvlakte 2 port expansion project. Credit: USGS/NASA Landsat Program. (Public domain.) The EarthView: Expansion at the Port of Rotterdam Description: A large infrastructure project has changed the shape of the coastline of the Netherlands while increasing the cargo capacity at Europe’s largest port. This pair of Landsat images spanning 15 years shows the Maasvlakte 2 project, which is an expansion of the Port of Rotterdam. The port provides accessibility for the transportation of cargo from Rotterdam to the rest of Europe. Land building at Maasvlakte 2 began in 2008. About 230 million cubic meters of sand were dredged from the North Sea to create about 5,000 acres of new land. In addition, 7 million metric tons of stone were used to construct new seawalls. In this Landsat 8 view of Rotterdam Harbor, taken on September 13, 2016, the completed Maasvlakte 2 project can be seen, which added about 5,000 acres of new land to the port. Credit: USGS/NASA Landsat Program. (Public domain.) Commercial cargo operations at the new Maasvlakte 2 facility began in December 2014. Its terminals currently can hold 2.7 million individual 20-foot shipping containers. There is more space for terminals to be built on the new land once demand increases, which would increase the port’s cargo handling capacity even more. The expansion of land resulted in some loss of permanently flooded sandbanks that affected the availability of food for some protected bird species, such as the common scoter, the sandwich tern, and the common tern. However, this loss was compensated for by establishing a protected seabed area south of the Maasvlakte 2 in the Voordelta. Also, three bird resting areas in the seabed were established where boat traffic is restricted. Landsat can help monitor this coast to ensure the positive impact of these protected areas as compensation for the land expansion. Hungry for some science, but you don’t have time for a full-course research plate? Then check out USGS Science Snippets, our snack-sized science series that focuses on the fun, weird, and fascinating stories of USGS science. #climatechange

EarthView–A Landsat Mosaic for Indiana’s Bicentennial: EarthViews is a continuing series in which we share a USGS Image of the Week featuring the USGS/NASA Landsat program. From the artistry of Earth imagery to natural and human-caused land change over time, check back every Friday to finish your week with a visual flourish! This Landsat mosaic was made of multiple images of Indiana stitched together. Credit: USGS/NASA Landsat Program. (Public domain.) The EarthView: A Landsat Mosaic for Indiana’s Bicentennial Description: Throughout 2016, Indiana has been celebrating its 200th anniversary of statehood. Joining the Union on December 11, 1816, as the 19th state, Indiana was the second state admitted from what was once known as the Northwest Territory. This satellite mosaic of the Hoosier State was created from several Landsat scenes stitched together to create one seamless image. Data from the National Elevation Dataset (NED) is also incorporated into the image. The names of major cities and county boundaries have been added. The Landsat images used for this mosaic were from summer months, so it shows the state at the height of the growing season. Since farmland makes up about 70% of the state’s land, much of the state appears green. By contrast, urban areas appear in shades of lavender. The large spot in the middle of the state marks the location of Indiana’s capital and largest city, Indianapolis. The Wabash River, the official state river, flows west across the northern part of the state and turns south to form part of the border with Illinois. Poster-sized images of all 50 states, plus Puerto Rico, are available for download at no charge at http://eros.usgs.gov/imagegallery/landsat-state-mosaics. Hungry for some science, but you don’t have time for a full-course research plate? Then check out USGS Science Snippets, our snack-sized science series that focuses on the fun, weird, and fascinating stories of USGS science. #climatechange

EarthView–As Glaciers Worldwide Are Retreating, One Defies the Trend: EarthViews is a continuing series in which we share a USGS Image of the Week featuring the USGS/NASA Landsat program. From the artistry of Earth imagery to natural and human-caused land change over time, check back every Friday to finish your week with a visual flourish! In this Landsat 8 image of the Southern Patagonia Icefield in Chile, taken October 22, 2016, Pio XI glacier can be seen having advanced in both directions. Credit: USGS/NASA Landsat(Public domain.) The EarthView: As Glaciers Worldwide Are Retreating, One Defies the Trend Description: Many glaciers around the world are losing ice mass and retreating. One such area is the Southern Patagonia Icefield (SPI) in Chile. However, one glacier in the SPI is actually defying the worldwide trend. The Pio XI Glacier is advancing, and based on scientific studies, there is no clear reason why. Pio XI flows from the SPI toward the west then splits into two fronts. From 1998 to 2014, the southern front advanced 593 meters. The northern front, which flows into Lake Greve, advanced 107 meters in the same time period. This pair of Landsat images shows that all of the other glaciers that flow down from the SPI into Lake Greve are retreating. In this Landsat 5 image of the Southern Patagonia Icefield in Chile, taken October 4, 1986, Pio XI glacier can be seen bordering Lake Greve. Credit: USGS/NASA Landsat(Public domain.) The complex behavior of glaciers involves more than just measuring where the ice ends. Scientists theorize that something is happening inside or beneath Pio XI to make it advance, rather than an external factor like climate. The glacier flows from a wide accumulation area into a narrow outlet, and the depth of the lakes it flows into, along with the speed of the glacier’s flow, may also be factors. Whatever the cause, glaciers continue to be closely monitored, and in the remote region of the SPI, that monitoring needs to be done with remote sensing. Landsat offers several observations per year in these areas and will help scientists understand the glacier’s future behavior. Hungry for some science, but you don’t have time for a full-course research plate? Then check out USGS Science Snippets, our snack-sized science series that focuses on the fun, weird, and fascinating stories of USGS science. #climatechange