Ecology, Climate Change and Related News

Conservation Science for a Healthy Planet

Tag Archive: ocean warming

  1. Hotter, longer, more frequent — marine heatwaves on the rise

    Leave a Comment
    • From 1925-2016, the study found the frequency of marine heatwaves had increased on average by 34% and the length of each heatwave had increased by 17%. Together this led to a 54% increase in the number of marine heatwave days every year.

    April 10, 2018 University of New South Wales

    We know heatwaves over land have been increasing, but now new research reveals globally marine heatwaves have also been increasing in length, number and intensity over the past century. More intriguing still, this trend has accelerated markedly since 1982.

    …Persistent warm water in the north Pacific from 2014-2016 led to fishery closures, mass strandings of marine mammals and harmful algal blooms along coastlines. That heatwave even changed large-scale weather patterns in the Pacific Northwest.

    More recently still, Tasmania’s intense marine heatwave in 2016 led to disease outbreaks and slowing in growth rates across aquaculture industries….

    ….”With more than 90% of the heat from human caused global warming going into our oceans, it is likely marine heatwaves will continue to increase. The next key stage for our research is to quantify exactly how much they may change.

    “The results of these projections are likely to have significant implications for how our environment and economies adapt to this changing world.”…

    Eric C. J. Oliver, Markus G. Donat, Michael T. Burrows, Pippa J. Moore, Dan A. Smale, Lisa V. Alexander, Jessica A. Benthuysen, Ming Feng, Alex Sen Gupta, Alistair J. Hobday, Neil J. Holbrook, Sarah E. Perkins-Kirkpatrick, Hillary A. Scannell, Sandra C. Straub, Thomas Wernberg. Longer and more frequent marine heatwaves over the past century. Nature Communications, 2018; 9 (1) DOI: 10.1038/s41467-018-03732-9

  2. Is warming in the Arctic behind this year’s crazy winter weather?

    Leave a Comment
    • the dipole pattern – abnormally high temperatures over much of the West along with chilly conditions in the East – has dominated North American weather in four of the past five winters
    • When ocean temperatures off the West Coast of North America are warmer than normal, as they have been most of the time since winter 2013, the jet stream tends to form a ridge of high pressure along the West Coast, causing storms to be diverted away from California and leaving much of the West high and dry…
    • The combination of natural and climate change-related effects– “It Takes Two to Tango–” is a concept that may help explain the Ridiculously Resilient Ridge observed frequently since 2013. Several new studies support this human-caused boost of a natural pattern, though controversy still exists regarding the mechanisms linking rapid Arctic warming with weather patterns farther south in the mid-latitudes
    • It’s hard to nail down whether this weather pattern – overall warmer winters in North America but longer cold snaps – will persist

    by Jennifer Francis, PhD  Rutgers University January 11 2018 Read full article here in theconservation

    Damage from extreme weather events during 2017 racked up the biggest-ever bills for the U.S. Most of these events involved conditions that align intuitively with global warming: heat records, drought, wildfires, coastal flooding, hurricane damage and heavy rainfall.

    Paradoxical, though, are possible ties between climate change and the recent spate of frigid weeks in eastern North America. A very new and “hot topic” in climate change research is the notion that rapid warming and wholesale melting of the Arctic may be playing a role in causing persistent cold spells.

    It doesn’t take a stretch of the imagination to suppose that losing half the Arctic sea-ice cover in only 30 years might be wreaking havoc with the weather, but exactly how is not yet clear. As a research atmospheric scientist, I study how warming in the Arctic is affecting temperature regions around the world. Can we say changes to the Arctic driven by global warming have had a role in the freakish winter weather North America has experienced?

    A ‘dipole’ of abnormal temperatures

    Weird and destructive weather was in the news almost constantly during 2017, and 2018 seems to be following the same script. Most U.S. Easterners shivered their way through the end of 2017 into the New Year, while Westerners longed for rain to dampen parched soils and extinguish wildfires. Blizzards have plagued the Eastern Seaboard – notably the “bomb cyclone” storm on Jan. 4, 2018 – while California’s Sierra Nevada stand nearly bare of snow….

    ….Regardless what it’s called, this dipole pattern – abnormally high temperatures over much of the West along with chilly conditions in the East – has dominated North American weather in four of the past five winters. January 2017 was a stark exception, when a strong El Niño flipped the ridge-trough pattern, dumping record-breaking rain and snowpack on California while the east enjoyed a mild month.

    Two other important features are conspicuous in the dipole temperature pattern: extremely warm temperatures in the Arctic near Alaska and warm ocean temperatures in the eastern Pacific. Several new studies point to these “ingredients” as key to the recent years with a persistent dipole.

    …Pacific Ocean temperatures fluctuate naturally owing to short-lived phenomena such as El Niño/La Niña and longer, decades-length patterns. Scientists have long recognized that those variations affect weather patterns across North America and beyond.

    The new twist in this story is that the Arctic has been warming at at least double the pace of the rest of the globe, meaning that the difference in temperature between the Arctic and areas farther south has been shrinking. This matters because the north/south temperature difference is one of the main drivers of the jet stream. The jet stream creates the high- and low-pressure systems that dictate our blue skies and storminess while also steering them. Anything that affects the jet stream will also affect our weather.

    When ocean temperatures off the West Coast of North America are warmer than normal, as they have been most of the time since winter 2013, the jet stream tends to form a ridge of high pressure along the West Coast, causing storms to be diverted away from California and leaving much of the West high and dry.

    If these warm ocean temperatures occur in combination with abnormally warm conditions near Alaska, the extra heat from the Arctic can intensify the ridge, causing it to reach farther northward, become more persistent, and pump even more heat into the region near Alaska. And in recent years, Alaska has experienced periods of record warm temperatures, owing in part to reduced sea ice…

    ….It is widely expected that global warming will produce fewer low-temperature records, a tendency already observed. But it may also be true that cold spells will become more persistent as dipole patterns intensify, a tendency that also seems to be occurring.

    It’s hard to nail down whether this weather pattern – overall warmer winters in North America but longer cold snaps – will persist. Understanding the mechanisms behind these complex interactions between natural influences and human-caused changes is challenging.

  3. Did Climate Change Intensify Harvey? Yes- amplifying worst effects

    Leave a Comment

    Robinson Meyer  read full article in The Atlantic

    Every so often, the worst-case scenario comes to pass.  As of Sunday afternoon, the remnants of Hurricane Harvey seem likely to exceed the worst forecasts that preceded the storm. The entire Houston metropolitan region is flooding: Interstates are under feet of water, local authorities have asked boat owners to join rescue efforts, and most of the streams and rivers near the city are in flood stage….“Local rainfall amounts of 50 inches would exceed any previous Texas rainfall record. The breadth and intensity of this rainfall are beyond anything experienced before,” said a statement from the National Weather Service. “Catastrophic flooding is now underway and expected to continue for several days. ”…
    This means that thousands of people—and perhaps tens of thousands of people—are facing a terrifying and all-too-real struggle to survive right now. In an age when the climate is changing rapidly, a natural question to ask is: What role did human-caused global warming play in strengthening this storm?Climate scientists, who specialize in thinking about the Earth system as a whole, are often reticent to link any one weather event to global climate change. But they say that aspects of the case of Hurricane Harvey—and the recent history of tropical cyclones worldwide—suggest global warming is making a bad situation worse.…Climate change is caused by the release of greenhouse gases like carbon dioxide and methane into the atmosphere. These gases prevent some of the sun’s rays from bouncing back into space, trapping heat in the planetary system and raising air temperatures all over the world….

    Storms like Harvey are helped by one of the consequences of climate change: As the air warms, some of that heat is absorbed by the ocean, which in turn raises the temperature of the sea’s upper layers.
    Harvey benefitted from unusually toasty waters in the Gulf of Mexico. As the storm roared toward Houston last week, sea-surface waters near Texas rose to between 2.7 and 7.2 degrees Fahrenheit above average. These waters were some of the hottest spots of ocean surface in the world. The tropical storm, feeding off this unusual warmth, was able to progress from a tropical depression to a category-four hurricane in roughly 48 hours.“This is the main fuel for the storm,” says Kevin Trenberth, a senior scientist at the U.S. National Center for Atmospheric Research. “Although these storms occur naturally, the storm is apt to be more intense, maybe a bit bigger, longer-lasting, and with much heavier rainfalls [because of that ocean heat].”……the hurricane churned up water 100 or even 200 meters below the surface, said Trenberth, but this water was still warm—meaning that the storm could keep growing and strengthening. “Harvey was not in a good position to intensify the way it did, because it was so close to land. It’s amazing it was able to do that,” he told me…

    …Trenberth says that the extra heat could make the storm more costly and more powerful, overpowering and eventually breaking local drainage systems.

    The human contribution can be up to 30 percent or so up to the total rainfall coming out of the storm,” he said. “It may have been a strong storm, and it may have caused a lot of problems anyway—but [human-caused climate change] amplifies the damage considerably.”…

    • How Harvey went from a little-noticed storm to a behemoth

    By Sandhya Somashekhar August 27 at 6:06 PM read full Washington Post article

    Even if Harvey had been a milder storm, spinning lazily across the Gulf of Mexico, there would have been reasons for alarm early last week. For starters, the jet stream — the air current that meanders across the continent, pushing storms along a familiar path — flowed far north of Texas, and thus when Harvey crashed into the state there was nothing in the atmosphere to shove it somewhere else. Harvey stalled.

    …Harvey also proved that the Gulf of Mexico — in late August, in a warming climate — can prove explosive for the development of what is generically called a tropical cyclone. In barely more than a day the storm went from a disorganized tropical depression to a significant hurricane and then all the way up to Category 4 — the second-highest rating on the Saffir-Simpson hurricane intensity scale, which is based on wind speed.

    The result: a record-setting storm that within 24 hours plunged much of the nation’s fourth-largest city and its surroundings under feet of choppy brown water. It threatens to submerge even more of the region during the next few days.

    “There are a lot of worst-case-scenario stars that aligned,” said Marshall Shepherd, a professor of atmospheric sciences at the University of Georgia and a past president of the American Meteorological Society. “As bad as it is now, we still have days of this to go.”

    ….A stunning amount of rain has fallen over Texas so far, and it is expected to continue for several more days as the storm creeps along, weakening slightly. In general, things will probably get worse before they get better; some areas might see as many as 50 inches of rainfall when all is said and done, wreaking damage that experts predict could lead to years of recovery across the region.

    As of Sunday afternoon, the storm had deposited 9 trillion gallons over Southeast Texas, as bands of rain picked up moisture from the Gulf. That’s enough water to fill up the Great Salt Lake twice over, meteorology student Matthew Cappucci wrote for The Washington Post….

    Experts say the lack of “steering currents” to move the storm along is unusual and probably responsible for the scale of the flooding. As of Sunday evening, the center of the storm was virtually parked at a spot about 25 miles northwest of the coastal town of Victoria — crawling southeast at 2 miles per hour toward the Gulf.

    With a more common tropical storm, the damage in any one place would be mitigated by the fact that the storms move quickly, spreading the rain over a larger area.

    Perhaps making things worse is something called the “brown ocean effect,” which hypothesizes that storms, which typically get their energy over the ocean or another large body of water, can absorb that energy and moisture from rain-soaked land. “The land, in effect, mimics the energy supply of the ocean,” University of Maryland Baltimore County professor Jeff Halverson wrote for the Capital Weather Gang….

    Related: What you can and can’t say about climate change and Hurricane Harvey

  4. A Galápagos seabird’s population expected to shrink with ocean warming

    Leave a Comment

     

    Posted: 25 Aug 2017 08:28 AM PDT  Read full ScienceDaily article here

    Within the next century, rising ocean temperatures around the Galápagos Islands are expected to make the water too warm for a key prey species, sardines, to tolerate. A new study uses decades of data on the diet and breeding of a tropical seabird, the Nazca booby, to understand how the future absence of sardines may affect the booby population.

  5. Texas in direct path of intensifying, ‘astounding’ Hurricane Harvey; Gulf waters warmer than normal; rainfall may equal annual total, shattering records

    Leave a Comment
    • When it comes ashore, forecasters said, it could have sustained winds of 125 miles per hour, with a 12-foot storm surge.
    • it is projected to stall on the Texas coast for several days, which could dump historic quantities of rain, with some places seeing as much as 35 inches, the hurricane center said.
    • In just a few days, the storm may dispense the amount of rain that normally falls over an entire year, shattering records.

    August 24 2017 see full Washington Post article here

    Texas is bracing for potentially catastrophic flooding and winds as Hurricane Harvey intensified Thursday and cruised toward a late Friday impact near Corpus Christi.

    The National Hurricane Center described Harvey’s sudden strengthening as “astounding.” The storm is expected to strike as a Category 3 hurricane — meaning with winds greater than 111 miles per hour — making it the most powerful storm to make landfall in the United States since Hurricane Wilma in 2005.

    …Harvey would be the first hurricane to hit Texas since Ike, a high Category 2 storm, came ashore in September 2008 in Galveston and caused tens of billions of dollars in property damage.

    Hurricane Harvey is seen in the Texas Gulf Coast on August 24, 2017. (NOAA/Reuters)

    …The Gulf of Mexico is vitally important for the nation’s oil infrastructure. Offshore platforms produce about 1.7 million barrels a day, nearly a fifth of U.S. crude oil production. More than 45 percent of U.S. petroleum refining capacity lies along the Gulf Coast as well as 51 percent of total U.S. natural gas processing plant capacity, according to Energy Department data

    —-

    Harvey forecast to slam Texas coast as major hurricane with ‘devastating’ flooding

    By Brian McNoldy and Jason Samenow August 25 at 10:10 AM Washington Post

    …Not only are the rain and flooding concerns huge, but the storm also has the potential to generate destructive winds and a devastating storm surge — or raise the water as much as 6 to 12 feet above normally dry land at the coast.

    …An incredible amount of rain, 15 to 25 inches with isolated amounts of up to 35 inches, is predicted along the middle and upper Texas coast, because the storm is expected to stall and unload torrents for four to six straight days. The National Hurricane Center said it expects “devastating and life-threatening” flash flooding. In just a few days, the storm may dispense the amount of rain that normally falls over an entire year, shattering records.

    …The National Weather Service office in Corpus Christi, near where the storm is expected to make landfall, said that due to the combination of flooding from storm surge and rainfall, “locations may be uninhabitable for an extended period.” It warned of “structural damage to buildings, with many washing away” and that “streets and parking lots become rivers of raging water with underpasses submerged.”…

    —-

    Here’s Why Hurricane Harvey Is So Scary and Unprecedented

    Emily Atkin New Republic

    ….According to Texas State Climatologist John Nielsen-Gammon, hurricanes usually come with only one of two awful characteristics—either heavy, persistent rainfall or strong, violent winds and storm surge. It looks like Hurricane Harvey could have both, because unique wind patterns may prevent the storm from moving quickly out of the region….

    ….“Climate change is definitely impacting the maximum intensity of rainfall,” Nielsen-Gammon told me, explaining how the warmer atmosphere is able to hold more moisture and therefore release more rainfall during storms….

    A Texas-size flood threatens the Gulf Coast, and we’re so not ready

  6. Warmer waters from climate change will leave fish shrinking, gasping for air

    Leave a Comment
    • Fish are expected to shrink in size by 20 to 30 per cent if ocean temperatures continue to climb due to climate change

    August 21, 2017 University of British Columbia read full ScienceDaily article here

    …A new study by researchers at the University of British Columbia provides a deeper explanation of why fish are expected to decline in size. “Fish, as cold-blooded animals, cannot regulate their own body temperatures. When their waters get warmer, their metabolism accelerates and they need more oxygen to sustain their body functions….There is a point where the gills cannot supply enough oxygen for a larger body, so the fish just stops growing larger.”…

    ….as fish like cod increases its weight by 100 per cent, its gills only grow by 80 per cent or less. When understood in the context of climate change, this biological rule reinforces the prediction that fish will shrink and will be even smaller than thought in previous studies.

    Warmer waters increase fish’s need for oxygen but climate change will result in less oxygen in the oceans. This means that gills have less oxygen to supply to a body that already grows faster than them. The researchers say this forces fish to stop growing at a smaller size to be able to fulfill their needs with the little oxygen available to them.

    Some species may be more affected by this combination of factors. Tuna, which are fast moving and require more energy and oxygen, may shrink even more when temperatures increase. Smaller fish will have an impact on fisheries production as well as the interaction between organisms in the ecosystems.

    Daniel Pauly, William W. L. Cheung. Sound physiological knowledge and principles in modeling shrinking of fishes under climate change. Global Change Biology, 2017; DOI: 10.1111/gcb.13831

  7. Macroscale patterns in body size of intertidal crustaceans provide insights on climate change effects.

    Leave a Comment

    Abstract: Predicting responses of coastal ecosystems to altered sea surface temperatures (SST) associated with global climate change, requires knowledge of demographic responses of individual species. Body size is an excellent metric because it scales strongly with growth and fecundity for many ectotherms. These attributes can underpin demographic as well as community and ecosystem level processes, providing valuable insights for responses of vulnerable coastal ecosystems to changing climate.

    We investigated contemporary macroscale patterns in body size among widely distributed crustaceans that comprise the majority of intertidal abundance and biomass of sandy beach ecosystems of the eastern Pacific coasts of Chile and California, USA…..

    Significant latitudinal patterns in body sizes were observed for all species in Chile (21° – 42°S), with similar but steeper patterns in Emerita analoga, in California (32°- 41°N). Sea surface temperature was a strong predictor of body size (-4% to -35% °C-1) in all species. Beach characteristics were subsidiary predictors of body size. Alterations in ocean temperatures of even a few degrees associated with global climate change are likely to affect body sizes of important intertidal ectotherms, with consequences for population demography, life history, community structure, trophic interactions, food-webs, and indirect effects such as ecosystem function. The consistency of results for body size and temperature across species with different life histories, feeding modes, ecological roles, and microhabitats inhabiting a single widespread coastal ecosystem, and for one species, across hemispheres in this space-for-time substitution, suggests predictions of ecosystem responses to thermal effects of climate change may potentially be generalised, with important implications for coastal conservation.

    Eduardo Jaramillo, Jenifer E. Dugan, David M. Hubbard, Heraldo Contreras, Cristian Duarte, Emilio Acuña, David S. Schoeman. Macroscale patterns in body size of intertidal crustaceans provide insights on climate change effects.  PLOS One.  May 8 2017. https://doi.org/10.1371/journal.pone.0177116

  8. Rising water temperatures endanger health of coastal ecosystems, study finds

    Leave a Comment

    April 20, 2017 University of Georgia Full ScienceDaily Article Here

    Increasing water temperatures are responsible for the accumulation of a chemical called nitrite in marine environments throughout the world, a symptom of broader changes in normal ocean biochemical pathways that could ultimately disrupt ocean food webs.

    Nitrite is produced when microorganisms consume ammonium in waste products from fertilizers, treated sewage and animal waste. Too much nitrite can alter the kinds and amounts of single-celled plants living in marine environments, potentially affecting the animals that feed on them, said James Hollibaugh, co-author of the study published recently in Environmental Science and Technology. It also could lead to toxic algal blooms and create dead zones where no fish or animals can live.

    “Typically, two groups of microorganisms work in really close concert with one another to convert ammonium to nitrate so that you don’t see nitrite really accumulate at all, but we found that the activity of those two groups was decoupled as a result of the increased water temperatures.

    …Nitrite accumulation can also result in more production of nitrous oxide, a powerful greenhouse gas that has more of an effect on climate change per molecule than carbon dioxide, Hollibaugh said. That nitrous oxide production then increases global temperatures more, causing more nitrite accumulation and creating a positive feedback loop.

    Sylvia C. Schaefer, James T. Hollibaugh. Temperature Decouples Ammonium and Nitrite Oxidation in Coastal Waters. Environmental Science & Technology, 2017; 51 (6): 3157 DOI: 10.1021/acs.est.6b03483

  9. Large Sections of Australia’s Great Reef Are Dead Due to Ocean Warming, Scientists Find

    Leave a Comment
    Washington Post March 19 2017  See full article here

    THE MEASURED warming of the planet is not hypothetical. Nor are its effects, which are happening now, not decades from now. An ecological catastrophe is unfolding off Australia’s coast: Humans are killing the Great Barrier Reef, one of the world’s greatest natural wonders, and there’s nothing Australians on their own can do about it. We are all responsible.

    An ocean water temperature spike last year caused a massive “bleaching” event, in which colorful corals turned an antiseptic, sickly white. Scientists believe that the reef will never be the same.

    The chances of the northern Great Barrier Reef returning to its pre-bleaching assemblage structure are slim given the scale of damage that occurred in 2016 and the likelihood of a fourth bleaching event occurring within the next decade or two as global temperatures continue to rise,” a major new study in the journal Nature reported last week….

    ….Alarmingly, but perhaps not surprisingly, the Australian government reports that sections of the reef are getting slammed again this year….

    There is little doubt that temperature is the culprit. Reefs far away from human runoff and other local risks are suffering. Corals in pristine water bleached just like those in dirty water. The Nature study quantified a relationship between exposure to warm water and the severity of observed bleaching.

    “Immediate global action to curb future warming is essential to secure a future for coral reefs,” the study warned. “Water quality and fishing pressure had minimal effect on the unprecedented bleaching in 2016, suggesting that local protection of reefs affords little or no resistance to extreme heat. Similarly, past exposure to bleaching in 1998 and 2002 did not lessen the severity of bleaching in 2016.”…

  10. Oceans warming 13% faster than thought, warming doubled in last 2 decades

    Leave a Comment

    New study improves estimates of the rate of ocean warming – a critical component of climate change

    • rate of CO2 into atmosphere 40% higher since 1980
    • ocean is warming about 13% faster than we previously thought.
    • ocean warming has accelerated– from 1992 its is almost 2x warming rate from 1960.
    • it is only since about 1990 that the warming has penetrated to depths below about 700 meters.

    New research has convincingly quantified how much the Earth has warmed over the past 56 years. Human activities utilize fossil fuels for many beneficial purposes but have an undesirable side effect of adding carbon dioxide to the atmosphere at ever-increasing rates. That increase – of over 40%, with most since 1980 – traps heat in the Earth’s system, warming the entire planet….

    …Since about 2005 a new type of sensing device has been deployed (the Argo float system). These floats (approximately 3500 in total at any time) are spread out across oceans where they autonomously rise and fall in the ocean waters, collecting temperature data to depths of 2000 meters.  When they rise to the ocean surface, they send their data wirelessly to satellites for later analysis. Hence we can now map the ocean heat content quite well…

    …a paper just published today in Science Advances uses a new strategy to improve upon our understanding of ocean heating to estimate the total global warming from 1960 to 2015….shows we are warming about 13% faster than we previously thought. Not only that but the warming has accelerated. The warming rate from 1992 is almost twice as great as the warming rate from 1960. Moreover, it is only since about 1990 that the warming has penetrated to depths below about 700 meters….