Scientists: Major Oxygen Loss to Oceans Linked to Warming Climate

— Posted with permission of SEAFOODNEWS.COM. Please do not republish without their permission. —

Copyright © 2017 Seafoodnews.com

SEAFOODNEWS.COM [Washington Post] by By Chris Mooney – February 16, 2017

A large research synthesis, published in one of the world’s most influential scientific journals, has detected a decline in the amount of dissolved oxygen in oceans around the world — a long-predicted result of climate change that could have severe consequences for marine organisms if it continues.

The paper, published Wednesday in the journal Nature by oceanographer Sunke Schmidtko and two colleagues from the GEOMAR Helmholtz Centre for Ocean Research in Kiel, Germany, found a decline of more than 2 percent in ocean oxygen content worldwide between 1960 and 2010. The loss, however, showed up in some ocean basins more than others. The largest overall volume of oxygen was lost in the largest ocean — the Pacific — but as a percentage, the decline was sharpest in the Arctic Ocean, a region facing Earth’s most stark climate change.

The loss of ocean oxygen “has been assumed from models, and there have been lots of regional analysis that have shown local decline, but it has never been shown on the global scale, and never for the deep ocean,” said Schmidtko, who conducted the research with Lothar Stramma and Martin Visbeck, also of GEOMAR.

Ocean oxygen is vital to marine organisms, but also very delicate — unlike in the atmosphere, where gases mix together thoroughly, in the ocean that is far harder to accomplish, Schmidtko explained. Moreover, he added, just 1 percent of all the Earth’s available oxygen mixes into the ocean; the vast majority remains in the air.

Climate change models predict the oceans will lose oxygen because of several factors. Most obvious is simply that warmer water holds less dissolved gases, including oxygen. “It’s the same reason we keep our sparkling drinks pretty cold,” Schmidtko said.

But another factor is the growing stratification of ocean waters. Oxygen enters the ocean at its surface, from the atmosphere and from the photosynthetic activity of marine microorganisms. But as that upper layer warms up, the oxygen-rich waters are less likely to mix down into cooler layers of the ocean because the warm waters are less dense and do not sink as readily.

“When the upper ocean warms, less water gets down deep, and so therefore, the oxygen supply to the deep ocean is shut down or significantly reduced,” Schmidtko said.

The new study represents a synthesis of literally “millions” of separate ocean measurements over time, according to GEOMAR. The authors then used interpolation techniques for areas of the ocean where they lacked measurements.

The resulting study attributes less than 15 percent of the total oxygen loss to sheer warmer temperatures, which create less solubility. The rest was attributed to other factors, such as a lack of mixing.

Matthew Long, an oceanographer from the National Center for Atmospheric Research who has published on ocean oxygen loss, said he considers the new results “robust” and a “major advance in synthesizing observations to examine oxygen trends on a global scale.”

Long was not involved in the current work, but his research had previously demonstrated that ocean oxygen loss was expected to occur and that it should soon be possible to demonstrate that in the real world through measurements, despite the complexities involved in studying the global ocean and deducing trends about it.

That’s just what the new study has done.

“Natural variations have obscured our ability to definitively detect this signal in observations,” Long said in an email. “In this study, however, Schmidtko et al. synthesize all available observations to show a global-scale decline in oxygen that conforms to the patterns we expect from human-driven climate warming. They do not make a definitive attribution statement, but the data are consistent with and strongly suggestive of human-driven warming as a root cause of the oxygen decline.

“It is alarming to see this signal begin to emerge clearly in the observational data,” he added.

“Schmidtko and colleagues’ findings should ring yet more alarm bells about the consequences of global warming,” added Denis Gilbert, a researcher with the Maurice Lamontagne Institute at Fisheries and Oceans Canada in Quebec, in an accompanying commentary on the study also published in Nature.

Because oxygen in the global ocean is not evenly distributed, the 2 percent overall decline means there is a much larger decline in some areas of the ocean than others.

Moreover, the ocean already contains so-called oxygen minimum zones, generally found in the middle depths. The great fear is that their expansion upward, into habitats where fish and other organism thrive, will reduce the available habitat for marine organisms.

In shallower waters, meanwhile, the development of ocean “hypoxic” areas, or so-called “dead zones,” may also be influenced in part by declining oxygen content overall.

On top of all of that, declining ocean oxygen can also worsen global warming in a feedback loop. In or near low oxygen areas of the oceans, microorganisms tend to produce nitrous oxide, a greenhouse gas, Gilbert writes. Thus the new study “implies that production rates and efflux to the atmosphere of nitrous oxide … will probably have increased.”

The new study underscores once again that some of the most profound consequences of climate change are occurring in the oceans, rather than on land. In recent years, incursions of warm ocean water have caused large die-offs of coral reefs, and in some cases, kelp forests as well. Meanwhile, warmer oceans have also begun to destabilize glaciers in Greenland and Antarctica, and as they melt, these glaciers freshen the ocean waters and potentially change the nature of their circulation.

When it comes to ocean deoxygenation, as climate change continues, this trend should also increase — studies suggest a loss of up to 7 percent of the ocean’s oxygen by 2100. At the end of the current paper, the researchers are blunt about the consequences of a continuing loss of oceanic oxygen.

“Far-reaching implications for marine ecosystems and fisheries can be expected,” they write.

Copyright © 2016 Seafoodnews.com

NOAA: ‘Arctic Is Warming at Least Twice as Fast as the Rest of the Planet’

The Arctic broke multiple climate records and saw its highest temperatures ever recorded this year, according to the National Oceanic and Atmospheric Administration’s (NOAA) annual Arctic Report Card released Tuesday.

Map: Temperatures across the Arctic from October 2015-September 2016 compared to the 1981-2010 average. Graph: Yearly temperatures since 1900 compared to the 1981-2010 average for the Arctic (orange line) and the globe (gray).NOAA

The report shows surface air temperature in September at the highest level since 1900 “by far” and the region set new monthly record highs in January, February, October and November. “The Arctic as a whole is warming at least twice as fast as the rest of the planet,” report author and NOAA climate scientist Jeremy Mathis told NPR.

Watch the video from NOAA on the annual Arctic Report Card below:

Report Card Highlights

• The average surface air temperature for the year ending September 2016 is by far the highest since 1900 and new monthly record highs were recorded for January, February, October and November 2016.

• After only modest changes from 2013-2015, minimum sea ice extent at the end of summer 2016 tied with 2007 for the second lowest in the satellite record, which started in 1979.

• Spring snow cover extent in the North American Arctic was the lowest in the satellite record, which started in 1967.

• In 37 years of Greenland ice sheet observations, only one year had earlier onset of spring melting than 2016.

• The Arctic Ocean is especially prone to ocean acidification, due to water temperatures that are colder than those further south. The short Arctic food chain leaves Arctic marine ecosystems vulnerable to ocean acidification events.

• Thawing permafrost releases carbon into the atmosphere, whereas greening tundra absorbs atmospheric carbon. Overall, tundra is presently releasing net carbon into the atmosphere.

• Small Arctic mammals, such as shrews, and their parasites, serve as indicators for present and historical environmental variability. Newly acquired parasites indicate northward sifts of sub-Arctic species and increases in Arctic biodiversity.

Read the original post: http://www.ecowatch.com/

Forget El Niño, the ‘PDO’ could be the real drought buster

An image showing the positive / warm phase of a PDO and the negative / cold phase. The terms warm and cold refer to the temperature of water off the west coast of America. JPL/NASA

A new forecast out Thursday on the El Niño climate pattern shows it could be one of the strongest on record. And that could deliver much needed rain to Southern California and possibly northern parts of the state, too. But El Niños are usually fleeting, lasting only a year or two.

Now, evidence is building that a longer-term climate pattern — one that might bring years of rainy winters — could be forming in the Pacific well north of the equatorial waters that give rise to El Niño.

The PDO game change

For the past several months, researchers have been tracking warmer temperatures in this northerly patch of ocean. And they’re beginning to question whether we’re about to see a switch in something called the Pacific Decadal Oscillation or PDO.

Given the data, the PDO could be shifting from a cool phase to a warm one — a shift that could mean a wetter decade ahead for much of California. Still, the phenomenon could also turn out be a short-lived blip, not a years-long flip.

Unlike El Niño, which focuses on sea surface temperatures in a stretch of the Pacific near the equator, the PDO looks at water in the northern part of the ocean, from Hawaii all the way to Alaska.

According to research scientist Nathan Mantua with the National Oceanic and Atmospheric Administration, the PDO has a warm phase and a cool phase, and each one can last anywhere from a few years to decades.

During the warm phase, waters along the coast of the western U.S. tend to heat up while the larger ocean about 200 miles off the coast cools down. During the cool phase these trends are reversed.

“When you have the warm pattern of the PDO, it tends to be wet in the southwest U.S. and northern Mexico,” he explained.

During those same years you are more likely to see drought in the Northern Rockies, Idaho, Eastern Washington, Western Montana and Southern British Columbia.

Likewise, the cool phase is linked to wetter periods up north but dry conditions in Southern California and neighboring states.

Mantua says the PDO has been mostly in a cool phase since 1998, coinciding with some of California’s driest years on record.

Climate scientist Bill Patzert with the Jet Propulsion Laboratory thinks it’s this PDO pattern that is responsible in large part for the severe drought in the region.

Long-term drought buster on the horizon?

However, since January of 2014, the PDO has been shifting into a warm mode.

Patzert thinks this could be the drought-buster the state has been hoping for.

“Perhaps in the long term, rooting for a [warm] PDO… is probably the most important thing for California and the American West,” he said.

Thursday and Friday at JPL’s von Kármán Auditorium, Patzert will give a free public lecture on the PDO, El Niño and drought.

He said even a strong El Niño isn’t likely to supply all the water needed to get California out of a drought this bad.

In fact, a recent NASA study found the state would need double the average rainfall in a single year to break the drought.

“In the long run these decadal or multi-decade variations in the Pacific are really the key to sustaining California agriculture and California civilization,” Patzert said.

That may be true for Southern California, but it is less clear how a warm PDO will affect Northern California, said NOAA’s Nathan Mantua.

That’s because the northern part of the state is between the two regions that switch from wet and dry as the PDO shifts.

“Northern California sort of sits between the ends of this sort of north-south see-saw,” he said.

Still, he’s optimistic that a warm PDO is coming, since the major index predicting this pattern has been positive for 19 months.

But Mantua cautions that even such a strong signal can result in a warm PDO that only lasts a year or so.

“Beyond that, it’s going depend on what the winds do and the weather patterns,” he said.

Sometimes those can change rapidly and dramatically, bringing drought conditions anew to California.

Another wild card, according to JPL’s Patzert, is how climate change will affect the PDO and related weather patterns.

“As we move into the 21st Century, climate is shifting beneath our feet… nobody really understands what the impact will be,” he said.

For now, climate watchers will keep their eyes on the ocean for signals of the weather to come.

Read/Listen to the original post: www.scpr.org

Above-normal rainfall now predicted

The National Oceanic and Atmospheric Administration is predicting our area to experience above-average rainfall this season. (Photo: Provided/NOAA)

By the end of this week, be sure to start battening down the hatches.

Weather officials on Monday updated a rain outlook for the month of December, saying now that there will be above-normal rainfall moving toward the New Year that will have a significant effect on the drought outlook.

Logan Johnson, warning coordination meteorologist at the National Weather Service in Monterey, said above-normal precipitation is expected across the entire state during December, and that for central and southern California, the wet stuff is likely to keep coming throughout the rainy season, which runs through February.

“This very welcome news and should improve drought conditions statewide,” Johnson said.

In fact, according to Rich Tinker of the Climate Prediction Center at the National Oceanic and Atmospheric Administration, the above-normal rainfall this season is knocking the Central Coast down a notch on the U.S. Seasonal Drought Outlook.

Up until Friday, the majority of California was listed as an area where “drought persists or intensifies.” Now, because of soppy month ahead, the Central Coast and most of the rest of the state is listed as “drought remains but improves.” Temperatures, however, are expected to remain warmer than normal, which will further support this year as one of the warmest on record.

Forecasters say the above-normal precipitation headed this way during the rainy season should not be thought of as any kind of drought-buster. The region has experienced too many years of drought for it to end in one above-average year; it would take several above-average years to get the area back to normal.

The early part of this week is forecast for sunny autumn weather, but a high-pressure ridge is expected to break down on Friday, allowing a rain front to move into Northern California that will work its way south by Saturday.

“There remains uncertainty with regards to exact timing and amount of rainfall expected with this frontal passage,” according to a statement issued early Monday afternoon by the NWS.

A rain-friendly, upper-level, low-pressure system will move into the Bay Area Sunday and Monday bringing with it widespread rain, the NWS predicts, but ends with a cautionary note that the amount of rain cannot be accurately predicted since the forecast is projected out five to eight days.

“However, there is increasing confidence that the [San Francisco/Monterey] region will enter into a wet period that will last into early next week,” the NWS said Monday.

Read original story here.

U.S. Climate Has Already Changed, Study Finds, Citing Heat and Floods

The effects of human-induced climate change are being felt in every corner of the United States, scientists reported Tuesday, with water growing scarcer in dry regions, torrential rains increasing in wet regions, heat waves becoming more common and more severe, wildfires growing worse, and forests dying under assault from heat-loving insects.

By Justin Gillis | May 6, 2014 | NYTimes.com

View the entire article here.

El Niño/Southern Oscillation (ENSO) Diagnostic Discussion

issued by
CLIMATE PREDICTION CENTER/NCEP
and the International Research Institute for Climate and Society
10 April 2014

ENSO Alert System Status: El NiñoWatch

Synopsis: While ENSO-neutral is favored for Northern Hemisphere spring, the chances of El Niño increase during the remainder of the year, exceeding 50% by summer.

ENSO-neutral continued during March 2014, but with above-average sea surface temperatures (SST) developing over much of the eastern tropical Pacific as well as near the International Date Line (Fig. 1).

The weekly SSTs were below average in the Niño1+2 region, near average but rising in Niño3 and Niño3.4 regions, and above average in the Niño4 region (Fig. 2).

A significant downwelling oceanic Kelvin wave that was initiated in January greatly increased the oceanic heat content to the largest March value in the historical record back to 1979 (Fig. 3) and produced large positive subsurface temperature anomalies across the central and eastern Pacific (Fig. 4).

Also during March, low-level westerly wind anomalies were observed over the central equatorial Pacific. Convection was suppressed over western Indonesia, and enhanced over the central equatorial Pacific (Fig. 5). Although these atmospheric and oceanic conditions collectively reflect ENSO-neutral, they also reflect a clear evolution toward an El Niño state.

The model predictions of ENSO for this summer and beyond are indicating an increased likelihood of El Niño this year compared with last month. Most of the models indicate that ENSO-neutral (Niño-3.4 index between -0.5oC and 0.5oC) will persist through much of the remainder of the Northern Hemisphere spring 2014 (Fig. 6), with many models predicting the development of El Niño sometime during the summer or fall.

Despite this greater model consensus, there remains considerable uncertainty as to when El Niño will develop and how strong it may become. This uncertainty is amplified by the inherently lower forecast skill of the models for forecasts made in the spring. While ENSO-neutral is favored for Northern Hemisphere spring, the chances of El Niño increase during the remainder of the year, and exceed 50% by the summer (click CPC/IRI consensus forecast for the chance of each outcome).

This discussion is a consolidated effort of the National Oceanic and Atmospheric Administration (NOAA), NOAA’s National Weather Service, and their funded institutions. Oceanic and atmospheric conditions are updated weekly on the Climate Prediction Center web site (El Niño/La Niña Current Conditions and Expert Discussions). Forecasts for the evolution of El Niño/La Niña are updated monthly in the Forecast Forum section of CPC’s Climate Diagnostics Bulletin. The next ENSO Diagnostics Discussion is scheduled for 8 May 2014. To receive an e-mail notification when the monthly ENSO Diagnostic Discussions are released, please send an e-mail message to: ncep.list.enso-update@noaa.gov.

Climate Prediction Center
National Centers for Environmental Prediction
NOAA/National Weather Service
College Park, MD 20740

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.html

A super El Niño on the way? Subtle signs emerging

Mashable’s Andrew Freedman has penned an intriguing and important piece suggesting the possible El Niño in the pipeline may be a doozy, comparable to the strongest ever recorded:

Since climate forecasters declared an “El Niño Watch” on March 6, the odds of such an event in the tropical Pacific Ocean have increased, and based on recent developments, some scientists think this event may even rival the record El Niño event of 1997-1998.

Recall an El Niño event is an episodic warming of the eastern tropical Pacific ocean, which often has worldwide weather implications.

Freedman interviews two scientists, Eric Blake from the National Hurricane Center and Paul Roundy from SUNY-Albany, who see early indicators reminiscent of the development stages of past whopper El Niño events.

One important possible indicator of the lead up to an El Niño is a reversal in the trade winds observed in the equatorial Pacific, from a prevailing easterly (from the east) to westerly (from the west) direction.  In recent weeks and months, there have been strong westerly “bursts”.

Read the full article here.

Assessing the Vulnerability of Fish Stocks in a Changing Climate

What is the Fish Stock Climate Vulnerability Assessment?
NOAA Fisheries, in collaboration with the NOAA Office of Oceanic and Atmospheric Research – “Earth System Research Laboratory, is finalizing a methodology to rapidly assess the vulnerability of U.S. marine stocks to climate change. The methodology uses existing information on climate and ocean conditions, species distributions, and species life history characteristics to estimate the relative vulnerability of fish stocks to potential changes in climate.

Climate change is already impacting fishery resources and the communities that depend on them.  Scientists are linking changes in ocean temperatures to shifting fish stock distributions and abundances in many marine ecosystems, and these impacts are expected to increase in the future.

To prepare for and respond to current and future changes in climate and oceans, fisheries managers and scientists need tools to identify what fishery resources may be most vulnerable in a changing climate and why certain fish stocks are vulnerable.  By providing this information, the methodology will be able to help fisheries managers and scientists identify ways to reduce risks and impacts to fisheries resources and the people that depend on them.  These kinds of climate change vulnerability assessments are increasingly being used to help assess risks to terrestrial and freshwater natural resources and man-made structures such as buildings and bridges.

Read the full article here.

El Niño may make 2014 the hottest year on record

Hold onto your ice lollies. Long-term weather forecasts are suggesting 2014 might be the hottest year since records began. That’s because climate bad-boy El Niño seems to be getting ready to spew heat into the atmosphere.

An El Niño occurs when warm water buried below the surface of the Pacific rises up and spreads along the equator towards America. For nine months or more it brings rain and flooding to areas around Peru and Ecuador, and drought and fires to Indonesia and Australia. It is part of a cycle called the El Niño-Southern Oscillation.

It is notoriously hard to make a prediction before the “spring barrier” as to whether there will be an El Niño in a given year. “The El Niño-Southern Oscillation cycle more or less reboots around April-May-June each calendar year,” says Scott Power from the Bureau of Meteorology in Melbourne, Australia.

The problem is that there is so much background variability in the atmosphere and ocean that it is hard to see any signal amidst the noise, says Wenju Cai from the CSIRO, Australia’s national research agency in Melbourne. “Even if there is a developing El Niño, it is hard to predict.”

Read the full article here.

Major climate changes looming

Washington — In his inaugural address last Monday, President Obama made climate change a priority of his second term. It might be too late.

Within the lifetimes of today’s children, scientists say, the climate could reach a state unknown in civilization.

In that time, global carbon dioxide emissions from burning fossil fuels are on track to exceed the limits that scientists believe could prevent catastrophic warming. CO{-2} levels are higher than they have been in 15 million years.

The Arctic, melting rapidly and probably irreversibly, has reached a state that the Vikings would not recognize.

“We are poised right at the edge of some very major changes on Earth,” said Anthony Barnosky, a UC Berkeley professor of biology who studies the interaction of climate change with population growth and land use. “We really are a geological force that’s changing the planet.”

 
Read more here