Ocean temperatures and their connections to weather trends have been making news. Five 91探花 experts offer their perspectives on the current El Ni帽o 鈥� a climate pattern in the tropical Pacific Ocean that affects weather worldwide. 91探花researchers comment on the current El Ni帽o, its effect on weather in the Pacific Northwest, as well as on regional and global ocean temperature trends.

, a 91探花research scientist at the , comments on the developing El Ni帽o:

“This El Ni帽o has evolved in a really interesting way. Since spring, the dynamical models have very confidently predicted an El Ni帽o event. But while the key region of the tropical Pacific has warmed quickly, the typical atmospheric response has lagged. The atmosphere in the tropical Pacific is only now becoming more typical of an El Ni帽o event, although it is still not fully matching the ocean surface. That鈥檚 unusual, because the tropical ocean and atmosphere tend to evolve together.

“It will be interesting to see how this El Ni帽o continues to evolve over the next few months, which will help determine the extent of impacts on our upcoming winter weather. Remote impacts in places like Seattle tend to be stronger for stronger El Ni帽o events. While sea surface temperature has typically been the main measure, the impacts might very well depend more on the atmospheric response. So the evolution of the system over the next few months will be key to the eventual local impacts in places like Seattle.”

Dennis Hartmann, professor of atmospheric sciences at the UW, on El Ni帽o and its effects:

“The impact of El Ni帽o on the Pacific Northwest varies a lot from one event to the other, depending on the spatial structure and size of the sea surface temperature changes in the tropics, and on the state of the atmosphere between the tropics and the Pacific Northwest. For that reason, the predictions of Pacific Northwest impacts based upon El Ni帽o events that happened in the past are quite uncertain.

“In addition, the climate has warmed significantly in both the tropics and outside the tropics since some of the prior big El Ni帽o events, in the 1970s and 1980s. That may add an additional complication to making an accurate forecast of how this winter will be different because of the current El Ni帽o event.”

Nick Bond, a research scientist at CICOES and Washington鈥檚 state climatologist, on El Ni帽o and its effects on Washington鈥檚 weather:

“El Ni帽o conditions are present now in the tropical Pacific Ocean, and they are very likely to persist through the coming winter. The effects on Washington鈥檚 weather are expected to feature relatively warm, and perhaps drier, weather than usual after Jan. 1, and ultimately a lower-than-normal snowpack in our mountains at the end of winter. El Ni帽o’s impacts on the weather in Washington state tend to be more consistent in the middle to latter part of the winter.

“But this is not written in stone 鈥� there has been variability among past El Ni帽os in terms of effects on Washington鈥檚 winter weather.”

Jan Newton, senior principal oceanographer at the 91探花Applied Physics Laboratory and director of the UW-based , on what oceanographers are seeing in regional waters:

“Conditions off Washington鈥檚 outer coast have varied and are mainly influenced by changes in coastal upwelling and downwelling in the Pacific Ocean. Temperatures off the outer coast are now 4 degrees Fahrenheit (about 2 degrees Celsius) above normal, though variable.

“In Puget Sound, we鈥檙e starting to see surface water temperatures shift from cooler than normal, or normal, to consistently warmer than normal, but only by less than one degree Fahrenheit (half a degree Celsius). Given the large-scale warmth in the satellite-measured sea surface temperatures offshore, I do expect that we will continue to see warmer-than-normal sea temperatures in Puget Sound.听 However, it鈥檚 hard to predict if these differences from the average will stay small or will increase. What happens next will depend on ocean conditions and local weather.”

LuAnne Thompson, 91探花professor of oceanography, on the :

“The recent acceleration of ocean warming in the Atlantic is unprecedented in the historical record, and has created an Atlantic-wide marine heat wave. The ability of the ocean to absorb and store vast amounts of heat makes these types of events last longer. I study marine heat waves with a focus on their evolution in time and space. However, with more long-lasting, basin-wide events, such as the one we are seeing now in the Atlantic Ocean, we will need to reevaluate our approach.

“At a particular location, a marine heat wave occurs when the sea surface temperature is above a threshold, defined by what is typical for that time of year, and lasts for at least five days. However, with the global warming projected over coming decades, these dangerous hot water events will no longer be localized and of finite duration 鈥� they will no longer fit the traditional definition of marine heat waves. Instead, these marine heat wave events will become more persistent and widespread, and eventually will cover entire ocean basins.”

For more information, contact Levine at aflevine@uw.edu, Hartmann at dhartm@uw.edu, Bond at nab3met@uw.edu, Newton at janewton@uw.edu and Thompson at luanne@uw.edu.

Armbrust has been named a in recognition of her outstanding contributions to ocean sciences and for embodying AGU鈥檚 values by fostering equity, integrity, diversity and open science; by mentoring; through public engagement; and in her communications. Fewer than 1% of AGU members are selected to receive this honor each year.

As a biological oceanographer, Armbrust combines lab- and field-based techniques to study diatoms, a type of plankton. She works from the level of the cell all the way up to the community scale to understand how these organisms both shape and are shaped by their environmental conditions.

Hartmann has been selected to receive the , which is given annually to one honoree in recognition of outstanding contributions in atmospheric sciences. The medal is named in honor of Roger Revelle, an oceanographer who made substantial contributions to the awareness of global climate change.

Hartmann is an atmospheric scientist who studies the atmosphere鈥檚 role in climate variability and change, and how the atmosphere interacts with the ocean in a changing climate. His principal areas of expertise are atmospheric dynamics, remote sensing, and mathematical and statistical techniques for data analysis.

Dennis Hartmann, professor of Atmospheric Sciences, has agreed to serve as interim dean in the from July 1 until Maya Tolstoy begins as the Maggie Walker Dean on Jan. 1, 2022.

听previously served as interim dean of the College when it formed in 2009 until July 1, 2010, when the outgoing dean, Lisa Graumlich, began her term. As an atmospheric scientist who studies the atmosphere鈥檚 role in climate variability and change, and how the atmosphere interacts with the ocean in a changing climate, Hartmann鈥檚 principal areas of expertise are atmospheric dynamics, remote sensing, and mathematical and statistical techniques for data analysis. He has been an Aldo Leopold Leadership Fellow and has received numerous awards throughout his career, including the NASA Distinguished Public Service Medal and the Carl-Gustaf Rossby Research Medal from the American Meteorological Society. Hartmann is an elected member of the U.S. National Academy of Sciences.

At the , Lauren Pressley and Denise Pan have agreed to share the duties of dean until Sept. 1, when Simon Neame begins his term. Pressley will hold the formal title of interim dean, while she and Pan will share the business title of co-interim deans.

As associate dean for research and learning services, is responsible for strategic visioning, policy and program development, management, and overall excellence in Access Services, Information Technology Services and Digital Strategies, Learning Services, Research Services, and Scholarly Communication and Publishing. Prior this, she was an associate dean of the 91探花Libraries and director of the 91探花Tacoma campus library. Pressley also was the director of听Learning Environments for Virginia Tech University Libraries and held several roles related to instruction and technology at Wake Forest University鈥檚 library.

is the associate dean of University Libraries for Collections and Content, leading the areas of Acquisitions and Rapid Cataloging Services, Cataloging and Metadata Services, Collection Analysis and Strategy and Preservation Services. Previously, she was the associate director of technical services for the Auraria Library, administered by the University of Colorado Denver, which also serves the Metropolitan State University of Denver and the Community College of Denver. Prior to that, Pan was the public services librarian at the Johnson & Wales University, Denver Campus.

A dozen scientists and engineers from the 91探花 have been elected to the . According to a statement released by the organization, the new members were selected for “their outstanding record of scientific achievement and willingness to work on behalf of the academy in bringing the best available science to bear on issues within the state of Washington.”

Three of the new members from 91探花were chosen because they had been elected recently to one of the National Academies 鈥� the National Academy of Sciences, the National Academy of Engineering and the National Academy of Medicine. The other nine were elected by current members.

In all, 91探花faculty make up half of the 24 new members, who will be formally inducted in September during an annual meeting at the Museum of Flight in Seattle.

Elected through recent admission to a National Academy:

: professor of computer science and engineering, to the National Academy of Engineering

: professor of atmospheric sciences, to the National Academy of Sciences

: professor of pediatrics, director of the Center for Clinical and Translational Research and associate director of the Pediatric Clinical Research Center at Seattle Children鈥檚, to the National Academy of Medicine

Elected by current members of the Washington State Academy of Sciences:听听

: professor and chair of chemical engineering, adjunct professor of bioengineering

: professor of sociology

: associate professor of physiology and biophysics

: professor of oceanography

: professor of nursing, adjunct professor of medicine

: professor of environmental and forest sciences

: professor and chair of bioengineering

: professor of biochemistry, professor of chemistry

: professor of chemical engineering, director of the Clean Energy Institute, adjunct professor of materials science and engineering

Incorporated by legislation in 2007, the Washington State Academy of Sciences initially had just 105 members. With this new crop of members from 91探花and other institutions around the state, the academy’s total membership will rise to 264. The academy’s mission is “to provide expert scientific and engineering analysis to inform public policymaking in Washington, and to increase the role and visibility of science in the state.”

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For more information, contact James Urton in the 91探花Office of News & Information at 206-543-2580 or jurton@uw.edu.

Hartmann joined the 91探花faculty in 1977 after earning his bachelor’s in mechanical engineering from the University of Portland and his doctorate in geophysical fluid dynamics from Princeton University. His research looks at the atmosphere’s role in climate variability and change, and how the atmosphere interacts with the ocean in a changing climate. He has authored a climate science and nearly 200 research papers, and is former chair of the 91探花Department of Atmospheric Sciences.

Hartmann has lectured since the early 1980s about the physics of greenhouse gases and climate change. In 2013, he was a coordinating lead author of the most recent of climate science, in which he helped review the evidence for global warming. Hartmann was previously elected as a fellow of the American Association for the Advancement of Science, the American Geophysical Union and the American Meteorological Society. Other honors include the NASA Distinguished Public Service Medal and the Carl-Gustaf Rossby Research Medal from the American Meteorological Society.

Newly elected scientists bring the total number of active academy members to 2,291 and the total number of foreign associates to 465.

The Paris talks were attended by thousands of delegates, including from the 91探花. At the time, 91探花researchers in Seattle the expansion of discussions to include public policy and human health, and emphasized the need for a timely, durable international agreement.

Now, a few 91探花faculty members comment on the signing as countries move toward implementing its contents.

, a 91探花professor of atmospheric sciences, calls the signing an “encouraging” step forward. But he notes that the United Nations Framework Convention on Climate Change was adopted in 1992, and the was signed in 1997, but never ratified by the U.S.

Since then, he said, the world has emitted more carbon dioxide than even the highest expert predictions at that time. The ‘s commitments are voluntary, he noted, with no mechanisms for enforcement, and its goals are modest.

“Much more aggressive steps are necessary to keep global warming in check, and time is running out,” Hartmann said. “The 2013 Intergovernmental Panel on Climate Change report [on which he was a ] showed that we are about halfway to the amount of greenhouse gas emissions that will produce 2 degrees Celsius of warming, and at present rates of release we will get there in about 25 years. We need to stop the increase in carbon dioxide to avert 2 C of warming, and the promises under the Paris Agreement will not achieve that. We need nations to do much more.”

, 91探花professor of oceanography and director of the 91探花, said the agreement “represents an important step for the international community in its effort to ‘limit dangerous inference of the climate’ as set out [in 1992] by the UN Framework Convention on Climate Change.”

She noted that each country sets its own voluntary . “Because of this bottom-up approach, the country pledges are more aspirational than was found in Kyoto, potentially resulting in much larger emission reductions than many thought possible.”

She added: “While some have said that the bold goal set in Paris of keeping warming below 2 C is unrealistic, the Paris Agreement gives confidence that the international community can work together to solve this defining challenge of this century. I am hoping for swift ratification of this agreement, and that countries with both large and small emissions pledge significant reductions in emissions.”

, a 91探花professor of political science and director of the 91探花, said “the Paris Agreement is a good step forward because China and India, along with industrialized countries, are on board.”

But he noted the pledges are voluntary. “Kyoto and other international agreements show that international agreements with mandatory targets face huge problems in domestic translation and implementation.”

He echoed others on the voluntary targets, and the lack of incentives to meet them. “This holds not only for China and India, but also for the U.S., where the Congress remains opposed to climate-change mitigation.” Prakash said he would like to see country-specific plans and budgets “before speculating on the possibility of the success of the Paris agreement.”

, a lecturer in the 91探花Jackson School of International Studies who writes on international relations and geopolitics, said “overall, it represents an essential step, a major move forward.”

But he wondered about the agreement’s focus on renewables 鈥� mainly solar and wind 鈥� rather than other options such as hydropower, fossil fuels with capture of carbon emissions, and especially nuclear power.

“We have seen, in the 1970s and 80s, what harm can be done by exaggerated claims about what renewable technologies can actually deliver,” Montgomery said. “Reducing carbon emissions significantly will require every means at our disposal.”

, a 91探花professor of marine and environmental affairs, called it “mission impossible.” She said: “We have a global-emissions goal we are not sure is correct, national goals that are in no way connected to it, and we really will [have no way to] know if we met it or not.”

She described the agreement’s more than per year to help developing countries enact new technology and mitigate and adapt to a changing climate as inadequate.

, a 91探花professor of chemical engineering and director of the 91探花, said that “the Paris Climate Agreement 鈥� combined with the [governmental] and [private] pledges to invest billions of new dollars in clean energy 鈥� is a signal that the world is committed to accelerating the development of scalable clean energy innovations.”

He noted that Washington state has already invested in the Clean Energy Institute and other efforts that join university researchers and national labs to develop new materials for renewable energy and integrate them into the electrical grid.

“What we need now is an ecosystem that has more fundamental scientific discoveries happening within earshot of the entrepreneurs and investors who share this same sense of urgency to mobilize against an environmental challenge that many of the world’s most powerful nations now recognize as a great threat to humanity.”

, a 91探花undergraduate in environmental sciences, forestry and economics who attended the summit as part of the International Forestry Students’ Association, said “to me, the signing of the Paris climate agreement is a signal 鈥� the sound of a call from the global world to this generation’s young professionals and students.

“It is telling us that we need to begin crafting creative solutions to accomplish these ambitious goals 鈥� this need stretches from finance to agriculture, international trade to urban design.”

Abraham recalls meeting people from around the world during her time in Paris.

“We all have a part to play, and the agreement is the reminder that we are not alone. In each country, each city, there will be hordes of people working to meet the goals of the agreement 鈥� and it is this new truth that I believe will make all the difference.”

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But while humans have pumped sulfur into Earth’s atmosphere since the Industrial Revolution, it’s been hard to measure how this affects the clouds above. New 91探花 research uses a huge volcanic eruption in Iceland to measure the change.

The , to be published in Geophysical Research Letters, a journal of the American Geophysical Union, shows that sulfur emissions do indeed result in smaller cloud droplet size, leading to brighter clouds that reflect significantly more sunlight.

“This eruption is a chance to nail down one of the big uncertainties in climate models,” said first author , a 91探花doctoral student in atmospheric sciences.

The study takes advantage of a unique geologic event. During six months from summer 2014 until early 2015, a crack in the seeped lava and sulfur gas. This was not one of Iceland’s huge explosive eruptions that fill the skies with ash and shut down airplane routes. Instead it was a long, slow, low-elevation seep of sulfur emissions that produced an amount of lava second only to in the recent history of Iceland eruptions.

The 91探花researchers looked at data for that region recorded by NASA’s , or Moderate Resolution Imaging Spectroradiometer, instrument to measure the size of droplets in the marine cloud layer. While the volcano was spewing sulfur, the droplets were the smallest in the 14-year record of observations.

“You can see the effect over an entire ocean for a two-month period,” McCoy said. “It was a pretty unique geophysical event within the satellite record.”

The results confirm that volcanoes cool the planet not just by emitting particles high in the atmosphere, but also by releasing low-level sulfur to influence cloud formation.

When the air contains aerosol particles, the same amount of water vapor condenses into many small drops, whose larger surface area reflects more sunlight. The difference in reflected solar radiation for September and October 2014 was 2 watts per square meter in the region over Iceland.

“The effect of volcanic emissions on clouds has been a difficult one to quantify because of the ephemeral nature of most events,” said co-author , a 91探花professor of atmospheric sciences. “This eruption provides a natural laboratory that lets us test how clouds respond to aerosols.”

The results may help understand humans’ impact on clouds. Human pollution since the Industrial Revolution is believed to have altered skies in the Northern Hemisphere. One uncertainty in climate models is how much human pollution has brightened the clouds, shielding the planet from the effects of the simultaneous rise in carbon dioxide.

“One of the big uncertainties regarding climate change is how much human-produced aerosols have offset the warming until now,” Hartmann said. “We hope the data from this eruption will improve the model simulations of cloud effects, and narrow the uncertainties in projections of the future.”

The most recent Intergovernmental Panel on Climate Change was the first to include a chapter on clouds and aerosols, one of the biggest uncertainties in global climate models. This study will provide a benchmark for modelers to check their simulations of clouds and aerosols and improve their algorithms for the next generation of climate models.

“The same way that the Mount Pinatubo eruption in 1991 was a big on-off signal that allowed us to evaluate models’ response to volcanic forcings, I think this Iceland eruption is a unique event that will help us to better understand the interaction between aerosols and clouds,” McCoy said.

The research was funded by NASA.

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For more information, contact McCoy at 206-395-6041 or dtmccoy@atmos.uw.edu and Hartmann at 206-543-7460 or dhartm@uw.edu.

New research led by the 91探花 and the Pacific Northwest National Laboratory suggest tiny ocean life in vast stretches of the Southern Ocean play a significant role in generating brighter clouds overhead. The were published July 17 in the online, open-access journal .

The study shows that plankton, the tiny drifting organisms in the sea, produce airborne gases and organic matter to seed cloud droplets, which lead to brighter clouds that reflect more sunlight.

“The clouds over the Southern Ocean reflect significantly more sunlight in the summertime than they would without these huge plankton blooms,” said co-lead author , a 91探花doctoral student in atmospheric sciences. “In the summer, we get about double the concentration of cloud droplets as we would if it were a biologically dead ocean.”

Although remote, the oceans in the study area between 35 and 55 degrees south is an important region for Earth’s climate. Results of the study show that averaged over a year, the increased brightness reflects about 4 watts of solar energy per square meter.

“Life in the ocean has a big effect on clouds,” said co-author , a 91探花professor of atmospheric sciences.

“This idea has been floating out there as a hypothesis, but there hasn’t been much evidence,” said cloud expert , a 91探花professor of atmospheric sciences.

McCoy and co-author , now at the University of Leeds, began this research as 91探花in 2014 looking at NASA satellite data for clouds over the parts of the Southern Ocean that are not covered in sea ice and have year-round satellite data. The space agency launched the first Moderate Resolution Imaging Spectroradiometer, or , instrument in 1999 to measure the cloud droplet size for all Earth’s skies.

Clouds reflect sunlight based on both the amount of liquid suspended in the cloud and the size of the drops, which range from tiny mist spanning less than a hundredth of an inch (0.1 mm) to large drops about half an inch (10 mm) across. Each droplet begins by growing on an aerosol particle, and the same amount of liquid spread across more droplets will reflect more sunlight.

Using the NASA satellite data, the 91探花team in 2014 that Southern Ocean clouds are composed of smaller droplets in the summertime. But that doesn’t make sense, since the stormy seas calm down in summer and generate less sea spray to create airborne salts.

The new study looked more closely at what else might be making the clouds more reflective. Co-lead author , a scientist at the Pacific Northwest National Lab in Richland, Washington, used an ocean biology model to see whether biological matter could be responsible.

Marine life can affect clouds in two ways. The first is by emitting a gas, such as dimethyl sulfide released by Sulfitobacter bacteria and phytoplankton such as , which creates the distinctive sulfurous smell of the sea and also produces particles to seed marine cloud droplets.

The second way is directly through organic matter that collects at the water’s surface, forming a bubbly scum that can get whipped up and lofted into the air as tiny particles of dead plant and animal material.

By matching the cloud droplet concentration with ocean biology models, the team found correlations with the sulfate aerosols, which in that region come mainly from phytoplankton, and with the amount of organic matter in the sea spray.

“The dimethyl sulfide produced by the phytoplankton gets transported up into higher levels of the atmosphere and then gets chemically transformed and produces aerosols further downwind, and that tends to happen more in the northern part of the domain we studied,” Burrows said. “In the southern part of the domain there is more effect from the organics, because that’s where the big phytoplankton blooms happen.”

Taken together, these two mechanisms roughly double the droplet concentration in summer months.

The Southern Ocean is a unique environment for studying clouds. Unlike in other places, the effects of marine life there are not swamped out by aerosols from forests or pollution. The authors say it is likely that similar processes could occur in the Northern Hemisphere, but they would be harder to measure and may have a smaller effect since aerosol particles from other sources are so plentiful.

Wood is part of a larger team听developing a field program to take direct measurements of Southern Ocean clouds and aerosols.

“We have really poor observations of everything in the Southern Ocean, and it’s a really important region,” Wood said. “It also provides a glimpse of how a pristine, pre-industrial area might behave.”

The research was funded by NASA, the U.S. Department of Energy and a graduate fellowship from the Air Force Office of Scientific Research. Other co-authors are and at Pacific Northwest National Laboratory and at Los Alamos National Laboratory.

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For more information, contact McCoy at 206-395-6041 or dtmccoy@atmos.uw.edu;听Burrows at susannah.burrows@pnnl.gov; Hartmann at 206-543-7460 or dhartm@uw.edu;听and Wood at 206-543-1203 or robwood@atmos.washington.edu. Also see the PNNL .

A long-lived patch of warm water off the West Coast, about 1 to 4 degrees Celsius (2 to 7 degrees Fahrenheit) above normal, is part of [a larger pattern driven by the tropical Pacific] that’s wreaking much of this mayhem, according to two 91探花 papers to appear in Geophysical Research Letters, a journal of the American Geophysical Union.

“In the fall of 2013 and early 2014 we started to notice a big, almost circular mass of water that just didn’t cool off as much as it usually did, so by spring of 2014 it was warmer than we had ever seen it for that time of year,” said , a climate scientist at the UW-based , a joint research center of the 91探花and the U.S. National Oceanic and Atmospheric Administration.

Bond coined the term “” last June in his monthly newsletter as Washington’s state climatologist. He said the huge patch of water 鈥� 1,000 miles in each direction and 300 feet deep 鈥� had contributed to Washington’s mild 2014 winter and might signal a warmer summer.

Ten months later, the blob is still off our shores, now squished up against the coast and extending about 1,000 miles offshore from Mexico up through Alaska, with water about 2 degrees Celsius (3.6 degrees Fahrenheit) warmer than normal. Bond says all the models point to it continuing through the end of this year.

The new explores the blob’s origins. It finds that it relates to a persistent high-pressure ridge that caused a calmer ocean during the past two winters, so less heat was lost to cold air above. The warmer temperatures we see now aren’t due to more heating, but less winter cooling.

Co-authors on the paper are at NOAA in Seattle and a 91探花affiliate professor of oceanography, at NOAA in Santa Cruz and at Canada’s Department of Fisheries and Oceans. The study was funded by NOAA.

The authors look at how the blob is affecting West Coast marine life. They find fish sightings in unusual places, supporting recent reports that West Coast and the by warm, less nutrient-rich Pacific Ocean water.

The blob’s influence also extends inland [to affect West Coast weather]. As air passes over warmer water and reaches the coast it brings more heat and less snow, which the paper shows helped cause current drought conditions in California, Oregon and Washington. [As air passes over warmer water it picks up heat, resulting in a tendency for warmer temperatures and reduced mountain snow packs, which may be exacerbating current drought conditions along the West Coast.]

The blob is just one element of a broader pattern in the Pacific Ocean whose influence reaches much further 鈥� possibly to include two bone-chilling winters in the Eastern U.S.

A study in the same journal by , a 91探花professor of atmospheric sciences, looks at the Pacific Ocean’s relationship to the cold 2013-14 winter in the central and eastern United States.

Despite all the talk about the “polar vortex,” Hartmann argues we need to look south to understand why so much cold air went shooting down into Chicago and Boston.

His shows a decadal-scale pattern in the tropical Pacific Ocean linked with changes in the North Pacific, called the North Pacific mode, that sent atmospheric waves snaking along the globe to bring warm and dry air to the West Coast and very cold, wet air to the central and eastern states.

“Lately this mode seems to have emerged as second to the El Ni帽o Southern Oscillation in terms of driving the long-term variability, especially over North America,” Hartmann said. The research was funded by the National Science Foundation.

In a last month, Hartmann focused on the more recent winter of 2014-15 and argues that, once again, the root cause was surface temperatures in the tropical Pacific.

That pattern, which also causes the blob, seems to have become stronger since about 1980 and lately has elbowed out the Pacific Decadal Oscillation to become second only to El Ni帽o in its influence on global weather patterns.

“It’s an interesting question if that’s just natural variability happening or if there’s something changing about how the Pacific Ocean decadal variability behaves,” Hartmann said. “I don鈥檛 think we know the answer. Maybe it will go away quickly and we won’t talk about it anymore, but if it persists for a third year, then we’ll know something really unusual is going on.”

Bond says that although the blob does not seem to be caused by climate change, it has many of the same effects for West Coast weather.

“This is a taste of what the ocean will be like in future decades,” Bond said. “It wasn’t caused by global warming, but it’s producing conditions that we think are going to be more common with global warming.”

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For more information, contact Bond at nab3met@uw.edu or 206-526-6459 and Hartmann at dhartm@uw.edu or 206-543-7460.

[Note: The 2nd and 9th paragraphs were updated for clarity on April 22, 2015.]

The full text of the fifth IPCC report was released today, and 91探花 atmospheric science professors and were among 209 researchers from 39 countries who were lead authors on the 900-page .

“Warming is unequivocal,” Hartmann said Friday at a news conference in Sweden. He was a coordinating lead author for Chapter 2, Observations of Atmosphere and Surface, which reviews the evidence for global warming in temperature records. Hartmann also helped draft the technical summary and the summary for policymakers, and was in Stockholm last week for the final line-by-line reviews of the 36-page .

“For the most part the conclusions of previous IPCC assessments can be given with even more certainty,” Hartmann commented by e-mail. “The surface of Earth is warming and humans are responsible.”

The new report moves from asking whether warming has occurred, he said, to determining exactly how much warming has taken place since 1750, around the beginning of the industrial age. This assessment also makes more forward-looking statements for policymakers.

“Simpler messages with more clarity can be given about how greenhouse gas release is related to future climate change,” Hartmann wrote.

The report recommends that, to keep temperature change within 3.6 degrees F (2 degrees C) of preindustrial levels, carbon emissions should not exceed 1 trillion metric tons. Without changes that level would be reached by 2040, Hartmann said.

While much of the report fills in the details of previous versions, that’s not a bad thing, Bretherton said.

“I think it is important that the basic conclusions of the assessment, about how much warming (will occur) and patterns of rainfall change in a warmer climate, are essentially identical to the previous IPCC assessments,” Bretherton said. He is a lead author on Chapter 7: Clouds and Aerosols, which for the first time was the subject of a separate chapter instead of being discussed in other sections.

“Clouds and aerosols are the single largest source of uncertainty in simulating the climate change of the next 50 to 100 years,” Bretherton said. Models have a hard time simulating clouds, he said, and it’s not well understood how clouds interact with human-produced aerosols such as pollution haze.

Chapter 7 authors also were asked to take a first IPCC look at geoengineering, a controversial idea to start trying to bury carbon dioxide or reflect sunlight by spraying aerosol particles into the top of the atmosphere. The summary text warns of technological limitations and possible side effects from implementing either of these techniques on a global scale.

This IPCC report was an even bigger undertaking than usual, with almost twice as many scientists contributing as last time.

“Maybe the next IPCC assessment, in 2020 or so, will be a much shorter update requiring a lot less effort from the global climate science community,” Bretherton said. “But I won’t bet on it.”

91探花faculty members who were not involved in drafting the report first saw the document Friday, when the summary was released to the public. Most agreed that this assessment reaffirms the science while providing some updates on sea-level rise and ocean changes.

“The biggest difference (between this report and the last one) is our confidence in the results,” said , an oceanography professor and director of the UW’s interdisciplinary . “It contains new information about how ice sheets at the poles are contributing to sea-level rise, changes in the chemistry of the ocean through ocean acidification. Also new are discussions of the long-term changes 鈥� of a thousand years or more 鈥� that we are already committed to” from long-lived carbon emitted since the beginning of the industrial age.

The full text of Working Group I, on the physical basis for climate change, was released Sept. 30. The reports of the other two IPCC working groups, on the effects of climate change and possible mitigation responses, will follow in 2014.

“The IPCC results emphasize the need to get serious about avoiding dangerous interference with the climate system and on preparing 鈥� globally, nationally and locally 鈥� for the changes already set in motion,” commented , director of the UW’s and co-author of an upcoming report on climate change impacts on the Pacific Northwest.

A full list of UW-affiliated authors on the report is available .

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For more information, contact Bretherton at 206-685-7414 or breth@atmos.washington.edu, Hartmann at听206-543-7460 or dhartm@uw.edu and Snover at 206-221-0222 or aksnover@uw.edu. Hartmann will be in Europe until Oct. 7.