NCDC Releases 2014 U.S. Climate Report

The 2014 annual average contiguous U.S. temperature was 52.6°F, 0.5°F above the 20th century average. This ranked as the 34th warmest year in the 1895–2014 record. Very warm conditions dominated the West, while the Midwest and Mississippi Valley were cool.

The average contiguous U.S. precipitation was 30.76 inches, 0.82 inch above average, and ranked as the 40th wettest year in the 120-year period of record. The northern United States was wet, and the Southern Plains were dry; the national drought footprint shrank about 2 percent. 

In 2014, there were eight weather and climate disaster events with losses exceeding $1 billion each across the United States. These eight events resulted in the deaths of 53 people. The events include: the western U.S. drought, the Michigan and Northeast flooding event, five severe storm events, and one winter storm event. 

This summary from NOAA's National Climatic Data Center is part of the suite of climate services NOAA provides to government, business, academia, and the public to support informed decision making.

Source: NOAA

Atlantic warming turbocharges Pacific trade winds

Tropical beach (stock image). Rapid warming of the Atlantic Ocean, likely caused by global warming, has turbocharged Pacific Equatorial trade winds, according to new research. Credit: © michaelfitz / Fotolia

New research has found rapid warming of the Atlantic Ocean, likely caused by global warming, has turbocharged Pacific Equatorial trade winds. Currently the winds are at a level never before seen on observed records, which extend back to the 1860s.

The increase in these winds has caused eastern tropical Pacific cooling, amplified the Californian drought, accelerated sea level rise three times faster than the global average in the Western Pacific and has slowed the rise of global average surface temperatures since 2001.

It may even be responsible for making El Nino events less common over the past decade due to its cooling impact on ocean surface temperatures in the eastern Pacific.

"We were surprised to find the main cause of the Pacific climate trends of the past 20 years had its origin in the Atlantic Ocean," said co-lead author Dr Shayne McGregor from the ARC Centre of Excellence for Climate System Science (ARCCSS) at the University of New South Wales.

"It highlights how changes in the climate in one part of the world can have extensive impacts around the globe."

The record-breaking increase in Pacific Equatorial trade winds over the past 20 years had, until now, baffled researchers.

Originally, this trade wind intensification was considered to be a response to Pacific decadal variability. However, the strength of the winds was much more powerful than expected due to the changes in Pacific sea surface temperature.

Another riddle was that previous research indicated that under global warming scenarios Pacific Equatorial Trade winds would slow down over the coming century.

The solution was found in the rapid warming of the Atlantic Ocean basin, which has created unexpected pressure differences between the Atlantic and Pacific. This has produced wind anomalies that have given Pacific Equatorial trade winds an additional big push.

"The rapid warming of the Atlantic Ocean created high pressure zones in the upper atmosphere over that basin and low pressure zones close to the surface of the ocean," said Prof Axel Timmermann co-lead and corresponding author from the University of Hawaii.

"The rising air parcels, over the Atlantic eventually sink over the eastern tropical Pacific, thus creating higher surface pressure there. The enormous pressure see-saw with high pressure in the Pacific and low pressure in the Atlantic gave the Pacific trade winds an extra kick, amplifying their strength. It's like giving a playground roundabout an extra push as it spins past."

Many climate models appear to have underestimated the magnitude of the coupling between the two ocean basins, which may explain why they struggled to produce the recent increase in Pacific Equatorial trade wind trends.

While active, the stronger Equatorial trade winds have caused far greater overturning of ocean water in the West Pacific, pushing more atmospheric heat into the ocean, as shown by co-author and ARCCSS Chief Investigator Prof Matthew England earlier this year. This increased overturning appears to explain much of the recent slowdown in the rise of global average surface temperatures.

Importantly, the researchers don't expect the current pressure difference between the two ocean basins to last. When it does end, they expect to see some rapid changes, including a sudden acceleration of global average surface temperatures.

"It will be difficult to predict when the Pacific cooling trend and its contribution to the global hiatus in surface temperatures will come to an end," Prof England said.

"However, a large El Niño event is one candidate that has the potential to drive the system back to a more synchronized Atlantic/Pacific warming situation."

Source: University of New South Wales

Tinkering with the Tao of pandas

This image shows a panda eating in China's Wolong Nature Reserve. Pandas habitat choices center around the ready availability of bamboo -- lots of bamboo.
 Credit: Sue Nichols, Michigan State University

Good news on the panda front: Turns out they're not quite as delicate -- and picky -- as thought.

Up until now, information gleaned from 30 years worth of scientific literature suggested that pandas were inflexible about habitat. Those conclusions morphed into conventional wisdom and thus have guided policy in China. But a Michigan State University (MSU) research associate has led a deep dive into aggregate data and emerged with evidence that the endangered animal is more resilient and flexible than previously believed.

Vanessa Hull is a postdoctoral research associate at MSU's Center for Systems Integration and Sustainability (CSIS). She has spent three years stalking giant pandas in China's Wolong Nature Reserve. Given the pandas' elusive nature, Hull had a lot of down time.

So she bided her time plowing through literature on panda habitat selection, discovering inconsistencies and lack of consensus on matters crucial as scientists and policymakers struggle to protect the estimated 1,600 remaining wild giant pandas in the 21,300 square kilometers to which the animals have been relegated.

"Panda habitat selection is a complex process that we are still trying to unravel," said Jianguo "Jack" Liu, Rachel Carson Chair in Sustainability and CSIS director. "Pandas are a part of coupled human and natural systems where humans have changed so much in their habitat."

It has been thought pandas demanded a forest with fairly gentle slope (easier to mosey around in while seeking bamboo) at a certain elevation in original, old forest, an abundance of bamboo, and plenty of distance from people. These recommendations, Hull said, come from often-scant research because pandas are difficult animals to study.

"Pandas are difficult to observe and follow in the wild, we're always 10 steps behind them," Hulls said. "We don't know why they're there -- or where they were before and after. There's a lot of guesswork."

Vanessa and her colleagues drew up analysis of all the research projects and sought to separate studies that focus on where pandas live from studies that examine what kind of choices pandas make when multiple types of habitat are available. They discovered that pandas may not be as picky as thought.

The research shows, for instance, that pandas are willing to live in secondary forests -- forests that have been logged and have regrown. They also don't seem as selective about slope, and are willing to climb depending on which of the many varieties of bamboo is growing, or what type of forest it was in. Same for elevation, and the amount of sunshine that hits a piece of panda home.

That's good news. Indications that forests once cut clean by timber harvesting can return to acceptable panda habitat validate current bans on forest harvesting.

They also found that there is a complex relationship between trees and bamboo. Pandas choose different forest types as places to spend their time, as long as bamboo is available.

Hull said consensus would be helpful for future panda habitat research, since the future guarantees change.

"It's exciting to see the flexibility pandas have, or at least see that pandas are choosing areas I didn't think could support them," Hull said. "It gives you hope. They've survived throughout many challenges over so many millions of years, it would be sad to think humans came along and threw it all away. This also suggests we should stay on board and try to make things better for them."

Source: Michigan State University

'Family' matters when predicting ecosystems' reaction to global change

This is a picture of the experimental setup in the greenhouse.
Credit: Jennifer Schweitzer, co-author and associate professor at UT

Humans are rapidly changing the look and function of earth's ecosystems, from the increase of greenhouse gases to the unintentional and harmful spread of plants and animals to new environments. A major challenge for ecologists is to understand how and why communities respond to factors that underlie global change.

A University of Tennessee, Knoxville, study is finding some clues. It shows that just as our family histories dictate what we look like and how we act, plant evolutionary history shapes community responses to interacting agents of global change.

The research, published in the open-access journal PLOS ONE, may help predict what ecosystems will look like in the future and how they will work.

"The issues of global change have already begun to jeopardize the natural functioning of ecosystems and important services that we often take for granted like clean air, clean water, food and fiber production," said Rachel Wooliver, lead author and doctoral student in ecology and evolutionary biology. "Our study is the first to experimentally show that plant communities with different evolutionary backgrounds will respond differently to human-caused physical and biological changes."

In other words, regarding the future effects of global change on ecosystem services and processes humans rely upon, it's all in the family.

Wooliver and colleagues from UT, the University of Tasmania and Villanova University used eucalypt species native to Tasmania, Australia, to compare plant growth in cultures of all the same species to that of mixtures with native species with an introduced hardwood plantation species. They analyzed plant activity in an ambient environment versus one of increased levels of carbon dioxide and soil nitrogen.

"We found that only those communities composed of native species within one evolutionary lineage responded significantly to elevated carbon dioxide and nitrogen by taking carbon from the atmosphere and sequestering it into biomass," said co-author John Senior of the University of Tasmania. "Communities from another lineage, on the other hand, showed no response, which suggests that they will play a less crucial role in offsetting the rise of carbon dioxide and global warming."

This means that evolutionary history will shape which species will effectively sequester carbon and which won't.

Further, the presence of the nonnative species in these communities influenced productivity differently depending on the evolutionary background of the interacting native species. Thus, family trees can be used to predict how the spread of nonnative species by humans will shape the look and function of ecosystems as global change continues.

"Overall, this study provides new direction for global change scientists by highlighting that evolutionary history is key to understanding outcomes of plant function and diversity with rapid ecological change," said Wooliver.

The work is promising to researchers that are trying to figure out if species interactions change how ecosystems are responding to global change, as well as conservation biologists who aim to determine which species might be at higher risk for extinction in the future.

Source: University of Tennessee

Solar activity impacts polar ozone

Scientists have been able to confirm, for the first time, the long-term implications of solar-driven electron impact on the upper middle atmosphere ozone. Credit: NASA

The increase in greenhouse gases explains, to a large extent, the rise in the average temperature of Earth. According to the research study published in Nature Communications today, the Sun affects middle atmosphere ozone with potential implications on smaller scale to regional, but not global, climate.

Humankind is responsible for the global warming of our climate by increasing the amount of greenhouse gases in the atmosphere. However, according results published today, fluctuations in the activity of the Sun impact middle atmosphere ozone, providing a potential link to regional scale climate variability. This climate variability is not a trend, like climate change, but rather year-to-year fluctuations following solar activity. "The detected ozone variation may in part help understand the alternation of local mild and cold winter seasons, as hints have been obtained in previous research that the ozone changes in the middle atmosphere may link as far as the surface of Earth and affect, among other things, polar wind streams," Finnish Meteorological Institute researcher Dr Pekka Verronen reflects.

The research team was able to confirm, for the first time, the long-term implications of solar-driven electron impact on the upper middle atmosphere ozone. The results showed strong effects in the polar latitudes. The amount of ozone at 70-80 km altitude was found to vary more than 30 percent during a solar cycle, a period of approximately 11 years. The ozone variation between the extremes of the Sun's activity is so great that it is likely to impact the temperature balance of the atmosphere. These temperature changes can in turn have an effect on atmospheric winds.

Electrons from space: Auroras and ozone loss

According to the research study conducted by the Finnish Meteorological Institute, University of Otago and the British Antarctic Survey, the electrons, similar to those behind the aurora, cause significant solar cycle variation in the polar mesosphere ozone. The amount of ozone is smaller when more electrons enter the atmosphere. "These results are only the first step but an important one, allowing us to better understand the long-term impacts of this type of solar activity, and its role in regional climate variability," says Dr Monika Andersson who lead the study at Finnish Meteorological Institute.

Earth's radiation belts are regions in near-Earth space that contain vast quantities of solar energetic electrons, trapped there by Earth's magnetic field. During magnetic storms, which are solar wind-driven, the electrons accelerate to high speeds and enter the atmosphere in the polar regions. In the atmosphere, the electrons ionize gas molecules, leading to the production of ozone-depleting catalyst gases. Based on currently available satellite observations, electron precipitation may, during solar storms lasting a few days, reduce ozone in the upper atmosphere (60-80 km) as much as 90 per cent on a momentary basis.

Source: Finnish Meteorological Institute

Cost of cloud brightening for cooler planet revealed

University of Manchester scientists have identified the most energy-efficient way to make clouds more reflective to the sun in a bid to combat climate change. Credit: © magann / Fotolia

Marine Cloud Brightening is a reversible geoengineering method proposed to mitigate rising global temperatures. It relies on propelling a fine mist of salt particles high into the atmosphere to increase the albedo of clouds -- the amount of sunlight they reflect back into space. This would then reduce temperatures on the surface, as less sunlight reaches Earth.
Clouds form when water droplets gather on dust or other particles in the air. Increasing the amount of salt particles in the atmosphere allows more of these water droplets to form, making the clouds denser and therefore more reflective.

A new paper, published in the journal Philosophical Transactions of the Royal Society A, has looked at four different ways of getting the particles into the sky, to compare how effective they may be. The researchers found that a technique called the 'Rayleigh Jet' proved to be best.

Named after Lord Rayleigh, who provided the theory, the technique relies on spraying a fine jet of water that breaks down into small droplets into the sky. The liquid droplets evaporate quickly, leaving behind just the salt particles.

These particles, say the paper's authors, could be generated from specially built ships that could travel the world's oceans spraying salt particles into the air where they then hang in the atmosphere for several days until they return to Earth as rain.

Previous studies have optimised the size of the salt particles needed to produce the best increase in cloud reflectance but haven't taken into account how much energy the technique would need and how much it would cost to operate. This new paper, by teams at the universities of Manchester, Washington and Edinburgh, tackled this question. The researchers tested each technique so there was an increase in reflection of 5%, a figure that would combat the predicted effects of increased carbon dioxide levels over the rest of this century. They then looked at how much energy each would consume.

The scientists say that the Rayleigh jet method could produce the desired effect using 30 megawatts of energy, about the same energy that two large ships produce.

Dr Paul Connolly, based in the School of Earth, Atmospheric and Environmental Sciences at The University of Manchester, said: "It can be incredibly energy intensive to propel water high into the atmosphere and the energy required had never really been tested before. Our paper optimises the salt particle sizes to produce the required change in cloud reflectance for the least energy cost. It is an important finding if these techniques should be needed in the future.

"I am not recommending that we use any of these techniques now, but it is important to know how best to use them should they become necessary. Should no progress be made to reduce CO2 levels, then geoengineering techniques, similar to this, might become necessary to avoid dangerous rises in global temperatures."

Source: Manchester University