Average temperature in Finland has risen by more than two degrees

Over the past 166 years, the average temperature in Finland has risen by more than two degrees. During the observation period, the average increase was 0.14 degrees per decade, which is nearly twice as much as the global average.

According to a recent University of Eastern Finland and Finnish Meteorological Institute study, the rise in the temperature has been especially fast over the past 40 years, with the temperature rising by more than 0.2 degrees per decade. "The biggest temperature rise has coincided with November, December and January. Temperatures have also risen faster than the annual average in the spring months, i.e., March, April and May. In the summer months, however, the temperature rise has not been as significant," says Professor Ari Laaksonen of the University of Eastern Finland and the Finnish Meteorological Institute. As a result of the temperature rising, lakes in Finland get their ice cover later than before, and the ice cover also melts away earlier in the spring. Although the temperature rise in the actual growth season has been moderate, observations of Finnish trees beginning to blossom earlier than before have been made.

Temperature has risen in leaps

The annual average temperature has risen in two phases, the first being from the beginning of the observation period to the late 1930s, and the second from the late 1960s to present. Since the 1960s, the temperature has risen faster than ever before, with the rise varying between 0.2 and 0.4 degrees per decade. Between the late 1930s and late 1960s, the temperature remained nearly steady. "The stop in the temperature rise can be explained by several factors, including long-term changes in solar activity and post-World War II growth of human-derived aerosols in the atmosphere. When looking at recent years' observations from Finland, it seems that the temperature rising is not slowing down," University of Eastern Finland researcher Santtu Mikkonen explains.

The temperature time series was created by averaging the data produced by all Finnish weather stations across the country. Furthermore, as the Finnish weather station network wasn't comprehensive nation-wide in the early years, data obtained from measurement stations in Finland's neighbouring countries was also used.

Finland is located between the Atlantic Ocean and the continental Eurasia, which causes great variability in the country's weather. In the time series of the average temperature, this is visible in the form of strong noise, which makes it very challenging to detect statistically significant trends. The temperature time series for Finland was analysed by using a dynamic regression model. The method allows the division of the time series into sections indicating mean changes, i.e. trends, periodic variation, observation inter-dependence and noise. The method makes it possible to take into consideration the seasonal changes typical of Nordic conditions, as well as significant annual variation.

Journal Reference:

S. Mikkonen, M. Laine, H. M. M?kel?, H. Gregow, H. Tuomenvirta, M. Lahtinen, A. Laaksonen. Trends in the average temperature in Finland, 1847–2013. Stochastic Environmental Research and Risk Assessment, 2014; DOI: 10.1007/s00477-014-0992-2

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Temperature anomalies are warming faster than Earth's average, study finds

It's widely known that Earth's average temperature has been rising. But research by an Indiana University geographer and colleagues finds that spatial patterns of extreme temperature anomalies -- readings well above or below the mean -- are warming even faster than the overall average.

And trends in extreme heat and cold are important, said Scott M. Robeson, professor of geography in the College of Arts and Sciences at IU Bloomington. They have an outsized impact on water supplies, agricultural productivity and other factors related to human health and well-being.

"Average temperatures don't tell us everything we need to know about climate change," he said. "Arguably, these cold extremes and warm extremes are the most important factors for human society."

Robeson is the lead author of the article "Trends in hemispheric warm and cold anomalies," which will be published in the journal Geophysical Research Letters and is available online. Co-authors are Cort J. Willmott of the University of Delaware and Phil D. Jones of the University of East Anglia.

The researchers analyzed temperature records for the years 1881 to 2013 from HadCRUT4, a widely used data set for land and sea locations compiled by the University of East Anglia and the U.K. Met Office. Using monthly average temperatures at points across the globe, they sorted them into "spatial percentiles," which represent how unusual they are by their geographic size.

Their findings include:

Temperatures at the cold and warm "tails" of the spatial distribution -- the 5th and 95th percentiles -- increased more than the overall average Earth temperature.Over the 130-year record, cold anomalies increased more than warm anomalies, resulting in an overall narrowing of the range of Earth's temperatures.In the past 30 years, however, that pattern reversed, with warm anomalies increasing at a faster rate than cold anomalies. "Earth's temperature was becoming more homogenous with time," Robeson said, "but now it's not."

The study records separate results for the Northern and Southern Hemispheres. Temperatures are considerably more volatile in the Northern Hemisphere, an expected result because there's considerably less land mass in the South to add complexity to weather systems.

The study also examined anomalies during the "pause" in global warming that scientists have observed since 1998. While a 16-year-period is too short a time to draw conclusions about trends, the researchers found that warming continued at most locations on the planet and during much of the year, but that warming was offset by strong cooling during winter months in the Northern Hemisphere.

"There really hasn't been a pause in global warming," Robeson said. "There's been a pause in Northern Hemisphere winter warming."

Co-author Jones of the University of East Anglia said the study provides scientists with better knowledge about what's taking place with Earth's climate. "Improved understanding of the spatial patterns of change over the three periods studied are vital for understanding the causes of recent events," he said.

It may seem counterintuitive that global warming would be accompanied by colder winter weather at some locales. But Robeson said the observation aligns with theories about climate change, which hold that amplified warming in the Arctic region produces changes in the jet stream, which can result in extended periods of cold weather at some locations in the mid-northern latitudes.

And while the rate of planetary warming has slowed in the past 16 years, it hasn't stopped. The World Meteorological Organization announced this month that 2014 is on track to be one of the warmest, if not the warmest, years on record as measured by global average temperatures.

In the U.S., the East has been unusually cold and snowy in recent years, but much of the West has been unusually warm and has experienced drought. And what happens here doesn't necessarily reflect conditions on the rest of the planet. Robeson points out that the United States, including Alaska, makes up only 2 percent of Earth's surface.

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Corals don’t lie: Centuries of rising sea levels and temperature data revealed

AIMS scientists together with a team from The University of Western Australia, CSIRO and the University of San Diego have analysed coral cores from the eastern Indian Ocean to understand how the unique coral reefs of Western Australia are affected by changing ocean currents and water temperatures. The research was published today in the international journal Nature Communications. The findings give new insights into how La Ni?a, a climate swing in the tropical Pacific, affects the Leeuwin current and how our oceans are changing.

“Due to the lack of long-term observations of marine climate we used long coral cores, with annual growth bands similar to tree rings, to provide a record of the past. We obtained records of past sea temperatures by measuring the chemical composition of the coral skeleton from year to year. This showed how changing winds and ocean currents in the eastern Indian Ocean are driven by climate variability in the western tropical Pacific Ocean,” said Dr Jens Zinke (Assistant Professor at the UWA Oceans Institute and AIMS-UWA scientist). The long coral records allowed the scientists to look at these patterns of climate variability back to 1795 AD.

La Ni?a events in the tropical Pacific result in a strengthened Leeuwin Current and unusually warm water temperatures and higher sea levels off southwest Western Australia.

“A prominent example is the 2011 heat wave along WA’s reefs which led to coral bleaching and fish kills,” said Dr Ming Feng CSIRO Principal Research Scientist.?

The international team found that in addition to warming sea surface temperatures, sea-level variability and Leeuwin Current strength have increased since 1980. The coral cores also reveal that the strong winds and extreme weather of 2011 off Western Australia are highly unusual in the context of the past 215 years. The authors conclude that this is clear evidence that global warming and sea-level rise is increasing the severity of these extreme events which impact the highly diverse coral reefs of Western Australia, including the Ningaloo Reef World Heritage site.

“Given ongoing global climate change, It is likely that future La Ni?a events will result in more extreme warming and high sea-level events with potentially significant consequences for the maintenance of Western Australia's unique marine ecosystems,” said Dr Janice Lough, AIMS Senior Principal Research Scientist.

The researchers used core samples of massive Porites colonies from the Houtman-Abrolhos Islands, the most southerly reefs in the Indian Ocean which are directly in the path of the Leeuwin Current. Using the chemical composition of the annual coral growth bands they were able to reconstruct sea surface temperature and Leeuwin Current for 215 years, from 1795 to 2010.

Journal Reference:

J. Zinke, A. Rountrey, M. Feng, S.-P. Xie, D. Dissard, K. Rankenburg, J.M. Lough, M.T. McCulloch. Corals record long-term Leeuwin current variability including Ningaloo Ni?o/Ni?a since 1795. Nature Communications, 2014; 5 DOI: 10.1038/ncomms4607

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As the temperature drops, risk of fracture rises

Record-setting winter weather in the U.S. has led to lots of road condition advisories, but could there also be a slip and fall alert?

By analyzing various conditions -- like snow, wind speed, temperature -- into a 'Slipperiness Score,' a University of Michigan Health System study helps identify what days are the most risky for slip and fall injuries.

The study, published in February's Plastic and Reconstructive Surgery Journal, focuses on Medicare patients, all over age 65, but authors note, the risk of falling exists for anyone during harsh winter weather.

"Although the concept that slippery footing increases your risk of falling isn't new, what we've been able to show is that these dangerous conditions result in more fractures in this already vulnerable population of adults," says lead study author Aviram Giladi, M.D., a resident in the U-M Department of Surgery's Division of Plastic Surgery.

The study findings include:

Based on a scale, ranging from 0 to 7, on a day with a score above 4 the risk of sustaining a wrist fracture increased by 21 percent.On the most slippery days, that additional risk went up to nearly 40 percent.In the winter, over 1,000 additional wrist fractures occurred among adults age 65 and older compared to other seasons.

Nearly 90,000 Medicare enrollees sustain wrist fractures each year, frequently from falls while standing and usually outdoors. The fractures can be quite limiting, and lead to a loss of independence for older patients. Medicare spends more than $240 million a year treating the injuries.

"Understanding the risk of these injuries can help inform prevention and preparation efforts, especially on days where the weather is bound to result in more slippery conditions," says senior study author Kevin C. Chung, M.D., professor of plastic surgery and orthopedic surgery and the Charles B. G. de Nancrede Professor of Surgery. "We hope to help people prepare for risky conditions and adjust where and when they walk outdoors."

Journal Reference:

Aviram M. Giladi, Melissa J. Shauver, Allison Ho, Lin Zhong, H. Myra Kim, Kevin C. Chung. Variation in the Incidence of Distal Radius Fractures in the U.S. Elderly as Related to Slippery Weather Conditions. Plastic and Reconstructive Surgery, 2014; 133 (2): 321 DOI: 10.1097/01.prs.0000436796.74305.38

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World temperature records available via Google Earth

Climate researchers at the University of East Anglia have made the world's temperature records available via Google Earth.

The Climatic Research Unit Temperature Version 4 (CRUTEM4) land-surface air temperature dataset is one of the most widely used records of the climate system.

The new Google Earth format allows users to scroll around the world, zoom in on 6,000 weather stations, and view monthly, seasonal and annual temperature data more easily than ever before.

Users can drill down to see some 20,000 graphs -- some of which show temperature records dating back to 1850.

The move is part of an ongoing effort to make data about past climate and climate change as accessible and transparent as possible.

Dr Tim Osborn from UEA's Climatic Research Unit said: "The beauty of using Google Earth is that you can instantly see where the weather stations are, zoom in on specific countries, and see station datasets much more clearly.

"The data itself comes from the latest CRUTEM4 figures, which have been freely available on our website and via the Met Office. But we wanted to make this key temperature dataset as interactive and user-friendly as possible."

The Google Earth interface shows how the globe has been split into 5? latitude and longitude grid boxes. The boxes are about 550km wide along the Equator, narrowing towards the North and South poles. This red and green checkerboard covers most of Earth and indicates areas of land where station data are available. Clicking on a grid box reveals the area's annual temperatures, as well as links to more detailed downloadable station data.

But while the new initiative does allow greater accessibility, the research team do expect to find errors.

Dr Osborn said: "This dataset combines monthly records from 6,000 weather stations around the world -- some of which date back more than 150 years. That's a lot of data, so we would expect to see a few errors. We very much encourage people to alert us to any records that seem unusual.

"There are some gaps in the grid -- this is because there are no weather stations in remote areas such as the Sahara. Users may also spot that the location of some weather stations is not exact. This is because the information we have about the latitude and longitude of each station is limited to 1 decimal place, so the station markers could be a few kilometres from the actual location.

"This isn't a problem scientifically because the temperature records do not depend on the precise location of each station. But it is something which will improve over time as more detailed location information becomes available."

This new initiative is described in a new research paper published on February 4 in the journal Earth System Science Data (Osborn T.J. and Jones P.D., 2014: The CRUTEM4 land-surface air temperature dataset: construction, previous versions and dissemination via Google Earth).

The CRUTEM4 data set is available from doi:10.5285/EECBA94F-62F9-4B7C-88D3-482F2C93C468.

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