Norwegian Meteorological Institute
Norwegian Meteorological Institute
The Norwegian Meteorological Institute , also known as MET Norway, is Norway's national institute which provides weather forecasts.Its three main offices are located in Oslo, Bergen and Tromsø. MET Norway has around 500 employees and some 650 part-time observers around the country. It also operated the last remaining weather ship in the world, MS Polarfront, stationed in the North Atlantic, until it was discontinued due to budgetary issues on 1 January 2010 and replaced with satellite and buoy data.The institute was founded in 1866 with the help of Norwegian astronomer and meteorologist Henrik Mohn who served as its director until 1913. He is credited with founding meteorological research in Norway.The institute represents Norway in international organizations like the World Meteorological Organization , the European Centre for Medium-Range Weather Forecasts , and EUMETSAT. The Institute is also partner to a number of international research and monitoring projects including EMEP, MyOcean, MyWave and the North West Shelf Operational Oceanographic System . Wikipedia.
News Article | April 21, 2017
A vast frozen tundra, the mountainous Finnmark plateau in Norway's far north, is experiencing a hot spell—relatively speaking—wreaking havoc on the centuries-old Sami way of life. "We already feel the effects of global warming here," says Per Gaup, a colourful reindeer herder in his 60s out on the job. "I can see that we're losing more reindeer because of climate change." Here, the continental climate with cold and dry winters is gradually becoming more like that of coastal areas, with milder temperatures and more rain. The change affects grazing conditions for the 146,000 or so semi-domesticated reindeer in the region who feed on lichen and moss under the snow. "When there's more snow and it turns hard, the animals die because there's less to eat, especially the young ones who are at the bottom of the hierarchy," says Gaup, astride his snowmobile with an orange lasso slung across his chest. One of the Sami dialects counts no fewer than 318 words to describe different types of snow. "Seanas", for example, means a kind of grainy snow ideal for reindeer, making it easy for them to dig out the lichen and moss with their hooves. But it has to be very cold to have that kind of snow. While temperatures in Kautokeino, Norway's main reindeer-herding hub, used to regularly drop to minus 40 degrees Celsius (minus 40 degrees Fahrenheit) for several weeks at a time, nowadays this happens only rarely and briefly. And today's conditions are just a taste of what is to come. The mercury is expected to rise by seven to eight degrees Celsius in winter in Finnmark by the end of this century, according to Rasmus Benestad, a researcher at the Norwegian Meteorological Institute. A recurring problem for the reindeer now is alternating periods of thaw and freezing, which create thick layers of ice that the starving reindeer are unable to penetrate with their hooves. When reindeer can't access the lichen and moss on their herder's grazing grounds, the flocks seek out other pastures. This can cause conflicts between herders over grazing grounds, which are not officially demarcated, and may require the herders to resort to the onerous and heavy task of putting out fodder. The changing climate also complicates the twice-yearly transhumance, when the herders move the reindeer from their summer grazing grounds along the coast to their winter pastures in the Finnmark mountains, and vice versa. Because of longer autumns, the ice, now often thinner and unpredictable, can give way under the weight of the reindeer as they cross waterways, sometimes taking the animals, and even their herders, into the deep. "It's getting worse and worse," says another herder, alarm in his voice. "Last year, I lost at least 12 reindeer that fell through the ice. They died. I wasn't able to get them out," he says. In November 2009, almost 300 animals from a single flock drowned in a river in neighbouring Sweden. "The reindeer have always lived with the changing climate and they've learned to adapt to nature," notes Anders Oskal, the director of the International Centre for Reindeer Husbandry. "Our main concern is that the Arctic is becoming increasingly accessible as it gets warmer, leading to an explosion of human activity," he says. Prospecting and development of mining and wind energy, along with the construction of roads and holiday cabins all compete with the Samis' ancestral practices, encroaching on their pastures. "The reindeer may be a semi-domesticated animal but it will always try to stay away from anything it associates with man, especially the females and the young," says Oskal. Mathis Andreas, a 47-year-old herder, is worried about the potential impact of a Canadian mining company's alleged interest in land near his pastures. "We can't welcome with open arms people who come and destroy our livelihood, our way of life, our traditional lands," he says. "No one besides us has ever lived here. A company would just turn up one day and grab what has belonged to us from generation to generation, for hundreds, if not thousands, of years?" Explore further: Rise in reindeer deaths in the Arctic linked with loss of sea ice and extreme weather
News Article | May 5, 2017
Friday is a happy day for most people since it means the weekend has almost arrived. For iPhone users, however, Fridays are bittersweet because they mean there’s only one more list of paid iPhone and iPad apps on sale for free to enjoy. Well, it’s here, and hopefully it’s good enough to tide you over until Monday. If not, you can always check back in Thursday’s post, where you’ll find a few more premium apps that are still free downloads. Don't Miss: There’s one thing that really has me worried about the iPhone 8 These are paid iPhone and iPad apps that have been made available for free for a limited time by their developers. There is no way to tell how long they will be free. These sales could end an hour from now or a week from now — obviously, the only thing we can guarantee is that they were free at the time this post was written. If you click on a link and see a price listed next to an app instead of the word “get,” it is no longer free. The sale has ended. If you download the app, you will be charged. Loved by TUAW, AppAdvice, and more than 950,000 users! Create awesome slideshows that you can share on Instagram, Facebook, YouTube or via email. 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Remember to hashtag #fliptastic for a chance to be featured on our Instagram account! “Best New App” – Apple Mic’d is the beautifully simple recording app that was made with the Apple Watch in mind. We cut the clutter so that nothing stands in the way of you and the recording you’re about to make. * Record on both iPhone and Apple Watch * Playback on both iPhone and Apple Watch * Use your watch as a remote to control iPhone recording and playback directly from your wrist. * Share your recordings with just a few taps * iCloud automatically backs up your recordings and makes them easy to share Mic’d for iPhone stands alone as a recording gem. With the Apple Watch, the things you can accomplish are limitless. Never again miss the moments in life that matter most. Happy recording. Here’s a bit more detail… Mic’d does not need the watch at all. It works just wonderfully on it’s own. If you do have a watch, however, then from your wrist, you can tell your iPhone to start and stop recording. Then you can tell your iPhone to playback those recordings. So many fun things to do when using your watch as a remote. But the watch is also a great standalone device. You can record and playback audio without even having your phone around. If you just want to know if your phone is recording or paused, just glance at your watch. Then start or stop it again with a tap. Available for iPad and iPhone. An intelligence quotient (IQ) is a score derived from one of several standardized tests designed to assess intelligence. The abbreviation “IQ” comes from the German term Intelligenz-Quotient, originally coined by psychologist William Stern. Try it. NOTE: This test is intended for entertainment purposes only. PicFace is a fast and fun way to customize and share awesome selfies and portraits with the world. This app retouches your picture automatically by applying skin filters. Add awesome design elements, frames and filters that will make your photos very unique. Pick from one of several gorgeous filters and frames and quickly share your photos to the Camera Roll, Facebook and Twitter. • Choose the best filter for your photo. • Share your photos on Twitter and Facebook! • Save it to your iPhone! • Email it to your friends! The app is a Safari extension that translates and speaks aloud the entire web page of Safari app. A must have app to translate and speak aloud web pages of Safari. Useful Features ● Translate the entire web page of Safari app – Support both Bing Translator (40+ languages) and Google Translate (60+ languages) translation services – Show both original web page and translation – Display the original text for each translated sentence ● Speak aloud the entire web page of Safari app – Speak 30+ languages – Read all unread web pages automatically – Swipe to control skipping sentences – Highlight word by word for each speaking sentence – Speak aloud the clicked web page – Add favorite web pages with “Starred” to speak aloud later – With funny bear and human face animations while speaking – Support useful speaking repeat, pause, speed and pitch options ● Optimize speak functions (Pro) – Background operation support: keep reading aloud web pages in the background while using another app – Lock screen support: play, pause, skip a sentence, adjust playback volume and see the sentences list on the lock screen – Headphone support: play, pause, adjust playback volume and detect headphone plugged and unplugged Features ● A Safari extension that translates the entire web page The app provides a Safari extension that translates the entire web page of Safari app. ● Supports both Bing Translator and Google Translate translation services The app supports both Bing Translator (40+ languages) and Google Translate (60+ languages) translation services. The service requires the internet connection while translating. ● Display the original text for each translated sentence The app could display the original text while taping the translated sentence. Show both original web page and translation. Switch between the translation and original web page (Google Translate, iPad). ● A Safari extension that speaks aloud the entire web page sentence by sentence The app integrates the system text-to-speech engine, speaks aloud sentence by sentence without internet connecting. Speak 30+ languages: Arabic (Saudi Arabia), Chinese (China), Chinese (Cantonese), Chinese (Taiwan), Czech (Czech Republic), Danish (Denmark), Dutch (Belgium), Dutch (Netherlands), English (Australia), English (Ireland), English (South Africa), English (United Kingdom), English (United States), Finnish (Finland), French (Canada), French (France), German (Germany), Greek (Greece), Hebrew (Israel), Hindi (India), Hungarian (Hungary), Indonesian (Indonesia), Italian (Italy), Japanese (Japan), Korean (South Korea), Norwegian (Norway), Polish (Poland), Portuguese (Brazil), Portuguese (Portugal), Romanian (Romania), Russian (Russia), Slovak (Slovakia), Spanish (Mexico), Spanish (Spain), Swedish (Sweden), Thai (Thailand) and Turkish (Turkey). The app supports one system language, you can make in-app purchases to buy extra languages. ● Add favorite web pages with “Starred” Add favorite web pages with “Starred” to speak aloud later. You can swipe to mark a starred item as read or unread, and flag or unflag a starred item. ● Read all unread web pages automatically The app can read all unread starred web pages automatically. ● Swipe to control skipping sentences You can skip a sentence or all below sentences while in Speak mode. ● Speak aloud the clicked web page If you click the link on web page while in Speak mode, the app will read the clicked web page automatically. ● Support useful speaking options Repeat times of the whole article, repeat times of each sentence, speaking pause seconds between sentences, speaking speed, speaking pitch and font size options. ● Highlight words while speaking The app will highlight word by word for each speaking sentence. The Random PW Generator allows them to easily generate random passwords, create your own, save and manage Passwords. Generate passwords with length of 4 to 26 characters. Character selection: big letters, small letters, numbers and special characters, combined with everything else. Special characters can be selected individually. Own password combined with generated characters. Save passwords, delete, print, move with iTunes file sharing on the computer, or send via AirDrop. iTunes File Sharing on – off function. App lock code allows you to keep the passwords from strangers eyes. Do not play with the security of your data! Avoid using the same password for multiple logins. Random PW generator helps you to solve these problems. With this app, your passwords remain only on the device! ***30 notifications included*** Share on Facebook and get unlimited notifications for free! WindPush is the ultimate app for anyone that needs specific wind conditions. Based on the settings you choose, you’ll be notified when the wind you are waiting for is forecasted. As an example you can get notified when the forecast says more than 15 knots from north-east or less than 5 knots from any wind direction. You can easily choose which days of the week you want to monitor, so you won’t be bothered when you’re busy. WindPush covers over 10 million locations worldwide and can also use the iPhone’s GPS to search for the location closest to your current position. Missing spot? If you can’t find the spot you’re looking for you can add it manually in Geonames’ database. Go to windpush.me/FAQ/ for further instructions. WindPush uses weather data from yr.no, delivered by the Norwegian Meteorological Institute and the NRK. Your use of WindPush is at your own risk, and we would like to point out that weather alerts for more than two or three days ahead can be very imprecise. We take no responsibility for any errors or omissions in the access to or use of weather data. Draw Pad Pro² is a simple yet powerful way to capture your thoughts, notes, and ideas. With a beautiful and clean interface designed for iOS 9, the app is a joy to use and easy to learn. Underneath the simplicity, Draw Pad Pro² packs powerful features. Each stroke you make is synced in real time to all your devices. Your work is organized into notebooks, with the ability to add titles to each page. Features: • Robust drawing engine • Beautiful iOS 9 design • Cloud Syncing to all your devices • Notebooks Galore Give Draw Pad Pro² a try today. We think you’ll love it! The Galaxy Note 8’s best new feature is supposedly coming early A OnePlus 5 like this might be the Galaxy S8’s only real rival There’s one thing that really has me worried about the iPhone 8 See the original version of this article on BGR.com
News Article | September 18, 2017
Since the late 1990s the share of diesel cars in the EU has risen to around 50% in the fleet, with important variations between countries. There are now more than 100 million diesel cars running in Europe, twice as many as in the rest of the world together. Their NOx emissions are however 4 to 7 times higher on the road than in official certification tests. Modern engine controls have been optimized by manufacturers for the specific laboratory testing but underperform in real-driving. In this new study we calculate the premature deaths from these excess NOx emissions for the population in all European countries. About 425,000 premature deaths annually are associated with the current levels of air pollution in EU28, Norway and Switzerland. More than 90% of these premature deaths are caused by respiratory and cardiovascular diseases related to exposure to fine particulate matter. NOx is a key precursor to this fine particulate matter. This new study estimates that roughly 10,000 premature deaths annually can be attributed to NOx emissions from diesel cars, vans and light commercial vehicles. About half--around 5,000 premature deaths annually--are due to NOx emissions being much higher than limit values in real-world driving. Petrol cars have much lower emissions. "If diesel car emissions were as low as petrol car emissions, three quarters or about 7,500 premature deaths could have been avoided" says Jens Borken-Kleefeld, transportation expert at the International Institute for Applied Systems Analysis (IIASA). The countries with the highest number of premature deaths attributable to fine particles from diesel cars, vans and light commercial vehicles are Italy, Germany and France. That is because of both their large populations and a high share of diesel cars. However, the risk per capita is almost twice as high in Italy as in France. "This reflects the very adverse pollution situation, particularly in highly populated Northern Italy", says research leader Jan Eiof Jonson from the Norwegian Meteorological Institute. The lowest risks are in Norway, Finland and Cyprus where risks are at least fourteen times lower than the EU28+ average. The study was conducted by the Norwegian Meteorological Institute in cooperation with the International Institute for Applied Systems Analysis (IIASA) in Austria, and the Dept. Space, Earth & Environment at Chalmers University of Technology in Sweden. In this study the Norwegian Meteorological Institute has calculated the pollutant concentrations and depositions based on NOx emissions from LDDVs from different countries and model years provided by IIASA. IIASA has also made the health effect calculations. This is not the very first calculation of health impacts for Europe. Notably, the Nature paper (Anenberg et al) came up with about 7,000 premature deaths due to excess NOx from LDDV. Their results were discussed and reported widely, but there was less focus on results in Europe, which we present here in detail. Jonson JE, Borken-Kleefeld J, Simpson D, Nyiri A, Posch M and Heyes C. (2017) Impact of excess NOx emissions from diesel cars on air quality, public health and eutrophication in Europe. Environmental Research Letters. 18 September 2017 The Norwegian Meteorological Institute is the meteorological service for both The Military and the Civil Services in Norway, as well as the public. Our mission is to protect life, property and the environment, and to provide the meteorological services required by society. http://www. The International Institute for Applied Systems Analysis (IIASA) is an international scientific institute that conducts research into the critical issues of global environmental, economic, technological, and social change that we face in the twenty-first century. http://www.
Agency: GTR | Branch: NERC | Program: | Phase: Research Grant | Award Amount: 530.51K | Year: 2014
Air pollution is the environmental factor with the greatest impact on human health in Europe. Despite substantial emission controls, the complexities of the processes linking emissions and air quality, means that substantial proportions - 80% and 97%, respectively, of the population in Europe lives in cities with levels of particulate matter (PM) and ozone (O3) exceeding EU limit and target values. The two pollutants are estimated to contribute 350,000 and 200,000 premature deaths across Europe. NERCs strategy document states: In the UK, air pollution costs the economy £15 billion every year in damage to human health, not including the cost of damage to our environment and crops. Understanding the key processes driving air quality across the relevant spatial scales, especially during pollution exceedances and episodes, is essential to provide effective prediction for both policymakers and the public. It is particularly important for policy regulators to understand the drivers of local air quality that can be regulated by national policies versus the contribution from regional pollution transported from mainland Europe or elsewhere. Urban areas are of particular concern since as well as being receptors of regional pollution, they have high local emissions from heating and road transport associated with their high population densities. They are also subject to an urban heat island effect which can impact on the chemistry of air pollution. Our overall aim is to use state-of-the-art modelling and measurements to quantify and reduce uncertainties in the key regional and local processes that control poor air quality in urban areas, both for present-day and in the future. This proposal will develop a novel model framework using a nested suite of models to bridge scales from regional to urban for simulating atmospheric composition and weather including urban heat island effects across the UK and over London. The proposal will further exploit state-of-the-art NERC measuements from recent ClearfLo and REPARTEE field campaigns in London bringing together modelling and measurements experts to determine controlling factors of high O3 and PM events. A detailed box model of the chemical environment based on these field measurements will be constructed, and used to calculate in situ chemical production of O3 during both average and episodic conditions. The coupled regional to urban model will be evaluated against these box model and field campaign results as well as extensive network measurements. Multiple approaches will be used to probe the regional and local contributions to O3 during high O3 events. The key processes driving PM episodes will also be determined using speciated field measurements and coupled model results. The role of nitrous acid on O3 and PM oxidation chemistry in urban areas is a key uncertainty that will be quantified. Air pollution events in the UK are usually associated with stagnation events, which in summer may be coincident with heatwaves. During heatwaves weather conditions may alter emission and deposition processes. The relative importance of these processes, such as reduced O3 deposition, that lead to elevated pollution levels will be established. To investigate the impact of future emissions and climate change on urban air quality, high-resolution climate-chemistry simulations that consistently account for changes in chemistry and transport from the regional to city scale will be performed and future impacts on air quality extremes evaluated. Proof of concept studies with the coupled model framework and with high-resolution climate projections demonstrate the viability of the intended research. This proposal comprises a strong collaboration between modelling and measurement scientists spanning the disciplines of fundamental chemistry, atmospheric composition, and climate change, to advance our understanding of the processes driving regional to urban-scale air quality now and in the future.
News Article | August 6, 2013
A starved polar bear found found dead in Svalbard as "little more than skin and bones" perished due to a lack of sea ice on which to hunt seals, according to a renowned polar bear expert. Climate change has reduced sea ice in the Arctic to record lows in the last year and Dr Ian Stirling, who has studied the bears for almost 40 years and examined the animal, said the lack of ice forced the bear into ranging far and wide in an ultimately unsuccessful search for food. "From his lying position in death the bear appears to simply have starved and died where he dropped," Stirling said. "He had no external suggestion of any remaining fat, having been reduced to little more than skin and bone." The bear had been examined by scientists from the Norwegian Polar Institute in April in the southern part of Svalbard, an Arctic island archipelago, and appeared healthy. The same bear had been captured in the same area in previous years, suggesting that the discovery of its body, 250km away in northern Svalbard in July, represented an unusual movement away from its normal range. The bear probably followed the fjords inland as it trekked north, meaning it may have walked double or treble that distance. Polar bears feed almost exclusively on seals and need sea ice to capture their prey. But 2012 saw the lowest level of sea ice in the Arctic on record. Prond Robertson, at the Norwegian Meteorological Institute, said: "The sea ice break up around Svalbard in 2013 was both fast and very early." He said recent years had been poor for ice around the islands: "Warm water entered the western fjords in 2005-06 and since then has not shifted." Stirling, now at Polar Bears International and previously at the University of Alberta and the Canadian Wildlife Service, said: "Most of the fjords and inter-island channels in Svalbard did not freeze normally last winter and so many potential areas known to that bear for hunting seals in spring do not appear to have been as productive as in a normal winter. As a result the bear likely went looking for food in another area but appears to have been unsuccessful." Research published in May showed that loss of sea ice was harming the health, breeding success and population size of the polar bears of Hudson Bay, Canada, as they spent longer on land waiting for the sea to refreeze. Other work has shown polar bear weights are declining. In February a panel of polar bear experts published a paper stating that rapid ice loss meant options such the feeding of starving bears by humans needed to be considered to protect the 20,000-25,000 animals thought to remain. The International Union for the Conservation of Nature, the world's largest professional conservation network, states that of the 19 populations of polar bear around the Arctic, data is available for 12. Of those, eight are declining, three are stable and one is increasing. The IUCN predicts that increasing ice loss will mean between one-third and a half of polar bears will be lost in the next three generations, about 45 years. But the US and Russian governments said in March that faster-than-expected ice losses could mean two-thirds are lost. Attributing a single incident to climate change can be controversial, but Douglas Richardson, head of living collections at the Highland Wildlife Park near Kingussie, said: "It's not just one bear though. There are an increasing number of bears in this condition: they are just not putting down enough fat to survive their summer fast. This particular polar bear is the latest bit of evidence of the impact of climate change." Ice loss due to climate change is "absolutely, categorically and without question" the cause of falling polar bear populations, said Richardson, who cares for the UK's only publicly kept polar bears. He said 16 years was not particularly old for a wild male polar bear, which usually live into their early 20s. "There may have been some underlying disease, but I would be surprised if this was anything other than starvation," he said. "Once polar bears reach adulthood they are normally nigh on indestructible, they are hard as nails." Jeff Flocken, at the International Fund for Animal Welfare, said: "While it is difficult to ascribe a single death or act to climate change it couldn't be clearer that drastic and long-term changes in their Arctic habitat threaten the survival of the polar bear. The threat of habitat loss from climate change, exacerbated by unsustainable killing for commercial trade in Canada, could lead to the demise of one of the world's most iconic animals, and this would be a true tragedy."
News Article | March 14, 2016
The carcass of a cow lies in a field in Disaneng village outside Mafikeng, South Africa, January 28, 2016. REUTERS/Sydney Seshibedi More OSLO (Reuters) - A record surge in temperatures in 2016, linked to global warming and an El Nino weather event in the Pacific, is adding urgency to a deal by 195 governments in December to curb greenhouse gas emissions to slow climate change, scientists said on Monday. Average global temperatures last month were 1.35 degree Celsius (2.4 Fahrenheit) above normal for February, the biggest temperature excess recorded for any month against a baseline of 1951-80, according to NASA data released at the weekend. The previous record was set in January, stoked by factors including a build-up of greenhouse gases in the atmosphere and the strong El Nino event, which releases heat from the Pacific. "I think even the hard-core climate people are looking at this and saying: 'What on Earth'?" David Carlson, director of the World Climate Research Programme at the U.N.'s World Meteorological Organization, said of the leap in temperatures. "It's startling," he told Reuters. "It's definitely a changed planet ... It makes us nervous about the long-term impact." Scientists say global warming is causing more powerful downpours, droughts and rising sea levels. Jean-Noel Thepaut, head of the Copernicus Climate Change Service at the European Centre for Medium-Range Weather Forecasts, said the long-term trend of warming "makes the implementation of the Paris agreement urgent." He noted that 15 of the 16 warmest years since records began were in the 21st century. In December 2015, 195 nations agreed in Paris to a climate deal with a goal of cutting greenhouse gas emissions to a net zero by 2100, shifting from fossil fuels in favor of greener energies such as solar and wind power. They set a goal of limiting global warming to "well below" 2C (3.6F) above pre-industrial times, while "pursuing efforts" for a 1.5C (2.7F) limit. Phil Jones, of the Climatic Research Unit at the University of East Anglia, said El Nino seemed less to blame for the current surge than the last big El Nino in 1998. "Based on 1998, March and probably April will also be very warm, before the El Nino influence wanes," he told Reuters. Ice in the Arctic Ocean was at the lowest recorded for February, the U.S. National Snow and Ice Data Center said. At Longyearbyen, on a Norwegian Arctic island, temperatures hit a peak of 6.6C (44F) on Jan. 2, against an icy average for a normal January of -15.3C (4.5F), data from the Norwegian Meteorological Institute showed. Reidun Skaland, a climate expert at the Institute, said there were always big swings in Arctic weather, "but it is a warning message when you see such high temperatures. There's an increasing trend."
Benestad R.E.,Norwegian Meteorological Institute
Journal of Climate | Year: 2011
A new set of empirical-statistical downscaled seasonal mean temperature scenarios is presented for locations spread across all continents. These results are based on the Coupled Model Intercomparison Project phase 3 (CMIP3) simulations, the Special Report on Emissions Scenarios (SRES) A1B story line, and arguably represent the largest downscaled multimodel ensemble to date in terms of worldwide distribution, length of time interval, and the number of global climate model simulations. The ensemble size of;50 members enables a crude uncertainty analysis for simulated future local temperature, and maps have been constructed for Europe, Africa, and the northwestern part of Russia and Scandinavia of the ensemble mean and 95th percentile for seasonal mean temperatures projected for 2100, as well as simulated probabilities for low or high temperatures. The results are stored as matrices of coefficients describing best-fit fifth-order polynomials, used to approximate the long-term trends in the temperature. These results suggest that the 95th percentile of the summer temperature is expected to increase 38-58C by 2100 over most of Europe, and that there will be reduced probabilities of winter temperature lower than 08C for all European locations, with the greatest reduction of;60% in areas where the winter temperature presently is around freezing point. A similar analysis for Africa suggests that the June-August mean temperatures may exceed 358C in isolated regions by 2100. For the northwestern part of Russia and Scandinavia, the analysis yields a 4.58-7.58C increase for the ensemble mean December-February temperature, with the most pronounced warming in the northeast, north, and over Finnmark County in Norway. © 2011 American Meteorological Society.
Isachsen P.E.,Norwegian Meteorological Institute
Ocean Modelling | Year: 2011
Theoretical tracer diffusivities given by linear Eady theory that accounts for non-zero bottom slopes are compared with diffusivities diagnosed from primitive equation simulations of thermally forced flows over an idealized continental slope. The behavior is discussed in terms of a bottom slope parameter δ̄, the ratio of the bottom slope to an expression roughly representing the depth-averaged isopycnal slope. The theoretical diffusivities, scaled by the total thermal wind shear and the first internal deformation radius, agree qualitatively with diagnosed diffusivities for δ̄≲0, the parameter regime appropriate for buoyant boundary currents flowing over continental slopes. But whereas Eady theory would suggest maximum diffusivities for moderate positive slopes, δ̄≃0.5, the diagnosed diffusivities are highest for δ̄=0, i.e. for flat bottoms. Finally, whereas Eady diffusivities should drop to zero for δ̄≳1, i.e. when the bottom becomes steeper than the mean isopycnal slope, the diagnosed diffusivities do not. Similarities and differences are discussed in terms of more general linear stability theory applied to the background density profile over the central slope region. It is found that interior potential vorticity gradients, neglected by Eady theory, both cause significant modification to the Eady mode and also enable non-Eady instabilities that are responsible for the non-zero diffusivities for δ̄≳1. Furthermore, estimates of kinetic energy spectral fluxes suggest that an inverse kinetic energy cascade is present, and it is speculated that this is responsible for the diagnosed maximum diffusivity for flat bottoms. © 2010 Elsevier Ltd.
Benestad R.E.,Norwegian Meteorological Institute
Theoretical and Applied Climatology | Year: 2010
A new method for predicting the upper tail of the precipitation distribution, based on empirical-statistical downscaling, is explored. The proposed downscaling method involves a re-calibration of the results from an analog model to ensure that the results have a realistic statistical distribution. A comparison between new results and those from a traditional analog model suggests that the new method predicts higher probabilities for heavy precipitation events in the future, except for the most extreme percentiles for which sampling fluctuations give rise to high uncertainties. The proposed method is applied to the 24-h precipitation from Oslo, Norway, and validated through a comparison between modelled and observed percentiles. It is shown that the method yields a good approximate description of both the statistical distribution of the wet-day precipitation amount and the chronology of precipitation events. An additional analysis is carried out comparing the use of extended empirical orthogonal functions (EOFs) as input, instead of ordinary EOFs. The results were, in general, similar; however, extended EOFs give greater persistence for 1-day lags. Predictions of the probability distribution function for the Oslo precipitation indicate that future precipitation amounts associated with the upper percentiles increase faster than for the lower percentiles. Substantial random statistical fluctuations in the few observations that make up the extreme upper tail implies that modelling of these is extremely difficult, however. An extrapolation scheme is proposed for describing the trends associated with the most extreme percentiles, assuming an upper physical bound where the trend is defined as zero, a gradual variation in the trend magnitude and a function with a simple shape. © The Author(s) 2009.
Benestad R.E.,Norwegian Meteorological Institute
Journal of Geophysical Research: Atmospheres | Year: 2013
Attributing changes in extreme daily precipitation to global warming is difficult, even when based on global climate model simulations or statistical trend analyses. The question about trends in extreme precipitation and their causes has been elusive because of climate models' limited precision and the fact that extremes are both rare and occur at irregular intervals. Here a newly discovered empirical relationship between the wet-day mean and percentiles in 24 h precipitation amounts was used to show that trends in the wet-day 95th percentiles worldwide have been influenced by the global mean temperature, consistent with an accelerated hydrological cycle caused by a global warming. A multiple regression analysis was used as a basis for an attribution analysis by matching temporal variability in precipitation statistics with the global mean temperature. Key Points Intense 24-hr precipitation changes due to global warming New method for downscaling 24-hr precipitation statistics Independent confirmation of earlier studies ©2013. American Geophysical Union. All Rights Reserved.