Climate Change Impacts in Norway

Specific Climate Impacts

In Norway the major observed impacts attributed to climate change are for biological systems and human and managed systems. They both are with medium confidence in attribution to climate change. The biological system includes terrestrial ecosystems, while the human and managed system includes livelihoods, health, and/ or economics. The key regional risks for Europe are increased economic losses where people will be affected by flooding due to increase in urbanization, sea level, erosion of the coast, and river discharge. Additionally people will be affected by extreme heat events which will have impacts on health. There will also be an significant reduction in water availability which will lead to an increase in water restrictions. This reduction in water ability is due to river and groundwater resources and also an increase in water demand. The increase in water demand has to do with irrigation, energy, and industry use. 

Regional Climate Projections

During the last 30 years the trends in annual mean temperature in Europe exceed the global mean land trend and it is very likely that the mean temperatures will increase in the future for all regions in Europe. For the last 60 years there has been an increase in number of warm days and nights in Europe and an decrease in cold days and night. The studies also indicate a general increase in the intensity of extreme precipitation during winter time for the last 40 years. The winter seasons in Northern Europe are projected to increase in mean precipitation, while the summer season the mean precipitation will only have small changes. Studies indicates that winter variability in Europe may be related to sea ice reduction in the Barents sea. It is suggested though that cold winters in Europe will continue in coming decades despite an overall warming. 

Detailed Look at Future Climate

Observed climate trends and future climate projections shows regionally varying changes in temperature and rainfall in Europe. There is an projected increase in temperature throughout Europe, and an increase in precipitation and in winter speed extremes in Northern Europe. There has also been an wide ranging affect on distribution and abundance of animals, fish and plant species throughout Europe. An increase in coastal- and river flood risks in Europe and also damages caused by this are projected due to sea level rise and an increase in extreme rainfall. There has been observed changes in extreme river discharge in some areas in Europe and also therefore changes in river flood occurrence. Cereal yields is likely to increase in Northern Europe, and climate change is very likely to increase the seasonal activity of plant diseases other places in Europe. The forest productivity in Northern Europe will increase due to climate change. There will be an increase in irrigation needs due to  damage of crops by heat waves and also because of an decrease in runoff. Marine fish species has shifted to higher latitudes and reduced their body size due to the observed warming.

Most interesting threaths

For me, the most interesting impact of climate change is the increase in frequency of avalanches and landslides in Europe. The reason for this is that as an geology student I have taken a course in mass movement, rock avalanches and landslides and learned about the hazard and risks around this topic. I have also been so lucky to visit a research-team in Norway and seen how they are monitoring some of the mountains that are likely to experience huge avalanches in the next 20 years. I would love to work with avalanches in the future, so even though an increase in the frequency of avalanches in Europe will most likely cause huge damages, it is exciting to me geologically. 

In the Alps there has been an increase in the frequency of rock avalanches and slides during the last 100 years. The frequency of landslides are projected to increase along with climate change. This is due to increase in precipitation and temperature changes which makes can make the already existing faults and cracks in mountainsides more unstable and cause failure which can lead to mass movement. 

This map is showing the changes in mean number of heat waves for the months march, june,  july, august and september for 2071-2100 ( RCP8.5) compared to 1971-2000 (RCP4.5). The map shows that almost all of Europe and will experience an increase in heat waves, and that  Norway is the country in Scandinavia that will experience the most. 

The map is downloaded from: https://ipcc-wg2.gov/AR5/images/uploads/WGIIAR5-Chap23_FINAL.pdf

This map is showing the seasonal changes in heavy precipitation in percent for the months june, july and august for 2071-2100 ( RCP8.5) compared to 1971-2000 (RCP4.5). The map shows that especially northern Europe will experience seasonal changes in heavy precipitation. This map is downloaded from:  https://ipcc-wg2.gov/AR5/images/uploads/WGIIAR5-Chap23_FINAL.pdf

Severe Weather in Norway

Tornadoes forms during severe thunderstorms. For thunderstorms to form cold and warm air masses have to meet, and the warmer and moister the warm air mass is, the more severe thunderstorms is created. A tornado is defined as a violent rotating column of air. The rotation is due to winds at different altitudes, blowing in different speeds which creates a wind share. The rotating air is rotating horizontally first but is lifted from the ground by the updraft of the thunderstorm. Once it is lifted nearly vertically it is considered a mesocyclone.

In the United States the tornadoes usually travels from southwest to northeast. This is because the tornadoes moves in the same direction as the thunderstorms that are producing them. The average number of tornadoes in the US each year is estimated to be over 1000 according to this webpage:
http://scienceline.ucsb.edu/getkey.php?key=1073

Tornadoes do also occur in Norway, but the tornadoes in Norway happen in a lot smaller scale of those in the US though. Because the tornadoes in Norway are at a F0 or F1 on the Fujita-scale the extent of damage is also very small compared to those than can develop in the US. In Norway the surface temperature is not high enough and also the temperature differences in the air masses is not big enough to create great tornadoes. Norway have experienced tornadoes at a F2 on the Fujita-Scale, but these tornadoes has been very short-term tornadoes.There is no recorded number on how often Norway experiences tornadoes each year. One reason is that a lot of the tornadoes in Norway are so small and often unnoticed. Each summer Norway experiences events of eddies, that can be somewhat similar to those like an tornadoes but of course not to compared to tornadoes. They are just both rotating winds.
Norway does experience on a average 100.000 thunderstorms each year though. Beneath are some web-pages where I found some information on Tornadoes in Norway. The last web-page said that Norway experiences "baby-tornadoes" every ten years.
http://no.wikipedia.org/wiki/Tornado#Tornadoer_i_Norge
http://forskning.no/klima-meteorologi-vaer-og-vind/2014/11/tornadoene-kommer-tettere
http://www.vg.no/nyheter/innenriks/vaer-og-uvaer/baby-tornado-herjet-soer-norge/a/125133/

This figure shows the distribution of tornadoes in the world. United States, Australia and Europe seems to experience the most tornadoes. Even though the US experience a lot more tornadoes and more extreme events of tornadoes, Europe is also considered as a tornado active continent. Norway is located in Europe and I have attached an arrow so it will be easier for you to locate Norway. As you can see the southern part in Norway experiences tornadoes, while the northern parts does not. 

The figure is downloaded from: http://www.ustornadoes.com/2013/07/25/from-domestic-to-international-tornadoes-around-the-world/

By looking at the graph there seem to have been an increase in tornado activity over time. People speculate if the increase in tornadoes is caused by the increase in temperatures due to global warming.

The graph shows an increase in tornadoes the last 30 years. It is hard to believe that we already have noticed such effect from the global warming. This does not necessarily mean that there are more tornadoes today than for 30 years ago. The reporting systems has changed over time, and I believe that more tornadoes is reported now, than from 30 years ago. Also, people most certainly know more now than for 30 years ago about weather and which weather events can be defined as tornadoes. 

For hurricanes to develop there need to be consistent heating of the surface, high humidity and cumulus or cumulonimbus clouds present. High surface temperatures and high humidity is mostly seen in the tropics, hence there is where the hurricanes is mostly seen. Norway is not located in the tropics but in the subarctics and do not have high enough surface temperature nor high enough air humidity to develop severe hurricanes. 

Hurricanes are not called hurricanes everywhere, but have other names depending on where they occur. In the Atlantic and the East Pacific the hurricanes are called hurricanes. In the Indian Ocean and near Australia the term "tropical cyclones" are used when taking about a hurricane. Off the coast of China and in Indonesia they use the name "Typhoons"when they are talking about events that we know as hurricanes. 

Figure downloaded from: http://www.learnnc.org/lp/editions/nchist-recent/6248

The general path of hurricanes in US is from southeast to northwest. The hurricanes often follow this path because the trade winds are taking the hurricanes with them when blowing from the east to west in the tropics. 

About five hurricanes strikes the coastline of US every 3 years according to this website:

http://www.ussartf.org/hurricanes.htm

Norway do experience hurricanes. The last big hurricane that reached Norway was in 1992, the year I was born, in New Years Eve. The hurricane was located in my home town and we still see evidences from the storm around my house, 22 years later..Scientists claims that such huge hurricanes will statically only occur every 200 years in Norway. 

Each year Norway experience only a couple events of winds that reach the strength to be called an hurricane. But normally these hurricanes only lasts for about ten minutes. 

http://www.kriseinfo.no/Vaer-og-natur/Ekstremvar/Hva-er-en-storm/

http://met.no/Nyttårsorkanen+1.+januar+1992.pBl77BFEFTN99TVQ721-U9or6XyogdVPL28nMhPLZB9MtlY05hRDI2p.ips

Daily Weather in Norway

My country's capital city is Oslo, and I am covering three days of forecasting of the weather in this city. These three days are october 29th, october 30th and october 31st. 

For october 29th the forecasted high is 48°F and the forecasted low is 34°F. The  change for precipitation is at 0%.  

For october 30th the forecasted high is 44°F and the forecasted low is 33°F. The  change for precipitation is at 0%. 

For october 31st the forecasted high is 39°F and the forecasted low is 38°F. The change for precipitation is at 90%. 

The average pressure over these three days are 29.98 inches. The pressure increases over this three day period. The average wind speed over these three days is 5.44 mph and the wind speed decreases over this period. 

    Figure 1: satellite image downloaded from www.wunderground.com

This satellite image shows that there are no clouds in the city of Oslo when this image was taken. Oslo is marked with a black arrow in this image. There are some clouds very far away from Oslo though, which are all cold, and low to middle clouds. You can tell if the clouds are high, middle or low by looking at the legend on the right side of the image, where the color blue represents low/middle clouds. The image shows a blue color which indicates middle frozen and no precipitation. 

The type of ground surface in Oslo is mostly represented by a grey color which indicates a city surface. There are also some small areas that has the color green which represents parks and forests, and by locking at the map I could see a big river going across the whole city of Oslo. 

                                Figure 2: image of Europe downloaded from www.intellicast.com

This image shows both high- and low pressures. The low pressure is located around the country of Norway, while the high pressures is located north and west from Norway. As you can see there are many different fronts. The red line represents a warm front that is located East of Norway. The purple line is a occluded front located North of Norway. The stationary front is located East of Norway and consist of both red and blue lines in-between each other. The cold front is located south of Norway and is represented by a blue line. There is also a cold front far East from Norway in the Russia-region in the right of this image.

                                Figure 3: image of North-western Europe downloaded from www.intellicast.com

                    

This image shows low pressures around Norway. As you can see there are many different fronts. The red line represents a warm front that is located East of Norway. The purple line is a occluded front located North of Norway. The stationary front is located East of Norway and consist of both red and blue lines in-between each other. The cold front is located south of Norway and is represented by a blue line. 

Global and Local Winds in Norway

Norway is located in the northern hemisphere at a latitude between 57° to 71° North and a longitude between 4° West to 31° East. Norway is therefore located in both the ferrel cell and the polar cell.  Norway is affected by the westerlies from south and the polar easterlies from north. The westerlies blows from west towards north east. The polar easterlies blows irregular from north and east towards south west. These warm, moist westerly winds meets the colder, dryer easterlies and makes up an front. This front is called the Polar front and represents a huge difference in temperature between these two winds. In the Polar front the warmer air masses from south meets the colder air masses from north and is pushed up by the colder air. This creates a low- pressure belt that influences the weather and climate in Norway.

Norway is located in the Westerly wind belt, and as I mentioned, the westerlies blows from west towards east. Norway has a long coastline located in west, so the climate and weather in Norway is very much affected by these westerly winds. 

With Norway being located so far north it is also strongly affected by the low-pressure system along the polar front. The polar front is located over Norway for the most of the time during the year. This low-pressure system is created near the surface, while higher up in the atmosphere there is a polar jet stream that carries these winds towards east. Norway is pretty long in extent though, so the northern part and the southern parts of Norway normally does not experience low-pressure at the same time. 

In the Polar front the warmer air masses from the westerlies meets the colder air masses from the polar easterlies and the warmer air gets pushed up. This warm, moist air is transported with the westerlies to the Norwegian western coast where the air masses is experiencing forced lifting by the mountains. This forced lifting creates orographic precipitation some miles from the coast, while the inner part of the country are lee areas in relation to the winds coming from west. The wettest areas is therefore near the coast (west), while the driest areas are located behind the coastal mountain ranges (east), in the "rain shadow areas". 

So, in Norway the westerly wind belt has a huge impact on both the coastal and the continental climate.

There is also a lot of frontal precipitation in Norway due to the Polar Front. When a cyclone develops along the polar front zone the warm air rises above the cold air, cools and releases precipitation. The polar front contributes with humid air masses over Norway throughout the whole year, but the cyclone activity is greatest in autumn and wintertime. 

Norway is a mountainous country and experiences a lot of different winds and breezes due to the differences in altitude. The three most typically winds or breezes that Norway experiences due to the mountains are mountain breezes, valley breezes, and orographic lifting. The mountain- and valley breezes are day and nighttime phenomena due to different heating of the valley floor and walls. Orographic lifting on the other hand is due to moist air getting pushed up when they meet the high mountains and the air starts condensing and clouds and precipitation occurs. Because of this relationship between the air and the mountains some parts of norway experience a lot of orographic precipitation, while others are more dry areas because their are located in flat areas or behind the mountains where there is a "rain shadow". 

Norway has a long coastline all the way from south to north along the west side of the country. Coastlines usually experience both sea breezes and land breezes. These breezes are day- and nighttime phenomenas, but also seasonally phenomenas. In the summer Norway experiences a lot of sea-breeze and land-breeze during the winter. These breezes are due to the differential heating of land and water and creates high and low pressures that forms the winds. This explains why there are stronger winds near the coasts then inland. 

Typical Weather and Tourism in Norway

In Norway Winter Solstice occur on december 21st. December is the last month of the year, but the first month of winter in Norway. This is the darkest month in Norway and snow is the type of precipitation that is most likely to occur.There can also be some sleet and hail, but rain is not that common during december. The average maximum temperature in Norway in december is 33.8°F and the average minimum temperature is 23°F. 

Summer Solstice occur on june 21st. June is the first of the summer months in Norway and is also the month where we have the long summer-nights. The average maximum temperature in Norway in june is 66.2°F and the average minimum temperature is 50°F. Precipitation that is likely to occur in june is mostly rain due to the temperatures being higher. I have actually several times experienced snow(!) falling down in my backyard though… in june...

Spring Equinoxes occur on march 20th. The average maximum temperature in march in Norway is 39.2°F and the average minimum temperature is 24.8°F. March is the first month of the spring in Norway. This is also the month where Norwegians starting to notice how much longer the days are becoming. The snow is starting to melt in the mountains during this months, but it still snows in march in Norway. Besides snow, march can experience both rain and sleet. 

Autumnal Equinoxes occur on september 23th. The average maximum temperature in Norway in september is 55.4°F and the average minimum temperature is 44.6°F. September is the first month of autumn in Norway. This is the season when  you could experience rain almost every day. The autumn is therefore the wettest season in Norway. Later in the autumn you could experience some sleet, but not in september. 

The spring is a positive season in Norway. This is the time when the norwegians "wakes up" from the long, cold, ongoing winter. March is the month where the days are getting longer, the flowers sprouts, and when the people up north can finally take of their heavy parkas and start wearing lighter jackets. 

Late march or april, during the easter holiday, would be the best time to visit Norway. This is a time where it is not as cold as the winter, but still some snow left up in the mountains to go skiing. In the spring, and especially during easter, Norwegians travels  up to their cabins in the mountains to go skiing and enjoy the easter sun. Even though the average temperatures are set to be very low  you could actually experience great weather in march, especially in the big cities of Norway. To walk down the shopping streets in Oslo during the spring is fantastic, and you would tell how pleased the Norwegians are when they are finally feeling the sun starting to warm them up again!

If you don't want to go skiing you should probably take a hike or visit Trollstigen, Preikestolen and Nordkapp. These are the most popular tourist attractions in Norway along with the cruise ships that will take you through the world-famous Norwegian fjords! 

Visit Norway! Go and see the northern lights or the midnight sun, or visit the world-famous Norwegian fjords,    mountains and glaciers!

Temperature Controls in the city of Oslo in Norway

There are five main controls on surface air temperature. Within a country, different cities can experience very different temperatures and weather due to the topography in the city, the location to the city with respect to latitude, the ocean, wind-direction, and so on. The five controls on surface air temperature are ocean currents, altitude, geographic position, cloud cover and albedo, and differential heating of land and water. Today I am going to talk about the city Oslo, and which controls on temperature that impact this city the most and the least.

Norway's capital city is Oslo and is located in the eastern Norway with a latitude 59°56'58"N and longitude 10°45'23"E. The warmest month in Oslo is july with an average monthly temperature of 64°F. The coldest month in Oslo is december with an average monthly temperature of 27°F. The annual range of temperature in Oslo is then 37°F. Here is the website where I found this information:www.met.no/English/

Oslo has a humid climate due to the Gulf stream. The Gulf Stream is an ocean current and an control of temperature, by keeping Oslo much milder in the winters, and much warmer in the summers. Even though the Gulf Stream doesn't effect just only Norway's capital city, but instead the whole country, I would say that this ocean current is the most important control on temperature in Oslo. 

Oslo has warmer summers and milder winters than it originally should have had, because of the warm Gulf stream waters. The Gulf Stream originates in the Gulf of Mexico and carries warm water across the Atlantic Ocean up to northern latitudes. In North, the Gulf Stream is also known as the "North Atlantic Drift". This is a powerful, warm Atlantic Ocean Current that are responsible from providing Oslo and Norway from not to share the same cold temperatures as Alaska, Greenland and Siberia which shares the same latitude. 

The Gulf Stream does not flow smoothly, but instead it circulates in a turbulent way. This circulation movement makes the gulf stream use longer time to pass the Norwegian coast. The longer time it uses to pass, the more time the warm ocean current have to warm up the air around the coast. This warm air blows mainly as westerly winds. These warm winds keeps Oslo milder. On average, Oslo is supposed to be 10°C colder than it is today. 

Among all the controls on temperature that I listed in the beginning of this text, I believe that altitude is the one that impact Oslo the least.  Norway is a very mountainous country, but Oslo is located at a relatively flat lying area so altitude does not impact Oslo as much as other cities of Norway.  

As we all know, our Earth is getting warmer, and this warming process is referred to as "global warming". What a lot of people might not know is that every place on earth will not certainly get warmer. Some of them might instead get colder. And that is what scientist are saying about Norway. They believe that Norway will get colder. My professor back in Norway told me about this theory of how Norway will get colder, and I will try to explain here what he told me. 

The global change have so far lead to severe melting of glaciers in the poles. Along with the melted ice and more precipitation up in north, the North Atlantic Ocean is receiving more freshwater. This increase in freshwater in the North Atlantic threatens the strength of the Gulf Stream in the future. This is because when the Gulf Stream passes Norway and goes further up North it eventually sinks down and becomes deep water. This sinking is due to the amount of salt that is in this southernly water, along with the cooling of the water. Saltier, colder water is more dense, and will sink. So, for the water to sink it has to contain salt, but the scientists concern is that this sinking, that leads to an "pumping" effect of the ocean circulation, will decrease because of the freshwater supply. 

If the Gulf stream decreases in its strength, the Norwegian weather will be colder. As I mentioned earlier, when the Gulf stream is strong, it brings more warm water towards Norway and Norway gets warmer. But if this theory proves to be correct, Oslo and Norway will experience a much different climate in the future. 

The research that I have done to find out what controls the temperatures in Oslo, have confirmed to me just how important the Gulf Stream is for us Norwegians up in North. Not only is the ocean currents a big factor to the whole country of Norway, but it is also the major control on temperature in the city Oslo. Scientists are sure of the fact that we are definetely in a period of global warming, but it will be interesting to keep following the research that will be done in the future, and to see if they will predict another outcome for Norway. Is Norway going to be warmer or colder? I certainly don't know..