Evaluation of temperature trends downscaled from global climate models forced with observed greenhouse gas emissions suggests that the downscaled results do span the observation-based trends at Svalbard Airport — Novel projections focussing on the Svalbard region indicate a future warming rate up to year three times stronger than observed during the latest years.
Also for precipitation, the long-term observational series indicate an increase and the projections indicate a further increase up to year The Arctic land areas have over the last decades experienced more warming that any other region on earth [ 1 , 2 ].
Similarly, Serreze et al. Climate models [ 1 , 2 , 6 ] furthermore indicate that anthropogenic global warming also in the future will be enhanced in the northern high latitudes by complex feedback mechanisms in the atmosphere-ocean-ice system. The most sophisticated tools for describing future long-term climate development are the atmosphere ocean general circulation models AOGCMs.
These models include a description of physical processes associated with the atmosphere, oceans, sea ice, and often land surface processes. The resolution in the AOGCMs is presently sufficient for modelling most of the large-scale features in the atmosphere, but in general still too coarse for reproducing the climate on regional or local scale.
For most studies of impacts of climate change, detailed scenarios are needed for specific locations, that is, with a much more detailed spatial resolution than the present simulations with global climate models. A large variety of national and international global climate model results incl. In regional attribution studies for the Arctic, the importance of natural variability must be recognized.
In climate model simulations, the Arctic signal resulting from human-induced warming is large but the variability noise is also large.
As the signal-to-noise-ratio may be lower in the Arctic than at lower latitudes [ 8 ], most of the projections in this study are focussing on the end of the 21st century.
In the Arctic, data scarcity and measuring problems are other important issues. To monitor the long-term variations of climate conditions in the Svalbard region, it is important to make optimal use of observational series from the region.
This paper describes the observed variations in temperature and precipitation during the latest years Section 2 , methods and background data for applying AOGCMs to provide regional and local climate information Section 3 , projections of climate development in the Svalbard region up to year Section 4 , and examples of projected changes in daily temperatures in the Longyearbyen Svalbard Airport area Section 5. The first permanent weather station at Svalbard was established in Green Harbour in [ 9 ].
During the last century, there have been several relocations of the different weather station in the Svalbard region Figure 1 [ 10 ]. Because of large climate gradients and the harsh weather conditions, even small changes at Arctic measuring sites may cause substantial changes in measuring conditions.
Identification of inhomogeneities in Arctic series is also complicated by the sparse station network. The average winter temperatures have increased by 3. The time series of annual mean temperatures for the stations in the Svalbard region show a quite similar long-term pattern Figure 2. The temperature has increased in all seasons cf.
Table 2 with the strongest increase in winter and spring. The smoothed graphs indicate that there is variability on a multidecadal scale, leading to mainly positive temperature trends before the s, then a relatively warm period during the subsequent two decades, a temperature decrease from the s to the s, and thereafter a general temperature increase. These features are discussed by Hanssen-Bauer [ 13 ] and are also seen for other parts of the Arctic e. Although data coverage was limited in the Arctic in the first half of the 20th century, the spatial pattern of the earlier warm period in the s and s appears to have been different from that of the current warm anomaly.
In particular, the current warm period is partly linked to the Northern Annual Mode and affects a broader region [ 14 ]. While the dynamics of the warming in Svalbard prior to the s is still not fully understood, the warming from the s to the mid s is clearly linked to atmospheric circulation patterns favouring increased southerly and south-westerly winds in the Svalbard area [ 15 ].
This agrees well with Rigor et al. The latest decade, however, show rather different patterns. While 5 of the 10 warmest winters in the Svalbard Airport composite series occurred after , , , , and , several of these winters were characterised by average or even low AO mode. Linear trends Table 2 were used to quantify the temperature development in Svalbard, even though there is certain scepticism against using linear trends as a measure for climate change, because such changes not necessarily occur linearly [ 19 ].
Also, linear trends for short time series are sensitive to the start and ending points. Earlier studies e. Figure 2. In the first period — , the composite Svalbard Airport series show a warming annually and during autumn and winter. In the next period — , all stations tend to show negative trends in annual temperatures.
The cooling was particularly strong 1. The annual temperature increase at Svalbard Airport and Hopen during the latest two decades is close to 1. The linear trend indicates an increase in mean annual temperature of 2. The warming has also accelerated considerably since the increase of 0. For the optimal series, all stations have statistically significant warming trends 0.
This reflects the fact that spring temperatures have increased more evenly throughout the century than, for example, the winter temperature. For the period —, it is possible to compare recent trends when all stations were running at the present sites. The linear trends in Table 2 indicate that during this year period, the annual temperature at the four stations has increased by 2.
The greatest increases were observed in autumn and winter. However, uncertainties in measuring precipitation in the harsh Arctic environment [ 22 ] and the sparseness of data in parts of the region limit confidence in these results. There are large regional variations in precipitation across the Arctic, and also large regional variations in the changes in precipitation. Since , annual precipitation has increased at about the same rate as during the first half of the 20th century. Also, IPCC [ 2 ] states that there has been a widespread increase in precipitation over northernmost Europe during — The harsh weather conditions e.
To reduce inhomogeneities because of instrumental changes, manual precipitation measurements are still performed at the stations used in this paper. Studies of long-term precipitation variability in the Svalbard region are hampered by several relocations of gauges.
The precipitation gauge in Longyearbyen was moved to Svalbard Airport in , but based on measurements at several sites, a composite, homogenised precipitation series back to was established by Nordli et al. However, this series is not homogenised after a new relocation in Also the Hopen series are not homogenised after relocation of the precipitation gauge in The precipitation series from the Norwegian high-Arctic stations show quite different individual long-term patterns both on an annual as well as a decadal timescale Figure 3.
This is in contrast to the quite similar development for temperature, and the main reason is that precipitation varies locally on a smaller spatial scale than air temperature. However, the series have one common feature: all series show a positive trend in annual precipitation throughout the period of observations cf.
Table 4. Longyearbyen weather by month. Click on each chart for more information. The daily average high red line and low blue line temperature, with 25th to 75th and 10th to 90th percentile bands. The thin dotted lines are the corresponding average perceived temperatures. Average Hourly Temperature in Longyearbyen Link. The average hourly temperature, color coded into bands.
The shaded overlays indicate night and civil twilight. Compare Longyearbyen to another city:. Cloud Cover Categories in Longyearbyen Link. The percentage of time spent in each cloud cover band, categorized by the percentage of the sky covered by clouds. Daily Chance of Precipitation in Longyearbyen Link.
The percentage of days in which various types of precipitation are observed, excluding trace quantities: rain alone, snow alone, and mixed both rain and snow fell in the same day.
Average Monthly Rainfall in Longyearbyen Link. The average rainfall solid line accumulated over the course of a sliding day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average snowfall. Average Monthly Snowfall in Longyearbyen Link. The average snowfall solid line accumulated over the course of a sliding day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands.
The thin dotted line is the corresponding average rainfall. Hours of Daylight and Twilight in Longyearbyen Link. The number of hours during which the Sun is visible black line.
From bottom most yellow to top most gray , the color bands indicate: full daylight, twilight civil, nautical, and astronomical , and full night. The solar day over the course of the year From bottom to top, the black lines are the previous solar midnight, sunrise, solar noon, sunset, and the next solar midnight.
The day, twilights civil, nautical, and astronomical , and night are indicated by the color bands from yellow to gray. The transitions to and from daylight saving time are indicated by the 'DST' labels. The time in which the moon is above the horizon light blue area , with new moons dark gray lines and full moons blue lines indicated. Humidity Comfort Levels in Longyearbyen Link. The percentage of time spent at various humidity comfort levels, categorized by dew point. Average Wind Speed in Longyearbyen Link.
The average of mean hourly wind speeds dark gray line , with 25th to 75th and 10th to 90th percentile bands. Wind Direction in Longyearbyen Link. The percentage of hours in which the mean wind direction is from each of the four cardinal wind directions, excluding hours in which the mean wind speed is less than 1.
The lightly tinted areas at the boundaries are the percentage of hours spent in the implied intermediate directions northeast, southeast, southwest, and northwest. Average Water Temperature in Longyearbyen Link. The daily average water temperature purple line , with 25th to 75th and 10th to 90th percentile bands.
The tourism score filled area , and its constituents: the temperature score red line , the cloud cover score blue line , and the precipitation score green line. It is the highest temperature officially recorded in Svalbard during November pic. Average temperature at the Russian archipelago of Severnaya Zemlya north of the Siberian mainland was as much as ten degrees Celsius warmer than normal in October. Houses are sagging as thawing permafrost makes the ground unstable.
Until last winter, Svalbard counted consecutive months with above normal temperatures. The Norwegian meteorological institute explains the heat with the negative spiral caused by climate change.
Less sea-ice and less white snow-covered land mean less of the sunlight being reflected back to space. Darker waters-surface and soil absorbs more heat, again accelerating the permafrost thaw and causes more sea-ice to melt. If global emissions continue to increase like today, the annual average temperature at Svalbard will be above zero degrees by the end of this century, the meteorological institute predicts.
Before today, it had only once ever reached 20C. That was back on 16 July, , when a temperature of Today, this record was smashed as the temperature soared to The measurement was taken at the Longyearbyen airport weather station between 5pm and 6pm.
The new record was announced via the Yr twitter account:. Mellom kl. The archipelago is the meeting place for cold polar air from the north and mild, wet sea air from the south. To many readers, In much of the world, it isn't!
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