Largescale Atmospheric Circulation

The Arctic must import heat from southerly latitudes due to the net radiation loss to space from the top of the atmosphere. Investigations have also shown that almost the entire deficit of energy is supplemented by atmospheric circulation (see previous chapter). This fact ascribes considerable importance to atmospheric circulation as a climatic factor. Schemes of general atmospheric circulation which are frequently published in handbooks show the occurrence of the so-called 'polar cell' in the...

Diurnal Temperature Ranges and Cloudiness

Based on the results presented in Section 4,2, the general pattern of influence of cloudiness on T and T seems to be quite similar. However, the existing differences in magnitudes of this influence (expressed by anomalies) are significant during some seasons and should cause appropriate changes of the DTR in the case of increasing or decreasing trends in cloudiness in the Arctic. The influence of cloudiness on DTR is presented in Table 4.4 and Figure 4.13. These data clearly show that, on an...

Cloudiness

Our current knowledge concerning cloudiness in the Arctic, as has already noted been by Raatz (1981), Barry et al. (1987) and Serreze and Rehder (1990), is still remarkably poor. Of the existing 15 distinct global cloud climatologies reviewed by Hughes (1984), only two (Scherr et al. 1968 and Berlyand and Strokina 1980) provide information about both poles while a further four have information for only one or other of the poles. In the second half of the 1980s and at the beginning of the 1990s...

References

AGASP (Arctic Gas and Aerosol Sampling Program), 1984, Geophys. Res. Lett., 11 (5). Ahlmann H.W., 1948, Glaciological Research on the North Atlantic Coasts, Roy. Geogr. Soc. Res. Ser. 1, London, 83 pp. Ahlmann H.W., 1953, Glacier Variations and Climatic Fluctuations, Bowman memorial lectures, ser. 3, Amer. Geogr. Soc., New York, 51 pp. Aleksandrov E.I. and Lubarski A.N., 1988, 'Stabilisation of norms under climate monitoring', in Voskresenskiy A.I (Ed.), Monitoring Klimata Arktiki,...

Latent Heat

Latent heat fluxes in the Arctic are significantly weaker in January than sensible heat fluxes. In this month (Figure 3.13), evaporation is very slight in the Arctic because of low temperature and a surface covered by sea ice and snow. As a result, the latent heat fluxes do not exceed -1 kJ cm in the central Arctic. Near the sea-ice edge the loss of energy gets higher (-4 kJ cm ) and in the open water areas it reaches its maximum (-39 kJ cm2). Polynya areas show a loss of energy up to -4 kJ...

Sunshine Duration

Knowledge about sunshine duration, aside from being important theoretically, is also of practical significance. The study of sunshine duration enables improved calculations of global solar radiation (e.g. Spinnangr 1968 Dahlgren 1974 Markin 1975). Such a possibility is very important for the Arctic, where only infrequent numerous and short scries of actinometric observations are available. Sunshine duration, having a strong relationship with cloudiness, can also supplement our information,...

The Influence of Atmospheric Circulation on Temperature

It is not possible to investigate the reasons for recent air temperature variations without discussing atmospheric circulation changes. It is widely known that the importance of circulation in the formation of climate is much greater here than at lower latitudes (see Alekseev et al. 1991, their Table 1). Alekseev et al. (1991) also found that the advcction of warmth from lower latitudes by atmospheric and oceanic circulation provides more than half the energy annually available in the Arctic...

Relative Humidity

Relative humidity describes the degree of saturation of air by water vapour. This parameter is almost always used to characterise the air humidity in the Arctic. Some of the above cited papers are devoted to studying this parameter, either entirely (Meteorology of the Canadian Arctic 1944 Rae 1951 Putnins 1970 Vowinckc and Orvig 1970 Sater et al. 1971 Pereyma 1983) or to a great extent (Petterssen et al. 1956 Zavyalova 1971). In winter, the relative humidity in the Arctic should be calculated...

Spatial Patterns

In January, representing winter conditions, the spatial distribution of cloudiness shows greater variation than in summer. The zone with highest cloudiness (> 80 ) spreads from the Norwegian Sea to Novaya Zemlya, covering a large part of the Barents Sea and even the southern part of Spitsbergen (Figure 5.4). Cloudiness above 60 occurs in the whole Atlantic region and in the south-eastern part of the Baffin Bay region. The lowest cloudiness (< 40 ) includes the belt spreading from the...

Air Humidity

Water vapour is a very important meteorological element because it is a crucial link in water circulation on the globe. Air humidity is most often characterised in meteorology using the following characteristics actual water vapour pressure, relative humidity, and saturation deficit. It should be mentioned here that, when relative humidity is used to describe the humidity conditions in the Arctic, a distinction should be made between the expression of relative humidity in terms of percentage of...

Przybylak Arctic Winds

Winds, as we know, are the result of both large-scale and synoptic-scale atmospheric circulation. n addition, local factors such as geography, orography, and topography (altitude and relief) can sometimes significantly influence the direction and speed of winds (Rae 1951 Wagner 1965 Markin 1975 Maxwell 1980, 1982 Ohmura 1981 Pereyma 1983 Wojcik and Przybylak 1991). There is a paucity of scientific literature describing winds in the Arctic in general. Some information may be found in the...

Mean Seasonal and Annual Diurnal Temperature Ranges

The highest mean annual Diurnal Temperature Ranges (DTRs) above 8 C occur over the continental parts of the Canadian and Russian Arctic which are located far from Atlantic and Pacific oceans (Figure 4.10). The lowest DTRs (< 5 C) are noted in the Norwegian Arctic, particularly in those areas which are not covered by sea ice. The region spreading from the Norwegian Arctic to Alaska which encompasses almost all islands lying here (from Spitsbergen to Ostrov Vrangciya) has a slightly higher DTR...

LsOo

-1T -15 -13-20 -18 -16-16 -14 -12-16 -14 -12-10 -8 -6 Figure 10,13. Variations in S S0 for the Svalbard ice cores (I) Westfonna. (2) Austfonna, (3) Lomonosov plateau. (4) Gronfjord-Fridtjof ice divide (after Vaikmac 1990). The LIA was interrupted in Spitsbergen in the 16' century. However, the pronounced warming occurred mainly in the lower located glaciers (Figure 10.13). On the other hand, on the Lomonosov plateau (1000 m a.s.l.) both warm and cold spells occurred during this period. Summer...

Period 1011 ka 1 ka BP

Precipitation Holocene Eurasia

The start of the Holocene is estimated most often between 10 and 11 ka before present (years BP, the present being defined as 1950 A.D.). However, glaciological proxy data show that this date should be shifted to about 11.6 ka (see e.g. Johnsen et al. 1992 or O'Brien et al. 1995). As can be seen from Figure 10.1, there is a dramatic change of climate at about this time. At the Summit and Dye 3 8lsO profdes, the change is equal to 3 4 o (it gives about a 5 7 C rise in temperature). Most of the...

Mean Monthly Seasonal and Annual Air Temperature

Air temperature is the most important, and therefore also most often studied, climatological clement. This is as true for the Arctic as it is for everywhere else. For this reason, our knowledge about this element, in comparison with others, is the best, but is still not sufficient for some parts of the Arctic (e.g. the central Arctic and the inner part of Greenland). The instrumental records of Arctic temperature arc brief and geographically sparse. Only five records (Upernavik commenced 1874...

Number of Days with Precipitation

The number of days with precipitation is a very important characteristic of the precipitation regime. Three categories of days with precipitation are mostly used 0.1 > 1.0, and > 10.0 mm. In the Arctic, as was mentioned in the previous section, light (< 1.0 mm) precipitation prevails. More intensive amounts of precipitation occur with a significantly lower frequency. Days with precipitation greater than 10.0 mm are particularly rare. Most authors presenting results for large parts of the...

Air Pollution

Until recently, the Arctic environment was treated as a pristine place unspoiled by man. If we take diaries or logbooks of polar explorers from the I9'h and early 20lh centuries, we will find a large number of phrases underlying the Arctic's cleanliness, its crystal air, and sparkling ice. Opinions about the lack of pollution in the Arctic continued to be held to the beginning of the 1970s, although the first documented report of arctic air pollution (coining the term 'Arctic haze') was...

Frequency Distribution

In climatology, the frequency occurrence of the given element within the arbitrary chosen intervals often supplements the information obtained from the analysis of the mean values. The relative frequency of occurrence of winter, summer, and annual precipitation sums in selected stations representing all distinguished climatic regions in the Arctic, is presented in Figure 7.10. Histograms of the frequency have been drawn for 25 mm and 50 mm intervals for seasonal and annual totals, respectively....

Temperature Inversions

Surface-based temperature inversions in the troposphere are one of the main features of the Arctic climate, particularly in the low-sun (or no-sun) periods. This differs from normal tropospheric conditions, in which temperature decreases with height from the surface. Because of the very high frequency of the temperature inversions in the Arctic in the annual march, the term 'semi-permanent inversion' is often used. Outside the Polar regions, the semi-permanent inversions occur only in the...

The Baffin Bay Region

The Baffin Bay region climatically is very similar to the Atlantic region, particularly to its southern and western sub-regions. The weather in winter in both these regions is shaped mainly by the cyclones developing over the North Atlantic. In the case of the Baffin Bay region, the cyclones move from the source areas through the Davis Strait and Baffin Bay. Cyclones bring large amounts of warmth and moist air to the areas where they enter. Therefore, air temperatures here are markedly higher...

Local Circulation and Mesoscale Disturbances

As mentioned at the beginning of previous section, local factors can sometimes significantly change the surface wind speed and direction. This change in many cases is so great that little or any connection with the large- scale circulation exists. In addition, local circulation and other mcsoscale phenomena such as polar (also called Arctic) lows can also markedly change the parameters of wind. Thus to describe large-scale atmospheric circulation, we cannot use the observations of wind speeds...

Fog

Four types of fog can be distinguished in the Arctic steam fog or Arctic smoke, The most common type is advection fog occurring mainly in summer (particularly from June to September) when relatively warm, moist air flows in over a cold surface. The most favourable conditions for the formation of this type of fog arc the open waters of the Kara, Laptev, East Siberian, and Chukchi seas. Warm water carricd by the northern extension of the Gulf Stream system significantly reduces the frequency of...

Boundaries of the Arctic

The Arctic is not an easily definable geographic entity similar to, for example, Iceland, Lake Baykal, or even the Antarctic. Therefore, until recently, it has not been possible to arrive at any single definition of the area. Since the 1870s a large number of researchers representing different disciplines such as geography, climatology, and botany have tried to establish a widely acccpted criterion to delimit the Arctic boundary (Figure 1.1). In almost all the geographical monographs and other...

Water Vapour Pressure

Generally speaking, because of the low air temperatures, water vapour contcnt is also low throughout the Arctic. This results both from limited evaporation and the small amount of water vapour which can be held by the cold air. The annual course of the water vapour pressure is therefore very similar to that of air temperature. In winter months, from November to March, and in some parts of the Arctic even to April (e.g. Spitsbergen), the water vapour pressure is the lowest and shows clear...