Atmospheric Circulation

Largescale Atmospheric Circulation

Sphere Svg

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...

Scenarios of the Arctic Climate in the 21si Century 1121 The GCM Method

Two types of GCMs can be distinguished equilibrium and transient models. The first group simulate changes of climate for C02 doubling occurring rapidly, while the second group compute the same for a gradually in creasing CO, (most often of a compounded increase per year). The second approach is more realistic and resembles the contemporary changes of CO, concentrations. The first equilibrium experiments conducted using atmospheric general circulation models simulated a very large increase 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...

Mean Monthly Seasonal and Annual Air Temperature

Single Sheet Origami Spiral Instructinos

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...

Synopticscale Circulation

Mean Winter Circulation

Similarly to the mid-latitudes, synoptic-scale disturbances control the daily weather events in the Arctic. Vangengeim (1952, 1961) showed that changes of synoptic processes in the Arctic are about 1.5 times faster than in moderate latitudes. Working from this and other facts given earlier, it can be concluded that the climate of the Arctic is significantly more sensitive to atmospheric circulation variability than the climates in both moderate and low latitudes. The first analysis of the...

The Annua Cycle

Variations of cloud amount in the annual march in different parts of the Arctic are very similar and rather straightforward. Analysing them allows us to distinguish three states winter, summer, and transitional (spring and autumn) (see Figure 5.1). In cold half-year (from November to April) the mean total cloud amounts are clearly at their iowesl and oscillate between 40 and 60 . In May an abrupt increase in cloudiness is observed, especially outside the Canadian Arctic. The highest cloudiness...

Temperature Variations After 1950

Table Place Cards Color

Detailed research into air temperature tendencies in the Arctic using data from 33 to 35 stations in the periods from 1951 to 1990 (Przybylak 1996a, 1997a, 2002a) and from 1951 to 1995 (Przybylak 2000a) revealed the predominance of negative trends, even though most of them were not statistically significant. Similar results have also been obtained by Chapman and Walsh (1993) Kahl et al. (1993a, b) Walsh (1995) Bom (1996) F0rland etal. 1997 and others. The areally averaged seasonal and annual...

Main Geographical Factors Shaping the Climate

Secret Garden Coloring Book

Undoubtedly, geographical latitude is the main factor determining the weather and climate both in the Arctic and elsewhere. For the purpose of this work, the Arctic has been defined after Atlas Arktiki (1985) (Figure 1.2). From Figure 1.2 it can be seen that the southern boundary of the Arctic thus defined ranges between about 54 N (the Labrador Peninsula) to about 75 N near Spitsbergen. No matter how we define the Arctic, its location in high latitudes limits significantly the magnitude of...

Przybylak Arctic Winds

Canada Atmospheric Circulation

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...

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...

Atmospheric Precipitation 711 Annual Cycle of Precipitation

Asian January Jul 850 Hpa Circulation

The amount of precipitation over any area depends on the moisture content of the air, the pattern of synoptic scale weather systems affecting the area, and the topography and the character of the underlying surface. The moisture contcnt of the air can be described using the concept of precipitable water. Precipitable water is defined as the depth to which liquid water would stand if all the water vapour in a vertical column of uniform cross-section, extending from the earth's surface to the top...

Net Radiation and Other Elements of the Heat Balance

Starship Enterprise Blueprints

The net radiation balance of the surface is a result of the subtraction of its long-wave component from its short-wave component. The net short-wave radiation in the Arctic is always positive or equal to zero (polar night). The effective radiation exists throughout the whole year and it is mainly positive in the sense given in the previous section. For the mean monthly and annual averages which we have analysed, it is always positive, as was shown in the previous section (see Figure 3.6)....

Air Pollution

Dimensions Tree Life Diagram

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....

Number of Days with Precipitation

420 Coloring Pages For Adults

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...

Longwave Net Radiation

Long-wave net radiation (so-callcd effective radiation) is a residual of two fluxes terrestrial radiation (upward infrared radiation) and the counter-radiation of the atmosphere (downward infrared radiation). The main factors determining effective radiation are air temperature and humidity, temperature of the surface, stratification of the atmosphere, and cloudiness (cloud amount and type, height and physical properties of clouds). Counter-radiation plays a very important role in the Arctic,...

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...

Shortwave Net Radiation

From a climatological point of view, knowledge about short-wave net radiation (or the absorbed solar radiation) is more important than about the potential global solar radiation reaching the earth's surface. Short-wave net radiation depends mainly on the declination of the sun and surface albedo. Along the same latitude only the albedo determines the amount of absorbed energy hy the earth's surface. On a local scale (in mountainous areas), however, differences in the elevation of the land, its...

The Canadian Region

This region is one of the largest areas in the Arctic. Therefore, of course, the differentiation of climate is particularly evident here. The estimates of magnitude of these differences are, however, not identical. For example, Barry and Hare (1974) write, The Canadian Arctic Archipelago extends over 15 of latitude but the climatic characteristics are relatively homogeneous. In turn, Maxwell (1982) noted that despite the northern latitudes of the Canadian Arctic Islands, the climate there is...

Development of Views on Atmospheric Circulation in the Arctic

In the late 19th century scientists undertook attempts to construct various schemes of atmospheric circulation in the Arctic on the basis of theoretical considerations. Ferrel (1882, 1889) argued that the mid-latitude westerlies circulate around a large low pressure system occurring in the Arctic with its centre above the Pole. His idea was preserved until the publication of the meteorological observations from the Fram drift (Mohn 1905), and according to Hobbs (1926) even until 1920. Mohn,...

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...

The Atlantic Region

In the cold half-year, the most striking feature of this region is its extreme high temperatures (relative to other parts of the Arctic) related to strong and vigorous cyclonic activity and the warm ocean currents which are branches of the Gulf Stream (see Figure 4.4). For example, the mean monthly air temperatures in Spitsbergen are about 20 C higher than in the Canadian Arctic at the same latitude. The anomalies get smaller to the north, northeast, and east because the influence of cyclonic...

The Interior Arctic Region

The horizontal gradients of meteorological elements here are the lowest in the Arctic. However, some differences in pattern distribution of these elements exist, which allow a distinction to be drawn between two separate sub-regions the sub-Atlantic and the sub-Pacific (Prik 1971 Atlas Arktiki 1985). The sub-Atlantic area quite often falls under the influence of the North Atlantic cyclones and therefore the temperatures here are higher than in the sub-Pacific sub-region, where anticyclones...

Relative Humidity

Relative Humidity Equation

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...

Radiation Conditions

In the history of actinometric measurements in the Arctic, five phases can be distinguished Phase 1. The 19lh ccnniry. During this period, measurements of solar radiation were made using ordinary thermometers, i.e. the difference between tiic readings of thermometers with shaded and exposed bulbs, placed in the sun and in the shade, was used to estimate the intensity of radiation. According to Gavrilova (1963) the first such measurements were made during the expeditions of John Franklin to the...

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...

Canadian High Arctic

Arctic Circulation

A review of the ice-core literature and data (e.g. Koerner and Fisher 1981 Bradley 1990 Koerner 1992) presenting the history of the climate in the Canadian Arctic in the Holocene period and particularly in last two to three millennia shows that in this part of the world the MWP is rarely distinguished. Generally most researchers indicate a steady decrease in temperature from 2000-3000 BP until the LIA period. Similar results have also been obtained based on glacial geology records (Blake 1981,...

Global Solar Radiation

Global Atmospheric Circulation Diagram

Global solar radiation is one of the important factors in the formation of the radiation regime, weather, and climate. Its role in both net radiation and energy balance is crucial. Luckily, this component of the radiation balance is very easy to measure. From the reasons mentioned above, global solar radiation measurements are most often conducted in actinometric stations, not only in the Arctic. In spite of this, the network of stations is still insufficient for analysing the field of global...

Climatic Regions

From the descriptions which have been presented earlier of the different elements of the Arctic climate, one can see that their spatial changes are extremely heterogeneous. Surprisingly, the greater horizontal gradients occur in winter, when the differentiated influence of the solar energy is meagre or equal to zero (polar night). During this time the differences in observable meteorological fields are caused mainly by the atmospheric circulation and, to a significantly lesser degree, by the...

Period 1011 ka 1 ka BP

Oxygen Isotopes Greenland

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...

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...

Mean Seasonal and Annual Diurnal Temperature Ranges

Meaning Spatial Figures

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...

Climatic Change And Variability In The Holocene

Polar regions play a very important role in shaping the global climate. Both empirical and modelling studies show that these are the most sensitive regions to climatic changes. As a consequence, warming and cooling epochs should be significantly more distinct here that in the lower latitudes. Climatic models indicate that they should also occur earlier. However, this is not always the case. It depends on the factor(s) causing the climate change (Przybylak 1996a, 2000a). The Arctic climate...

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...

Latent Heat

Starship Enterprise Blueprints

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...

Acknowledgements

It would not have been possible to carry out the research for the present volume without the financial support provided by the Nicholas Copernicus University in Torun. For their assistance in securing this support I would like to thank the Vice-Rector for Research and International Relations Prof. Marek Zaidlewicz, the Dean of the Faculty of Biology and Earth Sciences Prof. Andrzej Tretyn, the Director of the NCU Institute of Geography Prof. Jan Falkowski, and the Administrative Director Dr....

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,...

Atmospheric Precipitation And Snow Cover

Knowledge about precipitation and its changes in the Arctic is just as important as knowledge about air temperature. This information is needed first of all to correctly estimate the mass balance of the Arctic glaciers and the Greenland Ice Sheet. In turn, the mass balance influences the recession (negative balance) or advance (positive balance) of glaciers. As a result, changes of sea level are observed. Both these processes are very important for natural environment and for human industrial...

The Pacific Region

Cyclonic activity in winter in the Pacific region is significantly lower than in the Atlantic and Baffin Bay regions and, according to the calculations of Serreze et al. (1993), their frequency is lower than 3 . The low frequency of cyclones is caused by the occurrence of orographic barriers (zonally stretching mountains the Koryak, Chukchi, and Brooks Ranges). As a result, cyclones can enter to the Pacific region only through the narrow Bering Strait. The narrowness of this strait also limits...

The Analogue Method

The analogue studies use as analogues of a high-C02 world wann periods taken from either paleoclimatological reconstruction of, for example, the Medieval Warm Epoch, the mid-Holocene, and the last interglacial (Eemian) or instrumental period. For the Arctic, our knowledge concerning the climates of the above periods (other than the instrumental) is not sufficient. Therefore, only the second approach is acceptable. The major advantage of scenarios based on the instnimcntal records, according to...

Model Simulations of the Presentday Arctic Climate

One measure of the level of confidence in results generated by GCMs is the degree to which they reproduce the cunent global climate. A review of the first three IPCC reports (Houghton et al. 1990, 1992, 1996) and other works (e.g. Gates et al 1996, 1999) shows that the largest disagreement between coupled climate model simulations of prcscnt-day climate is in the Polar regions. It is worth adding, however, that in more rcccnt models this disagreement is still observable, though it is lower...

Scenarios Of The Arctic Climate In The 21st Century

Both observations and model studies have shown that the Arctic is a region of high climate sensitivity to increased concentration of greenhouse gases (see e.g. Houghton et al. 1990, 1992, 1996, 2001). Most climate model simulations suggest that a doubling of C02 will cause a rise in global mean surface air temperature from 1,4 C to 5.8 C (Houghton et al. 2001) with a two-to three-fold amplification in the Arctic. Atkinson (1994) gives the following reasons for this enhanced warming in the...

Eurasian Arctic Islands

Again, as in the previous section, the best proxy data for this part of the Arctic are to be found in Svalbard. Therefore, the history of the climate for the period analysed will be presented mainly using information from this area. Researchers investigating the history of the climate in the Holocene period (e.g. Tarussov 1992 Werner 1993 Svendsen and Mangerud 1997) generally do not mention the existence of the MWP. Most of them indicate late-Holoccne climatic deterioration (see also Section...

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...

The Climate of the Arctic

Atmospheric and Oc anographie Sciences Library A C.I.P Catalogue record lor this book is available from the Library ol Congress Published by Kluwor Academc Publishers. PO Bo* 17.3300 AA Dordrecht. The Netherlands Sold and distributed in North. Central and South Amonca 101 Philip Drive. Norwoll. MA 02061. U S A In all other countries, sold and distributed PO Box 322.3300 AH Dordrecht. The Netherlands. Layout and Composition Studio KROPKA dtp - P> oir Katoariski Tel 048 (56) 66 01 737 048 <...