In this study, weather conditions causing warm waves in north−western Spits − bergen, exemplified by Ny− Å lesund station, were analyzed. Between 1981 and 2010, 536 days with the maximum temperature exceeding 8.3 ° C (the value of 95 percentile) were selected. 37 warm waves, which altogether lasted 268 days, were identified. A typical feature of pressure pattern causing warm waves was the appearance of positive anomalies of both the sea level pressure and the height of isobaric surface 500 hPa in the Euro−Atlantic sector of the Arctic. This indicates a presence of high−pressure systems in this region. Extremely warm days appeared more often with the circulation from the eastern than the western sector. Longer and warmer heat waves occurring in the last decade of the analyzed period may be considered as a sign of climate warming, which has a significant impact on environment, i.e. reduction in area and thickness of glaciers, reduction of permafrost and snow cover, changes in biodiversity, etc . The increase in the air temperature and more frequent occurrence of heat waves may encourage development of tourism in polar areas, potentially causing further changes in the environment.

Meteorological and biometeorological conditions during the warm seasons (June– September) of 1979–2008 are described for the Hornsund area, Spitsbergen. The measure− ments were taken at four sites: at Hornsund, at the Hans Glacier (at its equilibrium line and in the firn section) and at the summit of Fugleberget. The variation of meteorological and biometeorological conditions was analysed in relation to altitude, distance from the sea and the ground type. In warm seasons, the air temperature at Hornsund was 2.2°C higher on aver− age than at the Hans Glacier (central section) and by 2.8°C than at the Hans Glacier (firn sec− tion) and at Fugleberget. The average wind speed recorded at Hornsund was higher (0.6ms−1) than at the Hans Glacier and lower (0.9ms−1) than at Fugleberget. Four biometeorological in− dices were used: wind chill index (WCI), predicted insulation of clothing (Iclp), cooling power (H) and subjective temperature index (STI). The strongest thermal stimuli were ob− served on the Hans Glacier and in the upper mountain areas. The study has found a consider− able degree of spatial variation between the meteorological elements investigated and the biometeorological indices in the Hornsund area. The impact of atmospheric circulation on meteorological elements and biometeorological indices is also presented. The mildest bio− meteorological conditions of the warm season found at Hornsund were associated with air masses arriving from the southwest and west.

The article presents the biometeorological impact of thermal and humidity conditions on the human body in the Hornsund area in the southern Spitsbergen, Svalbard. This was determined based on diurnal air temperature range, the day-to-day variation in average diurnal air temperature and the average diurnal relative humidity. The temporal variability of thermal and humidity biometeorological stimuli in Hornsund was examined for the period 01.11.1978–31.12.2017. A lessening of biometeorological impact was found in the southern Spitsbergen region, including a statistically significant negative trend in strongly- and severely-felt stimuli (according to diurnal air temperature range), and in significant and severe stimuli (according to day-to-day variation in average diurnal air temperature). A non-significant positive trend was observed in the number of days of relative humidity with humid and very humid air. To analyse the spatial variability of the stimuli around the Hornsund fjord, data were used from seven year-round measuring stations for the period 01.07.2014–31.06.2015. The most unfavourable conditions were found on the Hans Glacier, on the summit of Fugleberget and inside the fjord. The paper presents the role of atmospheric circulation on thermal and humidity stimuli. In the Hornsund region, the highest probability of unfavourable sensible temperatures for humans occurring during the year was mostly in winter and early spring. This was related to the advection of air masses from the north-east sector, regardless of baric regime type. It was found that very humid air (> 85%) flowed over Hornsund for practically the entire year from the S–SW as part of both cyclonic and anti-cyclonic systems.

Certain chemical parameters such pH, specific electric conductivity (SpC) and concentrations of chloride ions (Cl-) have been analysed in samples of precipitation collected close to the Polish Polar Station at Hornsund (PPS), SW Spitsbergen. On the basis of seasonal data from years 1993-1994 and 1998-1999, some differences are apparent from the two sets. There is also a marked difference in the seasonal results, especially with respects to pH values; summer precipitation (pH of which can be as low as 3.78) is much more acidic than winter. This was particularly notable in respect of the summer of 1993, and was presumably the result of a relatively unusual atmospheric circulation and a high influx of airborne contaminants from Europe. The wide variation in specific electrical conductivity measurements is considered to be related to variations in wind direction and speed. That precipitation the highest total dissolved salts, of 11.7 mm w.e. (water equivalent), (November 1993), provided 10.7 g of salt per square metre of tundra near the Polish Polar Station. The proximity of the sea, consequently the development of marine aerosols, largely determines the chemical nature of the precipitation. Thus, variations in the chloride ion concentrations during the study periods more or less reflect the variations in the marine aerosol influences on the nature of the polluted precipitation. An analysis of the atmospheric circulation reveals that the most acid precipitation occurs most frequently in the C-8 type of circulation (cyclonic S + SW) and also, less so, for type C-3 (anticyclonic S + SW).

This paper provides an overview of the results of research on changes in ground temperature down to 50 cm depth, on the Kaffiøyra Plain, Spitsbergen in the summer seasons. To achieve this, measurement data were analysed from three different ecotopes (CALM Site P2A, P2B and P2C) – a beach, a moraine and tundra – collected during 22 polar expeditions between 1975 and 2014. To ensure comparability, data sets for the common period from 21 July to 31 August (referred to as the “summer season” further in the text) were analysed. The greatest influence on temperature across the investigated ground layers comes from air temperature (correlation coefficients ranging from 0.61 to 0.84). For the purpose of the analysis of the changes in ground temperature in the years 1975–2014, missing data for certain summer seasons were reconstructed on the basis of similar data from a meteorological station at Ny-Ålesund. The ground temperature at the Beach site demonstrated a statistically−significant growing trend: at depths from 1 to 10 cm the temperature increased by 0.27–0.28 ° C per decade, and from 20 to 50 cm by as much as 0.30 ° C per decade. On the Kaffiøyra Plain, the North Atlantic Oscillation (NAO) has a greater influence on the ground an d air temperature than the Arctic Oscillation (AO).

In this study, atlases of wave characteristics and wave energy for the Barents Sea have been generated for the years from 1996 to 2015 based on ERA-Interim datasets from the European Centre for Medium-Range Weather Forecasts (ECMWF). The wave power resources in the Barents Sea can be exploited with sea ice extent declining in recent years. The entire Barents Sea has been divided into multi-year sea ice zones, seasonal sea ice zones and open water zones according to the 20-year averaged sea ice concentration. In the entire domain, the spatial distributions of the annual averaged and mean monthly significant wave heights and wave energy flux are presented. For the open water zones, 15 points have been selected at different locations so as to derive and study the wave energy roses and the inter-annual wave power variation. Moreover, the correlations between the wave energy period and the significant wave height are shown in the energy and scatter diagrams. The maximum wave power occurs in the winter in the western parts of the Barents Sea with more than 60kW/m. The wave energy can therefore be exploited in the open water zones.

This article aims to analyse the influence of weather types on meteorological

conditions in Petuniabukta (Svalbard) during July and August of 2016. The paper analyses

the daily courses of air temperature and humidity at four measurement points located on

the west bank of Petuniabukta near Adam Mickiewicz University Polar Station during

two different types of weather conditions: (i) cloudy and windy, (ii) calm and clear.

These weather types, distinguished on the basis of wind speed and cloudiness, allowed

for the creation of composite maps of the synoptic situation (SLP and geopotential

height of 500 hPa distribution) and its anomalies. In the study area, the air temperature

range in windy and cloudy weather conditions was larger (-10°C to 15°C) than that in

sunny and calm weather (0°C to 15°C), which contrasts the range of humidity values.

The diurnal cycle of meteorological elements in sunny and calm days is strongly related

to the sun elevation angle. In the above-mentioned weather types, the air temperature

was higher by several degrees (median 5°C to 8°C) than on windy and cloudy days

(median about 0°C to 6°C) at each measurement point. On days with sunny and calm

weather, a smaller vertical temperature gradient of air is observed (for sunny and calm

days 0.63°C and for windy weather 0.8°C).

This paper presents the spatial distribution of changes in the value of the predicted insulation index of clothing (Iclp) in the Norwegian Arctic for the period 1971-2000. For this study, data from six meteorological stations were used: Ny-Alesund, Svalbard Airport, Hornsund, Hopen, Bjřrnřya and Jan Mayen. The impact on the atmospheric circulation to the course of the Iclp index was analyzed using the catalogue of circulation types by Niedźwiedź (1993, 2002), the circulation index according to Murray and Lewis (1966) modified by Niedźwiedź (2001), the North Atlantic Oscillation Index according to Luterbacher et al. (1999, 2002), and the Arctic Oscillation Index (Thompson and Wallace 1998).

The objective of the study was to determine multi-annual changes and variability of occurrence of cold spells in summer and warm spells in winter on Spitsbergen in the period 1976–2016, and circulation conditions of their occurrence. Cold days in summer were defined as days with mean daily air temperature lower than temperature corresponding to the 10th percentile from daily temperature, and warm days in winter as days with mean daily air temperature exceeding the 90th percentile from daily air temperature. The research showed a statistically significant increase in mean air temperature, the rate of which in winter was more than four times higher than in summer. The observed warming translated into a decrease in the number of cold days in summer (-2.5 days/10 years in Svalbard Lufthavn and -1.3 days/10 years in Ny-Ålesund) and an increase in the number of warm days in winter (2.7 days/10 years in Svalbard Lufthavn and 2.4 days/10 years in Ny-Ålesund), and warm and cold spells related to the frequency of such days. The rate of the changes was higher in Svalbard Lufthavn than in Ny-Ålesund. The occurrence of cold days and cold spells was particularly related to the advection of air masses from the north-western sector. The occurrence of warm days and warm spells was related to the advection of air masses from the south-west.