WEATHER TYPES IN THE NORWEGIAN ARCTIC

In order to assess the usefulness of Norwegian Arctic bioclimatic conditions for outdoor activities in the years 1971–2000, the author applied his own weather typology developed on the basis of the classification proposed by Błażejczyk (1979). The typology classified four weather groups for the study area. Atmospheric circulation types proposed by Niedźwiedź (2002) were used to determine the synoptic situations and types of favourable weather conditions for outdoor recreation, tourism and work, as well as those that may pose a threat to human life.

BIOMETEOROLOGICAL CONDITIONS IN THE ARCTIC DURING THE FIRST INTERNATIONAL POLAR YEAR, 1882–1883

The article provides an initial description of the biometeorological conditions in the Arctic during the first International Polar Year (IPY 1) of 1882–1883. The study is based on hourly measurements taken from nine stations which represent most of the climatic regions in the Arctic. The diversity of biometeorological conditions was analysed in relation to the height above sea level, the distance from the sea and the character of the ground. The analysis made use of such biometeorological indices as wind chill index (WCI), predicted insulation of clothing (Iclp) and the cooling power of the air (H). A considerable spatial diversity of the biometeorological conditions was found during the period investigated. The least favourable thermal sensations occurred at the Sagastyr station, and the most favourable conditions were observed at Kapp Thordsen.

Exposure-Dependent Variations in Air Temperature and Humidity on the Moraine of the Aavatsmark Glacier (Nw Spitsbergen) in the Summer Season of 2010

The article presents results of research on the development of air temperature and relative humidity at a height of 5 cm above the active surface of the terminal lateral moraine of the Aavatsmark Glacier, relative to its exposure in the summer season of 2010. Variations in the two conditions were analysed for five measurement sites situated on northerly (SN), easterly (SE), southerly (SS) and westerly (SW) slopes, as well as on the flat top surface of the moraine (STop), in different weather conditions. The article also includes a temperature and humidity stratification in the near surface air layer (5-200 cm) above the moraine. The issues were investigated for mean values from the whole period of research, as well as for individual days demonstrating distinct degrees of cloudiness and wind speed

Selected meteorological phenomena posing a hazard to aviation: a case study on Bydgoszcz airport, central Poland

The article describes the occurrence of selected weather phenomena that are hazardous to aviation (thunderstorms, hail, fog and glaze) in Bydgoszcz. The work employs 1971–2010 data from the Bydgoszcz-Airport meteorological station. The hazardous atmospheric phenomena selected for analysis hinder or sometimes even prevent aviation. Of the analysed weather phenomena in Bydgoszcz, those most hazardous to aviation are fog and thunderstorms. The average annual numbers of days featuring them exceed 71 and 14, respectively. The analysis shows that statistically significant threats to aviation have decreased, e.g. number of days with fog (by 4.76 days/10 yrs) and days with thunderstorms (by 1.68 days/10 yrs). However, no clear trends can be seen for the number of days with hail (decrease of 0.14 days/10 yrs) and days with glaze (an increase of 0.16 days/10 yrs)

Bioclimatic features of Toruń according to the tourism climate index

The paper characterises the annual pattern and the long-term variability of the Tourism Climate Index (TCI) in Toruń in the years 1966–2020. In the annual variation, conditions for tourism and recreation were best from May to August. For the summer period (from June to August), the climatic conditions according to TCI were excellent, while for May they were assessed as very good. Meanwhile, the least favourable conditions for recreational and tourist activity occur in the winter months of January and December. In Toruń, there was a statistically significant increase of 0.9 pt/10yr in the annual average TCI value. An improvement in climatic conditions for humans was demonstrated for all seasons but was greatest in spring and autumn (respectively 1.6 and 1.0 TCI pt/10yr). Atmospheric circulation was also found to affect TCI. This was determined using a calendar of circulation types over central Poland, based on which indices of zonal, meridional and cyclonic circulation were used. The study has shown that anticyclonic circulation has the greatest impact on improving conditions for tourism.The paper characterises the annual pattern and the long-term variability of the Tourism Climate Index (TCI) in Toruń in the years 1966–2020. In the annual variation, conditions for tourism and recreation were best from May to August. For the summer period (from June to August), the climatic conditions according to TCI were excellent, while for May they were assessed as very good. Meanwhile, the least favourable conditions for recreational and tourist activity occur in the winter months of January and December. In Toruń, there was a statistically significant increase of 0.9 pt/10yr in the annual average TCI value. An improvement in climatic conditions for humans was demonstrated for all seasons but was greatest in spring and autumn (respectively 1.6 and 1.0 TCI pt/10yr). Atmospheric circulation was also found to affect TCI. This was determined using a calendar of circulation types over central Poland, based on which indices of zonal, meridional and cyclonic circulation were used. The study has shown that anticyclonic circulation has the greatest impact on improving conditions for tourism

Climatic conditions of the north−western part of Oscar II Land (Spitsbergen) in the period between 1975 and 2000

The paper describes climatic conditions of the north−western part of Oscar II Land (Spitsbergen) based on meteorological data from 1975 to 2000, which were taken from Ny Ålesund and Kaffiöyra−Heggodden stations. The changes in annual courses of main climatic elements are investigated. However, the authors focused mainly on the analysis of summer climate, because most of the field work is conducted at this time of the year. Aside from the standard climatic analysis, the influence of atmospheric circulation on selected meteorological elements was also investigated. The climate of the north−western part of Oscar II Land was compared with the climates of the remaining areas of the western coast of Spitsbergen. It was found that the climate of the studied area differs considerably from the climate of the central−inner and southern parts of the western coast of Spitsbergen (areas represented by the Svalbard Lufthavn and Hornsund stations respectively). The differences in climatic elements, however, are not stable throughout the year and in particular seasons and months can even change signs. Thus, any generalisation of results obtained based on seasonal data is inadmissible. It was also found that the wind conditions of the Kaffiöyra region are more representative of the north−western part of Oscar II Land than are the wind conditions of the Ny Ålesund region

Comparison of Early-Twentieth-Century Arctic Warming and Contemporary Arctic Warming in the Light of Daily and Subdaily Data

Significance Statement: It is well established that human activity (particularly increased greenhouse gas emissions) is the primary driving mechanism of the recent dramatic warming in the Arctic. However, the causes of a similar warming here in the first half of the twentieth century remain uncertain. The limited knowledge about the climate of that period—which mainly results from the low resolution of data—is a significant obstacle to a definitive determination of the forcing mechanisms. Therefore, the main aim of our paper is to improve our understanding of specific aspects of weather and climate (including extremes) using long-term series of daily and subdaily data that have rarely been applied for this purpose. This new, more comprehensive knowledge about the historical Arctic climate should allow the scientific community (particularly climate modelers) to better validate both climate models and reanalysis products and, consequently, to more precisely identify the causes of the early-twentieth-century Arctic warming. Data availability statement: Datasets for this research were derived from the following public domain resources: 1) All-Russia Research Institute of Hydrometeorological Information–World Data Centre (RIHMI-WDC), http://meteo.ru/; 2) The Government of Canada (Environment and Climate Change Canada), https://climate.weather.gc.ca/; 3) Danish Meteorological Institute (DMI), https://www.dmi.dk/publikationer/ [as cited in Cappelen (2020)].A review of many studies published since the late 1920s reveals that the main driving mechanisms responsible for the early-twentieth-century Arctic warming (ETCAW) are not fully recognized. The main obstacle seems to be our limited knowledge about the climate of this period and some forcings. A deeper knowledge based on greater spatial and temporal resolution data is needed. The article provides new (or improved) knowledge about surface air temperature (SAT) conditions (including their extreme states) in the Arctic during the ETCAW. Daily and subdaily data have been used (mean daily air temperature, maximum and minimum daily temperature, and diurnal temperature range). These were taken from 10 individual years (selected from the period 1934–50) for six meteorological stations representing parts of five Arctic climatic regions. Standard SAT characteristics were analyzed (monthly, seasonal, and yearly means), as were rarely investigated aspects of SAT characteristics (e.g., number of characteristic days, day-to-day temperature variability, and the onset, end, and duration of thermal seasons). The results were compared with analogical calculations done for data taken from the contemporary Arctic warming (CAW) period (2007–16). The Arctic experienced warming between the ETCAW and the CAW. The magnitude of warming was greatest in the Pacific (2.7°C) and Canadian Arctic (1.9°C) regions. A shortening of winter and lengthening of summer were noted. Furthermore, the climate was also a little more continental (except the Russian Arctic) and less stable (greater day-to-day variability and diurnal temperature range) during the ETCAW than during the CAW

GROUND TEMPERATURE AT THE HENRYK ARCTOWSKI STATION (KING GEORGE ISLAND, ANTARCTIC) – CASE STUDY FROM THE PERIOD JANUARY 2012 TO FEBRUARY 2013

The article presents the results of measurements of ground temperature in the context of general meteorological conditions at the Henryk Arctowski Station (King George Island, South Shetland Islands, Antarctic) from the period of 20 January 2013 to 22 February 2013. The measurements were taken using a Vantage Pro+ automatic weather station and the thermal conditions of the ground were measured by means of a HOBO automatic data logger. The variability of ground temperature was analysed in an annual and diurnal cycle. A clear recurrent diurnal pattern was observed in the summer season, resulting from more favourable insolation conditions in that part of the year. In the winter, on the other hand, no major differences in the diurnal cycle of ground temperature were found, particularly with a dense snow cover

Ground thermal regime on the Kaffiøyra Plain (NW Spitsbergen) in the period from 1 September 2012 to 31 August 2014

The article presents the results of ground temperature measurements taken at 1 cm to 100 cm below ground level on the Kaffiøyra Plain (NW Spitsbergen) from 1 September 2012 to 31 August 2014. Observations of thermal conditions were carried out at three sites located in characteristic Polar ecotopes: on a beach, in tundra and on a moraine. The results of ground temperature measurements for the Kaffiøyra Plain were compared to the observations of weather conditions at the nearby meteorological station in Ny-Ålesund. The variability of ground temperature was analysed in annual, seasonal and diurnal courses. These reflected the prevailing meteorological conditions at the time. Substantial differences in the ground thermal conditions were found between the ecotopes, which was due to the morphological diversity of the ground, its moisture content, vegetation and snow cover, as well as the depth of the permafrost

The Influence of Cloudiness and Synoptic Situations on the Solar Radiation Balance in the Area of Kaffiøyra (Nw Spitsbergen) in the Summer Seasons 2010 and 2011

This article describes the influence of cloudiness and synoptic situations on individual components of the radiation balance such as: global solar radiation; surface-reflected radiation; longwave terrestrial and atmospheric radiation, and the long- and shortwave balance of two types of ground cover typical to Spitsbergen (the Kaffiøyra region), i.e. morainal and glacial. The research was carried out in the summer seasons of 2010 and 2011, using a Kipp & Zonen CNR4 net radiometer. A substantial influence of the presence of clouds on the individual components of the radiation balance was observed. The type of air masses related to specific synoptic situations was also found to affect the incoming and outgoing solar radiation, as well as its losses