Variability in the occurrence of thermal seasons in Poland in 1961–2020

The article analyses the variability of thermal seasons in Poland in 1961–2020. Based on the average monthly air temperature values from 55 stations, the onset and end dates as well as the duration of the six thermal seasons were calculated. Taking into account the thermal thresholds of 0 C, 5 C and 15 C for each year, early spring, spring, summer, autumn, early winter and winter can be distinguished. A significant spatial differentiation of the dates of the beginning and duration of the thermal seasons in Poland was observed. The influence of continentalism (in the east) and oceanic climate (in the west) and the influence of the Baltic Sea are noticeable, and in mountainous regions, altitude above sea level is the main factor. The air temperature in Poland increases at the rate of 0.3 C–0.4 C/10 years. This causes significant changes in the occurrence and duration of the thermal seasons. An early beginning of early spring and spring was observed. Summer arrives earlier and is significantly longer, becoming the longest season of the year (above 110 days in the south of Poland). Autumn and early winter are delayed and get shorter, whereas winter comes much later. Throughout the country, winter is 44 days shorter, and in the north-west it does not occur at all. Changes in the onset of thermal seasons are a clear indicator of progressing global warming. They have also a decisive impact on the environment and human activity

The origin and course of severe thunderstorm outbreaks in Poland on 10 and 11 August, 2017

This study documents the evolution of severe thunderstorm outbreaks that occurred on 10 and 11 August, 2017 in Poland. This study used cloud-to-ground lightning-strike data from the PERUN lightning detection network managed by the Polish Institute of Meteorology and Water Management – National Research Institute. In the description of storm phenomena the authors also applied synoptic maps, meteorological radar data, vertical atmosphere soundings and meteorological data from the station in Poland. The aim of this study was to trace the causes of the upward movement of supercells including the Mesoscale Convective System day by day, and to examine relationships between lighting distributions on 10 and 11 August, 2017. In Poland, on August 10, 2017, 154,524 cloud-to-ground flashes (CG) occurred, and 56,510 CG flashes the next day. On August 10, around 18% of all flashes had a positive current, but 29% the next day. The spatial distribution of the lightning in Poland was computed for 10×10-km grid cells. Based on the map analysis it was found that on those two days most of the positive flashes occurred in Greater Poland and Kuyavian-Pomeranian voivodships, as well as on the border of Opolskie and Lower Silesia

Solar radiation variability at Koniczynka near Toruń (Central Poland) in the years 2003–2016

The paper presents the variability of global solar radiation (K↓) in the agriculture area (Koniczynka near Toruń) in the years 2003–2016. The variability of K↓ has been analysed with reference to atmospheric circulation. The mean yearly sum of K↓ in the analysed period was 3,816.0 MJ m-2. In an annual course the biggest mean values of K↓ occurred in June (608.3 MJ m-2) and the smallest in December (69.0 MJ m-2).The diurnal course of K↓ was symmetrical with respect to the solar noon.  Only 44.7% of the solar energy on the top of atmosphere reaches the ground. The highest transmittance occurred in spring and summer, and the lowest in December. The observations revealed an increase in the amount of K↓ (trend 13.6 MJm-2 year-1) and its considerable day-to-day and year-to-year variability. Its increase has been attributed to reduced emissions of aerosols in Poland and Europe (global brightening). The changes of K↓ depend on atmospheric circulation (cyclonic and anticyclonic situations), cloudiness and the optical characteristics of incoming air masses.

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

The influence of brine graduation towers on biometeorological conditions, on the example of Ciechocinek spa town (Poland)

The paper provides an analysis of the influence of brine graduation towers on biometeorological conditions, on the basis of the example of Ciechocinek – a spa town in Poland. Using the records of air temperature and relative air humidity in the years 2018-2020 at two locations near Graduation Tower 1 and at the reference site near Spa Hospital No. 1 it was demonstrated that the graduation towers caused a mean drop in air temperature of 0.5–0.7°C with maximum diff erences 7.5°C. The average humidity due to brine evaporation was 3.6–4.6% higher, but maximum differences exceeded 30%. Based on mobile measurements the effects of the graduation tower were found to be limited to its vicinity, where air temperature was lower and humidity higher. The distribution of air temperature and humidity changed depending on wind direction. Cooler and more humid air was carried downwind of the graduation tower. The calculated biometeorological indices showed that neutral, comfortable or refreshing conditions prevailed at the graduation tower and the sensation of heat or thermal stress leading to body overheating was less frequent

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

Air temperature and precipitation changes in the Kaffiøyra region (NW Spitsbergen) from 1975 to 2010

Air temperature and precipitation conditions in the Kaffiøyra region in the summer season (21st July–31st August) for the period of 1975–2010 are described: 1) on the basis of data gathered in 18 expeditions during which meteorological measurements were done, and 2) on the basis of complete series of data combining both original and reconstructed data. The latter ones were obtained using data from Ny Ålesund meteorological station, which are strongly correlated with the data from Kaffiøyra. Seasonal statistics presented for air temperature and precipitation based on these two sets of data reveal only slight changes. Temperature parameters (daily mean, maximum and minimum) for summer in Kaffiøyra in the study period (1975–2010) show upward trends, which are, however, statistically significant only for the daily mean. On the other hand, precipitation totals in the study period reveal a downward trend, but not statistically significant. Such thermal-precipitation behaviour in the study part of Spitsbergen in general terms is similar to those in other parts of Spitsbergen

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

Radiation balance diversity on NW Spitsbergen in 2010–2014

This article presents the results of observations of selected fluxes of the radiation balance in north-western Spitsbergen in the years from 2010 to 2014. Measurements were taken in Ny-Ålesund and in the area of Kaffiøyra, on different surface types occurring in the Polar zone: moraine, tundra, snow and ice. Substantial differences in the radiation balance among the various types of surface were observed. The observations carried out in the summer seasons of 2010–2014 in the area of Kaffiøyra demonstrated that the considerable reflection of solar radiation on the Waldemar Glacier (albedo 55%) resulted in a smaller solar energy net income. During the polar day, a diurnal course of the components of the radiation balance was apparently related to the solar elevation angle. When the sun was low over the horizon, the radiation balance became negative, especially on the glacier. Diurnal, annual and multi-annual variations in the radiation balance have a significant influence on the functioning of the environment in polar conditions

Zróżnicowanie wilgotności względnej i opadów atmosferycznych w rejonie Forlandsundet (NW Spitsbergen) w sezonie letnim 2010

W artykule przedstawiono zróżnicowanie wilgotności względnej powietrza oraz opadów atmosferycznych w rejonie Forlandsundet (NW Spitsbergen) w sezonie letnim (21 VII – 31 VIII) 2010 roku. Do analizy wzięto cogodzinne dane wilgotności względnej (z 18 stanowisk) oraz sumy opadów atmosferycznych z okresów 1-3 dniowych (z 11 stanowisk). Dla obydwu badanych elementów meteorologicznych stwierdzono znaczne przestrzenne zróżnicowanie ich wartości uwarunkowane rodzajem podłoża, wysokością nad poziom morza, odległością od morza, ekspozycją oraz lokalną cyrkulacją atmosferyczną. Zbadano wpływ cyrkulacji atmosferycznej na wartości wilgotności względnej i opadów atmosferycznych korzystając z kalendarza typów cyrkulacji dla Spitsbergenu