Analysis of hourly precipitation characteristics in Kraków, southern Poland, using a classification of circulation types

This paper investigates the relationship between maximum precipitation in Kraków and types of atmospheric circulation in southern Poland, as classified by Niedźwiedź. Three characteristics were used to define this relationship: maximum precipitation (Pmax), its duration (d) and probability of exceedance (p). The input data came from Kraków's uniquely long and homogenous pluviographic record spanning the period 1886–2007. Hourly precipitation values for the maximum precipitation events were identified and arranged in 1–24 hour intervals. They were then processed using the generalized extreme value (GEV) distribution to produce quantiles of maximum precipitation totals in each of the intervals and broken down by the corresponding circulation type. Differences between the development mechanisms are manifested in relationships between precipitation characteristics and their measure of randomness, i.e. exceedance probability. This paper demonstrates that maximum precipitation events depend on their duration d and atmospheric circulation. The maximum short-duration (one-hour) events occur primarily in either of two circulation types: (i) cyclonic with advection from the east and from the southeast or (ii) low-pressure centre and cyclonic trough. Maximum long-duration precipitation events (24 hour), on the other hand, occur in the cyclonic type of circulation with advection from the north and from the northeast.

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Relationship between Water Temperature of Polish Rivers and Large-Scale Atmospheric Circulation

Water ◽

10.3390/w11081690 ◽

2019 ◽

Vol 11 (8) ◽

pp. 1690 ◽

Cited By ~ 4

Author(s):

Renata Graf ◽

Dariusz Wrzesiński

Keyword(s):

Water Temperature ◽

Atmospheric Circulation ◽

Large Scale ◽

Statistical Significance ◽

Winter Season ◽

Circulation Type ◽

River Waters ◽

Positive And Negative Coefficients ◽

Circulation Types ◽

Temporal And Spatial Variability

The objective of the paper consisted in determining the effect of macroscale types of NAO, AO, EA, EAWR, SCAND, and AMO atmospheric circulation on changes in water temperature in Polish rivers. The study has made use of a broad body of hydrometeorological materials covering daily water temperature values for 96 water gauge stations located on 53 rivers and air temperature values for 43 meteorological stations. Percentage shares of positive and negative coefficients of correlation of annual, seasonal, and monthly circulation type indices with air and river water temperature were determined, demonstrating the character of teleconnection. Determinations were made of water temperature deviations in positive and negative phases of the analyzed indices from average values from the years 1971–2015, and their statistical significance ascertained. Research has shown that relations between the temperature of river waters in Poland and macroscale circulation types are not strong, however they are noticeable, sometimes even statistically significant, and both temporally and spatially diverse. NAO, AO, EA, and AMO indices are characterized by a generally positive correlation with temperature, whereas SCAND and EWAR indices are characterized by a negative correlation. Research showed a varying impact of types of atmospheric circulation, with their effectiveness increasing in the winter season. The strongest impact on temperature was observed for the positive and negative NAO and AO phases, when deviations of water temperature from average values are correspondingly higher (up to 1.0 °C) and lower (by a maximum of 1.5 °C), and also for the positive and negative SCAND phases, when water temperature are correspondingly lower (by a maximum of 0.8 °C) and higher (by 1.2 °C) than average values. The strongest impact on water temperature in summer, mainly in July, was observed for AMO. The results point to the complexity of processes determining the thermal regime of rivers and to the possibility of additional factors—both regional and local—exerting an influence on their temporal and spatial variability.

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An analysis of diurnal variations of heavy hourly precipitation in Kraków using a classification of circulation types over southern Poland

Physics and Chemistry of the Earth Parts A/B/C ◽

10.1016/j.pce.2009.11.003 ◽

2010 ◽

Vol 35 (9-12) ◽

pp. 456-461 ◽

Cited By ~ 7

Author(s):

Robert Twardosz

Keyword(s):

Diurnal Variations ◽

Southern Poland ◽

Hourly Precipitation ◽

Circulation Types

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Persistence and frequency of drought-relevant circulation types during temperature extremes in southern Central Europe

10.5194/egusphere-egu2020-21274 ◽

2020 ◽

Author(s):

Selina Thanheiser ◽

Markus Homann ◽

Andreas Philipp ◽

Christoph Beck ◽

Jucundus Jacobeit

Keyword(s):

Atmospheric Circulation ◽

Central Europe ◽

Circulation Type ◽

Efficiency Coefficient ◽

Cold Waves ◽

Temperature Anomalies ◽

Circulation Types ◽

Southern Central ◽

The Mean ◽

The Relationship

The German weather service reports a new record mean June temperature for Germany and intensive heat waves during 2018 and 2019. Between January 2018 and June 2019, three new monthly top extremes were recorded (April 2018, May 2018 and June 2019).In this study the relationships between the persistence and frequency of atmospheric circulation patterns related to drought and surface air temperature anomalies are investigated. The study area is in southern Central Europe, including parts of Germany and Switzerland as well as Austria and Czech Republic.Large-scale atmospheric circulation types (relevant to drought) have been derived by using the COST733 classi&#64257;cation software. Atmospheric variables from gridded daily JRA55 reanalysis data (Japanese Meteorological Agency 2018) and gridded precipitation data for the study area (6x6km, based on timeseries of 1756 weather stations from Zentralanstalt f&#252;r Meteorologie und Geodynamik 2018) were used for the classification. All input variables were specifically weighted in the classification process. Daily maximum temperature data from ECA&D (2019) for different stations within the study area are used to evaluate the relationship between a circulation type and heat (cold) waves.The drought-relevant circulation types are determined according to relative frequencies of circulation type days under a particular percentile of precipitation: If at least 20 percent of the circulation type days are below the 20th percentile of precipitation, the circulation type is defined as drought relevant.For the derived drought-relevant circulation types, the mean seasonal frequencies [in %] (April-September, October-March) and the mean persistence [in days] (1961-2017) are calculated. To evaluate the relationship between a circulation type and heat (cold) waves, an efficiency coefficient is calculated. The efficiency coefficient is defined as ratio between the frequency of the circulation type in heat (cold) waves and its mean seasonal frequency.For the study area, those circulation types relevant to drought with a high proportion of seasonal temperature anomalies could be identified. The circulation type with a dominant Azores high with ridges of high-pressure towards Central/Eastern Europe has the highest proportion of positive temperature anomalies in summer.

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Circulation types classification for hourly precipitation events in Lublin (East Poland)

Open Geosciences ◽

10.1515/geo-2016-0019 ◽

2016 ◽

Vol 8 (1) ◽

Cited By ~ 4

Author(s):

Krzysztof Bartoszek ◽

Dominika Skiba

Keyword(s):

Sea Level ◽

Central Europe ◽

Sea Level Pressure ◽

East Central Europe ◽

East Central ◽

Hourly Precipitation ◽

Circulation Types ◽

Objective Classification ◽

Precipitation Events

AbstractThe paper presents an objective classification of circulation types for East-Central Europe with application to hourly precipitation events in Lublin (East Poland) from May to September. The development of the classification utilized sub-daily sea-level pressure values (at the main standard synoptic hours,

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Synoptic climatology of fog in selected locations of southern Poland (1966–2015)

Bulletin of Geography Physical Geography Series ◽

10.1515/bgeo-2016-0010 ◽

2016 ◽

Vol 11 (1) ◽

pp. 5-15 ◽

Cited By ~ 5

Author(s):

Ewa Łupikasza ◽

Tadeusz Niedźwiedź

Keyword(s):

Atmospheric Circulation ◽

High Probability ◽

Synoptic Climatology ◽

Annual Number ◽

High Quality ◽

Air Mass ◽

Southern Poland ◽

Circulation Types ◽

Annual Scale

Abstract This paper investigates fog frequency in southern Poland in relation to various topography (concave and convex forms) and atmospheric circulation types. It also discusses long-term variability in the annual and seasonal number of days with fog. Daily information on fog occurrence was taken from three high quality synoptic stations representing various landforms: Kraków-Balice (bottom of the hollow), Katowice-Muchowiec (Silesian Upland) and Bielsko-Aleksandrowice (summit of Carpathian Foothill). In the central part of southern Poland during the last 50 years (1966-2015) fog occurred on average during 53-67 days a year. The annual number of foggy days in Kraków (67 days) located in a structural basin was by 14-15 days higher than in Bielsko (53 days) situated in the Silesian Foothills. In the annual course, high fog occurrence (above 6 days per month) was observed from September to January, with the maximum in Kraków (10 days in October). At every station the monthly minimum of fog occurrence fell in July (2 days). In summer and spring the highest probability of fog occurrence was found on days with anticyclonic types and air advection from the northeastern (Na, NEa) and eastern (Ea, SEa) sectors. In autumn, a high probability was also found for the anticyclonic types with advection of air mass from the eastern and southern sectors. In the Carpathian Foothills (Bielsko) the probability of fog occurrence in winter was significantly enhanced only for the cyclonic types with air advection from the eastern sector (NEc, Ec, SEc) and nonadvective types Cc (cyclone centre) and Bc (cyclonic trough). Trends in the fog frequency were mostly insignificant. The only significant decreasing trend was found in Kraków on the annual scale and in summer when fog frequency was low.

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Modified, threshold-based circulation type classification for Central Europe, on the basis of Lityński’s classification

Miscellanea Geographica ◽

10.2478/mgrsd-2018-0033 ◽

2019 ◽

Vol 23 (1) ◽

pp. 53-62 ◽

Cited By ~ 1

Author(s):

Kinga Kulesza

Keyword(s):

Atmospheric Circulation ◽

Central Europe ◽

Classification Scheme ◽

Circulation Type ◽

Zonal Index ◽

Circulation Types ◽

Meridional Index ◽

Type Classification

Abstract There are many classifications of atmospheric circulation types. In Poland, the most important one, used by Polish weather services, is the classification of circulation types developed by Lityński. This paper proposes four modifications to the currently used algorithm for determining atmospheric circulation types. The proposed algorithms have been compared and it has been shown which one produces a catalogue of circulation types in which the division of the distribution of the values of the three indices (the zonal index Ws, meridional index Wp and cyclonicity index Cp) into three classes is the closest to being equally likely. In 1986-2015, the classification scheme that deemed to be the best, differed in above 19% of cases from the currently used classification.

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Variability of global radiation under the influence of cloudiness, cloud types and atmospheric circulation in Southern Poland

10.5194/ems2021-97 ◽

2021 ◽

Author(s):

Dariusz Zajączkowski ◽

Ewa Łupikasza

Keyword(s):

Solar Radiation ◽

Atmospheric Circulation ◽

Extreme Values ◽

Global Radiation ◽

Meteorological Station ◽

Annual Data ◽

Southern Poland ◽

Circulation Types ◽

The Earth

Solar radiation reaching the Earth&#8217;s surface is a crucial energy source in the climate system and the primary factor regulating the planet energy balance. The amount of solar radiation reaching the Earth surface is conditioned by the atmosphere composition and its transparency that is determined by the content of aerosols, moisture and clouds. The G&#243;rno&#347;l&#261;sko-Zag&#322;&#281;biowska Metropolis (GZM) located in southern Poland, is the most urbanized part of the country and one of the most polluted parts of Europe, which has an impact on the atmosphere transparency and amount of global radiation at the Earth's surface. This study aims to determine the daily and annual variability in global radiation and its relationship with cloudiness, selected cloud types and atmospheric circulation.This study is based on unique 10-minute global radiation data measured in the centre of GZM&#160; at the meteorological station of the faculty of Earth Sciences. The data covers the periods between 2002 and 2019. Average radiation intensity was converted into hourly and daily radiation sums expressed in MJ/m2. Data on cloudiness were taken from the synoptic station Katowice Muchowiec located 9.6 km far from the meteorological station in GZM. The degree of cloud cover is expressed in a percentage of the sky covered with clouds. To analyse relationships between atmospheric circulation and global radiation, the calendar of circulation types and air masses for southern Poland was used.Daily course calculated based on annual data showed that global radiation reached its highest values of 1.5 MJ/m2 at 10 UTC. The highest hourly sums of global radiation varied seasonally from about 0.5 MJ/m2 in winter to 2.0 MJ/m2 in summer. The widest range of variability in particular hours was found in spring (the quartiles: 1.2 - 2.0 MJ/m2) and autumn (quartiles: 0.7 to 1.4 MJ/m2). It occurred that most cloudiness classes enhanced the global radiation compared to cloudless conditions. The highest radiation sums were recorded during the days with a cloudiness >0 and &#8804;20%. During such days, global radiation was higher by 3.2 MJ/m2 than during cloudless days and 7.0 MJ/m2 than the long-term average 2002-2019. Daily global radiation was lower than the long-term average by about 3.0 MJ/m2 only during days with cloudiness > 80%. Cirrus, cirrostratus, cirrocumulus and cumulus enhanced global radiation by about 40% compared to the long-term average. Altostratus, nimbostratus and stratus reduced the global radiation by about 75% compared to the long-term average. Global radiation also varied depending on circulation types. Extreme values of global radiation were registered under non-advective anticyclonic conditions and during southern advection (maximum 15.0 MJ/m2) and during cyclonic types with air advection from the north (minimum 6.8 MJ/m2)

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Representation of Extratropical Cyclones, Blocking Anticyclones, and Alpine Circulation Types in Multiple Reanalyses and Model Simulations

Journal of Climate ◽

10.1175/jcli-d-17-0350.1 ◽

2018 ◽

Vol 31 (8) ◽

pp. 3009-3031 ◽

Cited By ~ 17

Author(s):

Marco Rohrer ◽

Stefan Brönnimann ◽

Olivia Martius ◽

Christoph C. Raible ◽

Martin Wild ◽

...

Keyword(s):

Atmospheric Circulation ◽

Central Europe ◽

Climate Model ◽

Temporal Correlation ◽

Circulation Type ◽

Horizontal Resolution ◽

Reanalysis Dataset ◽

Model Simulations ◽

Ensemble Simulations ◽

Circulation Types

Abstract Atmospheric circulation types, blockings, and cyclones are central features of the extratropical flow and key to understanding the climate system. This study intercompares the representation of these features in 10 reanalyses and in an ensemble of 30 climate model simulations between 1980 and 2005. Both modern, full-input reanalyses and century-long, surface-input reanalyses are examined. Modern full-input reanalyses agree well on key statistics of blockings, cyclones, and circulation types. However, the intensity and depth of cyclones vary among them. Reanalyses with higher horizontal resolution show higher cyclone center densities and more intense cyclones. For blockings, no strict relationship is found between frequency or intensity and horizontal resolution. Full-input reanalyses contain more intense blocking, compared to surface-input reanalyses. Circulation-type classifications over central Europe show that both versions of the Twentieth Century Reanalysis dataset contain more easterlies and fewer westerlies than any other reanalysis, owing to their high pressure bias over northeast Europe. The temporal correlation of annual circulation types over central Europe and blocking frequencies over the North Atlantic–European domain between reanalyses is high (around 0.8). The ensemble simulations capture the main characteristics of midlatitudinal atmospheric circulation. Circulation types of westerlies to northerlies over central Europe are overrepresented. There are too few blockings in the higher latitudes and an excess of cyclones in the midlatitudes. Other characteristics, such as blocking amplitude and cyclone intensity, are realistically represented, making the ensemble simulations a rich dataset to assess changes in climate variability.

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Atmospheric Circulation Influence on the Winter Thermal Conditions in Poland in 2021-2050 Based on the RACMO2 Model

Contemporary Trends in Geoscience ◽

10.2478/ctg-2012-0002 ◽

2012 ◽

Vol 1 (1) ◽

pp. 13-20

Author(s):

Joanna Jędruszkiewicz ◽

Piotr Piotrowski

Keyword(s):

Atmospheric Circulation ◽

Climate Model ◽

Regional Climate ◽

Thermal Conditions ◽

Circulation Type ◽

The West ◽

Sea Level Pressure ◽

Circulation Types ◽

Scenario Period ◽

Daily Data

Abstract Thermal conditions are largely determined by atmospheric circulation. Therefore, projection of future temperature changes should be considered in relation to changes in circulation patterns. This paper assess to what extent changes in circulation correspond to spatial variability of the winter temperature increase in Poland in 2021-2050 period based on the RACMO2 model. The daily data of the mean temperature and sea level pressure (SLP) from selected regional climate model and observations were used. SLP data were used to determine the advection types and circulation character. Firstly, changes in frequency of circulation types between 2021-2050 and 1971-2000 periods were examined. Then changes in air temperature for specific circulation type in relation to reference period were studied. Finally, the influence of atmospheric circulation on spatial temperature variation was discussed. Considerably high increase in cyclonic situation of more than 18%, especially from the west and south-west direction, and decrease in anticyclonic situation mainly from the west and northwest in winter was noticed. Changes in frequency of circulation types result in temperature growth. For some types it is predicted that warming can reach even 3-4°C. The cyclonic (Ec, SEc, Sc) and anticylonic (SEa, Sa, Ea) types are likely to foster the highest warming in the scenario period.

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Variability and changes of drought-relevant circulation types in southern central Europe

10.5194/egusphere-egu21-2642 ◽

2021 ◽

Author(s):

Selina Thanheiser

Keyword(s):

Atmospheric Circulation ◽

Central Europe ◽

Climate Model ◽

Regional Climate ◽

Circulation Type ◽

Japan Meteorological Agency ◽

Climate Projections ◽

Circulation Types ◽

Daily Precipitation Data ◽

Observation Period

The estimation of regional extreme events (heavy precipitation and droughts) in Central Europe under ongoing climate change especially includes an evaluation of the relationship between atmospheric circulation types and regional droughts taking place in the bilateral research project WETRAX+ (WEather Patterns, Cyclone TRAcks, and related precipitation EXtremes). The study area is located in the south of central Europe, including Austria, parts of Germany, Switzerland, and the Czech Republic.For a precipitation-conditioned circulation type classification, atmospheric variable fields from gridded daily JRA55 reanalysis data (Japan Meteorological Agency 2018) and gridded daily precipitation data based on 1756 weather stations in the study area (Zentralanstalt f&#252;r Meteorologie und Geodynamik 2018) were used for the observation period 1961 to 2017. Seven different regional climate model runs of the Euro-Cordex &#8211; Initiative and from ReKliEs-De (Regional Climate Projections Ensemble for Germany) as well as three runs of the global climate model ECHAM6 (greenhouse gas scenario RCP 8.5) were used to estimate future changes in two projection periods (2031-2060 and 2071-2100).The large-scale atmospheric circulation types have been derived using a non-hierarchical cluster analysis provided in the COST733 Classi&#64257;cation Software. The drought-relevant circulation types are determined according to relative frequencies of circulation type days under a particular percentile of precipitation: If at least 20 percent of the circulation type days are below the 20th percentile of precipitation, the circulation type is defined as drought relevant. Drought-relevant circulation types are examined in terms of trends, persistence, changes in monthly occurrence frequencies, and within-type variability. When transferring the circulation types to the climate model data, each single day of the projection period is assigned to the circulation type to whose centroid fields the respective single fields have the smallest Euclidean distance.During the observation period, the trend analyses show that the occurrence of drought-relevant circulation types is significantly more often associated with higher temperatures and lower relative humidity. First results of the analysis for the future climate show an increase of central high-pressure areas over Central and Eastern Europe for the months April to September. Anticyclonic weather conditions with a resulting southwesterly flow occur less frequently.

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