Temperature anomalies of a cold period on the territory of Ukraine in 2010-2019

2020 ◽  
Vol 101-102 (3-4) ◽  
pp. 19-25
Author(s):  
Olena Nashmudinova
Keyword(s):  
Air Temperature ◽  
Heat Waves ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Negative Temperature ◽  
Cold Period ◽  
Positive Anomaly ◽  
Temperature Anomalies ◽  
Gradient Fields ◽  
Air Temperature Anomalies

Regional climate change in Ukraine in recent decades is accompanied by an increase in the repetitiveness of intense waves, both heat and cold; there is a tendency to increase the frequency of warm winters, but sometimes there are periods with significant decreases in temperature. The aim of the study is to determine the specifics of the formation of air temperature anomalies in the cold period 2010–2019. According to the distribution of the average monthly air temperature at the stations Odessa, Kiev, Kharkiv, Lviv investigated positive and negative deviations from the climate norm. In January, the average monthly air temperature in most cases was above normal, except for 1–3 years. The maximum positive anomaly was 4–5°C in Kyiv and Lviv (2015), the largest negative deviations were 3.8°C. In February, the trend continues – only 2–3 years with negative anomalies, the largest deviations to 3–6°C in 2011 and 2012, and positive deviations maximum in 2016. In March, negative temperature anomalies were observed 3–4 years, with a maximum of 2–3°C in 2018, positive anomalies in 4–6°C were observed in 2014, 2017. Temperatures in November were variable, with the prevailing positive anomaly, a high of 6–8°C in 2010. The distribution of air temperature in December was characterized by positive deviations of a maximum of 5–6°C in 2011, 2015, 2017 and 2019. Months of the greatest positive and negative air temperature anomalies over Europe have been highlighted. Among the colder months, the biggest anomaly stood out in January 2010 and February 2012 to 5–6°C. Among the warm months, the temperature anomaly was observed in February 2016, positive deviations from the norm to 8°C. Heat waves formed in winter with a zonal type of circulation, when warm moist air from the Atlantic shifted across the periphery of the Icelandic low. In March, waves of heat formed in low–gradient fields. Powerful waves of cold over the European sector were mainly formed under the influence of “eastern processes” in the spread of the Siberian anticyclone to Europe. In some years, significant cooling over Ukraine is formed in cyclonic systems with a high–altitude thermobaric field characterized by polar or ultrapolar hollow.

scholarly journals Relationships of surface air temperature anomalies over Europe to persistence of atmospheric circulation patterns conducive to heat waves

2008 ◽  
Vol 14 ◽  
pp. 243-249 ◽  
Author(s):  
J. Kyselý ◽  
R. Huth
Keyword(s):  
Atmospheric Circulation ◽  
Air Temperature ◽  
Heat Waves ◽  
Temperature Extremes ◽  
Human Society ◽  
Positive Temperature ◽  
Temperature Anomalies ◽  
Circulation Types ◽  
Circulation Patterns ◽  
Air Temperature Anomalies

Abstract. Heat waves are among natural hazards with the most severe consequences for human society, including pronounced mortality impacts in mid-latitudes. Recent studies have hypothesized that the enhanced persistence of atmospheric circulation may affect surface climatic extremes, mainly the frequency and severity of heat waves. In this paper we examine relationships between the persistence of the Hess-Brezowsky circulation types conducive to summer heat waves and air temperature anomalies at stations over most of the European continent. We also evaluate differences between temperature anomalies during late and early stages of warm circulation types in all seasons. Results show that more persistent circulation patterns tend to enhance the severity of heat waves and support more pronounced temperature anomalies. Recent sharply rising trends in positive temperature extremes over Europe may be related to the greater persistence of the circulation types, and if similar changes towards enhanced persistence affect other mid-latitudinal regions, analogous consequences and implications for temperature extremes may be expected.

Total air temperature anomalies as a metric for detecting high-altitude ice crystal events: Development of a failure indicator heuristic

2019 ◽  
Vol 105 ◽  
pp. 982-1005
Author(s):  
Álvaro Rodríguez-Sanz ◽  
Rosa Arnaldo Valdés ◽  
Fernando Gómez Comendador ◽  
Eduardo Sánchez Ayra ◽  
Javier Cano Cancela
Keyword(s):  
High Altitude ◽  
Air Temperature ◽  
Ice Crystal ◽  
Temperature Anomalies ◽  
Air Temperature Anomalies

40-years of Saharan dust events in the Carpathian Basin: background, frequency, intensity, changing patterns

2020 ◽  
Author(s):  
György Varga ◽  
Nadia Gammoudi ◽  
János Kovács
Keyword(s):  
Air Temperature ◽  
Surface Air Temperature ◽  
Flow Patterns ◽  
Carpathian Basin ◽  
Saharan Dust ◽  
Dust Deposition ◽  
Temperature Anomalies ◽  
Modis Aod ◽  
Dust Events ◽  
Air Temperature Anomalies

<p>Saharan dust events were investigated in the Carpathian Basin (Central Europe) for the period between 1979 and 2018 by using various satellite (TOMS and OMI Aerosol Index; MODIS AOD) and numerical forecast (Barcelona Supercomputing Centre’s DREAM, NMMB/BSC-Dust-model and SKIRON) products and modelled deposition of NASA’s Modern-Era Retrospective analysis for Research and Applications, Version 2. The identified 218 episodes were classified into three characteristic clusters based on synoptic background. 700 hPa geopotential height, wind vectors and meridional flow patterns, as well as backward trajectories of the episodes determined the classification.</p><p>Interannual variability of dust activity was remarkable, while seasonal frequencies of the episodes revealed clear spatiotemporal patterns with spring (40.2%) and summer (31.6%) maxima of the events. Mean values of dust deposition showed springtime maxima (44.1%) and dominance of wet deposition (77-93%), while amount of deposited dust material in the other seasons were quite similar, indicating the governing role of local weather conditions (e.g., precipitation patterns). Average warm advection of the episodes was 3.5°C (with spring minima, due to the more rain), but the decadal surface air temperature anomalies showed a general increasing trend.</p><p>Recently, a few more intense wintertime dust deposition events indicated changes in the deterministic atmospheric flow system. Seasonal and decadal zonal mean surface air temperature anomalies of dusty days showed clearly the increased warming of high latitudes during the last few winter episodes. The enhanced meridionality of (dust transporting) winds was also observable in the number of days with 15< m/s meridional wind component (at 700 hPa). Warmer Arctic region and more meandering air flow patterns could be responsible for these unusual dust episodes in the recent years.</p><p>Support of the National Research, Development and Innovation Office NKFIH KH130337 and NKFIH K120213 are gratefully acknowledged.</p>

Improving predictions of surface air temperature anomalies over Japan by Selective Ensemble Mean technique

2020 ◽  
Author(s):  
J. V. Ratnam ◽  
Takeshi Doi ◽  
Yushi Morioka ◽  
Pascal Oettli ◽  
Masami Nonaka ◽  
...  
Keyword(s):  
Air Temperature ◽  
General Circulation ◽  
Surface Air Temperature ◽  
Correlation Coefficients ◽  
Circulation Model ◽  
Skill Score ◽  
Temperature Anomalies ◽  
Selective Ensemble ◽  
Ensemble Mean ◽  
Air Temperature Anomalies

AbstractSelective ensemble mean (SEM) technique is applied to the late spring and summer months (May to August) surface air temperature anomaly predictions of the Scale Interaction Experiment-Frontier Research Center for Global Change Version 2 (SINTEX-F2) coupled general circulation model over Japan. Using the Köppen-Geiger climatic classification we chose four regions over Japan for applying the SEM technique. The SINTEX-F2 ensemble members for the SEM are chosen based on the anomaly correlation coefficients (ACC) of the SINTEX-F2 predicted and observed surface air temperature anomalies. The SEM technique is applied to generate the forecasts of the surface air temperature anomalies for the period 1983 to 2018 using the selected members. Analysis shows the ACC skill score of the SEM prediction to be higher compared to the ACC skill score of predictions obtained by averaging all the 24 members of the SINTEX-F2 (ENSMEAN). The SEM predicted surface air temperature anomalies also have higher hit rate and lower false alarm rate compared to the ENSMEAN predicted anomalies over a range of temperature anomalies. The results indicate the SEM technique to be a simple and easy to apply method to improve the SINTEX-F2 predictions of surface air temperature anomalies over Japan. The better performance of the SEM in generating the surface air temperature anomalies can be partly attributed to realistic prediction of 850hPa geopotential height anomalies over Japan.

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