В роботі використано дані реаналізу NCEP/NCAR для відбору екстремальних температур повітря нижче 5-го перцентиля функції розподілу у вузлах регулярної сітки на території України. Класифікація полів тиску з екстремальними від"ємними температурами дозволила визначити чотири основні типи синоптичних процесів. В роботі наводиться опис таких процесів, що призводять до аномально низьких температур за останні 20 років (1997-2017 рр.) в Україні в зимовий період.
В работе использованы данные реанализа NCEP/NCAR для отбора экстремальных температур в узлах регулярной сетки на территории Восточной Европы ниже 5-го перцентиля приземной температуры воздуха. Классификация полей давления с экстремально аномальными температурами позволила определить четыре основных типа синоптических процессов. В работе приводится описание таких процессов, приводящих к аномально низким температурам на протяжении последних 20 лет (1997-2017 гг.) в Украине в зимний период.
The article describes the typical synoptic processes that lead to extreme-cold winter temperatures over the past 20 years (1997-2017) in Ukraine. The NCEP/NCAR reanalysis data is used to select extreme temperatures below the 5th percentile of the surface air temperature 109 distribution function for a regular g&rid of the territory of Ukraine. The classification of pressure fields with extreme-cold temperatures allowed us to identify four main types of synoptic processes. The first type of synoptic processes is the cold air advection associated with the Sib&erian High. The low pressure at the middle troposphere is the characteristic feature. As a rule, this type of the processes leads to the lowest air temperatures as for Ukrainian climate conditions. The cold air usually expands practically throughout &all territory of Ukraine. In this case, the duration of such processes, as a rule, is longer relative to the other cold processes. The processes of the second type characterize the advection of cold air from the north into the territory of Ukraine. A&t the night time, the temperature of the air can vary within -16...-24 o C, which is relatively higher than in the case of Siberian cold air. The third type of synoptic processes describes advection of cold air from the northwest to the territory of &Ukraine. The advection of cold air from the northwest is characterized by the highest frequency in the first half of the winter season. The cold air flows are caused by cut-offs and the temperature at night practically throughout the territory of Ukr&aine may reach -15...-20 o C. For the field of surface pressure, a core of high pressure over northwestern Europe is observed. All the types of processes cause extreme cold air temperature over the territory of Ukraine which often is lower than a val&ue of 5-percentile air temperatures. The frequency of each type of process that leads to such extreme temperatures events in Ukraine during the winter season is approximately equal.
