Classification of surface atmospheric pressure fields in the Laptev and East Siberian seas
The need for classifying surface atmospheric pressure fields over the Arctic seas arose as a method was being developed for predicting the characteristics of discontinuities (leads) in the sea ice cover. Wind, which is determined by the atmospheric pressure field, acts on the ice cover and causes it...
| Published in: | Arctic and Antarctic Research |
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| Main Authors: | , , , |
| Other Authors: | |
| Format: | Article in Journal/Newspaper |
| Language: | Russian |
| Published: |
Государственный научный центр Российской Федерации Арктический и антарктический научно-исследовательский институт
2021
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| Subjects: | |
| Online Access: | https://www.aaresearch.science/jour/article/view/405 https://doi.org/10.30758/0555-2648-2021-67-4-394-405 |
| Summary: | The need for classifying surface atmospheric pressure fields over the Arctic seas arose as a method was being developed for predicting the characteristics of discontinuities (leads) in the sea ice cover. Wind, which is determined by the atmospheric pressure field, acts on the ice cover and causes it to drift. Leads are formed in the ice cover due to the irregularity of ice drift. Ice drift can be caused by several factors, such as skewed sea level, tidal waves and currents. However, the main cause of ice drift in the Arctic seas is wind. Each typical field of surface atmospheric pressure corresponds to a certain field of leads in the ice cover. This makes it possible to predict the characteristics of leads in the ice cover by selecting fields similar to predictive fields of atmospheric pressure based on archived data.The variety of atmospheric pressure fields makes it difficult to find an analogue to a given field by simply going through all the corresponding data available in the electronic archive. Classification of atmospheric pressure fields makes it possible to simplify the process of selecting an analogue.To develop the classification, we used daily surface pressure maps at 00 hours GMT for the cold seasons (from mid- October to the end of May) 2016–2021. The atmospheric pressure fields, which were similar in configuration, and hence the wind fields, belonged to the same type. In total, 27 types were identified, applicable both to the Laptev Sea and the East Siberian Sea. Within one type, a division into subtypes was made, depending on the speed of the geostrophic wind.The wind intensity was estimated by the number of isobars multiples of 5 mb on the surface atmospheric pressure map. All the surface pressure fields observed over the waters of the Laptev and East Siberian Seas over the past 5 years have been assigned to one of the types identified using cluster analysis. Each type of atmospheric pressure within the framework of the forecasting method being developed is supposed to correspond to a field of discontinuities in the ice cover. Поле атмосферного давления определяет направление ветра и его скорость. Ветер, воздействуя на ледяной покров, вызывает его дрейф. Неравномерность поля дрейфа является причиной образования разрывов в ледяном покрове. Каждому типовому полю атмосферного давления соответствует определенное поле разрывов в ледяном покрове. Подбор для прогностических полей атмосферного давления аналогичных типовых полей по архивным данным дает возможность прогнозировать характеристики разрывов в ледяном покрове. Для формализации подбора аналогов была разработана типизация полей атмосферного давления в морях Лаптевых и Восточно-Сибирском по ежесуточным синоптическим картам за холодные сезоны 2016–2021 гг. Всего было выделено 27 типов, которые разделены на подтипы в зависимости от интенсивности ветра. |
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