Intra-annual and long-periodic components in the changes of precipitation over the Antarctic Peninsula and their possible causes

Anatolii O Kornus,Serhii V Klok

doi:10.15421/112144

Abstract

   In order to identify and study the main mechanisms of the formation of atmospheric precipitation, in the article the monthly and annual amounts of precipitation were analyzed from the observations results at Vernadsky, Bellingshausen and Grytviken stations. For the last station, a small linear trend of precipitation increase was detected, while at Vernadsky and Bellingshausen station it is practically absent. At the next stage of the study, the characteristics of intra-annual component of the precipitation variability for these stations were obtained. In the annual course, the component of precipitation variability is represented by 3 peaks – March, July and October (at Bellingshausen station March and July only), with a well-pronounced 4-year periodicity. However, data from Vernadsky station indicates a decrease of the seasonal component in time, at Grytviken station the seasonal component is stable, while at Bellingshausen station is increasing of the seasonal component in time. The analysis of long-period components of the precipitation variability of was carried out on the remains of the data obtained after the analysis of the intra-annual component. For the long-period component of precipitation variability at Vernadsky station, five statistically significant harmonics were obtained, which are reflected in periods of 6.8, 2.4, 4.0, 5.1, and 5.3 years. For Grytviken and Bellingshausen stations, 4 statistically significant harmonics were obtained, the periods of which are 4.2, 0.8, 1.7, 8.9 years and 1.5, 2.0, 2.8, 0.2 years, respectively. Today, the main phases of solar activity are well known, which are about 11 years old. The long-period components of precipitation variability obtained in the work for the stations under consideration (to 10.3, 12 and 34.1 years) are identical (close) to the mentioned phase of solar activity. This allowed the authors to draw preliminary conclusions about the influence of solar activity on the conditions for the formation of precipitation in the region under study. However, direct correlation analysis did not confirm this, as in the case of the El Niño influence.  

Highlights

Changes in rainfall and other forms of precipitation will be one of the most critical factors determining the overall impact of climate change
The analysis of linear trends of the precipitation amount made it possible to establish that only for Grytviken station is a statistically significant positive trend of precipitation, while it is practically absent at Vernadsky and Bellingshausen stations, which is confirmed by the data from Table 2
We suggested that the 4-year periodicity is caused by El Niño/Southern Oscillation phenomenon (Oceanic... 2020), but their coordinated distribution showed on Fig. 10 does not confirm this

Summary

Introduction

Changes in rainfall and other forms of precipitation will be one of the most critical factors determining the overall impact of climate change. According to the RCP8.5 scenario (van Vuuren et al 2011) S. National Climate Assessment» shows that we are currently on track for RCP8.5 (Hayhoe et al 2018)), by the end of this century in high latitudes and the equatorial part of Pacific Ocean, an increase in the average annual rainfall is likely to take place. In many arid regions of mid-latitudes, as well as in subtropics, the average rainfall is likely to decrease, while in many humid regions of mid-latitudes, it is likely to increase by the end of this century (Pachauri et al 2014). For much of Europe, wetter winters are expected, but with drier summers over central and southern Europe

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Conclusion