A number of promising hydrocarbon deposits are known in the south-western part of the Kara Sea. A safe development of these deposits requires hydrometeorological support, including sea-level observations. The paper deals with sea-level data of autonomous anchored buoy station. The period of observation is about 2 years, and the observation dataset is divided into 2 periods due to the displacement of the buoy station. The coordinates of the first position of the buoy station are known but they had been changed after the displacement (possibly due to the action of the ice ridge keels).

Data from two time series of observations are studied by harmonic analysis, using the method of least squares by AARI version. According to the average monthly and mean annual values of the main tides it is found that the data includes two independent series. It is determined that the second series may be considered uniform. In order to locate of the anchored buoy station we calculated new coordinates using the empirical tidal charts of the M₂ wave.

As a result, the harmonic constants of the eight main tidal waves for the Belyi Island area are presented for the first time. The new data confirms the amphidromic system in tides O₁ and Q₁ , between the Zhelaniya Cape and the Belyi Island. According to the new data the maximum seasonal variation in the range of M2 tide was observed in June, and the minimum of the phase angle was observed in July. This unusual seasonal variation of the M₂ tide corresponds to previous observations data from the Uedinenia Island.

The authors have no competing interests.

The processing of 6-hourly intervals level measurements at the New Port polar station was previously difficult due to poor data quality and the lack of methodology for assessing them and bringing observations into uniform rows. Therefore, since the second half of the 20^th century, no research of wind-induced water has been carried out. In 2015, for the first time, the authors formed a base of residual levels (observations minus forecasting) for 1977–2012 on 6-hourly intervals observations of water level at the New Port station using the method of tide calibration. In the present work, a period of observations with relatively reliable data for 1977–1991 was selected for the research of the storm surges in the water level fluctuations. Surges are considered in comparison with the 5 % probability, and ranges with 95 % probability. The annual distribution of the number of surges and ranges showed an average of 12.4 surges and 11.2 ranges per year. The maximum number of surges and ranges was observed in 1981 and was 21 surges and 27 ranges. In the time course of fluctuations of residual levels during the above period, the maximum with the value of 634 cm was noted in 1987 and occurred during the autumn period (ice composition). The length of the surges varied between 0.25 days and 13.5 days. Most of the surges occurred in the period June-October (78.8 %) with the largest number in September (22,8 %). In the period January-May the number of surges decreases to 7.6 % and is zero in April. The lowest ranges residual level was observed in 1986 (343 cm above zero fasting). The total fluctuation of the residual level in New Port during the period of 6-hourly intervals level observations in 1977–1991 was 291 cm. This is 23 cm more than was recorded at the Cape Kamenny station. The length of the ranges varied from 1 day to 8 days. The majority of the intra-annual distribution of the number of ranges over a multi-year period was observed in July–October (83.7 %) with the maximum number in September (28.1 %). A small number of ranges were observed in January and March, and their total absence in April and May. The duration of surges and ranges is inversely dependent on their growth rate. Thus, the highest growth rate of the residual level at the deposit of 5.1 cm/hour corresponds to the duration of the deposit of 0.25 days. The greatest duration of growth of the surge level (9.25 days) corresponds to a speed of 0.14 cm/h. The drop in the level during the range occurred at the highest speed of 11.6 cm/h, the rise from the minimum residual level – at the speed of 6.97 cm/h. Corresponding to these rates, the duration of the decline and rise of the range level was 0.15 cm/h. The highest rise time of the residual range level was 5.25 days at an intensity of 0.44 cm/h.

The authors declare that they have no competing interests.

The goal of the present paper is to analyze the spatial-temporal variability of ice edge location in the Eastern Arctic seas of Russia (the Laptev, East-Siberian and Chukchi Seas) in late summer (August-September) during the period from 1981 to 2018, as well as to estimate the multi-year changes taking place in the 21st century. The special archive containing the information on latitude position of ice edge at the meridians between the Severnaya Zemlya Archipelago and Alaska was developed; the data of AARI (Arctic and Antarctic Research Institute) specialized observations and satellite images were used.

The inter-annual variability of ice edge position in the total area shows that the entire period 1981–2018 consists of two significantly different parts: the interval from 1981 to 2001 with southern ice edge position (mean latitude in September comprised 74,9° N), and the interval from 2002 to 2018 with northern ice edge position (mean latitude 78,7° N). The difference between the extreme values of ice edge latitude at some meridians reached 9 degrees of latitude (about 1000 km).

During the period from 2002 to 2018, the area of mostly active northward displacement of ice edge moved generally from east to west. From 2002 to 2010, the maximum northward displacement of ice edge was observed in the East-Siberian and Chukchi Seas; in 2007 the extreme northern position of ice edge was registered to the east of the New Siberia Archipelago (mean latitude comprised 84,0° N). However, during 2011–2018, the maximum northward displacement of ice edge was observed in the Laptev Sea; in 2014 the extreme northern position of ice edge was registered to the west of the New Siberia Archipelago (mean latitude comprised 84,5° N).

Typologically, the displacement of ice edge from south to north during the period from 2001–2018 looks like a wave; its crest and sole drift from the Chukchi Sea toward the Laptev Sea. Within the period from 2007 to 2010, the ice edge displacement reached its maximum, and after this, during 2011–2015, the reverse motion from north to south began. One can forecast that within the nearest coming years the ice edge oscillatory southward drift would continue, and by the end of 2020-s one can expect the ice edge to have the position typical for the period 2002–2006.

The author declares that he has no competing interests.

The problem of diagnosing and predicting the characteristics of the polar ionosphere can be investigated by studying the effect of magnetospheric disturbances on the high-latitude ionosphere. Our task is to investigate the dependence of the variations in the electron concentration F of the ionosphere region at the subauroral stations of vertical sounding (VS) Sodankyla, Lovozero and Gorkovskaya on variations in the geomagnetic field. The data of AE and PC of geomagnetic indices were used during substorms in the winter of 2011–2012. For analysis, the epoch overlapping method was used. As a result, it was shown that the perturbation in the electromagnetic field is accompanied by a subsequent amplification of variations during the critical frequencies fоF2, and hence the electron concentration, auroral and subauroral ionosphere.

We conclude that the geomagnetic indices AE and PC can serve as predictors of disturbances during the ionospheric parameter fоF2 of the high-latitude ionosphere in the winter season.

An increase in the amplitude level of AE from 100 to 350 nT (and PC > 2) during the night hours of the winter season precedes an increase in the critical frequencies of the ionosphere F2 layer by an average of 30% of the median. An increase in the amplitude level of AE from 180 to 520 nT (and PC> 2) in the winter season in the afternoon precedes the positive or negative deviation of the critical frequencies of the ionosphere F2 layer from the median by a mean of 10%. The response of the high-latitude ionosphere of the F2 layer to variations in the AE and PC indices appears in the first hour after the maximum during geomagnetic indices, the delay of the maximum deviation from the median 1 hour at night and 3 hours in the afternoon at Lovozero station, at Sodankyla and Gorkovskaya is about 3 hours at night and weakly expressed during the day.

I declare I have no competing interests.

The article presents the results of systematic measurements (2009−2017) of the total column abundances of methane (TC_CH₄ ) and the column-averaged concentration (X_CH₄ ) at the Antarctic station Novolazarevskaya. Solar radiation is recorded in the range 2990 – 3006 cm^–1 using a diffraction spectrometer with 0.2 cm^–1 resolution. The inverse task CH₄ total column determining is achieved using the SFIT4 v0.9.4.4 code. The analysis shows that during the measurement period the average TC_CH₄ was (3.4±0.8).10¹⁹ molecules/cm² during the measurement period, and the average X_CH₄ is (1663±34) ppbv. TC_CH₄ trend is (4.5±2.2).10¹⁵ molecules/cm² /month, and X_CH₄ trend is (0.28 ± 0.11) ppbv/month. The average TC_CH₄ values and trend at Novolazarevskaya are in good agreement with the measurements by the Brucker120HR instrument at the Arrival Heights station. Seasonal variations of atmospheric methane have the maximum in October–November and the minimum in May–July. The trends of surface methane concentrations at Sywa, the Halley station and the Amundsen-Scott South Pole station are 0.59 – 0.61 ppbv/month and exceed the trend of the column-averaged concentration at Novolazarevskaya and AIRS trends for the troposphere (0.24 – 0.32) ppbv/month, due to a decrease in the maximal values of TC_CH₄ in the period after 2014. The closest agreement of X_CH₄ variations at Novolazarevskaya with AIRS data is observed at the levels of 150–200 hPa. Significant semiannual harmonics varied with height are characteristic of CH₄ variations according to the AIRS data. The interference of annual and semiannual harmonics leads to the appearance of two maxima in the seasonal variations of methane with relative position to each other varies with height. The statistical model is developed for all the series considered. It approximates the trend, annual and semi-annual components of CH₄ oscillations.

The authors have no competing interests.

At present, oil-producing offshore structures, as well as transport vessels transporting oil products extracted in the seas of the Russian Arctic are equipped with ice load monitoring systems (ILMS) to prevent environmental disasters. The ice-resistant self-propelled platform (IRSPP) that is under construction now, according to the design should be equipped with this system. First of all this system is the main system for ensuring the platform’s safety in ice conditions, and secondly makes the platform’s hull a unique tool for solving a wide range of tasks to study the effects of ice on any construction.

The main goal of the research during the expedition “Transarktika-2019” was to obtain the necessary data for the development of an ice load monitoring system of the constructing IRSPP “North Pole” and testing the prototype of the ILMS at long vessel’s drift in ice.

The measurements of stresses in the hull structures of the R/V “Akademik Tryoshnikov” were carried out during impacts on ice ridges and during ice compressions.

The standard ship ice load monitoring system (SILMS) of the R/V “Akademik Tryoshnikov” and strain gauges additionally installed on the frames and a shell plating in the middle part of the hull were used to perform the measurements.

The analysis of the obtained data showed that the maximal loads on the hull occurred during the forcing of ice ridges but the level of maximum stresses was not a danger to the hull.

Compressions during the drift did not have a strong effect on the ship’s hull. The data obtained made it possible to identify a number of features for the operation of ILMS in similar conditions.

Based on the results of the expedition research, recommendations for the design of the architecture of the ILMS for IRSPP were issued. The results of further analysis of the obtained materials will be used in the development of data processing algorithms for ILMS for IRSPP, as well as for the development of the prospective programs of scientific research of deformation, fracture and other processes of various scales that occur in drifting ice during the future drifts of the IRSPP “North Pole”.

The authors have no competing interests.

This work describes the practical implementation of the method for digital noise suppression during processing images containing ice information to recognize automatically the contours of «ice-water» objects during aerial photography. Images containing ice information have special characteristic structural features related to noise, e.g.

granularity, glare, ice crumbs. This makes difficult or even impossible to recognize automatically the contours of ice-water objects. It is known that the success of the application of edge recognition methods depends on how much image noise is reduced. The paper discusses the construction method for the management of noise. The method is based on the sequential application of the Haar wavelet transform denoising using thresholding, clustering by k-means method. For the subsequent automatic construction of ice floes contours the Sobel operator is applied.

The aim of the work is to develop a method capable to process digital images effectively that contain ice information with strong digital noise. In this work we treated the images of one-year ice containing strong digital image noise in the form of granularity and in the form of ice crumbs. A description of the features of each of the steps of the proposed method and practical application is given.

As a result, the method was developed for processing images of ice information containing digital noise in absolute value commensurate with the basic data. It was noted that the use of the k-means method expands the scope. The k-rare method allows more detailed processing of ice information and distinguishes not only the contours of ice-water objects, but also the contours of ice crumbs.

The conclusion formulates the main advantages of the method and the possible application of the algorithm in the process of local exploration of the ice conditions of the Northern Sea Route channel using unmanned aerial vehicle for aerial photography. The usage of unmanned aerial vehicle for aerial photography will increase the frequency of weather forecast updates and predict the appearance of ice objects at the ship’s heading. That will allow us to select the safest and most economical efficient route along the Northern Sea Route.

The authors have no competing interests.