LOGO: an efficient local and global data collection mechanism for remote underwater monitoring

The oceans play an important role in our daily life and they form the lungs of our planet. Subsequently, the world ocean provides so many benefits for humans and the planet including oxygen production, climate regulation, transportation, recreation, food, medicine, economic, etc. However, the oceans suffer nowadays from several challenges ranging from pollution to climate change and destruction of underwater habitat. Hence, the use of remote sensing technologies, like sensor networks and IoT, is becoming essential in order to continuously monitor the wide underwater areas and oceans. Unfortunately, the limited battery power constitutes one of the major challenges and limitations of such technologies. In this paper, we propose an efficient LOcal and GlObal data collection mechanism, called LOGO, that aims to conserve the energy in remote sensing applications. LOGO is based on the cluster scheme and works on two network stages: local and global. The local stage is at the sensor node and aims to reduce its data transmission by eliminating on-period and in-period data redundancies. The global stage is at the autonomous underwater vehicle (AUV) level and aims to minimize the data redundancy among neighboring nodes based on a spatial-temporal node correlation and Kempe’s graph techniques. The simulation results on real underwater data confirm that LOGO mechanism is less energy consumption with high data accuracy than the existing techniques.

Another Record: Ocean Warming Continues through 2021 despite La Niña Conditions

The increased concentration of greenhouse gases in the atmosphere from human activities traps heat within the climate system and increases ocean heat content (OHC). Here, we provide the first analysis of recent OHC changes through 2021 from two international groups. The world ocean, in 2021, was the hottest ever recorded by humans, and the 2021 annual OHC value is even higher than last year’s record value by 14 ± 11 ZJ (1 zetta J = 1021 J) using the IAP/CAS dataset and by 16 ± 10 ZJ using NCEI/NOAA dataset. The long-term ocean warming is larger in the Atlantic and Southern Oceans than in other regions and is mainly attributed, via climate model simulations, to an increase in anthropogenic greenhouse gas concentrations. The year-to-year variation of OHC is primarily tied to the El Niño-Southern Oscillation (ENSO). In the seven maritime domains of the Indian, Tropical Atlantic, North Atlantic, Northwest Pacific, North Pacific, Southern oceans, and the Mediterranean Sea, robust warming is observed but with distinct inter-annual to decadal variability. Four out of seven domains showed record-high heat content in 2021. The anomalous global and regional ocean warming established in this study should be incorporated into climate risk assessments, adaptation, and mitigation.

ON THE PECULIARITIES OF THE STRUCTURE OF THE MULTIDECADE OSCILLATION OF THE WORLD OCEAN

One of the most remarkable peculiarities of the modern climate, undoubtedly, should be recognized as the climatic shift observed in the mid-70s of the last century. The reasons for this phenomenon for a long time, despite the activation of climatologists from all over the world, remained a mystery that requires its disclosure. First of all, this was due to the fact that the shift that took place turned out to be unexpected for scientists and was accompanied by rapid qualitative changes in the planetary climate. To date, thanks to the efforts of scientists using the results of rapidly developing numerical modeling, diagnostic calculations and observational data in large hydrophysical experiments in various regions of the World Ocean (WO), an understanding of the role of the ocean factor in the variability of the current climate has developed. It became clear that climatic shifts are an important feature of the internal dynamics of the climate system. The most obvious evidence of intrasystemic processes should be considered the discovered planetary structures in the atmosphere – Global Atmospheric Oscillation (GAO) and in the ocean – Multi-decadal Oscillation of the Heat content in the Ocean (MOHO), which are quasi-synchronous accompanying variations in the modern climate. GAO, its structure and features have been discussed in detail earlier in a number of studies. As for the MOHO, its structure and features are discussed in the proposed work. It is characteristic that the MOHO is located in the layer of the main thermocline (100-600 m). In a quasi-uniform layer (0–100 m), and in a deep layer (600-5500 m), the thermodynamic regime differs from the regime in the layer of the main thermocline. Probably, it is precisely this circumstance that did not allow earlier to draw attention to such an important detail in the structure of the WO thermodynamic variability. The presence of extreme multi-decadal temperature field disturbances at intermediate levels (200, 300, 400, 500, 600 m) should be noted as an important characteristic feature of the oscillation. Large-scale hydrophysical experiments (POLYGON-70, POLYMODE, etc.) made it possible to reveal the vortex structure in the dynamics of WO waters and to discover that the vortices of the open ocean have maxima of kinetic energy precisely in the layer of the main thermocline. This allows us to assume a connection between synoptic eddy activity and MOHO. However, the latter remains to be studied.

Challenges and environmental issues in developing hydrocarbon resources in the World ocean

The oil and gas industry has been evolving for 150 years. Despite the predictions on the diminishing role of hydrocarbons in the second half of the 21st century, today they play a leading role in the global energy sector. In view of this there is some interest to study current development trends of the industry. This paper reviews and analyses data for the period from 2011 to 2021, which relate to the development of hydrocarbon resources in the marine and ocean environment. It was important for the authors to consider how the trends they highlighted are affecting or will affect ecosystems. The conducted research has showed that today there are three main development trends in hydrocarbon mining in the World ocean: development of the marine Arctic, continental shelf and the possibility to organize commercial production in the deep sea areas of the World ocean. For each of the directions both existing and potential ecological risks have been identified. They include loss of marine biodiversity, activation of dangerous geological processes, unpredictability of ocean environment, man-made accidents and disasters, discharges of drilling and other industrial waste, etc. The work has also identified the challenges facing the oil and gas industry. These include the search for new technologies for deep-sea production, poorly understood depth of the World ocean, need for new approaches in environmental risk management, as well as the creation of a legal framework for subsoil use regulation in new environments and areas.

MICROPLASTICS POLLUTION MONITORING IN BOTTOM SEDIMENTS OF THE SEVASTOPOL REGION RECREATION ZONES

A study of the concentration of microplastic pollution (MP) in the bottom sediments of the water areas adjoining recreation zones (RZ) of the Sevastopol region in 2018 - 2020 was carried out. An increase in MP was registered practically in all areas, the average values of MP concentration were 13.4 items•kg-1 dry weight. As for the shape of microplastics (MPs) particles, the maximum share was made up by frag-ments (50-83%), fibers were also numerous (33%). A significant increase in the concentration of MP on the 0-20 m section of the underwater coastal slope from the water edge was recorded in zones with an open water area and presence of a cliff. The revealed level of MP is comparable to that in the Mediterra-nean, Caspian, Baltic Seas, but an order of magnitude lower than in other regions of the World Ocean.

SHIRSHOV INSTITUTE OF OCEANOLOGY 75 YEARS OLD

This year in 2021, Shirshov Institute of Oceanology celebrated 75 years old. Shirshov Institute is the largest and oldest research center of seas and oceans in Russia. In the past and present of the Institute, there are many significant discoveries and developments for world oceanology, the most complex expeditions and large-scale international projects. I am sure that our future as a Center for the Study of the World Ocean will be no less rich and bright.

Seasonal Variability of The Mixed Layer Depth in The Sulawesi Sea

The Sulawesi Sea is a semi-enclosed basin located in the Indonesian Seas and considered as the one of location in the west route of Indonesian Throughflow (ITF). There is less attention on the mixed layer depth investigation in the Sulawesi Sea. Concerning that the mixed layer plays an important role in influencing the ocean in air-sea interaction and affects biological activity, the estimation of mixed layer depth (MLD) in the Sulawesi Sea is important. Seasonal variation of the mixed layer in the Sulawesi Sea between 115°-125°E and 0°-8°N is estimated by using World Ocean Atlas 2013. Forcing elements on the mixed layer in terms of surface-forced turbulent mixing from mechanical forcing of wind stress and buoyancy forcing (from heat flux as well as freshwater flux) in the Sulawesi Sea is provided by using a reanalysis dataset. The MLD is estimated directly on grid profiles with interpolated levels based on chosen density fixed criterion of 0.03 kg.m^-3 and temperature criterion of 0.5°C difference from the surface. The results show that mixed layer depth in the Sulawesi Sea varies both spatially and temporally. Generally, the deepest MLD was occurred during the southwest monsoon (JJA), and the lowest MLD was occurred during the first transition (MAM) and second transition monsoon (SON). Strengthening and weakening MLD are influenced by mechanical forcing from wind stress and buoyancy flux. In the Sulawesi Sea, the mixed layer deepening coincides with the occurrence of a maximum in wind stress, and low buoyancy flux at the surface. This condition is the opposite when mixed layer shallowing occurs.

TWO UNUSUAL EXPEDITIONS OF THE INSTITUTE OF OCEANOLOGY RESEARCH VESSEL "DMITRY MENDELEEV" (6TH AND 18TH CRUISES)

50 years ago, in 1971, an expedition of RV “Dmitry Mendeleev” (her 6th cruise) departed to the islands of Oceania. The voyage was timed to coincide with the 100th anniversary of the first trip to island New Guinea by Nikolai Nikolaevich Miklukho-Maclay, a famous russian explorer, antropologyst, and ethnographers, and, simultaneously, with the 125th anniversary of his birth. Scientists 19 scientific institutions of the USSR, specializing in biological, geological and ethnographic research took part in the 6th cruise of R/V “Dmitry Mendeleev”, and the continuing expedition to the same area during her 18th cruise. Besides the ship crew and the scientific team, there were cameramen from Soviet state cinematography corporation Goskino, members of the Union of Artists of the USSR and other cultural and artistic figures were aboard the ship during both voyages. Nowadays, in 2021, in honor of the 175th anniversary of the birth of N.N. Miklukho-Maclay, a new exhibition named "Oceania distant and close" was opened in the Museum of the World Ocean in city of Kaliningrad. Among other artifacts, it includes photographs from the 18th cruise of the R/V “Dmitry Mendeleev” and paintings dedicated to Miklukho-Maclay's expeditions.