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January 29 | The FTP 2014-2020

Sea will be explored with anchors

Waiting for the sea weather is not so hopeless. It can be predicted to the parameters that were previously considered unpredictable – the water temperature and flow dynamics in coastal areas. Technologies to do it are being developed by the scientists of P.P. Shirshov Institute of Oceanology.

Technologies "cutting" the ocean

Ocean is studied worse than the space is. Despite its availability for research (it is located on our home planet) the knowledge about it is very superficial. Existing technologies allow you to measure what's going on in the upper layers of the water column - processes in the depths in their entirety, diversity and complex relationships are not completely subject to the science. But despite of it we have a progress. The oceans were studied in fragments just in the 90s of the last century: equipment were lowered from the research vessels in the certain areas, and hydro physical, biological and other parameters of the aquatic environment were measured. Today, science has more rich arsenal, helping to look global at the water spaces. It is being done, for example, using the invention of US - the so-called float "Argo" representing the system of drifting sensors, which perform desired measurements at different depths when afloat. The information obtained is transmitted to a satellite and from there into the data center. Floats operate in automatic mode, cover virtually the entire Oceans and allow scientists to see it "in the context". More precisely, the part of the ocean.

Floats are powerless in the polar regions where ice will not allow sensors neither dive under the water or float to the surface for communicating with satellites. They also have nothing to do on the shelf and in the area of continental slope where the water depth varies greatly from place to place. They often pinned down in the bottom there and may even get stuck, caught in the roughness of the bottom surface.

Distribution_mapDistribution map of Argo floats in the entire Oceans in February 2010 (3214 floats)

Scientists of P.P. Shirshov Institute of Oceanology develop technology that allows to control the situation just in the coastal zone - on the shelf and continental slope, experiencing the greatest human pressure and have strategic importance for the people.

Andrey Zatsepin, Project Manager, Head of the Laboratory of Experimental Physics of the ocean, commented:

"The coastal zone of the sea is characterized by a high spatial and temporal variability of physical processes, as all the processes - gyres, eddies, etc. – have smaller scale there. Sea areas are rapidly heated and cooled, they tend to be less salty because of the inflowing freshwater rivers. Thus, the areas of the sea close to the shore are as if separated from the deeper sections by so-called front ones. These relatively shallow areas are in need of systematic observation and research. Besides the other in order to determine the necessary conditions for environmentally safe solving of the applied problems of the national economy."

In the coastal waters - with a float and an anchor

To study these relatively small wayward areas of the ocean researchers decided to create moored autonomous measuring stations that transmit information online.

Autonomous_measuring_station
Autonomous measuring station – the analogues of the float

In fact, this station is a kind of analogue of the float, which measures the parameters of the aqueous medium at different depths up to 2000 meters and periodically pops up to transmit data to the onboard computer. It also rests on the surface with the floating body, but unlike "Argo" float it is not in the free floating and securely attached to the bottom by anchor. Sensors that capture all that scientists want to know about the state of the water column ply on the cable connecting domestic anchor and a float. It is, in particular, information on water temperature, conductivity, pressure, flow rate, oxygen saturation, "a" chlorophyll fluorescence.

As the sensors are permanently in one geographic location, they do not risk encountering an obstacle, like "Argo" drifting floats.

Scientists have established one such station, in the coastal zone of the Black Sea near the Gelendzhik city at a depth of 250 meters. It was produced jointly by experts from the Institute of Oceanology and the Bureau of oceanographic equipment, however, measuring sensors were purchased abroad. There are weather stations on the shore measuring the wind speed and direction, air temperature and humidity, as well as the sea level varies depending on the time of the year, and the center of the collection of information.

"Our approach is that the "Argo" float measures the continuous distribution of the elements in the water column, and we need to measure the vertical distribution of sea water parameters in the coastal zone as well - Andrey Zatsepin explains. - Besides, every two weeks we get down a small boat to a depth of 1500 meters, which also probes the water column, selects chemical water samples and samples of zooplankton and phytoplankton. All the information is complexly used to interpret the processes occurring in coastal areas. For example, it is impossible to know without it why there was a rapid algal blooms or flowering sluggish vice versa. We use other measuring systems on the shelf where the depth is less than 100 meters, for example, the bottom station with Acoustic Doppler Current Profiler, determining the rate of flow throughout the water column above this station. Or moored garlands of temperature sensors that measure the vertical distribution of temperature. Information is transmitted every 30 seconds to on-board computer via submarine cable. "

Cold "anomalies" of the Black Sea

Integrated use of various technical devices, united by the scientists into a single monitoring system lets you know a lot about the sea.

Thus, by comparing the data obtained with water and shore stations in Blue Bay, researchers found some previously unknown interdependencies of parameters of the water environment and atmosphere.

In particular, the coastal upwelling patterns - a process in which cold water from the depths rise to the surface within a short time. People who love summer holidays in Gelendzhik are certainly familiar with this phenomenon when, in spite of the beautiful weather on the coast the sea water suddenly cools down by more than 10 degrees for a few hours.

It turns out to blame the wind that blows from the northwest along the coast, but blows away from the coast the warm water at the same time, thus provoking the raise of cold deep layers. The study's authors argue that there is nothing paradoxical in the relationship they identified; it is due to the physical laws acting in a certain way in the northern hemisphere. Scientists have just made calculations to support this finding. Warm water slightly cooled down during the stirring to a cold front will be back to the beach during the day after the change in wind direction.

By the way, the sudden "cooling" of the sea near the shore is useful for the sea: it carries life-producing nutrients from the depths to the surface layers.

Ecology or economy?

Knowledge about the relationships of different processes in the sea can help in the organization of economic activity. For example, to calculate at what distance from the coast industrial and sewage should be not to allow for sure the impurities and harmful chemicals fall to the surface coastal waters, where vacationers bath, irrespective of any kind of wind and any kind of stream. Unfortunately they sometimes fall for now.

To prevent it from happening, the city government should listen to the scientists. Andrey Zatsepin notes that there is something to strive for in this respect for now. In his opinion, there is no effective cooperation between the employees of science, who are usually concerned with the environmental situation, its impact on the environment and human health, and city administrators, always concerned about financial savings, even in developed European countries. According to scientist, federal government could resolve these contradictions by increasing the sustainability requirements of economic activities in the coastal zone in the cities and towns, and the by introduction of penalties for non-compliance with the recommendations of scientists.

The project "Research of technology of monitoring and forecasting of ecological state of the aquatic environment of the sea shelf" is supported by the Federal Target Program "Research and development in priority areas of scientific and technological complex of Russia for 2014-2020"

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