Webinar on the NABOS program and Arctic marine research over the past few years
During the webinar, Vladimir Ivanov gave a presentation and replied to questions from the audience.
Does the program use data from the Barneo annual camp? Do you use any additional data for your research?
Yes, of course, we use additional data. In 2005-2008, Jimmy Morrison from the University of Washington deployed US stations there each year. He and I published several joint articles on the basis of joint NABOS and Barneo data. It seems we are not using such data in the past few years, although this would be very interesting.
How long can the batteries of profile meters operate?
It depends on how often this device goes up and down. The device can move back and forth for about one million meters, all told. But its service life has been calculated for temperate latitudes with warmer waters. Unfortunately, the device's service life is shorter in cold waters. The experience of the past two years has been more successful because all profile meters operated during this entire period, with sounding missions every two days. This serves our purposes well. During other less successful deployments, the device stopped functioning after six months.
What is the total duration of these expeditions?
In the early 2000s, they lasted 24-26 days, on average. These expeditions have lasted longer in the past few years. In 2015, the latest expedition was completed in 38 days. I suspect that the 2017 expedition will last about two months because of its highly ambitious program. It is impossible to conduct the expedition over a shorter time period; otherwise we would have to reduce its scale.
The deployment of all devices involves highly professional marine technicians. There are not many of them, they are wildly popular and they have a very busy schedule. That's why two months is already critical for them. But scientists it isn't so critical.
Does this mean that we need marine technicians?
Yes because these deployments are a very difficult task which should be accomplished by super-professionals. Any minor mishap may cause you to lose a device or the entire buoy station.
What should be done if ships are unable to reach buoys, retrieve them and collect data? How can we release buoys if their batteries are running low and if it's hard to detect them?
I would like to note two aspects here. First, ice-resistant vessels capable of smashing through thick ice formations are selected prior to deployments. Or we select icebreakers, including the Kapitan Dranitsyn. Second, we were unable to retrieve some devices using standard methods. Sometimes, they cannot be resurfaced using acoustic signals. The entire cluster does not rise to the surface and remains on the seabed. In such cases, we were able to use mine sweeps several times for retrieving the devices with cables after pinpointing their exact location. This does not happen very often, although several successful episodes have been recorded. Quite often, these devices are deployed over 2.5 kilometers beneath the surface, and it is sometimes hard to retrieve them by sweeps. Some devices did not respond; something happened to them; it was a dead-end, and they were listed as irretrievably lost.
Did you collect any biological data during this program?
Yes, the vessel carried groups of biologists, including from Laval University, the Shirshov Institute and the University of Alaska Fairbanks, in various years, including 2015. They conducted standard vertical and horizontal biological sweeps and collected materials. This is not the main part of this program.
Where can we find data on this program? Is there any special website where this data is stored?
Yes, if you type NABOS into a search engine, it will immediately show you this website. The website's domain is located at the University of Alaska Fairbanks and contains all data, plus hydro-physical data. As this is a joint Russian-US program, the National Science Foundation of the United States requires website administrators to post all processed data after preset deadlines have expired. This is about six months for data collected during sounding missions. If I'm not mistaken, buoy station data should be posted 12 months after processing. The website posts all data from past years.
As I understand it, you focus on chemical measurements of ice specifications during your work. Could you say a few words about changes in the chemical composition of ice formations over the past few years?
We mostly prioritize hydro-chemical measurements inside water layers. This is interesting in the context of tracing water masses and their origin. Today, we have many more opportunities for conducting accurate measurements of various exotic elements, including tiny concentrations of mercury, iron, etc. These measurements can be very informative. I'm not a hydro-chemist, and I'm therefore unable to go into detail. But, as a rule, we have a large hydro-chemical team. Its members conduct an entire range of hydro-chemical measurements aboard the vessel and simply select samples for subsequent laboratory measurements. To my mind, they have obtained a lot of interesting results.
To be honest, I don't think that serious changes in the chemical composition of ice formations are linked with the dwindling area of these formations. There is no salt left inside old freshwater ice formations. Year-old ice formations are not subjected to homogeneous freezing. These ice masses contain air bubbles and brine inclusions. Naturally, these substances may contain pollutants. Certainly, this is interesting in the context of analyzing pollutants. Until recently, however, I did not see any publications about catastrophic changes and noting that the ice has become much more polluted.
Have you found any significant changes in the chemical composition of water, and why do you conduct this research?
A large-scale open discussion is currently underway, with its participants discussing the possibility of obtaining methane from permafrost on the continental shelf. This data remains rather contradictory. The academic community is divided into two camps. Members of the first camp claim that this can be believed, that this process is taking place, and that it is the result of global warming. Their opponents believe that this process is far-fetched, that it has always taken place and that it has nothing to do with global warming. Some even claim that this is an artifact. This subject remains highly relevant. This mostly concerns the continental shelf in the Laptev and Eastern Siberian seas. I can only voice my opinion on this issue. It appears that this process is not seriously linked with global warming because the temperature of the seabed water layer… of course, the water heats up for a while even on shallow shelf sections during the summer season. But this takes place during a very short time period, that is, during 30-45 days, at most, and water temperatures reach 3-4 degrees Celsius. Frankly speaking, I don't quite understand how this can influence permafrost layers that are located hundreds of meters beneath the shelf. This is no objective evidence pointing to all-out warming that could melt the permafrost layer on the shelf. Currently, articles dealing with the appearance of methane bubbles in remote areas are being published. This raises the question of whether this is linked with permafrost in any way. Quite possibly, this process is partially linked with the mouths of ancient rivers that are now located underwater. In the past, they were located on land. This is not my specialty. I have read that no permafrost has ever been recorded in the mouths of these rivers. Therefore this may imply channels where methane was emitted. In that case, this process is not linked with global warming, and that the volume of specific emissions remains the same as in the past.
Do you perceive any trend?
It is very hard to assess specific trends because we started conducting measurements quite recently, and we have no reference point with which these measurements can be compared. It is possible to compare them with bore-core samples and to see what happened tens of thousands of years ago. This is a very topical issue.
Regarding the hydro-chemical composition, the tracing of various water masses presents the greatest interest because it appears that the changing state of ice formations influences the origin of water masses. Therefore it is possible to accomplish this with the help of hydro-chemical methods. The only problem is that this process is rather slow. Ice formations are receding much faster than these changes start influencing multi-layer water masses. They are slower, and specific trends will start manifesting themselves.