Surface manifestations of short-period internal waves of the Kuril-Kamchatka region and the Bering Sea according to satellite observations

Author(s):  
Egor Svergun ◽  
Alexey Zimin

<p>In the Bering Sea, as in the Kuril-Kamchatka region, which includes the waters near the Kuril Islands and the Pacific waters of the Kamchatka Peninsula, previously performed satellite radar observations show numerous scattered surface manifestations of short-period internal waves (SIW’s). However, the summative study of the characteristics of surface manifestations of SIW’s are currently not available in this region.</p><p>In this study, radar images from the Sentinel-1A and B satellites from July 1, 2019 to September 30, 2019 were used to record the surface manifestations of SIW’s. For each surface manifestation of SIW’s, such characteristics as the position of the manifestation, the wavelength, the arc length of the leading ridge in the packet, the direction of propagation, and the number of waves in the packet are determined. Wave detection on the radar images is performed using ESA SNAP and Matlab software.</p><p>In the study region, 1,540 SIW’s. manifestations with a wavelength of 80 to 1,900 meters and a leading crest length of 1 to 70 km were registered on 772 radar images. The ranges of variability of the main geometric characteristics of the manifestations in the Kuril-Kamchatka region and in the Bering Sea are very similar. The maximum number of manifestations in the Kuril-Kamchatka region was recorded in the first half of September, and in the Bering Sea – in the second half of July. This difference seems to be related to regional features of pycnocline formation.</p><p>Manifestations of internal waves are mainly recorded in the shelf zone. The constant occurrence of manifestations of internal waves located in the southern part of the Kuril Islands, around the Pacific coast of the Kamchatka Peninsula, East of the Litke Strait, and the Straits of the Aleutian chain. It was found that the areas of constant occurrence of the manifestations of SIW’s coincide with the areas of intense dissipation of the internal tide. In the Kuril-Kamchatka region, in contrast to the Bering Sea, manifestations of internal waves are recorded over significant depths at a great distance from the shelf zone, which is associated with the collapse of the internal tide reflected from the edge of the continental slope.</p><p>The information obtained in this study will allow us to improve our understanding of the field of short-period internal waves of the north-eastern Pacific Ocean.</p><p>The study of surface manifestations of internal waves in the Kuril-Kamchatka region was supported by RFBR grant No. 20-35-90054. The study of surface manifestations of internal waves in the Bering Sea was supported by RFBR grant No. 18-35-20078.</p>

2021 ◽  
Author(s):  
Eugene Morozov ◽  
Dmitry Frey ◽  
Elizaveta Khimchenko

<p>Observations of tidal internal waves in the Bransfield Strait, Antarctica, are analyzed. The measurements were carried out for 14 days on a moored station equipped with five autonomous temperature and pressure sensors. The mooring was deployed on the slope of Nelson Island (South Shetland Islands archipelago) over a depth of 70 m at point 62°21ꞌ S, 58°49ꞌ W. Analysis is based on the fluctuations of isotherms.  Vertical displacements of temperature revealed that strong internal vertical oscillations up to 30–40 m are caused by the diurnal internal tide. Spectral analysis of vertical displacements of the 0.9°C isotherm showed a clear peak at a period of 24 h. It is known that the tides in the Bransfield Strait are mostly mixed diurnal and semidiurnal, but during the Antarctic summer, diurnal tide component may intensify. The velocity ellipses of the barotropic tidal currents were estimated using the global tidal model TPXO9.0. It was found that tidal ellipses rotate clockwise with a period of 24 h and anticlockwise with a period of 12 h. The waves are forced due to the interaction of the barotropic tide with the bottom topography. Diurnal internal tides do not develop at latitudes higher than 30º over flat bottom. The research was supported by RFBR grant 20-08-00246.</p>


1972 ◽  
Vol 50 (2) ◽  
pp. 378-380
Author(s):  
Gerald A. Mulligan ◽  
Clarence Frankton

Rumex arcticus Trautv., a species found on the mainland of northwestern North America and in northeastern U.S.S.R., contains tetraploid (2n = 40), dodecaploid (2n = 120), and perhaps 2n = 160 and 2n = 200 chromosome races. Most North American plants are tetraploid and are larger in size and have more compound and contiguous inflorescences than typical R. arcticus. Typical plants of R. arcticus occur in the arctic U.S.S.R., St. Lawrence Island in the Bering Sea, and at the tip of the Seward Peninsula of Alaska, and they all have 120 or more somatic chromosomes. High polyploid plants of R. arcticus that resemble North American tetraploids in appearance apparently occur on the Kamchatka Peninsula. These have been called R. kamtshadalus Komarov or R. arcticus var. kamtshadalus (Kom.) Rech. f. by some authors.


1987 ◽  
Vol 9 ◽  
pp. 236-236
Author(s):  
D.J. Cavalieri ◽  
C.L. Parkinson

The seasonal sea-ice cover of the combined Bering and Okhotsk Seas at the time of maximum ice extent is almost 2 × 106 km2 and exceeds that of any other seasonal sea-ice zone in the Northern Hemisphere. Although both seas are relatively shallow bodies of water overlying continental shelf regions, there are important geographical differences. The Sea of Okhotsk is almost totally enclosed, being bounded to the north and west by Siberia and Sakhalin Island, and to the east by Kamchatka Peninsula. In contrast, the Bering Sea is the third-largest semi-enclosed sea in the world, with a surface area of 2.3 × 106 km2, and is bounded to the west by Kamchatka Peninsula, to the east by the Alaskan coast, and to the south by the Aleutian Islands arc.While the relationship between the regional oceanography and meteorology and the sea-ice covers of both the Bering Sea and Sea of Okhotsk have been studied individually, relatively little attention has been given to the occasional out-of-phase relationship between the fluctuations in the sea-ice extent of these two large seas. In this study, we present 3 day averaged sea-ice extent data obtained from the Nimbus-5 Electrically Scanning Microwave Radiometer (ESMR-5) for the four winters for which ESMR-5 data were available, 1973 through 1976, and document those periods for which there is an out-of-phase relationship in the fluctuations of the ice cover between the Bering Sea and the Sea of Okhotsk. Further, mean sea-level pressure data are also analyzed and compared with the time series of sea-ice extent data to provide a basis for determining possible associations between the episodes of out-of-phase fluctuations and atmospheric circulation patterns.Previous work by Campbell and others (1981) using sea-ice concentrations also derived from ESMR-5 data noted this out-of-phase relationship between the two ice packs in 1973 and 1976. The authors commented that the out-of-phase relationship is “... surprising as these are adjacent seas, and one would assume that they had similar meteorologic environments”. We argue here that the out-of-phase relationship is consistent with large-scale atmospheric circulation patterns, since the two seas span a range of longitude of about 60°, corresponding to a half wavelength of a zonal wave-number 3, and hence are quite susceptible to changes in the amplitude and phase of large-scale atmospheric waves.


2020 ◽  
Author(s):  
Andrey Serebryany ◽  
Valeriy Bondur ◽  
Viktor Zamshin

<p>When conducting work in the fall of 2015 on the Black Sea northeast shelf, we recorded internal waves, the unusualness of which attracts special attention for the following reasons. For the first time in 40 years of internal waves observations in the Black Sea, such high waves with amplitudes of 14–16 m were measured. The generation of these anomalous waves was connected with a cold atmospheric front passing over the sea. It was the first experimental evidence in the sea of such mechanism for internal waves generation. The observed internal waves had a clear seen character of nonlinear soliton-like waves.</p><p>We met the train of internal solitons during a sub-satellite survey conducted in the sea from a motor yacht equipped with ADCP “Rio Grande 600 kHz” in the waters near Cape Tolsty. The train was found at a point of the sea with a depth of 33 m and then was recorded on seven multidirectional tacks oriented normal to the coast. It moved across the shelf to the coast along the bottom thermocline, while the bottom currents accompanying it had a northwestern coastal orientation. The train included four waves of a soliton-like shape with sharpened crests and flattened troughs. Their lengths were 100-110 m, heights up to 14-16 m, vertical velocities in orbital currents reached 0.15-0.20 m/s. Another property of nonlinear waves was also expressed - the amplitude ranking of waves in the train. Traced on successive tacks for 2.5 hours, internal waves had preserved the soliton-like shape and as well the strong vertical component in their orbital currents. Despite the fact that the train was moving along the bottom thermocline, the effect of internal waves was sufficient to appear on satellite radar images of the sea surface of the study area. The performed processing of satellite images confirmed the wave parameters measured by contact methods.  An interesting fact of a long accompaniment of internal solitons by a school of fish was discovered. Fishes were concentrated in areas where internal waves carried the components of fish food supply to the surface from the bottom layers. The work was partially supported by RFBR grant 19- 05-00715.</p>


2019 ◽  
Vol 489 (4) ◽  
pp. 409-413
Author(s):  
E. I. Gordeev ◽  
S. N. Kulichkov ◽  
P. P. Firstov ◽  
O. E. Popov ◽  
I. P. Chunchuzov ◽  
...  

On December 18, 2018 at 23:48 UTC in the Earths atmosphere, at the height of 25,6 km over the Bering sea, destruction of a meteoroid with formation of a shockwave occurred. The mass of the Beringovomorsky meteoroid is estimated as 1600 tons, and its diameter is estimated as 9-14 meters. If assessment is right, then for the last 30 years it was the second in energy explosion of a space body in the Earths atmosphere. The nearest to the epicenter of meteoroid explosion station of the international system of infrasonic monitoring (IS44 station) is located on the Kamchatka peninsula at a distance of 1024 km. At IS44 station, an infrasonic signal from destruction of a meteoroid was registered. In this paper, the results of analysis of the infrasonic signal registered by IS44 are represented and the estimation of energy of this event is carried out.


1987 ◽  
Vol 9 ◽  
pp. 236
Author(s):  
D.J. Cavalieri ◽  
C.L. Parkinson

The seasonal sea-ice cover of the combined Bering and Okhotsk Seas at the time of maximum ice extent is almost 2 × 106 km2 and exceeds that of any other seasonal sea-ice zone in the Northern Hemisphere. Although both seas are relatively shallow bodies of water overlying continental shelf regions, there are important geographical differences. The Sea of Okhotsk is almost totally enclosed, being bounded to the north and west by Siberia and Sakhalin Island, and to the east by Kamchatka Peninsula. In contrast, the Bering Sea is the third-largest semi-enclosed sea in the world, with a surface area of 2.3 × 106 km2, and is bounded to the west by Kamchatka Peninsula, to the east by the Alaskan coast, and to the south by the Aleutian Islands arc. While the relationship between the regional oceanography and meteorology and the sea-ice covers of both the Bering Sea and Sea of Okhotsk have been studied individually, relatively little attention has been given to the occasional out-of-phase relationship between the fluctuations in the sea-ice extent of these two large seas. In this study, we present 3 day averaged sea-ice extent data obtained from the Nimbus-5 Electrically Scanning Microwave Radiometer (ESMR-5) for the four winters for which ESMR-5 data were available, 1973 through 1976, and document those periods for which there is an out-of-phase relationship in the fluctuations of the ice cover between the Bering Sea and the Sea of Okhotsk. Further, mean sea-level pressure data are also analyzed and compared with the time series of sea-ice extent data to provide a basis for determining possible associations between the episodes of out-of-phase fluctuations and atmospheric circulation patterns. Previous work by Campbell and others (1981) using sea-ice concentrations also derived from ESMR-5 data noted this out-of-phase relationship between the two ice packs in 1973 and 1976. The authors commented that the out-of-phase relationship is “... surprising as these are adjacent seas, and one would assume that they had similar meteorologic environments”. We argue here that the out-of-phase relationship is consistent with large-scale atmospheric circulation patterns, since the two seas span a range of longitude of about 60°, corresponding to a half wavelength of a zonal wave-number 3, and hence are quite susceptible to changes in the amplitude and phase of large-scale atmospheric waves.


Zootaxa ◽  
2017 ◽  
Vol 4268 (3) ◽  
pp. 301
Author(s):  
NINA SEDOVA ◽  
SERGEY GRIGORIEV

Description of larvae of three species: Pandalus eous, P. goniurus and P. tridens (family Pandalidae) from planktonic samples taken in the Okhotsk Sea, Avacha Gulf, and in the Bering Sea is given. Morphological features of larvae for the purpose of their identification are compared. Features which are not subject to significant intraspecific variation, and which is useful for the separation of these species in larval period are discussed. The most important features for identification of larvae of these species may be the structure of the rostrum, the presence or absence of denticles on the carapace and abdomen, the number of setae on different legs. The most reliable feature for the separation of larvae of these species into stages of zoea is the structure of the maxilla. A key to identify of species in larval stages and drawings of separate stages are given.


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