S. Gladyshev - Academia.edu (original) (raw)

Papers by S. Gladyshev

Journal of Geophysical Research, Oceans, 2013

1] Data from two boundary arrays deployed along 34.5 S are combined to produce the first continuo... more 1] Data from two boundary arrays deployed along 34.5 S are combined to produce the first continuous in situ time series observations of the basin-wide meridional overturning circulation (MOC) in the South Atlantic. Daily estimates of the MOC between March 2009 and December 2010 range between 3 Sv and 39 Sv (1 Sv 5 10 6 m 3 s 21 ) after a 10 day lowpass filter is applied. Much of the variability in this $20 month record occurs at periods shorter than 100 days. Approximately two-thirds of the MOC variability is due to changes in the geostrophic (baroclinic plus barotropic) volume transport, with the remainder associated with the direct wind-forced Ekman transport. When low-pass filtered to match previously published analyses in the North Atlantic, the observed temporal standard deviation at 34.5 S matches or somewhat exceeds that observed by time series observations at 16 N, 26.5 N, and 41 N. For periods shorter than 20 days the basin-wide MOC variations are most strongly influenced by Ekman flows, while at periods between 20 and 90 days the geostrophic flows tend to exert slightly more control over the total transport variability of the MOC. The geostrophic shear variations are roughly equally controlled by density variations on the western and eastern boundaries at all time scales captured in the record. The observed time-mean MOC vertical structure and temporal variability agree well with the limited independent observations available for confirmation.

Ocean Dynamics, 2011

... There, warm surface waters conveyed Responsible Editor: Jean-Marie Beckers V. Faure :M. Arhan... more ... There, warm surface waters conveyed Responsible Editor: Jean-Marie Beckers V. Faure :M. Arhan Laboratoire de Physique des Océans—UMR6523, CNRS/IFREMER/IRD/UBO IFREMER/Centre de Brest, BP 70, 29280 Plouzané, France ...

Journal of Geophysical Research, 2003

1] Russian historical data and recently completed conductivity-temperature-depth surveys are used... more 1] Russian historical data and recently completed conductivity-temperature-depth surveys are used to examine the formation and spread in the deep Ohkotsk Sea of dense shelf water (DSW) produced in the Okhotsk Sea polynyas. Isopycnal analysis indicates that all of the main polynyas contribute to the ventilation at s q < 26.80, including the Okhotsk Sea Mode Water (OSMW), which has densities s q = 26.7-27.0. At densities greater than 26.9 s q the northwest polynya is the only contributor to OSMW. (Although Shelikhov Bay polynyas produce the densest water with s q > 27.1, vigorous tidal mixing leads to outflow of water with a density of only about 26.7 s q ). In the western Okhotsk Sea the East Sakhalin Current rapidly transports modified dense shelf water along the eastern Sakhalin slope to the Kuril Basin, where it is subject to further mixing because of the large anticyclonic eddies and tides. Most of the dense water flows off the shelves in spring. Their average flux does not exceed 0.2 Sv in summer and fall. The shelf water transport and water exchange with the North Pacific cause large seasonal variations of temperature at densities of 26.7-27.0 s q (depths of 150-500 m) in the Kuril Basin, where the average temperature minimum occurs in April-May, and the average temperature maximum occurs in September, with a range of 0.2°-0.7°C. The average seasonal variations of salinity are quite small and do not exceed 0.05 psu. The Soya Water mixed by winter convection, penetrating to depths greater than 200 m, in the southern Kuril Basin also produces freezing water with density greater than 26.7 s q . Using a simple isopycnal box model and seasonal observations, the OSMW production rate is seen to increase in summer up to 2.2 ± 1.7 Sv, mainly because of increased North Pacific inflow, and drops in winter to 0.2 ± 0.1 Sv. A compensating decrease in temperature in the Kuril Basin implies a DSW volume transport of 1.4 ± 1.1 Sv from February through May. The residence time of the OSMW in the Kuril Basin is 2 ± 1.7 years.

Journal of Geophysical Research, 2000

For the northern Okhotsk Sea polynyas, five Russian CTD surveys taken during 1995 to 1997 are use... more For the northern Okhotsk Sea polynyas, five Russian CTD surveys taken during 1995 to 1997 are used to examine the evolution of the polynya dense water. The surveys show that consistent with other investigations, the largest potential densities are 26.99 •0, and the densest water occurs in Sakhalin and Shelikhov Bays. The surveys also suggest that the Shelikhov water drains directly into the deep Okhotsk, while on the northern shelves, gravity currents transport the dense water west to Sakhalin Bay. For comparison, determination of the polynya sizes and ice production from satellite passive microwave and meteorological observations shows that polynyas occur on the northwest shelf (NWS) between Ayan and Okhotsk City, on the northern shelf between Okhotsk City and Magadan, and in Shelikhov Bay. In contrast, the observations show that Sakhalin Bay is a region of land fast ice with no polynyas, so that the dense water observed here cannot form locally. For all polynyas the satellite observations show that the NWS contributes 60 to 70% of the total ice production, and due to the warmer 1997 air temperatures, the 1996 production is about 1.5 times the 1997 value. An estimate of the ice production from the surveys shows a similar regional distribution and enhancement of the 1996 production, with the satellite and ship estimates in agreement within their error bars. Finally, analysis of the dense water outflow shows that the upper Okhotsk Sea Mode Water has a renewal time of about 4 years; the lower part, about 14 years. the OSMW formation to tidal mixing in the Kuril Straits and to the formation and mixing of dense shelf water. There are two proposed mechanisms for the formation of the OSMW. First, Watanabe and Wakatsuchi [1998], who refer to the OSMW as Kuril Basin Intermediate Water, discuss the role of forerunner Soya Water (FSW) in the OSMW formation and conclude that the OSMW is the product of isopycnal mixing between the FSW, which is that water flowing through the Soya Strait in late spring, and the dense water in the East Sakhalin Current, which originates from the northern Okhotsk. Second, Alfultis and Martin [1987] and Wong et al. [1998] (hereafter W-98) assume that the OSMW, or what W-98 call the upper Sea of Okhotsk Intermediate Water (upper SOIW), forms by isopycnal mixing of North Pacific water with the dense shelf water. From CFC measurements, W-98 also estimate that the OSMW renewal time is 1.4 years and argue that there is insufficient water produced on the shelf for the second mixing mechanism to work alone, so that there must be an additional source for the OSMW. Although the formation of the NPIW and OSMW is generally attributed to ice processes on the northern shelves, little is known about the dy-26,281 Basin Kuril Basin I Penzhinskaya Magadan Bussol' Strait Kruzenshtern Strait Pacific Ocean 140E 145E 150E 155E 160E ß ß ß ß ß ß ß 14(•E -1.5 300 m 145E 5J' ' ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß 15(•E Longitude 155E 160E 140E 32.9 33.1 145E ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ßß i 33.0 33.2 2.0-0.0ß ß -2.0 , , 55N ß ß 200 rn ß 0.3 ß ß ß ß ß ß ß ß ß ß 200 ß 60N 55N 50 ß 20(•m ß ß ß ß ß , ß ß ß ß ß ß ß ß ß ß ß ß ß 140E Figure 11. The thickness and brine enrichment of dense water on the northern shelves in (a and b

1] A mean state of the full-depth summer circulation in the Atlantic Ocean in the region in betwe... more 1] A mean state of the full-depth summer circulation in the Atlantic Ocean in the region in between Cape Farewell (Greenland), Scotland and the Greenland-Scotland Ridge (GSR) is assessed by combining 2002-2008 yearly hydrographic measurements at 59.5°N, mean dynamic topography, satellite altimetry data and available estimates of the Atlantic-Nordic Seas exchange. The mean absolute transports by the upper-ocean, mid-depth and deep currents and the Meridional Overturning Circulation (MOCs = 16.5 AE 2.2 Sv, at s 0 = 27.55) at 59.5°N are quantified in the density space. Inter-basin and diapycnal volume fluxes in between the 59.5°N section and the GSR are then estimated from a box model. The dominant components of the meridional exchange across 59.5°N are the North Atlantic Current (NAC, 15.5 AE 0.8 Sv, s 0 < 27.55) east of the Reykjanes Ridge, the northward Irminger Current (IC, 12.0 AE 3.0 Sv) and southward Western Boundary Current (WBC, 32.1 AE 5.9 Sv) in the Irminger Sea and the deep water export from the northern Iceland Basin (3.7 AE 0.8 Sv, s 0 > 27.80). About 60% (12.7 AE 1.4 Sv) of waters carried in the MOCs upper limb (s 0 < 27.55) by the NAC/IC across 59.5°N (21.1 AE 1.0 Sv) recirculates westward south of the GSR and feeds the WBC. 80% (10.2 AE 1.7 Sv) of the recirculating NAC/IC-derived upper-ocean waters gains density of s 0 > 27.55 and contributes to the MOCs lower limb.

The Japan Sea and Okhotsk Seas have differing influences on water mass processes in the North Pac... more The Japan Sea and Okhotsk Seas have differing influences on water mass processes in the North Pacific. The Japan Sea, although deep and well-ventilated to the bottom, is connected to the Pacific only through very shallow straits. It funnels relatively saline subtropical Pacific waters to the subpolar North Pacific, thereby increasing the density of locally-formed waters in both the Okhotsk Sea and the Oyashio region. This directly impacts North Pacific Intermediate Water formation, which is the densest water formed within the North Pacific outside the Japan Sea. While much denser water is formed within the Japan Sea, this process is only part of the overall processes that modify Pacific waters on their passage through the Japan Sea. The transports and properties of waters passing through the straits, and the modification of waters within the Japan Sea are reviewed and further quantified. The Okhotsk Sea is much more connected to the Pacific Ocean, through the numerous Kuril straits ...

Carbon Dioxide Information Analysis Center, 2000

Proceedings of OceanObs'09: Sustained Ocean Observations and Information for Society, 2010

Deep Sea Research Part I: Oceanographic Research Papers, 2008

Rintoul, SR , Sparrow, M. , Meredith, MP , Wadley, V. , Speer, K. , Hofmann, E. , Summerhayes, C.... more Rintoul, SR , Sparrow, M. , Meredith, MP , Wadley, V. , Speer, K. , Hofmann, E. , Summerhayes, C. , Urban, E. , Bellerby, R. , Ackley, S. , Alverson, K. , Ansorge, I. , Aoki, S. , Azzolini, R. , Beal, L. , Belbeoch, M. , Bergamasco, A. , Biuw, M. , Boehme, L. , Budillon, G. , Campos, L. , Carlson, D. , Cavanagh, R. , Charpentier, E. , Chul Shin, H. , Coffin, M. , Constable, A. , Costa, D. , Cronin, M. , De Baar, H. , De Broyer, C. , De Bruin, T. , De Santis, L. , Butler, E. , Dexter, P. , Drinkwater, M. , England, M. , Fahrbach, E. , Fanta, E. , Fedak, ...

Journal of Geophysical Research, Oceans, 2013

1] Data from two boundary arrays deployed along 34.5 S are combined to produce the first continuo... more 1] Data from two boundary arrays deployed along 34.5 S are combined to produce the first continuous in situ time series observations of the basin-wide meridional overturning circulation (MOC) in the South Atlantic. Daily estimates of the MOC between March 2009 and December 2010 range between 3 Sv and 39 Sv (1 Sv 5 10 6 m 3 s 21 ) after a 10 day lowpass filter is applied. Much of the variability in this $20 month record occurs at periods shorter than 100 days. Approximately two-thirds of the MOC variability is due to changes in the geostrophic (baroclinic plus barotropic) volume transport, with the remainder associated with the direct wind-forced Ekman transport. When low-pass filtered to match previously published analyses in the North Atlantic, the observed temporal standard deviation at 34.5 S matches or somewhat exceeds that observed by time series observations at 16 N, 26.5 N, and 41 N. For periods shorter than 20 days the basin-wide MOC variations are most strongly influenced by Ekman flows, while at periods between 20 and 90 days the geostrophic flows tend to exert slightly more control over the total transport variability of the MOC. The geostrophic shear variations are roughly equally controlled by density variations on the western and eastern boundaries at all time scales captured in the record. The observed time-mean MOC vertical structure and temporal variability agree well with the limited independent observations available for confirmation.

Ocean Dynamics, 2011

... There, warm surface waters conveyed Responsible Editor: Jean-Marie Beckers V. Faure :M. Arhan... more ... There, warm surface waters conveyed Responsible Editor: Jean-Marie Beckers V. Faure :M. Arhan Laboratoire de Physique des Océans—UMR6523, CNRS/IFREMER/IRD/UBO IFREMER/Centre de Brest, BP 70, 29280 Plouzané, France ...

Journal of Geophysical Research, 2003

1] Russian historical data and recently completed conductivity-temperature-depth surveys are used... more 1] Russian historical data and recently completed conductivity-temperature-depth surveys are used to examine the formation and spread in the deep Ohkotsk Sea of dense shelf water (DSW) produced in the Okhotsk Sea polynyas. Isopycnal analysis indicates that all of the main polynyas contribute to the ventilation at s q < 26.80, including the Okhotsk Sea Mode Water (OSMW), which has densities s q = 26.7-27.0. At densities greater than 26.9 s q the northwest polynya is the only contributor to OSMW. (Although Shelikhov Bay polynyas produce the densest water with s q > 27.1, vigorous tidal mixing leads to outflow of water with a density of only about 26.7 s q ). In the western Okhotsk Sea the East Sakhalin Current rapidly transports modified dense shelf water along the eastern Sakhalin slope to the Kuril Basin, where it is subject to further mixing because of the large anticyclonic eddies and tides. Most of the dense water flows off the shelves in spring. Their average flux does not exceed 0.2 Sv in summer and fall. The shelf water transport and water exchange with the North Pacific cause large seasonal variations of temperature at densities of 26.7-27.0 s q (depths of 150-500 m) in the Kuril Basin, where the average temperature minimum occurs in April-May, and the average temperature maximum occurs in September, with a range of 0.2°-0.7°C. The average seasonal variations of salinity are quite small and do not exceed 0.05 psu. The Soya Water mixed by winter convection, penetrating to depths greater than 200 m, in the southern Kuril Basin also produces freezing water with density greater than 26.7 s q . Using a simple isopycnal box model and seasonal observations, the OSMW production rate is seen to increase in summer up to 2.2 ± 1.7 Sv, mainly because of increased North Pacific inflow, and drops in winter to 0.2 ± 0.1 Sv. A compensating decrease in temperature in the Kuril Basin implies a DSW volume transport of 1.4 ± 1.1 Sv from February through May. The residence time of the OSMW in the Kuril Basin is 2 ± 1.7 years.

Journal of Geophysical Research, 2000

For the northern Okhotsk Sea polynyas, five Russian CTD surveys taken during 1995 to 1997 are use... more For the northern Okhotsk Sea polynyas, five Russian CTD surveys taken during 1995 to 1997 are used to examine the evolution of the polynya dense water. The surveys show that consistent with other investigations, the largest potential densities are 26.99 •0, and the densest water occurs in Sakhalin and Shelikhov Bays. The surveys also suggest that the Shelikhov water drains directly into the deep Okhotsk, while on the northern shelves, gravity currents transport the dense water west to Sakhalin Bay. For comparison, determination of the polynya sizes and ice production from satellite passive microwave and meteorological observations shows that polynyas occur on the northwest shelf (NWS) between Ayan and Okhotsk City, on the northern shelf between Okhotsk City and Magadan, and in Shelikhov Bay. In contrast, the observations show that Sakhalin Bay is a region of land fast ice with no polynyas, so that the dense water observed here cannot form locally. For all polynyas the satellite observations show that the NWS contributes 60 to 70% of the total ice production, and due to the warmer 1997 air temperatures, the 1996 production is about 1.5 times the 1997 value. An estimate of the ice production from the surveys shows a similar regional distribution and enhancement of the 1996 production, with the satellite and ship estimates in agreement within their error bars. Finally, analysis of the dense water outflow shows that the upper Okhotsk Sea Mode Water has a renewal time of about 4 years; the lower part, about 14 years. the OSMW formation to tidal mixing in the Kuril Straits and to the formation and mixing of dense shelf water. There are two proposed mechanisms for the formation of the OSMW. First, Watanabe and Wakatsuchi [1998], who refer to the OSMW as Kuril Basin Intermediate Water, discuss the role of forerunner Soya Water (FSW) in the OSMW formation and conclude that the OSMW is the product of isopycnal mixing between the FSW, which is that water flowing through the Soya Strait in late spring, and the dense water in the East Sakhalin Current, which originates from the northern Okhotsk. Second, Alfultis and Martin [1987] and Wong et al. [1998] (hereafter W-98) assume that the OSMW, or what W-98 call the upper Sea of Okhotsk Intermediate Water (upper SOIW), forms by isopycnal mixing of North Pacific water with the dense shelf water. From CFC measurements, W-98 also estimate that the OSMW renewal time is 1.4 years and argue that there is insufficient water produced on the shelf for the second mixing mechanism to work alone, so that there must be an additional source for the OSMW. Although the formation of the NPIW and OSMW is generally attributed to ice processes on the northern shelves, little is known about the dy-26,281 Basin Kuril Basin I Penzhinskaya Magadan Bussol' Strait Kruzenshtern Strait Pacific Ocean 140E 145E 150E 155E 160E ß ß ß ß ß ß ß 14(•E -1.5 300 m 145E 5J' ' ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß 15(•E Longitude 155E 160E 140E 32.9 33.1 145E ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ß ßß i 33.0 33.2 2.0-0.0ß ß -2.0 , , 55N ß ß 200 rn ß 0.3 ß ß ß ß ß ß ß ß ß ß 200 ß 60N 55N 50 ß 20(•m ß ß ß ß ß , ß ß ß ß ß ß ß ß ß ß ß ß ß 140E Figure 11. The thickness and brine enrichment of dense water on the northern shelves in (a and b

1] A mean state of the full-depth summer circulation in the Atlantic Ocean in the region in betwe... more 1] A mean state of the full-depth summer circulation in the Atlantic Ocean in the region in between Cape Farewell (Greenland), Scotland and the Greenland-Scotland Ridge (GSR) is assessed by combining 2002-2008 yearly hydrographic measurements at 59.5°N, mean dynamic topography, satellite altimetry data and available estimates of the Atlantic-Nordic Seas exchange. The mean absolute transports by the upper-ocean, mid-depth and deep currents and the Meridional Overturning Circulation (MOCs = 16.5 AE 2.2 Sv, at s 0 = 27.55) at 59.5°N are quantified in the density space. Inter-basin and diapycnal volume fluxes in between the 59.5°N section and the GSR are then estimated from a box model. The dominant components of the meridional exchange across 59.5°N are the North Atlantic Current (NAC, 15.5 AE 0.8 Sv, s 0 < 27.55) east of the Reykjanes Ridge, the northward Irminger Current (IC, 12.0 AE 3.0 Sv) and southward Western Boundary Current (WBC, 32.1 AE 5.9 Sv) in the Irminger Sea and the deep water export from the northern Iceland Basin (3.7 AE 0.8 Sv, s 0 > 27.80). About 60% (12.7 AE 1.4 Sv) of waters carried in the MOCs upper limb (s 0 < 27.55) by the NAC/IC across 59.5°N (21.1 AE 1.0 Sv) recirculates westward south of the GSR and feeds the WBC. 80% (10.2 AE 1.7 Sv) of the recirculating NAC/IC-derived upper-ocean waters gains density of s 0 > 27.55 and contributes to the MOCs lower limb.

The Japan Sea and Okhotsk Seas have differing influences on water mass processes in the North Pac... more The Japan Sea and Okhotsk Seas have differing influences on water mass processes in the North Pacific. The Japan Sea, although deep and well-ventilated to the bottom, is connected to the Pacific only through very shallow straits. It funnels relatively saline subtropical Pacific waters to the subpolar North Pacific, thereby increasing the density of locally-formed waters in both the Okhotsk Sea and the Oyashio region. This directly impacts North Pacific Intermediate Water formation, which is the densest water formed within the North Pacific outside the Japan Sea. While much denser water is formed within the Japan Sea, this process is only part of the overall processes that modify Pacific waters on their passage through the Japan Sea. The transports and properties of waters passing through the straits, and the modification of waters within the Japan Sea are reviewed and further quantified. The Okhotsk Sea is much more connected to the Pacific Ocean, through the numerous Kuril straits ...

Carbon Dioxide Information Analysis Center, 2000

Proceedings of OceanObs'09: Sustained Ocean Observations and Information for Society, 2010

Deep Sea Research Part I: Oceanographic Research Papers, 2008

Rintoul, SR , Sparrow, M. , Meredith, MP , Wadley, V. , Speer, K. , Hofmann, E. , Summerhayes, C.... more Rintoul, SR , Sparrow, M. , Meredith, MP , Wadley, V. , Speer, K. , Hofmann, E. , Summerhayes, C. , Urban, E. , Bellerby, R. , Ackley, S. , Alverson, K. , Ansorge, I. , Aoki, S. , Azzolini, R. , Beal, L. , Belbeoch, M. , Bergamasco, A. , Biuw, M. , Boehme, L. , Budillon, G. , Campos, L. , Carlson, D. , Cavanagh, R. , Charpentier, E. , Chul Shin, H. , Coffin, M. , Constable, A. , Costa, D. , Cronin, M. , De Baar, H. , De Broyer, C. , De Bruin, T. , De Santis, L. , Butler, E. , Dexter, P. , Drinkwater, M. , England, M. , Fahrbach, E. , Fanta, E. , Fedak, ...