scholarly journals Monitoring open-ocean deep convection from space

2009 ◽  
Vol 36 (3) ◽  
pp. n/a-n/a ◽  
Author(s):  
Marine Herrmann ◽  
Jérome Bouffard ◽  
Karine Béranger
Keyword(s):  
Deep Convection ◽  
Open Ocean

Modeling Open-ocean Deep Convection

1997 ◽  
Author(s):  
John Marshall
Keyword(s):  
Deep Convection ◽  
Open Ocean

Modeling Open-Ocean Deep Convection

1999 ◽  
Author(s):  
John Marshall
Keyword(s):  
Deep Convection ◽  
Open Ocean

scholarly journals On the deep convection events and Antarctic Bottom Water formation in ocean reanalysis products

2017 ◽  
Author(s):  
Wilton Aguiar ◽  
Mauricio M. Mata ◽  
Rodrigo Kerr
Keyword(s):  
General Circulation ◽  
Bottom Water ◽  
Deep Convection ◽  
General Circulation Models ◽  
Open Ocean ◽  
Weddell Sea ◽  
Antarctic Bottom Water ◽  
Ocean Reanalysis ◽  
Ocean General Circulation Models ◽  
Bottom Water Formation

Abstract. Deep convection in open ocean polynyas are common sources of error on the representation of Antarctic Bottom Water (AABW) formation in Ocean General Circulation Models. Even though those events are well described in non-assimilatory ocean simulations, recent appearance of open ocean polynya in Estimating the Circulation and Climate of the Ocean Phase II reanalysis product raises a question if this spurious event is also found in state-of-art reanalysis products. In order to answer this question, we evaluate how three recently released high-resolution ocean reanalysis form AABW in their simulations. We found that two of them (ECCO2 and SoSE) create AABW by open ocean deep convection events in Weddell Sea, showing that assimilation of sea ice has not been enough to avoid open ocean polynya appearance. The third reanalysis – My Ocean University Reading – actually creates AABW by a rather dynamically accurate mechanism, depicting both continental shelf convection, and exporting of Dense Shelf Water to open ocean. Although the accuracy of the AABW formation in this reanalysis allows an advance in represent this process, the differences found between the real ocean and the simulated one suggests that ocean reanalysis still need substantial improvements to accurately represent AABW formation.

scholarly journals Transport by deep convection in basin-scale geostrophic circulation: turbulence-resolving simulations

2019 ◽  
Vol 865 ◽  
pp. 681-719
Author(s):  
Catherine A. Vreugdenhil ◽  
Bishakhdatta Gayen ◽  
Ross W. Griffiths
Keyword(s):  
Boundary Layer ◽  
Thermal Boundary Layer ◽  
Large Scale ◽  
Deep Convection ◽  
Ocean Basin ◽  
Open Ocean ◽  
Small Scale ◽  
Large Scale Circulation ◽  
Buoyancy Forcing ◽  
Basin Scale

Direct numerical simulations are used to investigate the nature of fully resolved small-scale convection and its role in large-scale circulation in a rotating $f$-plane rectangular basin with imposed surface temperature difference. The large-scale circulation has a horizontal geostrophic component and a deep vertical overturning. This paper focuses on convective circulation with no wind stress, and buoyancy forcing sufficiently strong to ensure turbulent convection within the thermal boundary layer (horizontal Rayleigh numbers $Ra\approx 10^{12}{-}10^{13}$). The dynamics are found to depend on the value of a convective Rossby number, $Ro_{\unicode[STIX]{x0394}T}$, which represents the strength of buoyancy forcing relative to Coriolis forces. Vertical convection shifts from a mean endwall plume under weak rotation ($Ro_{\unicode[STIX]{x0394}T}>10^{-1}$) to ‘open ocean’ chimney convection plus mean vertical plumes at the side boundaries under strong rotation ($Ro_{\unicode[STIX]{x0394}T}<10^{-1}$). The overall heat throughput, horizontal gyre transport and zonally integrated overturning transport are then consistent with scaling predictions for flow constrained by thermal wind balance in the thermal boundary layer coupled to vertical advection–diffusion balance in the boundary layer. For small Rossby numbers relevant to circulation in an ocean basin, vertical heat transport from the surface layer into the deep interior occurs mostly in ‘open ocean’ chimney convection while most vertical mass transport is against the side boundaries. Both heat throughput and the mean circulation (in geostrophic gyres, boundary currents and overturning) are reduced by geostrophic constraints.

The impact of SST front on the surface wind in the southern Indian Ocean

2020 ◽  
Author(s):  
Xuhua Cheng
Keyword(s):  
Indian Ocean ◽  
Deep Convection ◽  
Surface Wind ◽  
Polar Front ◽  
Open Ocean ◽  
Heat Fluxes ◽  
Southern Indian Ocean ◽  
Sst Front ◽  
Microwave Imager ◽  
The Impact

&lt;p&gt;&lt;span&gt;&amp;#160;&lt;/span&gt;Using 28-year satellite-borne Special Sensor Microwave Imager observations, features of high-wind frequency (HWF) over&lt;/p&gt;&lt;p&gt;the southern Indian Ocean are investigated. Climatology maps show that high winds occur frequently during austral winter,&lt;/p&gt;&lt;p&gt;located in the open ocean south of Polar Front in subpolar region, warm flank of the Subantarctic Front between 55&lt;sup&gt;o&lt;/sup&gt;E-78&lt;sup&gt;o&lt;/sup&gt;E,&amp;#160;&lt;/p&gt;&lt;p&gt;and south of Cape Agulhas, where westerly wind prevails. The strong instability of marine atmospheric boundary layer&lt;/p&gt;&lt;p&gt;accompanied by increased sensible and latent heat fluxes on the warmer flank acts to enhance the vertical momentum mixing,&lt;/p&gt;&lt;p&gt;thus accelerate the surface winds. Effects of sea surface temperature (SST) front can even reach the entire troposphere&lt;/p&gt;&lt;p&gt;by deep convection. HWF also shows distinct interannual variability, which is associated with the Southern Annual Mode&lt;/p&gt;&lt;p&gt;(SAM). During positive phase of the SAM, HWF has positive anomalies over the open ocean south of Polar Front, while&lt;/p&gt;&lt;p&gt;has negative anomalies north of the SST front. A phase shift of HWF happened around 2001, which is likely related to the&lt;/p&gt;&lt;p&gt;reduction of storm tracks and poleward shift of westerly winds in the Southern Hemisphere.&lt;/p&gt;

scholarly journals Topographic Preconditioning of Open-Ocean Deep Convection

1996 ◽  
Vol 26 (10) ◽  
pp. 2196-2213 ◽  
Author(s):  
Keith Alverson ◽  
W. Brechner Owens
Keyword(s):  
Deep Convection ◽  
Open Ocean

scholarly journals Open-ocean deep convection explored in the Mediterranean

Eos ◽  
1994 ◽  
Vol 75 (19) ◽  
pp. 217 ◽  
Author(s):  
Keyword(s):  
Deep Convection ◽  
Open Ocean ◽  
The Mediterranean

scholarly journals On deep convection events and Antarctic Bottom Water formation in ocean reanalysis products

Ocean Science ◽  
2017 ◽  
Vol 13 (6) ◽  
pp. 851-872 ◽  
Author(s):  
Wilton Aguiar ◽  
Mauricio M. Mata ◽  
Rodrigo Kerr
Keyword(s):  
Sea Ice ◽  
Bottom Water ◽  
Deep Convection ◽  
Open Ocean ◽  
Weddell Sea ◽  
Ocean Dynamics ◽  
Antarctic Bottom Water ◽  
Ocean Reanalysis ◽  
Reanalysis Product ◽  
Warm Deep Water

Abstract. Open ocean deep convection is a common source of error in the representation of Antarctic Bottom Water (AABW) formation in ocean general circulation models. Although those events are well described in non-assimilatory ocean simulations, the recent appearance of a massive open ocean polynya in the Estimating the Circulation and Climate of the Ocean Phase II reanalysis product (ECCO2) raises questions on which mechanisms are responsible for those spurious events and whether they are also present in other state-of-the-art assimilatory reanalysis products. To investigate this issue, we evaluate how three recently released high-resolution ocean reanalysis products form AABW in their simulations. We found that two of the products create AABW by open ocean deep convection events in the Weddell Sea that are triggered by the interaction of sea ice with the Warm Deep Water, which shows that the assimilation of sea ice is not enough to avoid the appearance of open ocean polynyas. The third reanalysis, My Ocean University Reading UR025.4, creates AABW using a rather dynamically accurate mechanism. The UR025.4 product depicts both continental shelf convection and the export of Dense Shelf Water to the open ocean. Although the accuracy of the AABW formation in this reanalysis product represents an advancement in the representation of the Southern Ocean dynamics, the differences between the real and simulated processes suggest that substantial improvements in the ocean reanalysis products are still needed to accurately represent AABW formation.

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