Super-heating oceans in the Southern Hemisphere

[Vice-Regent]

When freshwater injection on the Southern Ocean is halted, global temperature jumps back within two decades to the value it would have had without any freshwater addition (Fig. 10a). Quick recovery is consistent with the Southern Ocean-centric15picture of the global overturning circulation (Fig. 4, Talley, 2013), as the Southern Meridional Overturning Circulation (SMOC), driven by AABW formation, responds to change of the vertical stability of the ocean column near Antarctica (see Sect. 4) and the ocean mixed layer and sea ice have limited thermal inertia.Global cooling due to ice melt causes a large increase in Earth’s energy imbalance20(Fig. 10b), adding about+2 W m−2, which is larger than the imbalance caused by in-creasing GHGs. Thus, although the cold fresh water from ice sheet disintegration pro-vides a negative feedback on regional and global surface temperature, it increases the planet’s energy imbalance, thus providing more energy for ice melt (Hansen, 2005).This added energy is pumped into the ocean.

Southern Ocean Upwelling

North Atlantic Deep Water is primarily upwelled at the southern end of the Atlantic transect, in the Southern Ocean.^[8] This upwelling comprises the majority of upwelling normally associated with AMOC, and links it with the global circulation^[1]. On a global scale, observations suggest 80% of deepwater upwells in the Southern Ocean. ^[28]

This upwelling supplies large quantities of nutrients to the surface, which supports biological activity. Surface supply of nutrients is critical to the ocean's functioning as a carbon sink on long timescales. Furthermore, upwelled water has low concentrations of dissolved carbon, as the water is typically 1000 years old and has not been sensitive to anthropogenic CO2 increases in the atmosphere.^[29] Because of its low carbon concentration, this upwelling functions as a carbon sink. Variability in the carbon sink over the observational period has been closely studied and debated^[30]. The size of the sink is understood to have decreased until 2002, and then increased until 2012.^[31]

After upwelling, the water is understood to take one of two pathways: water surfacing near to sea-ice generally forms dense bottomwater and is committed to AMOC's lower cell; water surfacing at lower latitudes moves further northward due to Ekman transport and is committed to the upper cell. ^[8][32]

 

[AfewUniversesBelowNormal]

Wow, good point. I noticed much of the Winter patterns were in a fixed "what it could be" (land-ocean). Not ENSO or anything I don't think. 

[Vice-Regent]

 

51 minutes ago, AfewUniversesBelowNormal said:

Wow, good point. I noticed much of the Winter patterns were in a fixed "what it could be" (land-ocean). Not ENSO or anything I don't think. 

Without bottom water formation there is no known mechanism to cool the southern ocean. The situation is dire and warrants a closer examination. Forget 2100.

[etudiant]

Surely the punch line here is this:  

When freshwater injection on the Southern Ocean is halted, global temperature jumps back within two decades to the value it would have had without any freshwater addition 

Afaik, there has never been a halt to freshwater injections into the Southern Ocean, so this is a totally unverifiable claim.

Add to this a generous 20 year lag time to reach the new equilibrium, there is no way this can be tested or verified within a human lifetime.

Is this science?

 

[chubbs]

Very unlikely that the warming in the southern oceans over the past couple of weeks has anything to do with upwelling. Expansive Hadley cells a more likely explanation. Note that fresh water from Antarctica ice sheet is just starting to ramp-up and will take centuries to play out.

[Vice-Regent]

9 hours ago, chubbs said:

Very unlikely that the warming in the southern oceans over the past couple of weeks has anything to do with upwelling. Expansive Hadley cells a more likely explanation. Note that fresh water from Antarctica ice sheet is just starting to ramp-up and will take centuries to play out.

If true. There will be a near-term acceleration/increase in sea level contribution from the Southern Hemisphere. I agree with your sentiment it's more about downplaying the Adapt 2030 crowd who think we are about to go into an ice age or perhaps there is a negative feedback that will come and save us from ourselves.

[SENC]

On ‎2‎/‎26‎/‎2019 at 7:42 AM, chubbs said:

Very unlikely that the warming in the southern oceans over the past couple of weeks has anything to do with upwelling. Expansive Hadley cells a more likely explanation. Note that fresh water from Antarctica ice sheet is just starting to ramp-up and will take centuries to play out.

Maybe underwater Volcanos Or Geologic activity such as, (Movement of the Earths Magma),  might play a role? 

[bdgwx]

44 minutes ago, SENC said:

Maybe underwater Volcanos Or Geologic activity such as, (Movement of the Earths Magma),  might play a role? 

Where are these volcanoes and such that are warming the oceans at a rate of ~10e21 joules/year? How can volcanoes and such solve the faint young Sun paradox? Why did these volcanoes and such suddenly activate at the same time as the industrial revolution? Why is the stratosphere cooling? Where is the energy being trapped by GHGs going if not into the troposphere, hydrosphere, and cryosphere?

 

[Vice-Regent]

2 minutes ago, bdgwx said:

Where are these volcanoes and such that are warming the oceans at a rate of ~10e21 joules/year? How can volcanoes and such solve the faint young Sun paradox? Why did these volcanoes and such suddenly activate at the same time as the industrial revolution? Why is the stratosphere cooling? Where is the energy being trapped by GHGs going if not into the troposphere, hydrosphere, and cryosphere?

 

Ocean... the irony.