The Pentagon report describes a scenario in which human - caused global warming leads to a near - term collapse of the ocean's thermohaline circulation, which
brings warm surface waters from the tropics to the North Atlantic, warming parts of Western Europe.
Stronger easterlies in the Pacific spin up the gyres in both hemispheres and Ekman pumping in those regions intensifies,
bringing warmer surface waters to depth.
Not exact matches
They found that adding five years of strong trade winds created powerful ocean currents that buried the
warm surface water,
bringing cooler
water to the
surface.
The opposite occurred in 1997 and 1998, when
warm surface waters in the Pacific Ocean
brought about by El Niño pushed rainfall systems north, leaving parts of the southern and eastern Amazon forest dry and prone to fires.
Schimdt has found evidence that
warm ocean currents and convective forces beneath Europa's frozen shell can cause large blocks of ice to overturn and melt,
bringing vast pockets of
water, sometimes holding as much liquid as all of the Great Lakes combined, to within several kilometers of the moon's icy
surface.
This shift strengthens the ocean currents that
bring warm, salty
water to the
surface, where it accelerates the melting of Antarctic ice.
They mix
warm equatorial
surface water into greater depths, and help
bring cooler
waters to the
surface.
Furthermore, a deeper upper layer of
warm surface water may weaken the cold tongue if the Ekman pumping doesn't reach down below the thermocline to
bring up colder
water, and weakened trade winds would have a similar effect through reduced Ekman pumping near the equator.
With the removal of the
warm surface waters, an upwelling current is created in the east Pacific Ocean,
bringing cold
water up from deeper levels.
Even during the region's
warmest months, sea
surface temperatures can range from 80 down to below 70 degrees, and winter may
bring chilly
waters in the mid 60s, and occasionally as low as 58 degrees.
Stronger trade winds push
warm surface water towards the west, and
bring cold deeper
waters to the
surface to replace them.
Other factors would include: — albedo shifts (both from ice >
water, and from increased biological activity, and from edge melt revealing more land, and from more old dust coming to the
surface...); — direct effect of CO2 on ice (the former weakens the latter); — increasing, and increasingly
warm, rain fall on ice; — «stuck» weather systems
bringing more and more
warm tropical air ever further toward the poles; — melting of sea ice shelf increasing mobility of glaciers; — sea
water getting under parts of the ice sheets where the base is below sea level; — melt
water lubricating the ice sheet base; — changes in ocean currents -LRB-?)
Furthermore, a deeper upper layer of
warm surface water may weaken the cold tongue if the Ekman pumping doesn't reach down below the thermocline to
bring up colder
water, and weakened trade winds would have a similar effect through reduced Ekman pumping near the equator.
Hurricanes stirr up the sea (mixing or Ekman pumping), and if there is a thin
warm surface layer, colder
water underneath will be
brought up, and hence give rise to lower
surface temperatures (SST).
These record temperatures have been assisted by a very strong El Niño event, which
brought warm water to the ocean
surface, temporarily
warming global
surface temperatures.
Which is
bringing warmer water to the
surface at a pretty rapid rate,
warming the
surface and accelerating the rate at which this ice is melting.»
Convection sets in and
warmer water is
brought to the
surface which radiates and cools in turn.
The
warmer the ocean becomes, the less
water rises from deeper down, meaning fewer resources will be
brought to the
surface water where phytoplankton live.
A simple model of this process is an increased vertical circulation in the ocean, such as an enhanced PDO, that
brings cooler
water to the
surface faster and sequesters the
warmer water faster.
You can't deduce anything using heat conduction from
warm waters above because you'll find it's so tiny that would take ~ 125,000 years to
warm / cool the depths to same as
surface following a
surface MST anomaly if there were no currents
bringing cold
water through, so obviously the actual
warming from
waters above is 99 % + by fluid mixing.
Furthermore, researchers show the loss of sea ice reconnects the oceans with the winds causing a stirring effect that
brings warmer water to the
surface.
You may be familiar with part of this circulation, the Gulf Stream, which
brings warm, tropical
surface water northward along the East Coast of the United States and funnels toward the poles.
Global
surface temperatures in the last few years have received a bump in recent years because of a large El Niñ0 event, which
brought warm water up from the depths of the Pacific ocean and released the energy into the atmosphere.
If the
warm water heated by the sun is driven by the wind into the deeper layers, and also
bringing colder deep
waters to the
surface, the
surface stays cool, the heat is transferred down, and La Nina works its cooling magic on the globe.
ENSO (El Niño Southern Oscillation) variability is linked to the spinning up or down of the South Pacific gyre — as it
brings more or less cold Southern Ocean
water northward — along the Peruvian coast — to more or less displace
warm surface water and initiate upwelling.
The rush to identify El Niño, characterized by the periodic
warming of
surface water temperatures off the northwestern coast of South America, as California's savior was based in part on the belief that a strong El Niño would
bring as much rain as it did in the winters of 1997 - 1998 and 1982 - 1983.
And on top of that, convection MUST
bring the
warmer waters to the
surface for radiation.
They flush the cooled
surface waters down into the ocean depths, part of a giant conveyor belt that
brings more
warm surface water into the far north.
Apologies if this has already been stated, but my view on decreased Arctic ice cover is: - 1, as Judith pointed out, when ice is at a minimum the sun is already so low in the sky that there is no noticeable change to albedo, 2 when there is ice cover
warm water is kept at depth by differences in salinity, When there is open
water, storms mix the haline layers
bringing warm water to the
surface where it can more readily radiate it's energy into outer space.
Last year was the hottest since records began and with an El Nino now under way the
warm surface waters of the Pacific are releasing heat into the atmosphere with the result 2015 is likely to break last year's record and the global average
surface temperature could jump by as much as 0.1 degree this year alone
bring global
surface temperatures increases to 1 degrees or half way to the UN global limit.
On the other side, the oceanographer Wallace Broecker [Broecker, 1997] has argued that the present
warm climate in Europe depends on a circulation of ocean
water, with the Gulf Stream flowing north on the
surface and
bringing warmth to Europe, and with a counter-current of cold
water flowing south in the deep ocean.
Reduced equatorial cloud cover during La Nina (due to the cooler sea
surface temperature), combined with the strong upwelling (Ekman suction) in the eastern equatorial Pacific, does indeed lead to greater
warming of the ocean - because it's
bringing cool subsurface
water to the
surface, where it can be heated by the sun.