Despite being only 0.1 to 1 mm thick on average, this skin layer is the major player in the long -
term warming of the oceans.
That's why the long -
term warming of the ocean heat content for the tropical Pacific was plainly caused by the 3 - year La Niña events of 1954 - 57, 1973 - 76 and 1998 - 01, and during the freakish 1995/96 La Niña.
Not exact matches
This year, the Atlantic was
warmer than average — Klotzbach says August through October will likely rank third or fourth in
terms of highest tropical Atlantic
Ocean temperatures.
While natural patterns
of certain atmospheric and
ocean conditions are already known to influence Greenland melt, the study highlights the importance
of a long -
term warming trend to account for the unprecedented west Greenland melt rates in recent years.
«The beauty
of this study is that easily acquired measures
of reef complexity and depth provide a means
of predicting long
term consequences
of ocean warming events,» Dr Wilson says.
The coverage
of living corals on Australia's Great Barrier Reef could decline to less than 10 percent if
ocean warming continues, according to a new study that explores the short - and long -
term consequences
of environmental changes to the reef.
However, certain areas in the
oceans could be unusually
warm and skew the overall long -
term average temperature results
of some
of those prior studies, Shuman says.
«
Warm summers could weaken
ocean circulation: Long -
term observations reveal the influence
of increased surface freshening on convection in the subpolar North Atlantic.»
Caroline Ummenhofer
of Woods Hole Oceanographic Institution in Massachusetts and her colleagues wanted to know how much
of the blame laid with that year's La Niña — and how much was caused by longer -
term ocean warming.
The research, published in Nature Communications, examined preserved fossil remains
of coccolithophores from a period
of climate
warming and
ocean acidification that occurred around 56 million years ago — the Paleocene Eocene Thermal Maximum (PETM)-- and provides a much - needed long -
term perspective
of coccolithophore response to
ocean acidification.
A detailed, long -
term ocean temperature record derived from corals on Christmas Island in Kiribati and other islands in the tropical Pacific shows that the extreme warmth
of recent El Niño events reflects not just the natural
ocean - atmosphere cycle but a new factor: global
warming caused by human activity.
So the report notes that the current «pause» in new global average temperature records since 1998 — a year that saw the second strongest El Nino on record and shattered
warming records — does not reflect the long -
term trend and may be explained by the
oceans absorbing the majority
of the extra heat trapped by greenhouse gases as well as the cooling contributions
of volcanic eruptions.
Most people in the general public now know the
term, and they have a vague idea that it is some kind
of pattern in the Pacific
Ocean that means the U.S. will have a
warm winter... or snowy winter... or hot summer — or something.
«The information will be a critical complement to future long -
term projections
of sea level rise, which depend on melting ice and
warming oceans.»
«This kind
of study discusses the natural cycle and could help define the likely positive feedbacks we can expect in the long -
term future, [for example] as temperatures
warm, the
ocean will want to give up more CO2, or rather absorb less,» says climatologist Gavin Schmidt
of NASA's Goddard Institute
of Space Studies.
With the sun continuing to heat the
ocean water at the tropical latitudes regardless
of ice cap conditions up north, it would seem that the presence
of an ice cap would result in a
warmer ocean over the long
term, with the converse also being true.
Observations
of upper
ocean heat show some short
term cooling but measurements to greater depths (down to 2000 metres) show a steady
warming trend: However, the
ocean cooling myth does seem to be widespread so I'll shortly update this page to clarify the issue.
Unlike the Arctic, there is no long -
term submarine record
of ice thickness — but with the
warming Southern
Ocean, it seems likely that that has been going on as well.
The open
ocean around the atoll was 2 degrees Celsius
warmer than usual, but a short -
term change in weather conditions pushed temperatures on top
of the reef to 6 degrees Celsius above normal.
However, if one downweights these two events (either by eliminating or, as in Cane et al» 97, using a «robust» trend), then an argument can be made for a long -
term pattern which is in some respects more «La Nina» - like, i.e. little
warming in the eastern and central equatorial Pacific, and far more
warming in the western equatorial Pacific and Indian
oceans, associated with a strengthening, not weakening,
of the negative equatorial Pacific zonal SST gradient.
So, while the
oceans are a heat sink in the short -
term,
warmer oceans are a source
of climate gases in the long -
term.
(1) The
warm sea surface temperatures are not just some short -
term anomaly but are part
of a long -
term observed
warming trend, in which
ocean temperatures off the US east coast are
warming faster than global average temperatures.
The findings have important implications in
terms of planning for sea level rise, as ever - growing coastal communities might have to plan for even higher
ocean levels in a
warmer future.
Ocean surfaces have
warmed considerably over the last few years, and since
oceans cover roughly tw0 - thirds
of the globe's area, it is reasonable to examine how sea surface temperature evolution has played into the short -
term evolution
of GMST.
If more
of the heat from global
warming is going into the
ocean, does that reduce the amount
of surface
warming (both transiently and long -
term) that we should expect from doubling CO2?
The long -
term warming of the planet, as well as an exceptionally strong El Niño, led to numerous climate records in 2015, including milestones for global temperatures, carbon dioxide levels and
ocean heat, according to the World Meteorological Organization's annual State
of the Climate Report.
Mr. Trenberth was lamenting the inadequacy
of observing systems to fully monitor
warming trends in the deep
ocean and other aspects
of the short -
term variations that always occur, together with the long -
term human - induced
warming trend.
At the same time, increasing depth and duration
of drought, along with
warmer temperatures enabling the spread
of pine beetles has increased the flammability
of this forest region — http://www.nature.com/nclimate/journal/v1/n9/full/nclimate1293.html http://www.vancouversun.com/fires+through+tinder+pine+beetle+killed+forests/10047293/story.html Can climate models give different TCR and ECS with different timing / extent
of when or how much boreal forest burns, and how the soot generated alters the date
of an ice free Arctic
Ocean or the rate
of Greenland ice melt and its influence on long
term dynamics
of the AMOC transport
of heat?
The main point is that just as surface temperatures has experienced periods
of short
term cooling during long
term global
warming, similarly the
ocean shows short
term variability during a long
term warming trend.
The second is a short -
term period
of warmer surface waters in the Pacific
Ocean (called an El Niño).
In any year, temperatures around the world can be nudged up or down by short -
term factors like volcanic eruptions or El Ninos, when
warm water spreads over much
of the tropical Pacific
Ocean.
Buffalo City, as East London is charmingly known, not only lies on one
of the most sublime coastlines
of the world - think
warm Indian
Ocean waters and sub-tropical weather that allow visitors to enjoy the climate all year round - it also basks gloriously between the Nahoon River in the north and the Buffalo River to the south
of the city, and the phrase «unspoilt beaches» was
termed with East London's beaches in mind.
Given how much yelling takes place on the Internet, talk radio, and elsewhere over short -
term cool and hot spells in relation to global
warming, I wanted to find out whether anyone had generated a decent decades - long graph
of global temperature trends accounting for, and erasing, the short -
term up - and - down flickers from the cyclical shift in the tropical Pacific
Ocean known as the El Niño — Southern Oscillation, or ENSO, cycle.
A very consistent understanding is thus emerging
of the coupled
ocean and atmosphere dynamics that have caused the recent decadal - scale departure from the longer -
term global
warming trend.
Ice - sheet responses to decadal - scale
ocean forcing appear to be less important, possibly indicating that the future response
of the Antarctic Ice Sheet will be governed more by long -
term anthropogenic
warming combined with multi-centennial natural variability than by annual or decadal climate oscillations.»
Given that the cryosphere and
oceans are far better long -
term indicators
of changes in Earth's energy balance than the much more «noisy» troposphere, for anyone to suggest that the
warming of the Earth system has slowed or stopped over the past 10 years, means they are purposely ignoring the far bigger heat sinks
of the cryrosphere and
oceans, or they simply want to spout nonsense.
In general, the regions
of expanding
warming upwelling water in the Indian
Ocean, North Pacific, or wherever they are, must create slight bulges in the surface, and the regions
of shrinking, cooling, sinking water in the Arctic must create slight depressions in the sea surface (again, I mean in a very low pass sense — obviously storms, tides, etc, create all kinds
of short -
terms signals obscuring this).
In either case, we see no evidence
of any long
term warming trend, in either the atmosphere or the
ocean.
Long -
term effects
of warming and
ocean acidification are modified by seasonal variation in species responses and environmental conditions
However, if one downweights these two events (either by eliminating or, as in Cane et al» 97, using a «robust» trend), then an argument can be made for a long -
term pattern which is in some respects more «La Nina» - like, i.e. little
warming in the eastern and central equatorial Pacific, and far more
warming in the western equatorial Pacific and Indian
oceans, associated with a strengthening, not weakening,
of the negative equatorial Pacific zonal SST gradient.
When I wrote «In either case, we see no evidence
of any long
term warming trend, in either the atmosphere or the
ocean,» that should have read «long
term warming trend due to CO2 emissions...» There may be some evidence consistent with long
term warming in the
oceans, but I can't see how that could be due to CO2, for reasons given above.
In
terms of the gold that a climate science denier might find in the paper, at the very least, they could argue that the fact that the troposphere isn't
warming more quickly than the surface shows that the climate models are unreliable — even though the models predict just the pattern
of warming that we see — with the troposphere
warming more quickly than the surface over the
ocean but less quickly than the surface over land.
From what I see from the Global Historical Climatology Network (GHCN)
of land temperatures and the Comprehensive
Ocean - Atmosphere Data Set (COADS)
of SST data, temperatures there were higher around the 1930's than now, and there is not much long
term warming trend, except for the past few years.
This may lead to long
term heating and
warming cycles in the
oceans that are the result
of upwheling
of cool water from deep within the
oceans.
I asked Lee and McPhaden how a connection to greenhouse - driven
warming could be made, given the possibility that the Pacific shift could be the result
of long -
term oscillations in conditions in the
ocean unrelated to the buildup
of heat - trapping greenhouse gases in the air.
My understanding (I hope I have got this right) is that colder
oceans are vastly more productive in
terms of plankton than
warmer ones.
To clarify my above comment, I was suggesting that the observed rise in
ocean heat content would be substantial with or without the La Nina effect, representing primarily the persistence
of a long
term warming trend.
The real problem here is that this AMO explanation was picked up and broadcast by the press in a very uncritical manner, usually in these
terms: «Surface waters
of the Atlantic
ocean warm up then cool down in long, subtle cycles.
One
of the really troubling long -
term aspects
of oceanic
warming is the possibility
of anoxic
oceans, which have occurred in the deep past during «hothouse Earth» episodes.
Short -
term variations in
ocean heat uptake, such as the anomalous deep
ocean warming of late, are due to changes in the vertical & horizontal distribution
of heat in the
ocean — mostly the wind - driven
ocean circulation.