Temperature drop puzzles climate researchers
Ronin
Quirin Schiermeier, Nature
Temperature drop puzzles climate researchers.
Oceans cool off in hottest years
Ocean measurements suggest the world's seas have cooled substantially
during some of the warmest years in recent history. If real, the dip is
likely to reflect a short-term fluctuation in an ocean that is warming
overall, say climate scientists.
The years 2003 and 2005 saw the highest global average surface
temperatures in more than a century. An upcoming paper in Geophysical
Research Letters reports that during this period, the upper 750 metres
of the oceans lost around one-fifth of the heat accumulated over the
past 50 years.
But don't read too much into that, oceanographers warn. "Cooling on a
short-term scale doesn't challenge the long-term warming trend," says
Sydney Levitus, director of the World Data Center for Oceanography in
Silver Spring, Maryland. "What it does tell us is that we still don't
sufficiently understand how the global climate system works."
Oceans cover two-thirds of Earth's surface and have far more
heat-storing capacity than air or land. Overall, they have warmed in
recent decades. Between 1955 and 1998, for example, all of the world's
oceans, down to a depth of 3,000 metres, warmed by 0.037 °C (S.
Levitus, J. Antonov and T. Boyer Geophys. Res. Lett. 32, L02604; 2005).
But that warming has not proceeded steadily. The trend has reversed for
a few years at least once during the past half century. In fact, a drop
in temperature that occurred between 1980 and 1983 was almost twice as
pronounced as the current cooling.
But only for this latest cooling episode have oceanographers obtained
good enough global data to provide a convincing argument that the
effect is real. The report relies in part on data gathered by ARGO, a
global array of 2,500 floats. The ARGO floats descend to various depths
to probe ocean temperature and salinity, and surface occasionally to
transmit their data via satellites.
When ARGO data were removed from the analysis, the cooling was
significantly less pronounced, and the error bars became larger, say
the authors of the report, led by John Lyman of the National Oceanic
and Atmospheric Administration in Seattle, Washington. Some researchers
suspect that ARGO has provided the ability to detect short-term
temperature fluctuations. "We may be seeing different things just
because we are looking harder," says Brian King, a physical
oceanographer at the Southampton Oceanography Centre, UK.
We may be seeing different things just because we are looking
harder.
Better observation systems are showing the oceans are more changeable
than some people thought, says Gavin Schmidt, a climate modeller at the
NASA Goddard Institute for Space Studies in New York City. A short-term
cooling blip can't say much about the climate system in general. But
the latest study suggests, he says, that coupled ocean-climate models
fail to adequately capture intermittent fluctuations in ocean
temperature.
In theory, the recent cooling should have led to a 2-millimetre drop in
sea level due to the thermal contraction of water, which becomes denser
at lower temperatures. But satellites have measured a steady rise in
sea level between 1993 and 2005 - years covered by the study. For the
observations to be reconciled, melting ice sheets in Antarctica and
Greenland must be contributing far more to sea-level rise than
previously suspected, says Schmidt.
Of course, much of the observed ocean-temperature decrease could be an
artefact of sampling, says Tim Barnett, a climate researcher at the
Scripps Institution of Oceanography in San Diego, California. For
example, if warmer water has simply redistributed to areas where fewer
ARGO floats exist, the net cooling could be smaller than the data
suggest.
But assuming the trend is real, what caused the cooling and where did
the heat go? Aerosols, volcanic activity and small changes in ocean
circulations and convection processes may all play a role, says King.
But the simplest explanation is that less sunlight has reached the
ocean surface as cloud coverage has increased.
Global cloud coverage has increased by 1-2% since 1999 according to
data from the International Satellite Cloud Climatology Project,
presumably because of global warming and increased evaporation. Other
factors - such as cloud albedo (the extent to which cloud reflects
solar radiation) or cloud-top temperature - might have changed in the
same period, says William Rossow, a cloud expert at the Goddard
Institute. "It is completely insufficient to look for a simple
explanation of a short-term temperature change," he says, "as the
climate system is much more complex."
The heat itself could be hidden at greater depths in the ocean, or -
more likely, says Schmidt - it may have escaped into the atmosphere
and out into space. Yet a corresponding change in Earth's radiation
budget has not been observed.
"The system's internal variability might well be larger than we
thought," says Levitus. "This is exciting news, but food for
global-warming sceptics it is not."
nong...@hotmail.com
oamenii intel azii
in incercare disperata de aparare dupa ce a aparut hirtia de la
tribunalul suprem care
spune ca ei ca si Argon sint intel.
nsacia sint moarte mai moarte ca partidul lui Hitler in 1945 au omorit
2 miliarde de oamenii si ar mai fi omorit un miliard ca sa ia planeta
omorind pe drum totii semitii .
Daca nu fac gate in 24 de ore trecem toata planeta la euro si ii
cumparam cu chilotii cu tot plus ca ei nu hotarasc .
GAIA
Ronin
faceti ciocu mic, spargem planeta.
nong...@hotmail.com
Ronin wrote:
> Noi avem bomba cu rezonanta gravitationala, inceputa de Tesla. Daca nu
> faceti ciocu mic, spargem planeta.
Inteleg dar asta e o optsie mai proasta decit cea ce va oferim care cu
exceptia
nsacia si a uneii miinii de politicienii care pleaca la New Nurenberg
trials totii ceilaltii
cistiga iar Armata voastra in afara faptului ca nu e cu voi dupa ce ati
vrut sa o futetii
nu este cu voii si stiind ce Noi Procese Nurenberg vin asta in afara
faptului ca toate
systemele sint in fail safe multiple redudant mode si care macar
gindeste este si va
fi pe loc executat de tribunale militare.
In rest asta e un joc de suma zero pe care lati jucat 50 de anii si nu
are valuare .
In momentul cin ai scris asta tiai semnat soarta ca aia cu criza
rachetelor de data
asta la Nurenberg .
In rest lasativa de amenintarii debile de loosersii fara sperante de
genul fier in oceane si
topirea calotelor polare asta tot in modul vostru debil de mirroring .
Ati pierdut complect
comportativa cum trebuie cu cei care vau salvat de la sinucidere si va
dau un viitor care
altfel nu lati fi avut
de fapt nimenii pe planeta nu ar fi avut daca se facea ca voi
asa cum cei mai
marii dusmanii ai vostrii nsacia hotarisera .
Acum aka azi Gates -scr - Rf si restul dupa lege si Full Frame sub
supravegherea #EU .
GAIA
nong...@hotmail.com
Armata voastra a fost trimisa in missiune ultima de cucerire la tot
Holocaust
si sinucidere lucru care inca o data verifica toate datele la planul
vostru de
"noua" planeta odessa si mai ales de nou Rf pe toata planeta .
Dissregard all and any encoding .
http://images.google.com/images?svnum=10&hl=en&lr=&q=world+++map
Din 1977 Vrancea pina la 2007 toate planurile voastre sint clare .
77 represinta data la care ati hotarit sa eliminatii semitii .
Adevarat ca la data respectiva parea alceva dar asta e semnificatia.
Prin africa si terminind a doua oara in russia fosta ussr .
Uitate pe harta de la 1977 pina azii ia toate razboiele si marile
evenimente
treaba e super clara .
nong...@hotmail.com
> Noi avem bomba cu rezonanta gravitationala, inceputa de Tesla. Daca nu
> faceti ciocu mic, spargem planeta.
Cel mai important multumesc la confirmarea publica a armelor seismice .