Jellyfish 'may benefit from ecosystem instability'

by Mark Kinver, science & environment reporter, BBC News, October 29, 2010 
 
There is concern that a rise in jellyfish numbers could prevent depleted commercially important fish stocks recovering to historical levels.

However, a study by European scientists says more data is needed to understand what is happening beneath the waves.

The findings are set to be published in the journal Global Change Biology.

Researchers from the UK and Ireland said samples collected from the Irish Sea since 1970 have recorded an increase in material from cnidarians (the division of the animal kingdom that includes jellyfish and coral), "with a period of frequent outbreaks between 1982 and 1991."

"There does appear to have been an increase in abundance since 1994 for the Irish Sea," said co-author Christopher Lynam, a researcher at the Centre for Environment Fisheries and Aquaculture Science (Cefas).

The team added that previous studies had recorded changes to marine ecosystems as a result of various factors, such as the removal of top predators, and changes to the distribution and characteristics of plankton.

'Jellyfish joyride'
These changes have led to a growing concern that the oceans may become increasingly dominated by jellyfish because "many gelatinous zooplankton species are able to increase in abundance rapidly and adapt to new conditions."


In recent years, there have been a number of examples of sudden blooms of jellyfish in European waters -- including the Irish, Mediterranean and Black seas -- which have killed fish and closed beaches.

In 2007, an invasion of mauve stingers (Pelagia noctiluca) wiped out Northern Ireland's only salmon farm, killing more than 100,000 fish.

However, Dr Lynam was keen to point out that the team's study was dominated by the common moon jellyfish (Aurelia aurita), which was not responsible for wiping out the salmon.

The main concern, the team wrote, was the establishment of a "never-ending jellyfish joyride" in which the creatures become so established that it makes it almost impossible for commercial fish stocks to return to historical levels.

But Dr Lynam told BBC News: "I don't think that the hypothesis that jellyfish will come into an area and dominate, not allowing anything to come back again, is really supported.

"Such a nightmare scenario does not seem to be the case, when you consider the data and studies that have been carried out."

Complicated picture
He explained that the team looked at whether factors such as changes to the climate and overfishing were responsible for the increase in jellyfish abundance.

"It is quite a complicated set of possible linkages that need to be drawn, which we really only have a vague insight at the moment.

"For the recent period where we have good data, it appears as if sea surface temperature is the most important variable.

"This does not necessarily prove it of course, but it does appear to be benefiting jellyfish."

The team, using data provided by the UK Met Office, commented: "The regional seas of the northeast Atlantic have been warming for the past 15 years at a rate not experienced in recent centuries."

Overfishing has also been linked to the rise of jellyfish populations. Research suggests that commercial fishing during the 20th Century had resulted in a change in the Irish Sea's ecosystem.

The researchers wrote: "The overexploitation of herring during the late 1970s was followed by a period of ecosystem instability in the 1980s in which the frequency of occurrence of cnidarian material... rose to high levels, indicating outbreaks of jellyfish."

Dr Lynam added: "If you take out a lot of the plankton feeders, there could be more food for jellyfish so they might become more abundant. There may be feedback mechanisms that we are not aware of, so there does need to be further study."

But he cited examples in the North Sea and Black Sea where fish species had declined, leading to an increase in jellyfish abundance, but the introduction of measures such as limits on catches had resulted in a recovery of fish stocks.
The team urged for the monitoring of jellyfish to continue, and concluded: "The move to ecosystem-based fisheries management requires extensive ecological knowledge and an understanding of the risks posed by any indirect effects... of our utilisation of the sea's resources."

Link:  http://www.bbc.co.uk/news/science-environment-11644500

Proceedings of the National Academy of Sciences, Vol. 107, No.  43, pp. 18354-18359 (October 26, 2010; published online before print October 11, 2010), doi: 10.1073/pnas.1006282107

Persistence of climate changes due to a range of greenhouse gases

Susan Solomon, John S. Daniel, Todd J. Sanford, Daniel M. Murphy, Gian-Kasper Plattner,
Reto Knutti and Pierre Friedlingstein

Abstract



Link to abstract:  http://www.pnas.org/content/107/43/18354.abstract 


Link to free, open-access, full article: http://www.pnas.org/content/107/43/18354.full.pdf+html

Climate of the Past, 5 (2009) 769-783; www.clim-past.net/5/769/2009/

Pliocene three-dimensional global ocean temperature reconstruction

H. J. Dowsett, M. M. Robinson and K. M. Foley (United States Geological Survey, MS 926A, 12201 Sunrise Valley Drive, Reston, VA 20192, U.S.A.)

Abstract



Final Revised Paper (PDF, 3065 KB)   Supplement (65 KB)   Discussion Paper (CPD) 


Link:  http://www.clim-past.net/5/769/2009/cp-5-769-2009.html

1 December 2009

Major sea level rise likely as Antarctic ice melts

By Richard Black, Environment correspondent, BBC News, December 1, 2009 The Southern Ocean is the world's most important feeding ground for whales Sea levels are likely to rise by about 1.4 m (4.5 ft.) globally by 2100 as polar ice melts, according to a major review of climate change in Antarctica. Conducted by the Scientific Committee on Antarctic Research (SCAR), it says that warming seas are accelerating melting in the west of the continent. Ozone loss has cooled the region, it says, shielding it from global warming. Rising temperatures in the Antarctic Peninsula are making life suitable for invasive species on land and sea. The report - Antarctic Climate Change and the Environment - was written using contributions from 100 leading scientists in various disciplines, and reviewed by a further 200. Rising seas: A tale of two cities SCAR's executive director Dr Colin Summerhayes said it painted a picture of "the creeping global catastrophe that we face." "The temperature of the air is increasing, the temperature of the ocean is increasing, sea levels are rising - and the Sun appears to have very little influence on what we see," he said. SCAR's report comes 50 years to the day after the Antarctic Treaty, the international agreement regulating use of the territory, was opened for signing, and a week before the opening of the potentially seminal UN climate summit in Copenhagen. High rise Two years ago, the Intergovernmental Panel on Climate Change (IPCC) projected that the global average sea level would probably rise by 28-43 cm (11-16 in.) by the end of the century. But it acknowledged this figure was almost certainly too low, because it was impossible to model "ice dynamics" - the acceleration in ice melting projected to occur as air and water temperatures rise. Launching the SCAR report in London, lead editor John Turner from the British Antarctic Survey (BAS) suggested that observations on the ground had changed that picture, especially in parts of the West Antarctic ice sheet. "Warmer water is getting under the edges of the West Antarctic ice sheet and accelerating the flow of ice into the ocean," he said. Glaciers: If the world's mountain glaciers and icecaps melt, sea levels will rise by an estimated 0.5 m Thermal expansion: The expansion of warming oceans was the main factor contributing to sea level rise, in the 20th Century, and currently accounts for more than half of the observed rise in sea levels Ice sheets: These vast reserves contain billions of tonnes of frozen water - if the largest of them (the East Antarctic ice sheet) melts, the global sea level will rise by an estimated 64 m By the end of the century, he said, the sheet will probably have lost enough ice alone to raise sea levels globally by "tens of centimetres." The remainder of the projected rise would come from melting of the Greenland cap, melting of mountain glaciers in the Himalayas and Andes, and the expansion of seawater as it warms. A number of research teams have come up with similar projections. But this is the first time that an international body such as SCAR has endorsed the likelihood that sea levels will rise enough to threaten some of the world's biggest cities by the end of the century. Cold store The Antarctic Peninsula - the strip of land that points towards the southern tip of South America - has warmed by about 3 °C over the last 50 years, the fastest rise seen anywhere in the southern hemisphere, according to the report. But the rest of the continent has remained largely immune from the global trend of rising temperatures. ANTARCTIC CLIMATE CHANGE Full report from the Scientific Committee on Antarctic Research [20MB] Most computers will open this document automatically, but you may need Adobe Reader Download the reader here Indeed, the continent's largest portion, East Antarctica, appears to have cooled, bringing a 10% increase in the sea ice extent since 1980. This report backs the theory that it has bucked the global trend largely because of ozone depletion - the chemical havoc wrought over 30 years by chlorofluorocarbons (CFCs) and other agents in the stratosphere above the polar region. "We used to have a big blanket of ozone, and when we took it away we saw a cooling," said Professor Turner. "The Antarctic has been shielded from the impacts of global warming." But, the report concludes, that will not last forever. The ozone hole is expected to repair itself in about 50 years, now that the Montreal Protocol has curbed the use of ozone-destroying substances. As it does so, the SCAR team predicts that greenhouse warming will come to dominate the temperature change across Antarctica, as in other parts of the planet. Doubling of greenhouse gas concentrations in the atmosphere would warm the continent by 3-4 °C, it says. The majority of Antarctica is so cold that a rise of this magnitude in air temperature would have little impact. But more warming of the oceans would speed ice loss still further, the report concludes. On the basis of declines seen around the Antarctic Peninsula, it would also be expected to bring significant reductions in the abundance of krill, a key foodstuff for baleen whales and other animals. Among humankind, the frozen continent was once a preserve of explorers and scientists. But now, about 30,000 tourists a year visit, some setting foot on outlying parts of the peninsula. This increased human traffic, plus the warming on land and sea, are going to change the region's ecology, according to Julian Gutt, allowing organisms to enter and survive that were previously excluded through climate or simple geography. "A good candidate is the stone crab (aka king crab) such as those found throughout Norwegian waters - they're more than a metre across from toe to toe. "There are hints of it hopping across from South America - and that could completely change the ecosystem on the sea floor," said the Alfred Wegener Institute researcher. About one third of one percent of Antarctica's land surface is ice-free; but already, non-native species are competing with native mosses for this meagre resource, Dr Gutt noted. Richard.Black-INTERNET@bbc.co.uk

Link:  http://news.bbc.co.uk/2/hi/science/nature/8387137.stm

Sorry, I can see that the right side of the graph is cut off -- just click on it to display it in full.

This graph is, for me, without a doubt, one of the scariest images out there on the net.

I do not know what the problem is, but I cannot get into the www.remss.com site.
I have had this problem for over a year, and I have tried every browser under the sun, and my settings are correct.

If someone would like to send me the most recent graph (it used to be about Figure 7 on their webpage), I would be most grateful.

Send to apaixonada.por.rio@gmail.com

Thanks!

Marine Ecology Progress Series, Vol. 393, pp. 111-129; published online October 30, 2009

Geophysical Research Letters, 36 (2009) L20709; doi: 10.1029/2009GL039491.

How well is Argo able to observe global ocean changes?

Global coverage is essential, but for global change applications, Argo data must also have high accuracy and minimal systematic errors. Therefore, a high priority for Argo is to continue work aimed at identifying and correcting pressure measurement errors, especially those with systematic impacts. High quality shipboard CTD transects are critical for assessing data quality in nearby profiling floats.

Global change observations
Ocean temperature and heat content
Ocean salinity and freshwater content
Steric sea level
Ocean circulation

Ocean temperature and heat content Over the past 50 years, the oceans have absorbed more than 80% of the total heat added to the air/sea/land/cyrosphere climate system (Levitus et al., 2005). As the dominant reservoir for heat, the oceans are critical for measuring the radiation imbalance of the planet and the surface layer of the oceans plays the role of thermostat and heat source/sink for the lower atmosphere.

Domingues et al. (2008) and Levitus et al. (2009) have recently estimated the multi-decadal upper ocean heat content using best-known corrections to systematic errors in the fall rate of expendable bathythermographs (Wijffels et al., 2008). For the upper 700 m, the increase in heat content was 16 x 10²² J since 1961. This is consistent with the comparison by Roemmich and Gilson (2009) of Argo data with the global temperature time-series of Levitus et al. (2005), finding a warming of the 0 - 2000 m ocean by 0.06 °C since the (pre-XBT) early 1960s.







Steric sea level Steric sea level provides a great example of Argo's complementary relationship with other observing system elements, particularly the altimeter Jason. Argo provides the capability to understand sea level change by measuring its component due to subsurface temperature and salinity. The steric component is dominant over the mass component in regional sea level variability and on a global basis it accounts for about 1/3 of total sea level increase in the past half century (Domingues et al., 2008). Accurate projections of future sea level require an understanding of the causes of sea level change in the modern record.



Ocean circulation

Link: http://www.argo.ucsd.edu/global_change_analysis.html

In hot water: World sets ocean temperature record (Update)

by Seth Borenstein, AP Science Writer, August 20, 2009

The water temperature was 72 °F -- more like Ocean City, Md., this time of year. And Ocean City's water temp hit 88 °F, toasty even by Miami Beach standards.


Kramer, 26, who lives in the seaside town of Scarborough, said it was the first time he's ever swam so long in Maine's coastal waters.

It's not just the ocean off the Northeast coast that is super-warm this summer. July was the hottest the world's oceans have been in almost 130 years of record-keeping.

The average water temperature worldwide was 62.6 °F, according to the National Climatic Data Center, the branch of the U.S. government that keeps world weather records. June was only slightly cooler, while August could set another record, scientists say. The previous record was set in July 1998 during a powerful El Nino.

Meteorologists said there's a combination of forces at work: A natural El Nino weather pattern just getting started on top of worsening man-made global warming, and a dash of random weather variations. The resulting ocean heat is already harming threatened coral reefs. It could also hasten the melting of Arctic sea ice and help hurricanes strengthen.

The Gulf of Mexico, where warm water fuels hurricanes, has temperatures dancing around 90 °F. Most of the water in the Northern Hemisphere has been considerably warmer than normal. The Mediterranean is about three degrees warmer than normal. Higher temperatures rule in the Pacific and Indian Oceans.

The phenomena is most noticeable near the Arctic, where water temperatures are as much as 10 °F above average. The tongues of warm water could help melt sea ice from below and even cause thawing of ice sheets on Greenland, said Waleed Abdalati, director of the Earth Science and Observation Center at the University of Colorado.

Breaking heat records in water is more ominous as a sign of global warming than breaking temperature marks on land, because water takes longer to heat up and does not cool off as easily as land.

"This warm water we're seeing doesn't just disappear next year; it'll be around for a long time," said climate scientist Andrew Weaver of the University of Victoria in British Columbia. It takes five times more energy to warm water than land.

The warmer water "affects weather on the land," Weaver said. "This is another yet really important indicator of the change that's occurring."

Georgia Institute of Technology atmospheric science professor Judith Curry said water is warming in more places than usual, something that has not been seen in more than 50 years.

Add to that an unusual weather pattern this summer where the warmest temperatures seem to be just over oceans, while slightly cooler air is concentrated over land, said Deke Arndt, head of climate monitoring at the climate data center.

The pattern is so unusual that he suggested meteorologists may want to study that pattern to see what's behind it.

The effects of that warm water are already being seen in coral reefs, said C. Mark Eakin, coordinator of the National Oceanic and Atmospheric Administration's coral reef watch. Long-term excessive heat bleaches colorful coral reefs white and sometimes kills them.

Bleaching has started to crop up in the Florida Keys, Puerto Rico and the Virgin Islands. Typically, bleaching occurs after weeks or months of prolonged high water temperatures. That usually means September or even October in the Caribbean, said Eakin. He found bleaching in Guam Wednesday. It's too early to know if the coral will recover or die. Experts are "bracing for another bad year," he said.

The problems caused by the El Nino pattern are likely to get worse, the scientists say.

An El Nino occurs when part of the central Pacific warms up, which in turn changes weather patterns worldwide for many months. El Nino and its cooling flip side, La Nina, happen every few years.

During an El Nino, temperatures on water and land tend to rise in many places, leading to an increase in the overall global average temperature. An El Nino has other effects, too, including dampening Atlantic hurricane formation and increasing rainfall and mudslides in Southern California.

Warm water is a required fuel for hurricanes. What's happening in the oceans "will add extra juice to the hurricanes," Curry said.

Hurricane activity has been quiet for much of the summer, but that may change soon, she said. Hurricane Bill quickly became a major storm and the National Hurricane Center warned that warm waters are along the path of the hurricane for the next few days.

Hurricanes need specific air conditions, so warmer water alone does not necessarily mean more or bigger storms, said James Franklin, chief hurricane specialist at the National Hurricane Center in Miami.

Link:  http://www.physorg.com/news169993833.html

Dear Readers,

The post below is number 1,500 since this blog started in 2007.  Never in my wildest dreams could I have imagined that I would have posted so many articles here.  Nor could I have imagined that this blog would receive an average of nearly 500 visitors per day, with upwards of 800 pages per day viewed, now bringing total page views to nearly 200,000.

Over time, as the scientific articles have accumulated here, this blog has become a database for the advanced layperson seeking more knowledge of climate science.

I admit that I cannot nor do I try to cover all of the vast number of aspects of the science of climate change.  The blog's focus has been on the Arctic and on changing patterns of atmospheric and oceanic circulation all around the globe, although many other subjects are covered.

It is to be hoped that the blog's contents have been found useful by you, the reader.

I salute all of you for seeking the truth.

Sincerely,

Tenney Naumer


Link to first webpage here:  http://www.arctic.noaa.gov/reportcard/

Please click on the headings below to go to the various sections of the report.

Atmosphere
Large scale wind patterns impacted by loss of summer sea ice

There is evidence that, by creating a new major surface heat source, the recent extreme loss of summer sea ice extent is having a direct feedback effect on the general atmospheric circulation into the winter season (Francis et al., 2009). Fall air temperature anomalies of greater than +1.0 °C were observed well up into the atmosphere (Figure 3A), when averaged over 2003–2008 relative to a 1968–1996 base period. The higher temperatures in the lower troposphere decrease the atmospheric air density and raise the height of upper-air-constant-pressure levels over the Arctic Ocean (Figure 3B). These increased heights north of 75° N weaken the normal north-to-south pressure gradient that drives the normal west-to-east airflow in the upper troposphere. In this sense, the effect of higher air temperatures in the lower Arctic atmosphere is contributing to changes in the atmospheric circulation in both the Arctic and northern mid-latitudes. For example, Honda et al. (2009) suggest a remote connection between loss of Arctic sea ice and colder temperatures over eastern Asia.

The climate of the Arctic is influenced by repeating patterns of sea level pressure that can either dominate during individual months or represent the overall atmospheric circulation flow for an entire season. The main climate pattern for the Arctic is known as the Arctic Oscillation (AO) with anomalous winds that blow counter-clockwise around the pole when the pattern is in its positive phase. A second wind pattern has been more prevalent in the 21st century and is known as the Arctic Dipole (AD) pattern (Wu et al., 2006; Overland et al., 2008). The AD pattern has anomalous high pressure on the North American side of the Arctic and low SLP on the Eurasian side. This implies winds blowing more from south to north, compared to the AO, and increasing transport of heat into the central Arctic Ocean. The AD pattern occurred in all summer months of 2007 and helped support the major 2007 summer reduction in sea ice extent (Overland et al., 2008). Fall 2008 and winter/spring 2009 showed a return of the AO pattern, but also considerable month to month variability in the presence of these various climate patterns.

Sea Ice
Multi-year sea ice is being replaced by first year sea ice

Ocean
Upper ocean remains warm and less salty

Land
Increased runoff in Siberia, less snow in North America

Greenland
Ice sheet loss continues

Biology
High Arctic species impacted by loss of sea ice

Link to complete report (pdf file):  http://www.arctic.noaa.gov/reportcard/ArcticReportCard_full_report.pdf

Skeptical Science explains how we know global warming is happening: It’s the oceans, stupid!

by Joseph Romm, Climate Progress, October 10, 2009

The empirical data has spoken. Cancel the global cooling party. Global warming is still happening.

The planet is heating up, thanks to human-generated emissions of greenhouse gases.  But as a new NOAA-led study, “An observationally based energy balance for the Earth since 1950” (subs. req’d, release here) concluded:

[S]ince 1950, the planet released about 20 percent of the warming influence of heat-trapping greenhouse gases to outer space as infrared energy. Volcanic emissions lingering in the stratosphere offset about 20 percent of the heating by bouncing solar radiation back to space before it reached the surface. Cooling from the lower-atmosphere aerosols produced by humans balanced 50 percent of the heating. Only the remaining 10 percent of greenhouse-gas warming actually went into heating the Earth, and almost all of it went into the ocean.

Note that this Journal of Geophysical Research-Atmospheres study was done “without using global climate models.”

Figure 1: “Total Earth Heat Content [anomaly] from 1950 (Murphy et al. 2009). Ocean data taken from Domingues et al 2008.”

That figure comes from the first of two posts by the terrific website Skeptical Science, which I repost below.  Skeptical Science is an excellent, well-organized site to send convincible people for a shredding of the standard, long-debunked denier talking points.

Now I’m sure the deniers and delayers out there are shrieking, “There are peer reviewed analyses that document that upper ocean warming has halted since 2003!” — a claim I dealt with in my July post, “Like father, like son: Roger Pielke Sr. also doesn’t understand the science of global warming — or just chooses to willfully misrepresent it.”

Subsequently, however, another JGR article, “Global hydrographic variability patterns during 2003–2008” (subs. req’d, draft here) details an analysis of “monthly gridded global temperature and salinity fields from the near-surface layer down to 2000 m depth based on Argo measurements.”  Background on Argo here.  

Their findings are summed up in this figure:

Figure [2]: Time series of global mean heat storage (0–2000 m), measured in 10⁸ Jm^-2.

Still warming, after all these years!  And just where you’d expect it.  The study makes clear that upper ocean heat content, perhaps not surprisingly, is simply far more variable than deeper ocean heat content, and thus an imperfect indicator of the long-term warming trend.

UPDATE:  Yes, I am aware of the recent upper-ocean heat content data on the web.  Please note that plots of very recent, highly variable upper-ocean content heat data down to 700 meters from unpeer-reviewed sources do not trump peer-reviewed analysis of much longer-term data down to 2000 m.  Is it too much to ask people to actually read this entire post before posting comments?

What follows is a repost of two articles from Skeptical Science discussing these figures and the recent studies in more detail:

[I have renamed the figure in Part 2, "Figure 2" for the sake of clarity.]

How we know global warming is still happening, Part 1

Skeptics proclaim that global warming stopped in 1998. That we’re now experiencing global cooling. However, these arguments overlook one simple physical reality — the land and atmosphere are only one small fraction of the Earth’s climate (albeit the part we inhabit). Global warming is by definition global. The entire planet is accumulating heat due to an energy imbalance. The atmosphere is warming. Oceans are accumulating energy. Land absorbs energy and ice absorbs heat to melt. To get the full picture on global warming, you need to view the Earth’s entire heat content.

This analysis is performed in An observationally based energy balance for the Earth since 1950 (Murphy 2009) which adds up heat content from the ocean, atmosphere, land and ice. To calculate the Earth’s total heat content, the authors used data of ocean heat content from the upper 700 metres. They included heat content from deeper waters down to 3000 metres depth. They computed atmospheric heat content using the surface temperature record and the heat capacity of the troposphere. Land and ice heat content (eg – the energy required to melt ice) were also included.
[See Figure 1 above.]

A look at the Earth’s total heat content clearly shows global warming has continued past 1998. So why do surface temperature records show 1998 as the hottest year on record? Figure 1 shows the heat capacity of the land and atmosphere are small compared to the ocean (the tiny brown sliver of “land + atmosphere” also includes the heat absorbed to melt ice). Hence, relatively small exchanges of heat between the atmosphere and ocean can cause significant changes in surface temperature.

In 1998, an abnormally strong El Nino caused heat transfer from the Pacific Ocean to the atmosphere. Consequently, we experienced above average surface temperatures. Conversely, the last few years have seen moderate La Nina conditions which had a cooling effect on global temperatures. And the last few months have swung back to warmer El Nino conditions. This has coincided with the warmest June-August sea surface temperatures on record. This internal variation where heat is shuffled around our climate is the reason why surface temperature is such a noisy signal.

Figure 1 also underscores just how much global warming the planet is experiencing. Since 1970, the Earth’s heat content has been rising at a rate of 6 x 10²¹ Joules per year. In more meaningful terms, the planet has been accumulating energy at a rate of 190,260 GigaWatts. Considering a typical nuclear power plant has an output of 1 GigaWatt, imagine 190,000 nuclear power plants pouring their energy output directly into our oceans.

Figure 1 only goes as far as 2003 as the ocean heat data used (Domingues 2008) only goes that far. What has global warming been doing since then? Since 2003, ocean heat data has been measured by the newly deployed Argo network. However, there have been teething problems with the Argo buoys experiencing pressure sensor issues that impose a cooling bias on the data.

Consequently there have been several data analyses on ocean heat since 2003. One reconstruction of ocean heat show cooling since 2003 (Willis 2008). Other analyses of the Argo data show ocean warming (Levitus 2009, Leuliette 2009, Cazenave 2009).

How do we determine which analyses are more accurate? Ocean heat data can also be independently determined through other empirical means. Cazenave 2009 uses satellite gravity measurements to create two independent estimates of ocean heat – both find warming. Sea level has been inexorably rising since 2003. As a large portion of sea level rise is due to thermal expansion from ocean warming, this is an indirect confirmation of warming.

Lastly, the planet’s energy imbalance is confirmed by satellite measurements of incoming and outgoing radiation. Earth’s Global Energy Budget (Trenberth 2009) examines satellite measurements for the Mar 2000 to May 2004 period and finds the planet is accumulating energy at a rate of 0.9 ± 0.15 W m⁻². This is consistent with the amount of heat accumulating in the ocean. Preliminary analysis on the latest CERES satellite data shows an increasing energy imbalance from 2004 to the end of 2008 (although this data is yet to be published, more on this later).

So the point to remember when considering short term cooling trends in surface temperature records is that the atmosphere is only one small part of a planet which is in energy imbalance. Empirical measurements show the planet continues to accumulate heat. More energy is coming in than is radiating back out to space. Global warming continued past 1998 and is still happening.

How we know global warming is happening, Part 2

In our last post, we determined whether global warming was still happening by adding up all the heat content of the climate system.  Murphy 2009 performed this analysis and found that that planet has been accumulating heat up to 2003. Unfortunately their data ends there as the ocean data they used from Domingues (2008) stops at the end of 2003. So how do we find out what’s happened from 2003 until now? Unfortunately, there is no time series (that I know of) of the planet’s total heat content up to present time. However, we do have the next best thing.

Global hydrographic variability patterns during 2003–2008 (Schuckmann 2009) analyses ocean temperature measurements by the Argo network, constructing a map of ocean heat content down to 2000 metres (H/T to Chris for bringing it to my attention). This is significantly deeper than other recent papers that focus on upper ocean heat, only going down to 700 metres. They constructed the following time series of global ocean heat:
[See Figure 2 above.]

Globally, the oceans have still been steadily accumulating heat right to the end of 2008. Combined with the results of Murphy 2009 who finds the planet accumulating heat right to 2003, we now see a picture of unbroken global warming. Over the last 5 years, the oceans have been absorbing heat at a rate of 0.77 ± 0.11 Wm⁻².

So what is our planet’s total energy imbalance? Indulge me as I perform some rough back-of-a-napkin calculations. Murphy 2009 found that about 5.6% of the planet’s energy imbalance went into the land and atmosphere. In other words, 94.4% of global warming goes into the oceans. So if the ocean is absorbing 0.77 ± 0.11 Wm⁻², this puts the total energy imbalance at around 0.82 ± 0.12 Wm⁻². This is a slight underestimate as Murphy 2009 included ocean heat down to 3000m (remember this is back-of-a-napkin stuff).

How does this value compare to other estimates of energy imbalance? Hansen 2005, using ocean heat data, calculated the planet’s energy imbalance around 2003 to be 0.85 Wm⁻². Trenberth 2009 examined satellite measurements of incoming and outgoing radiation for the March 2000 to May 2004 period and found the planet accumulating energy at a rate of 0.9 ± 0.15 Wm⁻².

All these estimates are consistent with each other. Most importantly, all find a statistically significant positive energy imbalance. The empirical data has spoken. Cancel the global cooling party. Global warming is still happening.

Precisely.

Link to Climate Progress blog:  http://climateprogress.org/2009/10/10/skeptical-science-global-warming-not-cooling-is-still-happening-ocean-heat-content/

Journal of Climate, 19, 5008-5033, doi:10.1175/2008JCLI2104.1

Global-scale energy and freshwater balance in glacial climate: A comparison of three PMIP2 LGM simulations

S. Murakami, R. Ohgaito (Frontier Research Center for Global Change, JAMSTEC, Yokohama, Japan) A. Abe-Ouchi (Center for Climate System Research, University of Tokyo, Kashiwa, and Frontier Research Center for Global Change, JAMSTEC, Yokohama, Japan), M. Crucifix (Institut d’Astronomie et de Géophysique Georges Lemaître, Université catholique de Louvain, Louvain-La-Neuve, Belgium) and B. L. Otto-Bliesner (National Center for Atmospheric Research, Boulder, CO, U.S.A.)

Figure 1. Geographical maps of (top) vertically integrated northward DSE flux transported by transient eddies, (middle) rms 250-hPa height anomaly from the annual mean climatology, and (bottom) synoptic-scale waves using the MIROC for the (left) CTL and (right) LGM simulations. Contour intervals are 0.05 × 108 W m^-1, 30 m, and 30 m, respectively. High resolution figure

Abstract

Three coupled atmosphere–ocean general circulation model (AOGCM) simulations of the Last Glacial Maximum (LGM: about 21 000 yr before present), conducted under the protocol of the second phase of the Paleoclimate Modelling Intercomparison Project (PMIP2), have been analyzed from a viewpoint of large-scale energy and freshwater balance. Atmospheric latent heat (LH) transport decreases at most latitudes due to reduced water vapor content in the lower troposphere, and dry static energy (DSE) transport in northern midlatitudes increases and changes the intensity contrast between the Pacific and Atlantic regions due to enhanced stationary waves over the North American ice sheets. In low latitudes, even with an intensified Hadley circulation in the Northern Hemisphere (NH), reduced DSE transport by the mean zonal circulation as well as a reduced equatorward LH transport is observed. The oceanic heat transport at NH midlatitudes increases owing to intensified subpolar gyres, and the Atlantic heat transport at low latitudes increases in all models whether or not meridional overturning circulation (MOC) intensifies. As a result, total poleward energy transport at the LGM increases in NH mid- and low latitudes in all models. Oceanic freshwater transport decreases, compensating for the response of the atmospheric water vapor transport. These responses in the atmosphere and ocean make the northern North Atlantic Ocean cold and relatively fresh, and the Southern Ocean relatively warm and saline. This is a common and robust feature in all models. The resultant ocean densities and ocean MOC response, however, show model dependency.

Murakami, S., R. Ohgaito, A. Abe-Ouchi, M. Crucifix & B.L. Otto-Bliesner. 2008: Global-scale energy and freshwater balance in glacial climate: A comparison of three PMIP2 LGM simulations. Journal of Climate, 19, 5008-5033, doi:10.1175/2008JCLI2104.1.

Link to abstract: http://ams.allenpress.com/perlserv/?request=get-document&doi=10.1175%2F2008JCLI2104.1&ct=1

Nature Geoscience, 2 (2008) 67-72, published online 30 November 2008; doi: 10.1038/ngeo382

Surprising return of deep convection to the subpolar North Atlantic Ocean in winter 2007–2008

Kjetil Våge¹, Robert S. Pickart¹, Virginie Thierry², Gilles Reverdin³, Craig M. Lee⁴, Brian Petrie⁵, Tom A. Agnew⁶, Amy Wong⁶ and Mads H. Ribergaard⁷

AbstractLink to abstract: http://www.nature.com/ngeo/journal/v2/n1/abs/ngeo382.html

ICES Journal of Marine Science, 66(7) (2009) 1448-1454; doi:10.1093/icesjms/fsp094

On the effect of the North Atlantic Oscillation on temperature and salinity of the subpolar North Atlantic intermediate and deep waters

Artem Sarafanov

Shirshov Institute of Oceanology, 36 Nakhimovskiy Prospect, 117997 Moscow, Russia

Received 15 August 2008; accepted 18 February 2009; advance access publication 17 April 2009.

Abstract

Key words: Labrador Sea Water, long-term changes, North Atlantic Oscillation, overflow, Subpolar Gyre, Subtropical Gyre

tel: +7 916 279 7324; fax: +7 499 124 6142; e-mail: sarafanov@mail.ru

Sarafanov, A. 2009. On the effect of the North Atlantic Oscillation on temperature and salinity of the subpolar North Atlantic intermediate and deep waters. ICES Journal of Marine Science, 66: 1448–1454.

Link to abstract: http://icesjms.oxfordjournals.org/cgi/content/abstract/66/7/1448

Discovery News: World's oceans set temperature record

by Seth Borenstein, Associated Press

Aug. 20, 2009 -- July marked the hottest the world's oceans have been in almost 130 years of record-keeping. Meteorologists said a combination of forces are at work: A natural El Nino system on top of worsening man-made global warming and a dash of random weather variations.

The resulting ocean heat is already harming threatened coral reefs. It could also hasten the melting of Arctic sea ice and help hurricanes strengthen.

The average water temperature worldwide in July was 62.6 °F, according to the National Climatic Data Center, the branch of the U.S. government that keeps world weather records.

June was only slightly cooler, while August could set another record, scientists said.

The previous record was set in July 1998 during a powerful El Nino weather pattern.

The Gulf of Mexico, where warm water fuels hurricanes, has temperatures dancing around 90. Most of the water in the Northern Hemisphere has been considerably warmer than normal. The Mediterranean is about three degrees warmer than normal. Higher temperatures rule in the Pacific and Indian Oceans.

The heat is most noticeable near the Arctic, where water temperatures are as much as 10 °F above average. The tongues of warm water could help melt sea ice from below and even cause thawing of ice sheets on Greenland, said Waleed Abdalati, director of the Earth Science and Observation Center at the University of Colorado.

Breaking heat records in water is more ominous as a sign of global warming than breaking temperature marks on land, because water takes longer to heat up and does not cool off as easily as land.

"This warm water we're seeing doesn't just disappear next year; it'll be around for a long time," said climate scientist Andrew Weaver of the University of Victoria in British Columbia. It takes five times more energy to warm water than land.

The warmer water "affects weather on the land," Weaver said. "This is another yet really important indicator of the change that's occurring."

Georgia Institute of Technology atmospheric science professor Judith Curry said water is warming in more places than usual, something that has not been seen in more than 50 years.

Add to that an unusual weather pattern this summer where the warmest temperatures seem to be just over oceans, while slightly cooler air is concentrated over land, said Deke Arndt, head of climate monitoring at the climate data center.

The pattern is so unusual that he suggested meteorologists may want to study that pattern to see what's behind it.

The effects of that warm water are already being seen in coral reefs, said C. Mark Eakin, coordinator of the National Oceanic and Atmospheric Administration's coral reef watch. Long-term excessive heat bleaches colorful coral reefs white and sometimes kills them.

Bleaching has started to crop up in the Florida Keys, Puerto Rico and the Virgin Islands -- much earlier than usual. Typically, bleaching occurs after weeks or months of prolonged high water temperatures. That usually means September or October in the Caribbean, said Eakin. He found bleaching in Guam Wednesday. It's too early to know if the coral will recover or die. Experts are "bracing for another bad year," he said.

The problems caused by the El Nino pattern are likely to get worse, the scientists said.

An El Nino occurs when part of the central Pacific warms up, which in turn changes weather patterns worldwide for many months. El Nino and its cooling flip side, La Nina, happen every few years.

During an El Nino, temperatures on water and land tend to rise in many places, leading to an increase in the overall global average temperature. An El Nino has other effects, too, including dampening Atlantic hurricane formation and increasing rainfall and mudslides in Southern California.

Warm water is a required fuel for hurricanes. What's happening in the oceans "will add extra juice to the hurricanes," Curry said.

Hurricane activity has been quiet for much of the summer, but that may change soon, she said. Hurricane Bill quickly became a major storm and the National Hurricane Center warned that warm waters are along the path of the hurricane for the next few days.

Hurricanes need specific air conditions, so warmer water alone does not necessarily mean more or bigger storms, said James Franklin, chief hurricane specialist at the National Hurricane Center in Miami.

Link: http://dsc.discovery.com/news/2009/08/20/ocean-temperature.html