There are some interesting articles reporting rapidly rising temperatures in key ocean currents – scientists compared “five ocean currents that run along the east coasts of Africa, Japan, the USA, Brazil and Australia” and “that over the past century the water in the currents has warmed two to three times faster than the rest of the world’s oceans.” http://www.abc.net.au/worldtoday/content/2012/s3418386.htm >
These temperature changes will affect the distribution of marine life and I suspect are likely to impinge on the distributions of pelagic bird species. It would be an interesting exercise to overlay species sightings with sea temperatures and to see how bird distributions change over time.
Perhaps a thesis topic for someone …
Regards, Laurie. ===============================
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Laurie, I welcome your constructive and courteous disagreement. But, Nikolas, it is best not to personalise responses, I think. The topic is now parked, so far as I am concerned.
Martin (scientist: peer-reviewed publication record from 1968 on).
g’Day all
As many of you would be aware, the problem of using surface sea temperature measurements recorded from pelagic trips is that because of many variables, the data good for a seasonal guide but is almost useless for meaningful scientific comparison.
Invariably data is recorded from sensors embedded in the fish finder (depth sounder) transducer fitted below the water line of the vessel. The sea surface temperature displayed on the instrument will nearly always be different between two transducer sensors even when fitted to the same vessel and also significantly different between two vessels unless properly calibrated. The reasons are many but include the mounting position and the depth below the sea surface of the sensors located on a vessel hull. The quality of the sensor also comes into the mix of considerations but will usually vary even between two new quality sensors such as Furuno connected to the same instrument.
Picture two calibrated transducers, one stern mounted on a dinghy or small vessel (approx 0.2m below water line), the second through hull mounted in the deepest fwd hull section of a deep sea fishing trawler (say 2.0m or greater below water line). At the same location when day atmospheric temperatures are hot with calm sea conditions combined with little water movement (gentle tide and current), surface readings will be significantly different between the two vessels. In still water, temperature varies by the Cm. Then there are daily variability factors of sea water surface temperature. Apart from sensor variability, sea surface temperature readings are affected by water turbulence determined by prevailing wind, tide, current and cloud cover and also turbidity.
Occasionally I have observed daily variations of up to 2C sea surface temperature at the same location when using the same calibrated sensor. But I could not speculate the consequences of a permanent 2C deg rise of sea temperature on sea birds however it is well known and expected that sea surface temperatures will rise in various parts of the world’s oceans during La Nina weather patterns. See http://www.globalweathercycles.com/elninoforecastgwo.html
Regards
Ian May St Helens, Tasmania currently at Price, SA. 0428337956
Laurie Knight wrote:
g.Day all ===============================
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If we can park the issue of scientific credibility, I would like the tread to return to the original point. What is the impact of a rapid increase in the temperature of ocean currents, such as the East Australian Current on the distribution of pelagic birds? I know that Paul Walbridge measured the sea temperature on each trip out of Southport that I went on, so I presume that the subject of sea temperature is of potential interest to pelagic birders …
Regards, Laurie.
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Dear Birding-Aus,
Not sure if everyone here knows the difference between a scientific article such as the one by Wu et al. in Nature Climate Change and someones personal blog. I am not a climatologist but I am a scientist, too. Manuscripts submitted to any journal of the Nature Publishing Group (NPG) and to their serious competitors (e.g. Science and many others) undergo a thorough peer-review – usually by experts in the field. The main journal of the group, Nature, has a rejection rate of more than 90%, which shows how hard it is to get an article published in such a journal. But yes, it happens once in a while that a story gets published and later turns out to be wrong. Then other serious scientists – not some dubious bloggers – have the chance to correct the error in a professional peer-reviewed paper.
M. complains about the lack of “REAL data” and calls the Wu et al. paper “flawed”. O.K., maybe or maybe not? Where are the “REAL data” then that prove the Wu et al. paper wrong, M.?Finally, M.’s lack of understanding of the topic climate change is documented by his comment regarding “tiny differences in ocean temperatures”.
Why am I writing this? In doubt, it makes more sense to incorporate a professionally published article into public knowledge than someone’s un-peer-reviewed blog that reflects the opinion of the writer rather than real science!
Cheers,
Nikolas
P.S. Maybe the webmaster should take this whole counterproductive debate off the web?
Martin
I don’t think you can raise the question of scientific rigour and then refer to the web-site you do.
John Leonard
Anthony Watts has no climatology qualifications, and his blog is devoid of any meaningful science. He has continually been debunked by actual scientists and is only a source of misinformation. Two degrees is a massive change for average temperatures. It’s important to remember that the average global temp during the last ice age was *only* five degrees lower than now, and most of Europe, North America, and Tasmania were covered in ice. Averages are not the same as single day temperatures.
Jeremy O’Wheel
Why do you say that a 1.5 to 2C change over 100 years is tiny, Martin? I would have thought a temperature change of that magnitude is quite significant.
Anyhow, the article in question is available at http://www.nature.com/** nclimate/journal/vaop/**ncurrent/full/nclimate1353.**html< http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate1353.html>
The abstract is as follows:
“Enhanced warming over the global subtropical western boundary currents • Lixin Wu, • Wenju Cai, • Liping Zhang, • Hisashi Nakamura, • Axel Timmermann, • Terry Joyce,• Michael J. McPhaden, • Michael Alexander, • Bo Qiu, • Martin Visbeck, • Ping Chang • & Benjamin Giese
Nature Climate Change (2012) doi:10.1038/**nclimate1353Received 06 May 2011 Accepted 30 November 2011 Published online 29 January 2012
Subtropical western boundary currents are warm, fast-flowing currents that form on the western side of ocean basins. They carry warm tropical water to the mid-latitudes and vent large amounts of heat and moisture to the atmosphere along their paths, affecting atmospheric jet streams and mid-latitude storms, as well as ocean carbon uptake1, 2, 3, 4. The possibility that these highly energetic currents might change under greenhouse-gas forcing has raised significant concerns5, 6, 7, but detecting such changes is challenging owing to limited observations. Here, using reconstructed sea surface temperature datasets and century-long ocean and atmosphere reanalysis products, we find that the post-1900 surface ocean warming rate over the path of these currents is two to three times faster than the global mean surface ocean warming rate. The accelerated warming is associated with a synchronous poleward shift and/or intensification of global subtropical western boundary currents in conjunction with a systematic change in winds over both hemispheres. This enhanced warming may reduce the ability of the oceans to absorb anthropogenic carbon dioxide over these regions. However, uncertainties in detection and attribution of these warming trends remain, pointing to a need for a long-term monitoring network of the global western boundary currents and their extensions.”
The point remains that a lot of pelagic birding occurs along the East Australian Current and a 2C warming may have a significant impact on marine activity off SE Australia.
Regards, Laurie.
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Yes, I agree with Laurie that we should welcome any study that seeks to obtain REAL data. With such tiny differences in ocean temperatures, it might be difficult to detect impacts on bird distributions. Nevertheless, real data is the stuff that counts.
But flawed studies such as Wenju Cai’s ocean ‘hot-spots’ give the game away when they state:
“Detecting these changes has been hindered by limited observations but with a combination of multi-national ocean watch systems and computer simulations we have been able to reconstruct an ocean history…”
We should view with considerable scepticism studies such as these which rely so heavily on computer modelling to reach what is clearly a pre-determined conclusion.
See also http://wattsupwiththat.com/2012/01/30/oh-noes-wind-driven-global-warming-hot-spots/
Why do you say that a 1.5 to 2C change over 100 years is tiny, Martin? I would have thought a temperature change of that magnitude is quite significant.
Anyhow, the article in question is available at http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate1353.html
The abstract is as follows:
“Enhanced warming over the global subtropical western boundary currents • Lixin Wu, • Wenju Cai, • Liping Zhang, • Hisashi Nakamura, • Axel Timmermann, • Terry Joyce,• Michael J. McPhaden, • Michael Alexander, • Bo Qiu, • Martin Visbeck, • Ping Chang • & Benjamin Giese
Nature Climate Change (2012) doi:10.1038/nclimate1353Received 06 May 2011 Accepted 30 November 2011 Published online 29 January 2012
Subtropical western boundary currents are warm, fast-flowing currents that form on the western side of ocean basins. They carry warm tropical water to the mid-latitudes and vent large amounts of heat and moisture to the atmosphere along their paths, affecting atmospheric jet streams and mid-latitude storms, as well as ocean carbon uptake1, 2, 3, 4. The possibility that these highly energetic currents might change under greenhouse-gas forcing has raised significant concerns5, 6, 7, but detecting such changes is challenging owing to limited observations. Here, using reconstructed sea surface temperature datasets and century-long ocean and atmosphere reanalysis products, we find that the post-1900 surface ocean warming rate over the path of these currents is two to three times faster than the global mean surface ocean warming rate. The accelerated warming is associated with a synchronous poleward shift and/or intensification of global subtropical western boundary currents in conjunction with a systematic change in winds over both hemispheres. This enhanced warming may reduce the ability of the oceans to absorb anthropogenic carbon dioxide over these regions. However, uncertainties in detection and attribution of these warming trends remain, pointing to a need for a long-term monitoring network of the global western boundary currents and their extensions.”
The point remains that a lot of pelagic birding occurs along the East Australian Current and a 2C warming may have a significant impact on marine activity off SE Australia.
Regards, Laurie.
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