The Sydney Morning Herald ran this article – Typhoon Haiyan influenced by climate change, scientists say – there must be hundreds of articles written along the same general drift. In this case a map of sea surface temperature (SST) anomalies is presented by the SMH for the period 3rd to 5th Nov.
Note the location of the warm anomaly is from 160-165 East and between 5 South & 5 North.
Here is a map of Typhoon tracks including the Haiyan path extended as far east to its origins as I can find.
Note that Haiyan originated in the grid box 155-160 East and 5-10 North. A fair distance from the grid box where the weak SST anomalies highlighted in the SMH article were supposed to cause the Typhoon to form.
Note also that the storm moved westwards to near 145 East before the windspeeds attracted attention and the Typhoon was reported.
At this NOAA site you can make SST anomaly maps for 3 or 4 day periods and personally I am not seeing SST anomalies that stand out as being exceptional in late October – early November.
I have been looking for an animation of the jet streams in that region, no luck so far. I thought this page was interesting discussing the Madden-Julian oscillation.
They obviously don’t read Bob Tisdale …
Warwick
It is not about skin ocean temperature – it is about ocean temperature in depth (oceanic heat content). Greg Laden has a good description on his web site. There are anomalous positive OHC values in the region, and this trend towards higher OHC has been evident for a number of decades.
I quickly googled a couple of examples off the web
onlinelibrary.wiley.com/doi/10.1034/j.1600-0870.1996.t01-1-00010.x/pdf
www.apl.washington.edu/project/project.php?id=typhoons
onlinelibrary.wiley.com/doi/10.1002/grl.50096/abstract
For most (though not necessarily all) intense typhoons the top 100m of the ocean is the correct metric to be looking for.
One individual severe typhoon is NOT an indicator of AGW. A typhoon reaching MPI (maximum potential intensity) is a function of many factors, including wind shear and mid level moisture. It is true to say, however, that OHC in this region has increased significantly over recent decades, and this region has some of the strongest markers for global warming.
George
George, Greg Laden has been described as an undergraduate kid who has no understanding of basics science (or engineering science such as heat transfer or fluid dynamics) . No one should take notice of known alarmists who lack technical understanding.
The radiation from the sun warms the ocean surface to a very small depth. Evaporation makes up over 95% of the heat transfer from the surface to the atmosphere.
If you have a swimming pool you could measure the heat in and the evaporation. I have a floating thermometer and found the surface temperature with the pool blanket on to be upto 50C in the top 50 mm while 300 mm down the temperature was less than 20C. Take the pool blanket off and temperature in the top 50-100mm is more like 25C due to evaporation. Pool blankets are useful to prevent evaporation and extend the season. At night the sun does not heat so reduced evaporation and there is some radiation to space. So leaving the blanket off in the evening can be used to control the pool temperature from becoming too hot.
This www.co2science.org/subject/s/summaries/stormsna.php gives some information on trends of storms over the last 50 to 100 years. No where has there been an increase with suppose temperature increase.
Cementafriend
Your personal opinion of Greg Laden is irrelevant – his post (for the most part) contains valid commentary using well established scientific principles that have been validated by observations.
Did you look at the Jangmi et al wake data that I referenced above?
You analogy with swimming pool, whereby heating only impacts the top 50 to 300mm under a pool blanket with no wave or wind impacts, does not map to the real world where breaking waves, currents and eddy effects are mixing the surface layers downwards.
Finally, it is well understood in the tropical community that there has been no observable trend in tropical cyclone maximum intensity. This is not surprising in that the vast majority of system never achieve their maximum potential intensity (MPI) in the first place due to other factors such as wind shear, mid level moisture deficit, and transition over land.
However it is a relatively simple calculation to show that MPI, in the absence of other factors, will be higher if oceanic heat content increases. It may be, in a warmer world, that these other factors make achieving MPI less likely.
George, that link to a Bob Tisdale Post in comment 1 looks at the difference (anomalies) at different depths, showing why people like Laden cherry pick to achieve their agendas. Bob Tisdale shows there is little change in OHC of the area in question.
.. A third attempt at posting .. perhaps my comments are being moderated?
If you read the references I provide you’ll see why 100m of OHC is the sweet spot. It indicates a deeper thermocline. That is – the water is the same temperature as per normal in the top 50m, but the next 25 to 50m are warmer than normal.
Severe typhoons generally overturn the top 100m of the ocean – see the observed impacts of Typhoon Fanapi in the references I provided.
Cement’s reference to water in a pool only warming the top 50 to 300mm is inappropriate – wave action and eddy currents mix the ocean down to the thermocline – far different to the environment in your backyard pool.
This is all (reasonably well) understood and observed science.
The note about moderation being enabled is just code for the anti-spam setup to be operating. If it was not then comments would be swamped by idiot spam.
I rarely check the spam list after 6.30pm EST – so if a comment gets picked up by the anti-spam whatsit – it could sit for 12 hrs till I tick it for release.
Just now spam is not too bad but comes in waves – was hundreds a day earlier this year.
Sometimes my own comments can get picked up by the a-s.
Over 3 links in a comment means it is almost certain to trigger a-s.
Re the Typhoon – the post was about the origins – when windspeed had not built much. I doubt conditions at 100m have any impact then. I am interested in what triggers the cyclonic storm – not what happens when it is a cs.
I suspect the influence of jetstream perturbations but have not found an animation for that region & period.
If increasing OHC is causing increased pacific cyclone activity we should see it in the ACE index.
Pacific ACE ranked by intensity at the link below. No year 2000 or later is in the top 10 years.
Pretty conclusive I’d say that whatever OHC is doing cyclone activity isn’t increasing.
en.wikipedia.org/wiki/Accumulated_cyclone_energy
It seems obvious that an increase in stronger cyclones results from fewer cyclones developing. More OHC available to the smaller number of cyclones. The important question is, why are we seeing fewer cyclones?
Warwick, I am not an expert on cyclones but do know of an Australian Professor (George Walker) who had much to do with establishing the Cyclone Testing Station at James Cook University (www.jcu.edu.au/cts/research) and has been involved in identifying the paths and damage of cyclones. Two things are clear with Cyclones, Hurricanes and Typhoons. They are associated with a zone of low pressure and with water vapor. For the latter, these weather events start over water and dissipate over land. More evaporation occurs at low pressure at any ocean surface temperature. Dr Anstassia Makarieva (see here www.bioticregulation.ru/contacts.php and then click publications)has proposed with Dr Gorshkov that condensation of water vapor will lead to reduced pressures so feeding cyclone/hurricane strength. They dissipate because they lose energy over land and are no longer fed with evaporated water (unless the surface is covered with water from floods)
I think you are right about jetstream perturbations. These come about through the mixing of cold and warm air streams. In USA Tornados (strong Willi Willis in Australia) result from the mixing of cold air streams coming south from Canada and warm air moving north from the Gulf. It is possible that the Great Lakes help to feed some of the more severe ones.
The SOI (Southern Oscillations Index)which is calculated from pressure differences between Tahiti and Darwin, can be positive or negative. This shows changes in the stability of air flows near the equator. Records for SOI go back to 1876. Articles have been written associating positive SOI with higher rainfall on Australia’s north east coast (Qld to NSW north coast) ie where cyclones can make landfall. There is no evidence of a change to ENSO with changes to the level of CO2 or supposed surface temperature increases. One of the largest floods in the Brisbane area was in 1893 when a cyclone crossed the coast in the vicinity of the Sunshine Coast.
There is no evidence that cyclones are getting stronger. Cyclone Yasi was no where near as strong as some past cyclones (eg the 1974 cyclone which hit Darwin, note Brisbane also had floods that year)but the evidence showed it was one of the widest (which is related to lower intensity) and so wide spread damage occurred.
There have been many more severe Typhoons/cyclones/hurricanes than the recent one in the Philippines.
Philip
You introduced a strawman argument that you then proceeded to demolish. Where in this thread did anyone suggest that increasing OHC had lead to an increase in Pacific cyclone activity?
In other news, the answer to your question depends on location/seasons. That is, in some areas/season it is due to increased wind shear, other times to a lack of high amplitude MJO forcing.
Warwick
There is nothing overly special about Haiyans genesis – why would you expect to see a marker inn SSTs? Initially the storm in feed would have sampled warmer than average SSTs, but that is not a determinant for its final intensity.
Cementafriend.
Best wishes. Nothing I write will change your mind.
George
George –
Re: There is nothing overly special about Haiyans genesis – why would you expect to see a marker inn SSTs?
Answer: The suggestion is not Warwick’s but comes from the article he criticises, where it says:
George Bailley, I take note of people that I have met and have judged to be experts in their field. Dr George Walker is an expert in earthquakes (prepared a report on the Christchurch NZ earthquakes) and in cyclones (prepared a report on the path and damage caused by the recent cyclone Yasi Queensland). Warwick had some interesting seismic records about the Christchurch earthquake. I visited Christchurch just after the first Sept quake, and then again a little later after the large Feb. quake which killed so many people. I discussed that with George Walker. I also discussed cyclones with him after Yasi. As a fellow engineer I respect his knowledge see here (www.jcu.edu.au/cts/existing-content/public/groups/everyone/documents/advice/jcuprd-045615.pdf and note the words “It attracted a young New Zealand engineer working in the United Kingdom in
the nuclear power industry who had a PhD in earthquake engineering. The new staff member
was George Walker. He never got interested in rock mechanics, but in due course the
appointment was also to prove significant in the establishment of the Cyclone Testing Station.” )
On technical topics, particularly those involving engineering subjects, (cyclones involve heat transfer and fluid dynamics) I do not accept the word or writings of people I assess as a) having no qualifications in the related subject particularly where it involves engineering science b) having no practical experience in the related subject c) refer to so-called higher authority such as the IPCC d)refer to work that I judge to be wrong, incomplete, incompetent or taken out of context.
You have used the word “forcing” which makes me doubtful of your knowledge. In engineering a force is defined as mass times acceleration. So-called climate scientists, who have little understanding of engineering science, have misused the word to describe actions or output/input from things like cloud cover, CO2 in the atmosphere, volcanic activity etc without considering units or dimensions (Newton =(kg.m)/s2). Non-engineers appear to know nothing of dimensionless numbers such as the Reynolds Number used in fluid dynamics or the Nusselt Number used in heat transfer.
David
The statement in the article is correct. Water was warmer than normal in the genesis area. That’s not overly special. It may have made genesis more likely. However the determining factor in Haiayan’s final intensity was the large OHC that it could access near the Philippines.
No-one has pointed out any factual errors in the article.
Cementafriend.
Best wishes again. Nothing I write will change your mind.
George
George Bailley, I think you have not read your own references. Your 2nd reference and the Journal Article by D’Asaro et al 2011 has “The warm ocean water that energizes typhoons is only a thin layer on top of a deep, cold ocean. The typhoon’s winds and waves mix these layers, churning the cold water to the surface. After the storm runs over the array of instruments you can see this cold wake has formed and it’s a pretty dramatic feature. It is about 26.5 degrees … so about 2.5 to 3 degrees cooler than the sea surface temperature was before.” The article says that mixing of water to a possible depth of 100m is the consequence of a Cyclone or Typhoon not the cause. This paragraph supports my observation that the evaporation occurs from a very thin layer at the surface of the ocean. On a clear day with little wind the water surface temperature can get to over 30C in the top 50mm. That already has considerable evaporation from natural convection (I suggest you look at some Psychrometric data in texts such as Perry’s Chemical Engineering Handbook). Then impose a low pressure cell say 98Pa with upper cold air which condenses the water vapor. The condensation causes a lowering of pressure while the energy released by the condensation increases wind velocities allowing a core vortex to form. Lowering of pressure increases evaporation of warm water at the surface and feeds the cyclone/typhoon. Severe storms can have core pressures as low as 91kPa. The colder wake,mixing of water behind the storms, and ocean heat below the thin surface layer have nothing to do with peak wind velocities and storm water surge (which do all the physical damage.
Hi Cementafriend
The mixing occurs during the cyclone passage – as well as after the cyclone – remember there are 10 to 20m waves in the eyewall. If there is a shallow thermocline then cooler water will be mixed up very quickly.
Breaking waves and extreme winds turn the top layers of the ocean into a foaming mass. Mariners report that it is hard to tell where the ocean stops and the atmosphere begins!
So in shallow thermocline regions a key input (warm SSTs) to storm dynamics is impaired.
However, I am convinced that nothing I say will change your mind. Never the less – best wishes once more!
George
George,
Full marks for good manners, but if you are going to persuade us, you must first address the points we are making.
Warwick’s point was that the article insinuated that global warming was behind Haiyan based on inadequate evidence; in particular, on the fact that temperatures were 0.5 to 1 degree warmer than normal where Haiyan formed. Warwick pointed out that the origin of Haiyan did not seem to coincide with the warm pool shown on the map in the article, which was nothing special anyway.
Your first point of criticism of Warwick was that:
It is not about skin ocean temperature – it is about ocean temperature in depth (oceanic heat content). Greg Laden has a good description on his web site. There are anomalous positive OHC values in the region, and this trend towards higher OHC has been evident for a number of decades.
Well, maybe, but ocean heat content (OHC) is not what the article talked about. Instead it provided a map and numerous statements about sea surface temperatures. This was what Warwick had criticized.
Then Philip pointed out that in any case increasing OHC has not led to increased total cyclone energy. For this you hit him with:
You introduced a strawman argument that you then proceeded to demolish. Where in this thread did anyone suggest that increasing OHC had lead to an increase in Pacific cyclone activity?
Well, actually you introduced the “strawman argument” about increasing OHC (see your first quote above and your statement that “maximum potential intensity (MPI) … in the absence of other factors, will be higher if oceanic heat content increases.”) Philip only flagged that “whatever OHC is doing cyclone activity isn’t increasing”, a valid point.
You then hit Warwick with:
There is nothing overly special about Haiyans genesis – why would you expect to see a marker inn SSTs?
But Warwick never said he expected to see a marker in SSTs, and never asserted that there was anything special about Haiyan’s genesis – in fact, quite the opposite, he said there was nothing special about it, and in particular, no marker in the SSTs.
When I pointed out to you that it was not Warwick but the article itself that advanced the 0.5 to 1 degree warm anomaly as an explanation for Haiyan, you replied:
The statement in the article is correct….No-one has pointed out any factual errors in the article.
But I had not said the statement in the article was incorrect – although it may well be, as Warwick pointed out on the map. All I had said was that it was the article, and not Warwick, that had promoted warm sea surface temperature as a cause of Haiyan.
Warwick’s original points remain. There was nothing unusual about sea surface temperature at Haiyan’s origin; it was probably not even the trivial 0.5 to 1 degree warmer than usual suggested in the article; and the insinuations in the article that global warming is to blame for Haiyan are bunk.
Hi David
Nice try! You write that “.. if you are going to persuade us, you must first address the points we are making.”
Not at all. I am convinced that a particular cohort within the community will not change their minds, no matter how strong the evidence is, and I’m sure I’m not going to be able to persuade them otherwise. The facts are (for the most part) well established and if people choose not to believe then so be it.
IMHO the article is surprisingly well written for a “lay article”, with perhaps my only criticism that it doesn’t cover OHC and uses SST as a proxy.
Note that Warwick states “where the weak SST anomalies highlighted in the SMH article were supposed to cause the Typhoon to form”. Where does the article say that SSTs anomalies caused the typhoon to form?
On your first point, the bulk of the article was about the maximum intensity of Haiyan. NB the first line “Extreme storm events such as super typhoon Haiyan, which wreaked havoc in the Philippines on Friday, are more likely in the future as the build-up of greenhouse gases warms the planet, scientists say.” The extremeness of typhoons is not dictated by SST but by OHC. I corrected the article – not Warwick.
You seem pretty clued up and are probably aware that your second point was a real stretch – so lets just take that as given.
Finally, on your third and fourth points – I can’t see what your problem is. Where does the article say that the warmer than normal SSTs caused the typhoon to form? It makes a factually correct statement. Mind you, I’d strongly expect that SSTs anomalies of +1 degree would make formation far more likely that SSTs anomalies of -1 degree but the article merely points out that SSTs were warmer than normal at formation.
However, my apologies to you if you thought I was asserting that you believed the article to be incorrect.
Your final sentence is both amusing and sad. After all that has been said and demonstrated – if that is all you have to take away this – then I can only wish you the best of luck in the future.