Talk:Tropical cyclone/Archive 2

Catarina

Some anon is on some crusade to change all mentions of Cyclone Catarina to Hurricane Catarina. Is there some consensus I missed here, and does it matter? --Golbez 03:54, July 16, 2005 (UTC)

I'm confused the Atlantic Hurricane Season isn't defined as just the North Atlantic Basin, or else it would say that. So why havn't they counted the 3 tropical systems in the South Atlantic Basin as part of the North Atlantic Basin. Vince formed in an odd spot, but it has an official name.

World Book basins image

I removed the image again. It was placed on the page (twice) by anon users, and somebody named Rickyboy (no user page) is saying that Cyrius is vandalizing the article by removing it, which, Rickyboy is highly unlikely and an unfair charge considering the amount of work Cyrius does around these topics.

It would be good to have a graphic like this, but not this one if it's copyrighted. DON'T put it back unless you can prove it has no copyright problems. DavidH 08:18, July 18, 2005 (UTC)

Chubasco?

Someone removed the mention about hurricanes being called Chubasco in Mexico. Was this incorrect? AySz88 21:08, July 21, 2005 (UTC)

Rearrangement of article sections

I moved the pieces of this article around so that the sequence of topics (more or less) follows the formation, development/movement and dissipation of a tropical cyclone; I think this order makes more sense when you're reading through the whole article. I also tried to group article sections that discussed similar topics together to help with further editing. Please restore content if I accidentally deleted anything. Kitesailor 17:09, August 4, 2005 (UTC)

Think I'd avoid question headings like "When do storms form?" cause they make it sound like a FAQ. Glad you went for it, but don't be surprised if it gets rearranged again. Personally, I'd like to see the science all come first, and what I consider trivia (how names are chosen, unusual cases, which countries call them wili wili or wiki wiki or whatEVER) come last. DavidH 03:47, August 5, 2005 (UTC)

Coriolis effect

The article says

The earth's rotation also imparts a force (termed the Coriolis Force or Coriolis Effect). This force causes cyclonic systems to move toward the earth's poles in the absence of strong steering currents. Thus, tropical cyclones in the Northern Hemisphere are deflected toward the north pole, cyclones in the Southern Hemisphere are deflected toward the South Pole, if no strong pressure systems are counteracting the Coriolis Force.

I thought the Coriolis force on a moving object depended on the direction of movement, besides which hemisphere it is on. Am I missing something?

Do you mean whether a storm is moving westward or eastward, or whether the rotation of the storm is clockwise or counterclockwise? I know one thing, the Coriolis effect is difficult to explain briefly; see the ongoing discussion at talk:coriolis effect. In light of the disagreements about simple explanations, we may want to gloss over (in a helpful way) this whole question and say something like, "in the absense of steering currents, a complex interaction of forces affects rotating systems, including tropical cyclones, imparting a motion toward the poles." Just to avoid having the same problems they are having in the Coriolis article. Best, I suppose, would be some succinct explanation from a weather textbook or NOAA hurricane article. Glad to hear your suggestions. DavidH 22:01, August 6, 2005 (UTC)

The forementioned is a side effect of Coriolis forcing: The Coriolis forcing is latitude depending, i.e., it is almost exactly proportional to the sinus of latitude. This leads to the effect that winds of a large rotating system, such as a hurricane, are more strongly deflected to the right (N hemisphere) or left, respectively, at their poleward side. As a result the system is altogether steered into the direction of the pole.

Chubasco not a hurricane

A chubasco is not a hurricane in México -or anywhere as far as I know. It is a squall or sudden downpour. It's usually very windy and fast-moving. It can happen anywhere, but it is nothing like to a hurricane when near a shore. A hurricane is a huracán.

• Chubasco is effectively a windy storm, but not always is related with hurricanes. I know it, I'm from Mexico. juan andrés 06:16, 6 February 2006 (UTC)

A question

Who thought of nuking a hurricane, and why exactly would it not work? That's one of the bizarrest things I've ever come across at wikipedia

I don't know who thought of it, but the basic reason why it won't work is that nuclear weapons aren't powerful enough. From http://www.aoml.noaa.gov/hrd/tcfaq/C5c.html :

"Now for a more rigorous scientific explanation of why this would not be an effective hurricane modification technique. The main difficulty with using explosives to modify hurricanes is the amount of energy required. A fully developed hurricane can release heat energy at a rate of 5 to 20x10^13 watts and converts less than 10% of the heat into the mechanical energy of the wind. The heat release is equivalent to a 10-megaton nuclear bomb exploding every 20 minutes. According to the 1993 World Almanac, the entire human race used energy at a rate of 10^13 watts in 1990, a rate less than 20% of the power of a hurricane."

Even if it were feasible, the sheer amount of radioactive fallout produced by such an attempt would be a huge problem, especially considering that you'd be throwing it into the middle of a giant storm that is going to scatter it over a very large area. Colin M. 10:59, 29 August 2005 (UTC)

>>>>>>>>>>>>>>>>>>>>>>>>>>>

According a humble opinion as my: Those terrible large energies produced by our only source of energies on this planet the sun rays radiation. We using just a very small amount of energy radiation which falling on each and every sq. inch on earth.

Just the energy in the sun radiation may change the amount/direction of those terrible energies which is its product!

Mitigate energies accumulated in hurricane just an UTOPIA in our time, and according to today science/developing level.

I repeate in our time and science developing level.

If an Einstein will raise to change our vision for energies?

[hanatomy@012.net.il]

Text from katrina on global warming

Someone keeps inserting stuff like

Some scientists and critics have stated that global warming was responsible for the raise in ocean surface temperatures that caused Katrina to go from a tropical storm to a devastating hurricane as it crossed the Gulf of Mexico between south Florida and New Orleans.[1][2] "There's no question that the warm waters of the Gulf provided the heat that turned Katrina into a major storm," said Ross Gelbspan, a Pulitzer Prize-winning reporter and author of books on global warming. [3] Other scientists acknowledge the possible long term effects of global warming on cyclonogenisis, but attribute the strength of Hurricane Katrina to a 12 year cycle. [4] [5]

Into hurricane katrina. Info on the formation and powering of hurricanes doesn't belong there.. If this is worth while, can someone merge it here? 24.165.233.150 04:00, 3 September 2005 (UTC)

Orkan "Lothar"

What was the storm with an eye that ravaged Germany, France, and the UK? Many sites call it Orkan (Hurricane) Lothar and its power was similar to a Category 1-2 hurricane. Does this phenomenon have any relation to hurricanes?

I'm trying to find more information on it, but based on its date (December 26), it's not likely a tropical storm. According to this PDF, it was an extratropical storm. It may warrant mention, however, both on extratropical cyclone and our section on extratropical storms here, since it's commonly referred to as a "hurricane" (But it's not). That PDF has a satellite image on it, and it has the trademark comma shape of an extratropical storm. --Golbez 00:17, September 4, 2005 (UTC)

Orkan in German seems to refer to any storm with wind speeds exceeding 117 km/h, corresponding to 12 on the Beaufort scale and therefore to a hurricane. But a true hurricane (a tropical cyclone in the North Atlantic) is called Hurrikan in German. Basically, an Orkan can hit Germany, but a Hurrikan/hurricane can't. I don't know if there is a good translation for Orkan in English. "Hurricane-strength windstorm", maybe? --Angr/_{tɔk tə mi} 19:28, 6 September 2005 (UTC)

European windstorm seems to be the English for Orkan. --Angr/_{tɔk tə mi} 19:33, 6 September 2005 (UTC)

Power

There is a comment above about power, which was never really resoled, as far as I can see.

I've removed: The average hurricane contains a massive amount of power, from 10EXP+15 to 10EXP+17 Watts of energy for every second it is alive from the intro, and This is two hundred times the total rate of human electrical production, and is equivalent to detonating a 10-megaton nuclear bomb every 20 minutes. from effects.

The second doesn't obviously belong in effects and (as pointed out above) doesn't look consistent with other figures.

Besides which, a glance at the NOAA page http://www.noaa.gov/questions/question_082900.html shows that the energy use question is rather more nuanced that these figures show.

William M. Connolley 12:21:01, 2005-09-04 (UTC)

Naming Map

The term used to describe tropical cyclones with maximum sustained winds exceeding 33 meters per second (63 knots, 73 mph, or 117 km/h) depends on the region:

* hurricane in the North Atlantic Ocean, North Pacific Ocean
east of the dateline, and the South Pacific Ocean east of 160°E,
and unofficially in the South Atlantic Ocean
* typhoon in the Northwest Pacific Ocean west of the dateline
* severe tropical cyclone in the Southwest Pacific Ocean
west of 160°E or Southeast Indian Ocean east of 90°E
* severe cyclonic storm in the North Indian Ocean
* tropical cyclone in the Southwest Indian Ocean

Maybe somebody could create a world map that shows what it's called in different areas, visually.--Sonjaaa 16:04, September 5, 2005 (UTC)

GW bit.

I'm going to hack this section. I've removed:

Some in the media have stated that global warming was responsible for the raise in ocean surface temperatures that have caused an increase in the number of intense tropical storms in the atlantic.[4] "There's no question that the warm waters of the Gulf provided the heat that turned Katrina into a major storm," said Ross Gelbspan, a Pulitzer Prize-winning reporter and author of books on global warming.

This is a non-sequitor. Note that the RG quote says nothing about GW, only warm waters. Even if it said GW caused warm waters, it still wouldn't address the first sentence, which is about the *number* of storms.

I also revised the intro somewhat. The intro said, we can't attribute them to GW so we attribute them to natural cycles. This is wrong, logically. You can neither attribute them to GW nor to natural cycles. Also, ftp://texmex.mit.edu/pub/emanuel/PAPERS/NATURE03906.pdf is an online publically available PDF. William M. Connolley 19:28:20, 2005-09-05 (UTC).

Teriffic, ... I'd inserted that section although I regarded it as crap... it was derrived from one of the many examples that people keep sticking into Hurricane Katrina. The media is doing a pretty good job as usual of misrepresenting the issue to the public. I made a couple of changes to the changed text to further reflect that SST changes may have been caused by many factors, including known and poorly understood ones... I think it needs to be made more clear that Kerry Emanuel's paper isn't really telling us anything new, most of the existing hurricane prediction is based on models where SST drives the storm. The SST->intensity link is a great big duh, and it would have been shocking only if it concluded otherwise. But the news is aparently reporting it like it is a big deal, so we need to take a little more care in our text to clear that misconception. --24.165.233.150 20:26, 5 September 2005 (UTC)

I have to disagree with that: Emanuels work *is* a new thing (or it wouldn't be in Nature, it wouldn't have caused the fuss it has, amongst climatologists as well as the press). I may have been a bit hasty though and mixed your edit into those by the other anon, which I rather disliked. I've essentially removed the edits by the other anon: stuff like KE "alleges" is quite inappropriate language for the conclusions of a paper in Nature. William M. Connolley 08:40:43, 2005-09-06 (UTC)

Twas I that stated that Emanuels conclusions on SST being related to strength were not new, but it doesn't appear that KE would disagree. The existing models for hurricane strength estimate energy gain by, in large integrating energy gained across the path as a function of temperature ratios. KE's only strong conclusion is that SST is related to central pressure and probably wind-speed. A couple of news articles have gone on to imply that this somehow meant that global warming caused Katrina. It looks like Kerry Emanuel is pretty unhappy about that himself, check out the FAQ on his site [6]. For the record, I'm not the anon in question that added "alleges", .. I can't find the versions with that... But I do feel somewhat guilty for the crufting over here, as I've been punting people who are trying to insert global warming theories into Hurricane katrina over here, where there are editors like you who give a hoot about scientific accuracy... --24.165.233.150 01:38, 7 September 2005 (UTC)

I dislike the NOAA quote: The U.S. National Oceanic and Atmospheric Administration says in their Hurricane FAQ that "it is highly unlikely that global warming has (or will) contribute to a drastic change in the number or intensity of hurricanes."[7] and this reflects existing consensus.. This is a strawman: its like saying "climatologists say that GW will not cause a runaway greenhouse effect". A more interesting Q is "has GW contributed to a change in the intensity of hurricanes"? and NOAA is silent on this. Because of that, I don't like the NOAA para leading this section. William M. Connolley 16:16:52, 2005-09-07 (UTC).

NOAA is also a government agency, under an administration that global warming proponents accuse of trying to suppress scientific evidence of global warming in general. Presenting their official conclusion as the final word on the issue seems a bit POV to me. 68.47.234.131 10:54, 1 February 2006 (UTC)

User:Fredhutter removed parts saying "recent abstracts disagree; nothing noticable 'til after 2050; rv unfounded speculation"

I presume this is from reading Emanuel FAQ [8] If you read the FAQ carefully I think it is saying if you only examine US landfall damage which represents just .2% of the data for hurricanes then you will be unable to detect a change until 2050. The trend would still be there but it would be hidden by random noise. If you examine all the data you can already notice that something is probably happening.

So I am going to put back what was removed. However, it may also be appropriate to put something to the effect that number of people living in susceptible coastal areas and building regulations play a much bigger part in damage trends than global warming. crandles 18:55, 8 September 2005 (UTC)

Pretty soon, all bad weather will be connected to GW, which is becoming almost a new religion. Anthropocentric view of nature. When patterns are cyclical, of course news outlets (and publicity seeking scientists) will get all excited when the roller coaster (cyclic) approaches the heigher level again. "In one, Steve Gray, an Arizona-based research associate with the U.S. Geological Survey, led a team that tracked the weather cycles backward by studying ancient tree rings from Europe and the southern United States. Healthy weather produced wide tree rings. Drought or other trauma caused narrow rings. The climate cycles kept repeating. "It's been working in the same way for at least five centuries or so," said Gray, whose study was published last year." http://www.sptimes.com/2005/09/13/Worldandnation/Storm_frenzy_is_not_a.shtml 84.190.231.9 20:36, 21 September 2005 (UTC)

NPOV section notice

Lets compare this: "virtually all climatologists seem to agree that a single storm or even a single season cannot clearly be attributed to a single cause such as global warming or natural variation" "This consenus is now questioned ... Kerry Emanuel", with Kerry Emanuel's FAQ on the subject: "it would be absurd to attribute the Katrina disaster to global warming". Previously this statement and the FAQ were linked from this section... Also, the language of the entire section has been weakened to the point of making it in ccurate through the insertion of 'some' and other such terms without justification. Finally, the insertion of political related claims about global warming coverups has no place in an article discussing the mechnisms of tropical cyclones. ... Taken as a whole, frankly, the entire section now just looks like POV pushing nonsense.

I have no clue how to fix it other than reverting it wholesale to a previous version which did not have these problems. I would prefer not to do this without some level of consensus, but I would fully support it if someone else also thinks it is the right action. I'm going to leave the standing version alone for a while, with NPOV tag attached, to allow others to make a pass at fixing it. If it isn't improved then I'll come back around and revert it to an older version and make an attempt to merge in whatever I can that doesn't look too POV pushing. --Gmaxwell 22:09, 8 September 2005 (UTC)

I see User:Golbez has already started working on it. Thank you! --Gmaxwell 22:12, 8 September 2005 (UTC)

There seems to be an issue with local POV, at least for some users. I fixed Ylai's edits, which were meant to solve this issue but sounded a bit contrived. I hope this is fine by him/her and whoever else is striving for NPOV. -Parallel or Together? 07:33, 9 September 2005 (UTC)

I don't see the current section as any better (well, in fact worse) than the last by me. My preference would be to revert to that. OTOH I don't see the current version as deserving the NPOV header. does anyone still want it? William M. Connolley 18:55:16, 2005-09-09 (UTC).

The person who added it thanked me for my good work, so I'll be bold and remove it. If you still want it, GMaxwell, just pipe up. --Golbez 19:11, September 9, 2005 (UTC)

Energy source quibbles

The article says:

In order to continue to drive its heat engine, a tropical cyclone must remain over warm water, which provides the atmospheric moisture needed. The evaporation of this moisture is driven by the high winds and reduced atmospheric pressure present in the storm, resulting in a sustaining cycle. As a result, when a tropical cyclone passes over land, its strength will diminish rapidly.

I consider the bit in bold dodgy. and reduced atmospheric pressure looks completely bogus to me. But also the driven by high winds bit I doubt: I think that the hurricanes feed on the pre-existing atmos structure: there is no time *during* the storm to re-evap more energy. They die over land because the pre-existing atmos structure has less moisture. Or so I think, but didn't feel sufficiently confident to edit. William M. Connolley 18:58:50, 2005-09-06 (UTC).

*rerail* There's a very long and detailed heat engine analogy here. In it, it says "...assuming optimum conditions still prevail..., the feedback process between the release of latent heat, decreasing air pressure at the surface, and increasing surface winds will ultimately upgrade sustained wind speeds to 119 km/hr (74 mph)." However, it doesn't seem to me that it provides details as to why those things increase evaporation. AySz88^-^ 02:23, 25 September 2005 (UTC)

The article [Formation, 1] says that a water temperature of over 26.5 degrees C. to a depth of 50 meters is warm enough to generate a hurricane.

Is there data available on normal surface temperatures of the Gulf of Mexico, or the Atlantic off of the U.S. Coast during the hurricane season and the high and low temperature temperature differentials during major and minor hurricanes? And world-wide too. [User:Ray Marshall ]23:30, 2005-09-23 (UTC).

Here is a NOAA Chart taken from the BBC that implies that the water temperature range is quite small. Over 60 years (1944-2004) it appears to be only a degree difference in average annual temperature high and low. "Sea Surface Temperatures"

http://news.bbc.co.uk/2/hi/science/nature/4276242.stm Last Updated: Friday, 23 September 2005, 16:21 GMT 17:21 UK Hurricanes and Global Warming -- a Link? Analysis by Richard Black Environmental Correspondent, BBC News website [User:Ray Marshall ]02:00, 2005-09-25 (UTC).

Etymology

What do these words mean? Is there a translation of the Arabic Tufon?

The English version, maybe. But definitely not the Chinese version. According to this acount at http://photino.cwb.gov.tw/rdcweb/lib/cd/cd02tyrp/cd_00002.htm, we have the following quote:

颱風是威脅臺灣最嚴重之自然災害之一….. 颱風一詞由來甚久，根據(周1992)臺灣風雨歲月中之記述，早年因鄭和七次下西洋明永樂三年至宣德五年(1405-1430)經歷之引述，導致阿拉伯航海者選用阿拉伯語tufan (旋轉) 一詞表示颱風現象，至明萬曆年間(約公元1588) 始有英文touffon， 至清嘉慶二十四年(1819) ，現用之typhoon一詞才出現。至於中文颱字最早出現於清康熙二十四年 (1685)編撰之「臺灣記略」及康熙三十三年之「臺灣府志」中，颱風一詞據林紹豪教授的考據，是為閩南語「風篩」演變而來，且早在宋(960-1278)、元(1260-1341)兩代之時，風癡 (或癡風)一詞即已被華南華東航海者普遍使用(按：癡、呆、篩、臺及颱字在閩南方言發音均近似)。

This means the Chinese record for the word 颱風 (typhoon) already appeared in 1685. Moreover, in the local dialect, the word order was reversed (hong-thai), which is indicative that it has a pre-sinitic origin where the word order was Austronesian-like. This evidence must be taken into account. And as the website points out, the origin of the Chinese term probably goes back to the 10th century, when no Europeans were in the East.

Not to mention that it's the least interesting part of the article, a lurch into linguistic trivia when we should be getting to the meat of the science, IMHO. I'd like to see the whole section cut or at least moved to the bottom. DavidH 06:50, 22 January 2006 (UTC)

I think it's probably fine in length, it's fairly short, and can probably be even shorter if we whittled the entymology down to only the verified bits. Can be moved down though. --AySz88^-^ 16:58, 22 January 2006 (UTC)

Done. DavidH 17:53, 20 March 2006 (UTC)

Faroese Christmas Storm of 1988

In late December 1988 the Faroe Islands experienced the most powerful storm ever recorded here. As far as I remember, the gusts were up to 277 km/h and at that time many of the wind measurers couldn't withstand the winds and simply fell over. If anyone wants to add this storm, which in terms of wind speeds should be a category 5 (or 4?) hurricane, you could probably get the info needed from the Danish weather service Dansk Meterologisk Institut: www.dmi.dk Mulder1982 04:21, 24 September 2005 (UTC)

Questions about mechanism

In the section "Definition: a heat engine", the caption to the image is oversimplified.

"The air heats up, rising further, which leads to more condensation" is just wrong. Once the air heats up, there will be absolutely no more condensation of water from _that_ air. Any water vapor remaining will _not_ condense. Later in the text of the section, we see that what actually happens is water vapor evaporates from the warm ocean surface into the packet of denser air which displaced the warmer less dense air. Then this newly evaporated water condenses and heats the packet which expands and gets displaced upward by another packet of cooler denser air. There are two sources of energy here: heat from the warm ocean, and the gravitational potential energy of cooler air which has not (yet) been warmed by condensation of water vapor from the warm ocean.

The heat energy from the ocean gets transmitted to the air not by diffusion of heat, but by evaporation of water which forms cool water vapor. The water vapor mixes with air near the ocean surface. After a while it condenses (why? Maybe nucleation by dust?), heating the air.

I think an important point which is not mentioned anywhere in the article is Dalton's law of partial pressure. When water condenses, the total pressure in the air packet drops because the partial pressure of water dropped. The temperature of the remaining gas increases, increasing the pressure. How does this balance out? I guess the net change is a decrease in pressure, considering that the total pressure drops as hurricane intensity increases.

(I guess this must be an important well known fact of meterology, but I personally never made the connection until very recently between condensation of water leading to lower partial pressure of water vapor vs. the decrease in atmospheric pressure associated with storms. If there is a section of an article which discusses this, it should be linked to from the hurricane article.)

The gas density decreases: less water and higher temperature. Gravity causes the packet of air to rise: the total gravitational potential energy is lower when heavier objects displace lighter objects.

Where does the condensed water go? I guess it's obvious that it falls as rain, but the article doesn't come out and say this.

What is different about the eye? What causes the eye? What is the humidity in the eye? I guess since it isn't raining there, the humidity is probably low, which also agrees with low pressure, but surely someone has measured it?

--

I think there ought to be a recitation of the facts about a hurricane and then an explanation of how physical theory explains these facts. Maybe the explanation would be in other articles. (I haven't gone looking for articles about displacement of lighter air by heavier air, etc.)

I thought of this approach when I recognized that I know the pressure in the eye is lowest, that the pressure increases if the hurricane moves over colder water, that it isn't raining in the eye and winds are calm, that it is raining and winds are very high outside the eye wall.

I explain these facts and predict that humidity in the eye must be low: Originally water condensed, heated the air, the hot air was displaced by denser cold air, more air started moving inward but the Coriolis effect (how do I link to the "Flow around a low pressure area" section?) prevented more cold air from reaching the eye. Hence the eye must be dry and warm: the air there was warmed by condensation of water which fell into the ocean, but the Coriolis effect prevented displacement by cooler air so the warm dry air did not rise but stayed in place. Evaporation from the ocean surface will increase humidity in the layer of air just above the surface, but due to the lack of turbulence in the eye, that humid air will stay in place and the higher air will remain dry because diffusion is much slower than convection. (Those are my predictions: I don't know for a fact that the humidity in the eye is low or that the temperature is high, and I didn't calculate diffusion rates or anything else).

--

Reading the remark above (Energy Source Quibbles), yes, reduced atmospheric pressure doesn't cause evaporation. It's reduced partial pressure of water caused by condensation which would permit evaporation. Suggest changing the wording to reflect this.

Or actually, evaporation and condensation both occur at the ocean surface. The rate of evaporation will depend on ocean temperature, the rate of condensation on the partial pressure of water in the nearby air.

The effect of high winds on evaporation: yes, winds do increase the rate of evaporation, because they move the packet of air into which water evaporated away from the surface and replace it with a packet with lower partial pressure of water. But the article ought to say this more explicitly.

-- 10:14, 24 September 2005 (UTC)

rare hurricanes

However, it is possible for tropical cyclones to form within this boundary if another source of initial rotation is provided. These conditions are extremely rare, and such storms are believed to form at a rate of less than one a century.

Do we have an example of this? 131.111.8.97 13:09, 24 September 2005 (UTC)

Typhoon Vamei. —Cuiviénen (Cuivië) 04:55, 18 February 2006 (UTC)

Etymology (see also Archive 1)

For typhoon roughly two possibilities arise, < Arabic < Greek or < Chinese. This is an unsolved issue, a fact that should be reflected in the text. We are not here to re-write history.

In the article on typhōn is also a bit about etymology. We might want to check the consistency and (perhaps) create a separate article on this. Shinobu 14:24, 26 September 2005 (UTC)

Artificial dissipation

The following sentence was recently added to the "artificial dissipation" section: "A new approach was proposed in 2005 to pinpoint special locations at the correct time to destroy the pattern of a hurricane's eye", with a link to a non-peer-reviewed paper published on GeoCities. I read this paper. The feeling I got from it was that it was mere conjecture and not up to the scientific standards set by the rest of the article. I'm interested in what others think about the inclusion of this paper. (It's not long, not technical, only 5 pages, and a lot of pictures, so it's not a big time investment to read.) My personal opinion is that it should be removed entirely, as it's not been established as a plausible theory and doesn't come from someone notable or reliable in weather matters (whose opinion would be worth discussing in the article). Failing that, it should just be listed as a reference or external link. Colin M. 07:23, 29 September 2005 (UTC)

If I recall, it was on geocities, which pretty much kills any intellectual stock it has. Maybe if he gets it published in Science, but wikipedia is not Science. --Golbez 13:20, 29 September 2005 (UTC)

Hurricanes are a natural disaster phenomenon. "Artificial dissipation" expresses that there’s no hope for humans to influence hurricanes, because of the size of hurricanes. "Weaken the Hurricane" points out that we should pinpoint a very small critical area at a special time to weaken, not destroy, the hurricane to minimize the destruction. If you don’t agree with it, you can certainly argue about it. However, if you argue about the difference of publishing it in Science or GeoCities, then your more concerned with the support rather than the science. Who do you think is an authority at destroying hurricanes? --Luckybeargod 17:14, 29 September 2005 (UTC)

No one. However, we do have science journals who check such things. We can't include every single theory on the web. If and when it gets published, come back to us. --Golbez 17:32, 29 September 2005 (UTC)

We noticed that your problem is with the number 666 (we can't add any crackpot 666 theory - by Golbez); you must know, this number is linked to the Golden Ratio mathematically. If you have a problem with the Golden Ratio, you probably need to go back to elementary school to relearn it. Hurricanes are not totally understood by humans yet, so this section leaves the question of artificial dissipation open. Since humans have no way to compete with Nature's power, the only left for us to do is work on local areas. If you have any suggestions on how to make it work, please argue about that. If you notice anything wrong, you can also argue about that. Otherwise, you're just removing something you don't know and don't understand. --Luckybeargod 20:02, 29 September 2005 (UTC)

This is not the place to add debated theories unless the article itself is about an important debated theory (as in the theory's reach and effects).

But I'll say why I think that the source is at least untrustworthy and possibly just joking.

I am familiar with the "cooler temperature" map but it's not temperature at all, but altimeter readings of ocean currents, though it does show that Rita's strength is very well correlated with the locations of the currents.

By the way, the first picture of a "second eye" in Hurricane Rita is not blue - it's a grey-shaded area of especially intense convection; look at the legend and you'll see that the color beyond red is grey. (The second picture is probably dry air entrainment, but I don't know enough about that to give a complete response, but the only remaining "second eye" map ends up showing no evidence of actual rotation of clouds around the "second eye" that I can see.)

Already, these have demonstrated that the source isn't reliable.

I really doubt that air would follow a logarithmic spiral in the exact same ratio of the Fib spiral; though it could, of course, be some other log spiral; I don't know enough about that. (My calculus textbook derives this as vectors of a hurricane model with vortex k and sink flow q: -1/(2pi(x^2+y^2) + [(qx+ky)i+(qy-kx)j] ) I don't know if some streamline of this would produce a fib-style logarithmic spiral expanding at exactly Phi^4, but I really doubt real hurricanes would follow that exact spiral.)

AySz88^-^ 21:08, 29 September 2005 (UTC)

We noticed you put the "altimeter readings of ocean currents" map on wikipedia. However, we got the image from here. Here is a quote from that site:

"The sea-surface height image shows the warm Loop Current and a near, warm-water eddy known as Eddy Vortex standing 35 centimeters to 60 centimeters higher than the surrounding water, said Leben. In the Gulf, a tight correlation exists between the sea-surface height and the temperature of the waters, said Leben. The higher the sea-surface is above the mean surface height, the deeper the warm water is beneath it. Warmer waters provide more energy to hurricanes, increasing their intensity, he said."

Therefore, it is in essence a "temperature map."

And for your second point, take a look at the index; there's gray at the beginning of the index too... I truly doubt that they would have a square for every color and then a big bar of gray. And gray is not the end of the index, the last color is white; does that mean the borders of the storm are more powerful than the center? Obviously not. In our image, all the colors are original; we did no image retouching except for adding an arrow.

For your third point, we were talking about extremely strong hurricanes that may correlate with the Golden Spiral, for example, Hurricane Gilbert, the strongest hurricane ever measured in the Atlantic. There are many mathematical models of hurricanes, and none of them are perfect in showing the shape of the storms. Otherwise, we would be able to predict and simulate exactly where they would go, which is obviously beyond our technology right now. For example, Rita forced 2.5+ Million people to evacuate Houston, which escaped major damage. The Golden Spiral model helps us to understand why there is only one eye in the hurricane. A simple mind experiment will prove this: an object orbiting around one center in a circular orbit will easily maintain its fixed speed, however, this is not possible in an elliptical orbit. Therefore, breaking the eye of hurricanes into multiple centers is the way for hurricanes to weaken or die.

We hope this will help clear things up, and thank you for your scientific critique. --Luckybeargod 22:20, 29 September 2005 (UTC)

I can confidently say that the grey portion of the bar is indeed part of the spectrum: see the current satellite images of Tropical Storm Stan [9]. If the grey is an area of subsidence as you claim, then Stan would be a thin ring of thunderstorms with the center cleanly cookie-cuttered out and devoid of clouds. A look at the visible satellite [10] confirms this is obviously not the case.

Comparing colors with the Navy site [11] reveals that the grey probably corresponds to cloud tops colder than -80 degrees Celcius.

This is all irrelevant to this Wikipedia article, though. I think we would really need papers published in books, journals, or other scholarly media in order to cite them. If you're the article's author, perhaps submit the article to some source to ensure it has been reviewed for factual content and trustworthiness by experts, since anyone can upload any old made-up thing on Geocities and try to pass it off as fact. AySz88^-^ 19:34, 3 October 2005 (UTC)

Spam

A look at the history shows that someone seems to be repeatedly adding links to "Foxfire Technology" - this appears to be advertising spam. I'm removing all mention of this, as the linked website does not appear to be peer-reviewed and it's a commercial site, please let me know on this discussion page if there are any objections. Dilaudid 10:23, 21 October 2005 (UTC)

Bdutton (talk · contribs · deleted contribs · nuke contribs · logs · filter log · block user · block log) was doing this, I think they've stopped now; please post a note at Wikipedia:Vandalism in progress#RU_Moderate if they start again. It looks like User:Titoxd and I missed some of the links, sorry about that. Zack 17:54, 21 October 2005 (UTC)

Main picture

Just curious, why is Hurricane Catarina the main picture on the screen. In my opinion, it should be Gilbert, Wilma, Katrina, Andrew, something strong and impressive looking. I would even be content with a Linda or a Tip, but I just find it curious that the first picture you see is an extremely rare hurricane that isn't very strong that is seen elsewhere in the article. Hurricanehink 02:42, 9 November 2005 (UTC)

It's a good picture. The old one up there was Ivan from the ISS, which I think is a much better picture. If you can find a good PD visual image of those storms you mention (Maybe Mitch - the pic we have of Mitch is amazing) then please tell us. --Golbez 04:11, 9 November 2005 (UTC)

The Ivan image was too faint; the image of Catarina, on the other hand, is crisp. Furtheremore, Catarina's appearence from space is textbook, and it's a featured picture. --tomf688^{talk} 04:41, 9 November 2005 (UTC)

North Atlantic basin/Vince

The North Atlantic basin section has mention of rare hurricanes hitting Canada. Should there be some mention that the Iberian penninsula was hit by Vince? PK9 22:15, 21 November 2005 (UTC)

Insert non-formatted text here== Retirement of Greek letters ==

The sentence regarding retirement of Greek letters is not consistent with what is said in the 2005 Atlantic Hurricane Season article. I'm not sure which one is correct, but one needs to be changed so that we have internal consistency. PK9 22:18, 21 November 2005 (UTC)

While I think the information on this page (Tropical cyclone) may be correct in the long run, it is much more speculative than the one on the 2005 Atlantic Hurricane Season page, and the latter has a source as well. I will change this page to match the 2005 Season page.

EWS23 | (Leave me a message!) 06:33, 22 November 2005 (UTC)

Tornado Fingers

I remember seeing a thing on TV that said little tornado fingers came out of the outside of the eye wall. I think I remember seeing a film of them. --Gbleem 01:08, 12 December 2005 (UTC)

Organization

Shouldn't the "Movement and track" section be combined with the "Monitoring, observation and tracking" (and probably "Dissipation" as well)? Good kitty 04:12, 22 December 2005 (UTC)

The difference seems to be that "Movement and track" describes the actual movement, while "Monitoring...." seems to be about how people track the storm. I'm not sure what to do about "Dissipation". Perhaps things can be reorganized into a "Lifecycle" section? --AySz88^-^ 04:44, 22 December 2005 (UTC)

What's in a Name?

For the record, the first named storm was Hurricane Carol, 1954. (And I destroyed Miami on Create-a-Cane.) Dr. Trekenstein, 02.39 24 Dec 2005

Improvement drive

Hurricane Katrina has been nominated to be improved by WP:IDRIVE. Support it with your vote and help us bring it up to featured standard! Vote here. --Fenice 12:45, 30 December 2005 (UTC)

Lesser Known Hurricanes

Lesser Notable but strong Hurricanes. http://en.wikipedia.org/wiki/User_talk:HurricaneCraze32 My new Article set. I could use your opinion and a couple of things. Some need pictures.I need a button set cause that ToC is too big. Anyone?HurricaneCraze32 23:18, 7 January 2006 (UTC)

That discussion is more appropriate to Wikipedia_talk:WikiProject Tropical cyclones. Jdorje 02:19, 8 January 2006 (UTC)

A question on the eye

I've been doing som research on why the eye forms in a hurricane, and one site says because the pressure gradients coming towards the centre never make it because of the coriolis force, while another talks about the conservation of angular momentum and centrifugal force. which one is right? Also i think someone should come right out and explain why an eye forms in the parts of a hurricane section.

What forms the eye is air spinning really fast. Just like a whirlpool when water is sucked into a drain, once the air starts moving quickly enough friction increases and pulls it into a circular formation. "Quickly enough" happens at approximately 74 mph. Jdorje 05:30, 15 January 2006 (UTC)

I'm not sure that's right... This is how it was explained to me recently, so I might not be right, and I can't quite remember the names of every principle involved. Imagine a ring of air contracting since it's getting sucked into the center of the hurricane. The spinning - the tangential velocity initially produced by the Coriolis force - becomes more and more apparent as the radius contracts. As the air spins faster and closer, more and more of the "sucking" force gets "used up" as centripetal force - which is basically the force needed to prevent the air from flying back outward (think of spinning anything around your head - you need to hang on harder if the object moves faster and if the object moves closer). Eventually the spinning gets to be too much and the "sucking" force isn't enough to keep drawing the air in. Somewhere around that point, the air stops getting sucked inwards and ends up sucked upwards into the eyewall, where the heat released by condensation drives more sucking.

The eye also ends up having a little bit of sinking air, which I assume is what was meant by the pressure gradient lessening, though I don't think that's a cause of the eye formation. Reading this, it would seem the sinking air is due to the rising air right around the center (in the eyewall) having nowhere left to go but inwards and down into the calm eye. --AySz88^-^ 06:30, 15 January 2006 (UTC)

Well, there are lots of "effects" that drive the formation and strengthening of hurricanes. You're right that collapsing of the air around a low-pressure center causes the velocity of the spinning air to increase because of conservation of angular momentum. However the eye form itself comes about just the same way a whirlpool does: the spinning air naturally gravitates into that formation. (Also, the Coriolis force becomes *less* important as the air contracts...it is the initial spin given to the system before its contraction that is what causes the system to spin quickly once it is contracted. In fact I'm pretty sure coriolis force plays a minimal role in maintaining the strength of a hurricane once it has formed - and I wonder if it would ever be possible to have an anti-cyclonic hurricane.) Jdorje 06:48, 15 January 2006 (UTC)

It probably happened with that storm that crossed the equator....twice, I think. :p I can't remember its name, though. --AySz88^-^ 06:52, 15 January 2006 (UTC)

Ok. So it seems that the eye is formed from a combination of the coriolis force, centripetal force, and conservation of angular motion. My conclusion is around the same lines as the second post, but here it goes: the pressure gradients going towards the core start to speed up, as they get nearer, due to the conservation of angular motion, which is the reason why figure skaters spin faster when their hands are nearer to their bodies. These pressure gradients are encountering centripetal force, as they want to move ever closer to the low-pressure core of the hurricane, but alas, because of the Coriolis force, the already spiralling wind actually starts to circle around the core, and forms the dangerous eyewall. Thus, almost all of the wind never reaches the eye, and the eye actually stays mostly the same during the course of a hurricane. Excuse my horrible meteorolgy, I had to learn of all of this on my own. Oh yes, could one give the example of swirling a glass of water, for the formation of the eye? I'm pretty sure when you swirl a glass of water fast enough, sometimes theres an emtpy space in the middle. Or is that sometihng else? —Preceding unsigned comment added by Ultimate dooms elf (talk • contribs) 16:17, January 15, 2006 (UTC)

Well, I decided to not be lazy this time and looked up all the names:

I think you might be confusing centripetal force and centrifugal force (which technically doesn't "really" exist, in the same way that the Coriolis force doesn't "really" exist). The balance is really between the centrifugal "force" and pressure gradient force taking the role of the centripetal force, because the Coriolis force shrinks and becomes negligible as you get closer to the center. --AySz88^-^ 18:19, 15 January 2006 (UTC)

You guys are explaining what causes the air to spin. But what causes the eye to form isn't coriolis force or centripital force, it is just spinning air. When air spins about a central point, the air at the central point is not spinning (get some water in a cup and stir it around, and you'll see the same thing). As the air spins faster and faster, friction pulls it into a circular formation and causes the central non-spinning area to become more clearly defined (stir the water in the cup faster and faster, and you'll see this too). Jdorje 21:01, 15 January 2006 (UTC)

Doesn't that only explain why v = 0 for a single point, not a disk like the eye? The spinning water doesn't form anything like an eye unless angular velocity increases towards the center (i.e. it's draining) and a funnel forms. The thing defining the radius of the circular formation is the centrifugal "force" vs. the centripital force. --AySz88^-^ 22:07, 15 January 2006 (UTC)

At low velocities v=0 at the center, with a gradual increase in velocity as you go outward. However as the velocity increases, the spinning fluid is pulled into more of a torus, with a well-defined central area of lower pressure and v=0. This is not a meteorological effect or anything to do with coriolis effect; it is simple fluid dynamics. It is *exactly* the same thing you see on a small scale when you stir water in a cup. Jdorje 23:19, 15 January 2006 (UTC)

Ah, I see what you mean now, though I'm not certain about what would happen when you have additional lowering of pressure being added into the system by the condensation and such. --AySz88^-^ 23:42, 15 January 2006 (UTC)

Evaporation and condensation serve to lower the pressure in the eye - water vapor is lighter than air and tends to rise, plus the eye is warm-core and the air will generally rise - as well as raising the temperature when the water vapor condenses higher in the atmosphere. Lowered pressure in and around the eye provides centripital acceleration which serves to *accelerate* the winds in the eyewall (without this acceleration it is impossible for cyclones to strengthen; polar lows can have an eye quite easily but they cannot strengthen further); the more the winds accelerate the more the eye is pulled into a perfect circular shape. Diabolically, the more the pressure drops in and around the eyewall the faster the water will evaporate from the ocean - if it dropped far enough, the water would literally boil. High winds in the eyewall also serve to roil the ocean, which both aids evaporation (by increasing surface area) and to uplift water from deeper in the ocean (which is a good thing, if the warm water runs deep). It is this feedback effect that allows tropical cyclones to intensify so far beyond what is normally seen in other weather phenomena. The only things that will stop the intensification are lack of water (from the cyclone moving over or partially over land, or approaching land and drawing in dry air), lack of warmth (from a colder sea surface, or cold air being entrained), and friction (friction increases proportionally to the square of the wind velocity; friction happens between the cyclone's winds and adjacent air masses (especially ones with shear), land masses, or simply the ocean itself). Jdorje 01:40, 16 January 2006 (UTC)

I know everything else (though to be nitpicky, the centripital part of the pressure gradiant force, by definition, cannot increase the speed of the winds since the force is always perpendicular to the direction of motion). What I meant was, in a spinning container of water, the centripital force doesn't get stronger as you move towards the middle, as I think the force there is being exerted by the container, while in a tropical system without an eye the pressure gradiant is strongest where convection is the strongest, shrinking the radius of the region of v=0. Instead of the normal force which decreases towards the center, the pressure gradient force continues to increase towards the center of a strengthening cyclone (I think?), but eventually doesn't increase quite as fast as what would be needed to keep the spinning.

I think we might be talking about the same thing from different perspectives; I'm going outside-in, and I think you're going inside-out? --AySz88^-^ 02:32, 16 January 2006 (UTC)

Yes, I know my rant was off-topic ;-). (To be nitpicky, I believe a perpendicular acceleration can increase the speed of winds, although this typically only happens as the eyewall contracts.) Next, I wasn't talking about a spinning container of water but a cup of water that you stir with a spoon; however, you're right that it's not an inward force applied from the middle but rather a forward force applied from the point of the spoon (i.e., in the "eyewall"). However if you think in terms of water going down a drain, you see the exact same result - an effect of fluid dynamics (water going down the drain is almost exactly comparable to a tropical cyclone, except that a TC has air not water and it goes up not down). Anyway, my point is you are explaining *why* the air is spinning - but what causes the eye formation is simply the spinning air, which is why the exact same behavior is seen in whirlpools, tornadoes, and polar lows. Jdorje 03:19, 16 January 2006 (UTC)

(Side note: wikipedia used to have a picture of a polar low that looked almost exactly like Vince or Epsilon; I can't find it now, maybe it was a copyvio. In the poles, such things can easily form because coriolis effect is much stronger; large-scale spinning wind at about 74 mph will form an eye no matter what causes it to spin. However they cannot normally continue to strengthen because they are cold-core.) Jdorje 03:25, 16 January 2006 (UTC)

Well, that clears everything right up. At first I was confusing the spinning of the air and the formation of the eye, and all of the forces related with them. But now I think everything seems to be order. So the eye is the centre of rotation, so it never rotates. However, why do the pressure gradients neevr reach the centre? Ya sure the eye forms due to fluid dynamics, and the air spins, but the pressure gradients want to get to the centre, but they never do. why? Oh wait, does the hot air make the pressure gradients rise into the eyewall and never reach the centre? Or has the centre been reached already when the pressure gradients reach the eyewall (considering that the eye is a huge centre)and they just go up? -- Ultimate_dooms_elf

I'm not entirely sure what you mean. Do you mean, why does the pressure remain low in the eye rather than increasing as air rushes in toward the low-pressure center? Note that air in the eyewall is moving perpendicular to the eye - not toward it - and the pressure pushing it in toward the lower-pressure center acts as a perpendicular force; it is that force that causes the rotation to continue but it does not cause the air to actually make it into the eye. In the absence of friction the eyewall will just keep spinning forever, and the low-pressure eye center will maintain the spin without ever rising in pressure. However, friction (between air and air, air and water, air and land) is of course present and it slows the eywall winds and this does cause air in the eyewall to move into the eye (if the eyewall goes over mountains, the storm will die almost instantly). What balances this is the intensification tendency of a tropical cyclone over warm waters, which acts to continually remove air from the eye by moving up into the upper atmosphere and ultimately outward away from the high-pressure center that exists *over* the eye. Jdorje 23:39, 16 January 2006 (UTC)

CDO?

Is the CDO essentially the body of a hurricane?

Central Dense Overcast (CDO): The Central Dense Overcast is a dense shield of very intense thunderstorm activity that make up the inner portion of the hurricane. This contains the eye wall, and the eye itself. The classic hurricane contains a symmetrical CDO, which means that it is perfectly circular and round on all sides.

I thought CDO referred more to the high-level outflow seen as cirrus over a storm to 50,000 feet AGL. Is CDO just a technical name for the body a hurricane? And if so, why say it's the "inner portion" ? (and BTW, "perfectly circular" and "round on all sides" seems kinda redundant.) DavidH 17:05, 18 January 2006 (UTC)

I think "inner portion" just excludes feeder bands, probably? (And I agree it can be shortened to "perfectly circular".) --AySz88^-^ 03:01, 19 January 2006 (UTC)

Thanks AySz88. Still wondering if it doesn't refer to more to the "overcast" over the cyclone rather than the thunderstorm core. Seeking refs anybody. DavidH 22:31, 21 January 2006 (UTC)

Cirrus clouds are neither dense nor an overcast. Jdorje 01:00, 22 January 2006 (UTC)

Forget cirrus, I mean all the outflow, which can appear dense (in visible light at least). Anyway, AMS glossary definition of CDO: "The region of dense cloud near the core of a tropical cyclone." If the core is the eye/eyewall, CDO is near -- outside? The body of the storm excluding the core, it seems, not what the article says -- that it is the core. DavidH 03:27, 22 January 2006 (UTC)

The core is the eye. Near the core would be the eyewall. Jdorje 03:47, 22 January 2006 (UTC)

Thanks, but to me "core" means central part only -- it's not a technical term, don't see "core" exactly equal to the distinct meteorological structure of "eye". Weathermen all the time say "core" to mean (bad) central part of the storm's mass ("Don't worry, you're going to be in the eyewall, but won't get the "core"??). The article says CDO = inner portion, that seems to mean "core" to me, while AMS says CDO = region near "the core." I'll find more references and decide whether to edit it. DavidH 04:17, 22 January 2006 (UTC)

Excuse un-P.C. "weathermen" too.DavidH 04:18, 22 January 2006 (UTC)

Core means center. Near the core means near the center. Overcast means clouds. Central means center. Dense means thick. So it's the thick clouds near the center of the storm. How is this confusing? Jdorje 05:50, 22 January 2006 (UTC)

OK. Wonder if anyone else thinks there's nothing contradictory in saying the CDO is a dense overcast area that includes the eye:

"The Central Dense Overcast is a dense shield of very intense thunderstorm activity that make up the inner portion of the hurricane. This contains the eye wall, and the eye itself."

Doesn't seem "clear" to me. DavidH 06:48, 22 January 2006 (UTC)

<--

I think the confusion is in whether or not the CDO includes clear area of the eye? I would say it doesn't include the eye, as the eye isn't really dense or overcast. --AySz88^-^ 16:55, 22 January 2006 (UTC)

what is a typhoon?what can a typhoon do?

—Preceding unsigned comment added by 207.71.212.13 (talk • contribs) 17:13, January 23, 2006 (UTC)

This is in the article. They're the same as hurricanes except they have a different name in the western Pacific Ocean. As for what they can do, try Tropical cyclone#Effects. --AySz88^-^ 17:27, 23 January 2006 (UTC)

Assessment comment

The comment(s) below were originally left at Talk:Tropical cyclone/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

An article about RSMCs and about Tropical cyclolysis might eventually be needed, but not as urgently. Everything else is listed on Talk:Tropical cyclone#To do. Titoxd(?!?) 20:38, 5 December 2006 (UTC)

Last edited at 17:23, 28 December 2006 (UTC). Substituted at 20:55, 4 May 2016 (UTC)