Talk:Intertropical Convergence Zone

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Merger or redirect?[edit]

This page and Monsoon trough both acknowledge that they are the same thing. Should they be merged?

I'm wondering the same thing. Since monsoon trough has already reached GA, I'd propose it being the main article. Thegreatdr (talk) 20:30, 28 December 2008 (UTC)
With no input since December, expect this article to become a redirect to monsoon trough shortly, since there is nothing unique in this article worth saving. Thegreatdr (talk) 08:56, 4 June 2009 (UTC)

Todo[edit]

2004 February 15 --

"Advective (horizontal) motion is due entirely to air replacing that carried aloft by convection, is a languorous process at best."

Note that the second 'is' is superfluous; the 'is' following the word 'motion' is the verb in the sentence. This sentence is correct as it currently stands in the article.

Denni 00:27, 2004 Feb 16 (UTC)

Merge ?[edit]

This page and Monsoon trough both acknowledge that they are the same thing. Should they be merged?

ITCZ and/or ITC?[edit]

I'm working on the German Article and there some Questions:

  • ITC - Inter Tropic Conversion
  • ITCZ - InterTropical Convergence Zone
  • ITC - Inner Tropic Conversion
  • ITCZ - InnerTropical Convergence Zone

These are often used terms for ITC or ITCZ if someone wants to explain where the abbreveation comes from. Aren't they used in English too? --Saperaud 12:20, 19 Mar 2005 (UTC) PS: Whats with Thermal equator?

"Inter-Tropical Convergence Zone" (ITCZ) is favored by US meteorologists at the National Hurricane Center. -- Cyrius| 02:24, 5 Jun 2005 (UTC)
Shouldn't the words of title of the article be all capitalized (because it would be Intertropical Convergence Zone)? I doubt that only the I is capitalized (as it currently stands in the first sentence of the article). --AySz88^-^ 17:12, 10 December 2005 (UTC)
Yes, the article title is incorrect, but I cannot get it to accept the change as the software for moving articles does not distinguish between Intertropical convergenze zone (incorrect) and Intertropical Convergence Zone (correct). - Marshman 00:05, 5 January 2006 (UTC)
The fix was fairly straight forward: move the article to a completely different name, then move it again to one with the correct caps (then clean up the double redirect left behind). Denni 02:06, 5 January 2006 (UTC)

Some changes of mine...[edit]

I changed [1]:

It is formed, as its name indicates, by the convergence of warm, moist air from the latitudes above and below the equator.

to

It is formed by the vertical ascent of warm, moist air from the latitudes above and below the equator.

I think the latter is correct: if it were formed by convergence (for whatever reason) it would be a *high* pressure area. Its a *low* pressure area because the ascent is effectively sucking air in.

I also changed:

Because of the strength of the Hadley cells on either side of it, weather systems familiar to mid-latitude dwellers do not have the chance to form, and as a result, there are no prevailing winds. Advective (horizontal) motion is due entirely to air from the trade winds replacing that carried aloft by convection, a slow, languorous process at best.

to:

Within the ITCZ the average winds are slight, unlike the zones north and south of the equator where the trade winds feed in.

I don't think the former is correct. You don't get traditional mid-latitude weather systems in the tropics because (a) the coriolis effect is different and (b) the forcing is different too (which gets into yucky why-is-the-ferrel-cell territory). The key point is that in the trades, there are steady winds which are the hadley cell inflows. Directly under the updrafts, this inflow stops and thats why there are doldrums: it *isn't* anything to do with the strength of the hadley circ.

OK, thats my take, discussing as promised. Over to... William M. Connolley 21:58, 15 May 2006 (UTC)

Question[edit]

How significant is the ITCZ to the formation of tropical cyclones? It obviously has something to do with them, else the NHC would not bother mentioning it in their tropical weather discussions. However, I don't know how important its influence is (hence the low TC importance) and this article does not clarify that situation at all.--Nilfanion (talk) 09:44, 12 June 2006 (UTC) It is very significant. The "tropical waves" that are referenced by the NHC are the result of the ITCZ, and typically form the seeds of disturbed weather for hurricanes forming in the eastern Atlantic. Hurricanes form elsewhere in the Atlantic due to other conditions, but a significant amount of hurricane activity arises from tropical waves coming off Africa as a result of the ITCZ. --76.91.70.47 (talk) 15:53, 22 September 2011 (UTC)

Question[edit]

I heard in highschool that this region was also referred to as The Horse Lattitudes because Spanish vessels that traveled to the New World and got caught in this belt would dump their horses overboard to lighten their load to hopefully pick up speed. Any word on the truth of this? Improvclifton 9:00, 12 July 2006 (UTC)

Yes, and no. The horse latitudes are a different area of poor sailing conditions. —Cuiviénen 02:43, 4 March 2007 (UTC)
Just to flesh this response out a bit, the Horse Latitudes are found between 30 and 35 degrees north and south of the equator. The ITCZ lies right on the equator, give or take a few degrees each side. It is likely horses were thrown overboard for the more immediate need to preserve water. Dennitalk 19:19, 4 March 2007 (UTC)

low spirits?[edit]

"Within the ITCZ the average winds are slight, unlike the zones north and south of the equator where the trade winds feed in. Early sailors named this belt of calm the doldrums because of the low spirits they found themselves in after days of no wind. To find oneself becalmed in this region in a hot and muggy climate could mean death in the era when wind was the only motive force."

doldrums has two meanings in the dictionary:"a state of inactivity or stagnation, as in business or art" and "a dull, listless, depressed mood; low spirits." Why is only the low spirits reason listed for the naming of the area, wouldn't the first definition fit better?

also, there is no reference backing that section up

Slash's snakepit 21:04, 10 September 2006 (UTC)

"The Doldrums" is the "saltyspeak" word for the intertropical convergence zone. It is commonly used amongst the sailors and seamen even today. The name is due to the fact that weather can be really depressing there - low pressure combined with becalmed wind, being an apt name for the zone.62.237.141.27 (talk) 15:44, 12 December 2009 (UTC)
I doubt that the original usage of the term had anything to do with low spirits or depression, and believe based on etymology that the usage of doldrums to describe feelings is a more recent development. The apparent first printed usage of the word was 1811, and it was derived from an Old English term "dol" referring to a dullard or foolish person. So "inactivity or stagnation" seems to be the reason the word has been applied to weather pattern of this area (i.e., the weather is as inactive and dull as a dullard), rather than a depressed mood or low spirits resulting from the typically unfavorable weather. It makes a lot more sense for "doldrums" to be referring to the typical state of weather than to feelings about traveling through the area. I strongly suspect the usage of the word to also describe feelings came later.--76.91.70.47 (talk) 16:07, 22 September 2011 (UTC)

Importance[edit]

Raised to high importance, simply because this is the intertropical convergence zone we're talking about here. --Coredesat talk. o_O 18:49, 11 September 2006 (UTC)

Jan/July Image?[edit]

Doesn't look very accurate to me!!

What does it mean "ABOVE and BELOW the Equator"? I saw this in the first paragraph of the article. In geography there's no such thing as Up and Down. There are North and South. Because "above the Equator" could mean "over the equator in the atmosphere", and even "on geostationary orbit". "Below the equator" is the earth's crust, than the mantle, after that the liquid and the solid core. Please be accurate and use the proper geographic concepts "to the North" and "to the South".


Agree: the image is completely wrong. The ITCZ never crosses the Sahara desert, the Middle East or China! A look at a satellite picture in July will immediately confirm this. The image should be removed. —Preceding unsigned comment added by 78.133.32.227 (talk) 08:46, 27 August 2010 (UTC)

Out Of India Theory[edit]

It is extremely simple. The OIT is proposed by a number of academic scholars in the field. It has also been recently burgeoned by genetic studies done in the last 5 years. So to claim it is "rejected" by scholars is patently false, as there are some scholars who are far more knowledgeable in the field than you or I who are currrently advocating it.

Doldrums redirect[edit]

Doldrums should not redirect here. The doldrums is a particular area of the atlantic ocean (and maybe other oceans, but at any rate not any of land mass) which has a particular weather pattern perhaps caused by the ITCZ but with particular history, cultural significance and maritime relevance. To explain the term "Doldrums" in an encyclopedia purely by reference to this physical, technical description of its meteorology seems to me to miss something pretty significant. For example, does this article capture the sense of the doldrums conveyed by Coleridge's Rime of the Ancient Mariner? I don't think it does. A Doldrums article (which I don't feel qualified to write, by the way) ought to hyperlink into this article, but should all the same be separate. ElectricRay (talk) 22:44, 15 January 2008 (UTC)

Being Bold, I have just gone ahead and removed the redirect, and had a stab at adding a piece about Coleridge. ElectricRay (talk) 23:11, 15 January 2008 (UTC)

Question about 'Position' and the picture[edit]

In the article it says: Over the oceans, where the convergence zone is better defined, the seasonal cycle is more subtle, as the convection is constrained by the distribution of ocean temperatures.

I have 3 questions to this paragraph:

1) What does it mean it is better defined? 2) What does it mean that the cycle is more gentle? 3) Also when I look at the picture with Jan/Jun it seems that 'is constrained by the distribution of ocean temperatures' applies only to Atlantic and not to Pacific, but my conclusions are probably wrong because of wrong understanding of 1) and 2) maju (talk) 08:12, 17 May 2008 (UTC)

Map is wrong[edit]

According to the map ITCZ january-july.png, the January ICZ is on or very slightly south of the Equator, while the July one is considerably north of the Equator (up to Japan, 30 degrees N). Also, the July ICZ goes through the Sahara desert, the Arabian desert, Iran, the Tibetan plateau... which are regions known for being very dry. However, the ICZ is characterised by heavy rainfall.

Both the other map Omega-500-july-era40-1979.png and the outside reference the ITCZ in Africa show the ICZ to be much closer to the Equator in July (only 5-10 degrees N). Since the map ITCZ january-july.png, doesn't seem to have any sources, it should be removed. Any objections? AtikuX (talk) 09:46, 30 September 2008 (UTC)

Agreed; pic removed. I drew the omega plot from ERA data; sadly I didn't draw January too. There are some more pix available from http://www.ecmwf.int/research/era/ERA-40/ERA-40_Atlas/docs/section_D/parameter_vva500hpa.html# Layer heating http://www.ecmwf.int/research/era/ERA-40/ERA-40_Atlas/docs/section_D/parameter_lhf500hpat700hpa.html# looks much the same. Sadly they don't do monthlies - seasonal stuff smears it out William M. Connolley (talk) 21:53, 30 September 2008 (UTC)
Belated comment: Omega is not a good way to estimate the ITCZ position, especially if you draw it from jsut one year. I think the original map is close to the truth, and will try to find a better "source" if I can. -- Soap Talk/Contributions 16:28, 29 October 2009 (UTC)
 ? Omega *is* the ITCZ position William M. Connolley (talk) 21:51, 29 October 2009 (UTC)
Doesnt omega just indicate vertical velocity? I'd think it would be hard to distinguish the ITCZ from storms that form spontaneously in permanent troughs caused by land patterns. Also, the pressure patterns at 500mb wont always line up with those on the ground. For example, the American southwest often experiences shallow lows in summer due to the heat, but at 500mb it shows up as a high. In any case, I have always thought that most scientists agree that the Asian summer monsoon is considered to be an arm of the ITCZ, even when it moves very far north, and even when it becomes very dry. If this is not so, I stand corrected ... I know that I've read that in sources outside of Wikipedia, though. -- Soap Talk/Contributions 21:56, 29 October 2009 (UTC)
Omega is vertical velocity, yes. 500 hPa is mid-atmosphere so a good level. The ITCZ is essentially the rising branch of the Hadley circulation which is traced by omega. As for the Asian monsoon - doesn't the omega pic show that? I'm not a monsoon person though so could be wrong William M. Connolley (talk) 10:05, 30 October 2009 (UTC)

Undid redirect[edit]

Undid redirect to Monsoon trough, since that term is only used for a portion of the ITCZ. This ITCZ article needs to be updated to describe the differing CZ terms and which part of the world they're associated with. Also, the Monsoon trough article seems to put more emphasis on the Pacific, not the Atlantic. --Funandtrvl (talk) 18:44, 4 June 2009 (UTC)

Monsoon trough is merely used for active portions of the ITCZ, it so appears. Per the comment in the upper part of this talk page, this move was advertised six months in advance, so it should hardly be a surprise that I followed through on the suggestion when there was no feedback to the contrary. New evidence has surfaced from two different sources that around Australia, the ITCZ and monsoon trough are separate features, which may be the only place globally that this is the case. If we go with the preface that active portions of the ITCZ are known as the monsoon trough, then technically the quiet ITCZ is not responsible for TC genesis, but that the active monsoon trough portions are. We need to minimize the overlap between these two articles, while not sacrificing monsoon trough's GA status. You began the process, I'm just following along. I guess sooner or later, this all had to be addressed. It's been my goal for some time to get all the articles I've significantly edited to GA, and I did restructure this article into its current form, so long ago. Thegreatdr (talk) 19:59, 5 June 2009 (UTC)

Monsoon Trough Definition Unsupported[edit]

The references attached to the footnotes do not support the definition for a monsoon trough included in this article. A monsoon, by definition, including the definitions provided in the foonotes, is a land-sea dynamic system. Not all convectively active portions of the ITCZ involve monsoon systems. Many are simply phenomena of convergence, sea surface temperature differences or the result of the passage of tropical waves. The article should be amended. Tmangray (talk) 16:52, 24 October 2009 (UTC)

I guess that's true by definition. However, this would mean that only the portion of the ITCZ in the central Pacific ocean cannot be referred to as a monsoon trough. Everywhere else though, such as near Asia, Australia, Mexico, South America, and Africa, it can be called the monsoon trough since the ITCZ position in those areas is strongly affected by those nearby landmasses. Thegreatdr (talk) 21:26, 29 October 2009 (UTC)
And also the mid Atlantic and the mid Indian Oceans. Nonetheless, the ITCZ is a distinct entity with its own dynamics. The usage is also mainly limited to Asia and Australia. Tmangray (talk) 22:34, 29 October 2009 (UTC)
The African portion which extends into the eastern Atlantic (out towards 40W) is also referred to as a monsoon trough during late summer. That doesn't leave much of a gap in the Atlantic ...maybe 600 nm/1000 km. Thegreatdr (talk) 02:05, 31 October 2009 (UTC)
Not universally it isn't. Most meteorologists outside of Australia and parts of Asia refer to the ITCZ, even when it interacts with a monsoon. Even the sources cited in this article do so. Tmangray (talk) 17:43, 3 November 2009 (UTC)
This link talks about the monsoon trough in South America, which is separate from the ITCZ, while this book talks about the monsoon trough near Africa. Many people use the terms interchangably, even if there appear to be minor differences in definitions between the two features. Thegreatdr (talk) 18:48, 3 November 2009 (UTC)

What it rong with the external link *ITCZ in March 2011 Scientific American ?[edit]

What it rong with the external link *ITCZ in March 2011 Scientific American ? 99.181.157.185 (talk) 01:44, 3 March 2011 (UTC)

It doesn't seem to be about the ITCZ. — Arthur Rubin (talk) 05:16, 3 March 2011 (UTC)
https://www.scientificamerican.com/article.cfm?id=a-shifting-band-of-rain is now fully accessible. 209.255.78.138 (talk) 20:31, 31 March 2011 (UTC)
Cool! Thank you. 75.219.240.3 (talk) 21:14, 31 March 2011 (UTC)
Sweet. Thank you, Special:Contributions/209.255.78.138. 99.181.128.253 (talk) 23:35, 31 March 2011 (UTC)
Thanks 209...x 97.87.29.188 (talk) 21:40, 1 April 2011 (UTC)
Added related earlier article on "the band" written in the Scientific American article above: Nature Geoscience Rain Zone ("the band") Moving North http://www.scientificamerican.com/podcast/episode.cfm?id=rain-zone-moving-north-09-07-02 The current article needs a subscription to see it is about the ITCZ. 99.109.127.154 (talk) 18:44, 3 March 2011 (UTC)

What is the time window to confirm a source?[edit]

  • podcast? Are you sure this is under editorial control? However, my comment stands. However, rather than summarily deleting the comment and reference, as should be done, I'm willing to wait for some credible editor to confirm the source. — Arthur Rubin (talk) 09:44, 31 March 2011 (UTC)
The newer article is accessible now: https://www.scientificamerican.com/article.cfm?id=a-shifting-band-of-rain A Shifting Band of Rain: By mapping equatorial rainfall since A.D. 800, scientists have figured out how tropical weather may change through 2100 by Julian P. Sachs and Conor L. Myhrvold March 7, 2011 excerpt: "The area in which it moves is known as the Intertropical Convergence Zone (ITCZ)." 209.255.78.138 (talk) 20:31, 31 March 2011 (UTC)
Added as an external link. Thank you for finding the reference. — Arthur Rubin (talk) 20:47, 31 March 2011 (UTC)
Mr. Rubin, please see my Talk page. 209.255.78.138 (talk) 20:12, 7 April 2011 (UTC)

Merger proposal[edit]

Proposing that near-equatorial trough be merged in here.

"The Intertropical Convergence Zone is the area encircling the earth near the equator where the northeast and southeast trade winds come together. When it lies near the equator, it is called the near-equatorial trough." Huh ?

--Jerome Potts (talk) 18:17, 9 August 2013 (UTC)

NASA uses this term http://earthobservatory.nasa.gov/GlobalMaps/view.php?d1=MYDAL2_M_SKY_WV and the article near-equatorial trough appears to fit into a "Intertropical Convergence Zone (section)".

On a second look i understand that NET can also be the term for a through which is not directly connected to the ICZ, example: monsoon through which enters NET. Though i do not understand what talk means with "Huh?", since the quote from him above describes a through from the ICZ when it's closest to the NET. Prokaryotes (talk) 19:56, 3 January 2014 (UTC)

Closed as no consensus. Vsmith (talk) 12:25, 3 March 2015 (UTC)