231:
92:
22:
278:
166:
116:, the monsoon trough associated with the Australian monsoon reaches its most southerly latitude in February, oriented along a west-northwest/east-southeast axis. North-south-oriented mountain barriers, like the Rockies and the Andes, and large massifs, such as the Plateau of Tibet, also influence atmospheric flow.
307:, or MJO. This mirrors tropical cyclone genesis near these features, as genesis clusters in 2–3 weeks of activity followed by 2–3 weeks of inactivity. Tropical cyclones can form in outbreaks around these features under special circumstances, tending to follow the next cyclone to its poleward and west.
156:
when their temperature gradient becomes minimal, wind surges can cross the equator in oceanic regions and enhance a monsoon trough in the other hemisphere's summer. A key way of detecting whether a wind surge has reached a monsoon trough is the formation of a burst of thunderstorms within the monsoon
323:
are generally reverse oriented. The failure of the monsoon trough, or the ITCZ, to move south of the equator in the eastern
Pacific Ocean and Atlantic Ocean during the southern hemisphere summer, is considered one of the factors causing tropical cyclones to not normally form in those regions. It has
177:
over the continent, and a wind surge will occur at its periphery. Such a circulation which is broad in nature within a monsoon trough is known as a monsoon depression. In the
Northern Hemisphere, monsoon depressions are generally asymmetric, and tend to have their strongest winds on their eastern
185:
poleward and west of the system can enhance its development by leading to increased diverging air aloft over the monsoon depression, which leads to a corresponding drop in surface pressure. Even though these systems can develop over land, the outer portions of monsoon depressions are similar to
299:-rich low level environments, with significant low level spin, lead to a better than average chance of tropical cyclone formation due to their inherent rotation. This is because a pre-existing near-surface disturbance with sufficient spin and convergence is one of the six requirements for
314:
along its periphery will move with a westward motion. If it reverses its orientation, orienting southwest to northeast, tropical cyclones will move more poleward. Tropical cyclone tracks with S-shapes tend to be associated with reverse-oriented monsoon troughs. The
265:. Its abrupt movement to the north between May and June is coincident with the beginning of the monsoon regime and rainy seasons across South and East Asia. This convergence zone has been linked to prolonged heavy rain events in the
111:
in
Australia during February. Its poleward progression is accelerated by the onset of the summer monsoon which is characterized by the development of lower air pressure over the warmest part of the various continents. In the
252:
Since the monsoon trough is an area of convergence in the wind pattern, and an elongated area of low pressure at the surface, the trough focuses low level moisture and is defined by one or more elongated
489:
352:
95:
February position of the ITCZ and monsoon trough in the
Pacific Ocean, depicted by area of convergent streamlines offshore Australia and in the equatorial eastern Pacific
581:
640:
611:
598:
178:
periphery. Light and variable winds cover a large area near their center, while bands of showers and thunderstorms develop within their area of circulation.
751:
752:
Specific
Tropical Cyclone Track Types and Unusual Tropical Cyclone Motions Associated with a Reverse-Oriented Monsoon Trough in the Western North Pacific.
310:
Whenever the monsoon trough on the eastern side of the summertime Asian monsoon is in its normal orientation (oriented east-southeast to west-northwest),
194:
events. Monsoon depressions are efficient rainfall producers, and can generate a year's worth of rainfall when they move through drier areas, such as the
423:
303:. There appears to be a 15- to 25-day cycle in thunderstorm activity associated with the monsoon trough, which is roughly half the wavelength of the
79:. The migration of the ITCZ/monsoon trough into a landmass heralds the beginning of the annual rainy season during summer months. Depressions and
714:
734:
202:
391:
486:
364:
681:
269:
river as well as northern China. Its presence has also been linked to the peak of the rainy season in locations within
Australia.
186:
tropical cyclones. In India, for example, 6 to 7 monsoon depressions move across the country yearly, and their numbers within the
103:
during the late summer when the wintertime surface ridge in the opposite hemisphere is the strongest. It can reach as far as the
547:
83:
often form in the vicinity of the monsoon trough, with each capable of producing a year's worth of rainfall in a matter of days.
60:
exist poleward of the trough. Right along its axis, heavy rains can be found which usher in the peak of a location's respective
132:
of the monsoon trough. Wind surges can lead to this increase in convergence. A strengthening or equatorward movement in the
578:
469:
462:
522:
446:
403:
136:
can cause a strengthening of a monsoon trough as a wind surge moves towards the location of the monsoon trough. As
599:
A Study of a
Monsoon Depression Bringing Record Rainfall over Australia. Part II: Synoptic–Diagnostic Description.
360:
320:
316:
38:
420:
777:
772:
304:
206:
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in the
Pacific, the frequency of tropical cyclones is 2 to 3 times greater than when it lies closer to
25:
August position of the ITCZ and monsoon trough in the
Pacific Ocean, depicted by area of convergent
153:
137:
128:, or spin, with the monsoon trough are normally a product of increased wind convergence within the
711:
149:
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653:
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If a circulation forms within the monsoon trough, it is able to compete with the neighboring
625:
Impact of
Southern Oscillation on the Frequency of Monsoon Depressions in the Bay of Bengal.
698:
26:
8:
407:
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is most commonly used in monsoonal regions of the Western Pacific such as Asia and
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would have characteristics of a monsoon depression throughout their lifetime. The
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493:
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427:
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Effects of the Northeast Monsoon on the Equatorial Westerlies Over Indonesia.
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187:
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443:
91:
174:
57:
42:
612:
A Diagnostic Analysis of Two Intense Monsoon Depressions over Australia.
21:
243:
182:
141:
65:
61:
45:
showing the locations of minimum sea level pressure, and as such, is a
217:
is the first system recognised as a fully monsoon depression by JTWC.
191:
444:
Chapter-II Monsoon-2004: Onset, Advancement and Circulation Features.
296:
125:
76:
49:
between the wind patterns of the southern and northern hemispheres.
699:
Climate Variability of Tropical Cyclones: Past, Present and Future.
277:
254:
100:
64:. The monsoon trough plays a role in creating many of the world's
266:
247:
235:
195:
145:
53:
523:"Atmosphere - Effect of continents on air movement | Britannica"
99:
Monsoon troughing in the western Pacific reaches its zenith in
566:
SECTION 3. DYNAMIC CONTRIBUTORS TO TROPICAL CYCLONE FORMATION.
623:
O. P. Singh, Tariq Masood Ali Khan, and Md. Sazedur Rahman.
324:
also been noted that when the monsoon trough lies near
291:
A monsoon trough is a significant genesis region for
712:
Tropical Cyclone Formation/Structure/Motion Studies.
56:
winds lie in its equatorward portion while easterly
41:in the Western Pacific, as depicted by a line on a
281:Months of peak tropical cyclone activity worldwide
764:
442:National Centre for Medium Range Forecasting.
510:1.2 Pacific Ocean Surface Streamline Pattern.
430:Ohio State University. Retrieved 2009-03-08.
421:Global Pattern of Surface Pressure and Wind.
641:TWP-ICE Synoptic Overview, 1 February 2006.
272:
203:Regional Specialized Meteorological Centres
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558:
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20:
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487:Lesson 4 – Seasonal-mean Wind Fields.
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347:
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201:Some tropical cyclones recognised by
654:"North Indian Ocean Best Track Data"
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463:Australian Broadcasting Corporation
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190:increase during July and August of
107:in East Asia during August and the
13:
597:Sixiong Zhao and Graham A. Mills.
408:Severe Weather Information Centre.
342:
225:
169:Monsoon depression near Bangladesh
14:
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404:World Meteorological Organization
152:during their winter, normally as
610:N.E. Davidson and G.J. Holland.
321:South Atlantic convergence zones
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361:American Meteorological Society
181:The presence of an upper level
730:Joint Typhoon Warning Center.
656:. Joint Typhoon Warning Center
515:
479:
456:
413:
397:
317:South Pacific convergence zone
39:Intertropical Convergence Zone
1:
335:
579:Climate Variability on CNMI.
207:Joint Typhoon Warning Center
7:
213:as a category in 2015, and
10:
794:
284:
241:
124:Increases in the relative
737:19 September 2006 at the
326:20 degrees north latitude
305:Madden–Julian oscillation
717:29 November 2007 at the
472:23 February 2001 at the
273:In tropical cyclogenesis
220:
357:Glossary of Meteorology
29:in the northern Pacific
684:11 August 2008 at the
492:22 August 2009 at the
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239:
170:
96:
30:
754:Retrieved 2006-11-26.
741:Retrieved 2006-11-26.
721:Retrieved 2006-11-26.
701:Retrieved 2006-11-26.
697:Christopher Landsea.
688:Retrieved 2008-05-03.
675:Bureau of Meteorology
643:Retrieved 2008-05-03.
637:Bureau of Meteorology
627:Retrieved 2008-05-03.
614:Retrieved 2008-05-03.
601:Retrieved 2008-05-03.
588:Retrieved 2008-05-03.
568:Retrieved 2006-11-26.
550:Retrieved 2008-05-03.
512:Retrieved 2006-11-26.
496:Retrieved 2008-05-03.
476:Retrieved 2008-05-03.
453:Retrieved 2008-05-03.
426:18 March 2009 at the
410:Retrieved 2008-05-03.
394:Retrieved 2008-05-03.
330:10 degrees north
301:tropical cyclogenesis
287:Tropical cyclogenesis
280:
238:after a monsoon rain.
233:
168:
120:Effect of wind surges
94:
87:Movement and strength
24:
778:Atmospheric dynamics
773:Tropical meteorology
584:22 June 2007 at the
449:21 July 2011 at the
37:is a portion of the
161:Monsoon depressions
114:Southern Hemisphere
527:www.britannica.com
485:Dr. Alex DeCaria.
392:The Asian Monsoon.
283:
240:
211:monsoon depression
171:
97:
31:
16:Weather phenomenon
710:Patrick A. Harr.
679:Climate of Giles.
312:tropical cyclones
293:tropical cyclones
263:satellite imagery
140:move through the
134:subtropical ridge
81:tropical cyclones
785:
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750:Mark A. Lander.
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363:. Archived from
353:"Monsoon trough"
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234:View of central
130:convergence zone
47:convergence zone
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367:on 17 June 2009
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732:Typhoon Polly.
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285:Main article:
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198:of Australia.
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73:monsoon trough
35:monsoon trough
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261:when viewing
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259:thunderstorms
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215:Cyclone Komen
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209:(JTWC) added
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188:Bay of Bengal
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109:20th parallel
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658:. Retrieved
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577:Chip Guard.
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564:U. S. Navy.
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530:. Retrieved
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508:U. S. Navy.
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369:. Retrieved
365:the original
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62:rainy season
51:
34:
32:
18:
175:thermal low
154:shear lines
66:rainforests
58:trade winds
43:weather map
27:streamlines
767:Categories
390:Bin Wang.
336:References
244:Wet season
242:See also:
183:jet stream
150:hemisphere
142:subtropics
297:Vorticity
126:vorticity
77:Australia
71:The term
52:Westerly
735:Archived
715:Archived
682:Archived
582:Archived
490:Archived
470:Archived
467:Monsoon.
447:Archived
424:Archived
157:trough.
101:latitude
267:Yangtze
248:Monsoon
236:Kolkata
196:outback
192:El Niño
148:of one
146:tropics
54:monsoon
660:25 May
532:13 May
371:4 June
138:fronts
255:bands
221:Roles
662:2020
534:2024
373:2009
319:and
246:and
144:and
33:The
257:of
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555:^
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501:^
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