ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

Monsoons and Local Winds

Updated on December 23, 2012


The monsoon is a system of winds in which the direction of the winds is reversed between the summer and the winter season. According to the traditional thermal theory of monsoon they are a result of the differential heating of land masses and the oceans. In summer the land area gets heated more than the sea and hence low pressure develops over the interior parts of the land masses. Thus in summer season winds blow from sea to the land. During winter season a high pressure is formed over the continents as the temperature there is very low. On the other hand the pressure over the oceans is comparatively lower and the winds start blowing from land to the sea. This forms the monsoon system. Monsoon winds are prominent in India, Pakistan and other Southeast Asian countries.

However, the modern meteorologists do not explain the monsoon in terms of the differential heating of the land and sea. They explain it in terms of the dynamic theory of monsoon. According to the dynamic theory of monsoon, this system of winds is a result of the poleward shift of the Inter-tropical Convergence (ITC) under the influence of the vertical sun during the summer season. During the northern summer, in the months of May and June the sun shines vertically near the Tropic of Cancer and the ITC shifts northward of the equator. The ITC is the convergence zone of the Trade winds blowing from northeast in the northern hemisphere and from the southeast in the southern hemisphere. As the ITC shifts northward of the equator, the southeast trade winds start blowing north of the equator to reach the ITC and as they cross the equator, their direction is altered due to the influence of the Coriollis force, i.e. they are deflected towards their right and thus it gives rise to the equatorial westerlies blowing between the equator and the ITC. These westerlies in the months of May and June blow from the equator towards the ITC from southwest to northeast and they are called the southwest monsoon.

During the winter season the ITC again moves southward and the areas north of the equator which experienced the equatorial westerlies during the summer season, now come under the influence of the northeast trade winds. These northeasterly winds are called the northeast monsoon. During this very season the ITC shifts southward of the equator and the northeast trades blowing towards ITC, get deflected upon crossing the equator southward. Here they give rise to the equatorial westerlies blowing from northwest to southeast, replacing the trade winds of the southern hemisphere between the ITC and the equator. Thus the areas situated in the tropical zone come under the influence of the trade winds during the respective winter and the equatorial westerlies during the respective summer season. Thus the direction of the winds is reversed seasonally and it makes up the monsoon system of these regions.

Local Winds

Local winds owe their characteristics to the local topography or the local temperature conditions. One of the local winds blowing in the northern plains of India in the summer season are the loo winds. They blow from the Thar Desert into the Ganga Plains and cause the temperature to rise in these plains. Similarly a warm dry wind blows on the eastern side of the Rockey mountains in North America. The warm character of this wind is result of the descending current of air on the eastern slopes of the mountain range. This wind is called Chinook. The very cold winds of polar origin blowing into the temperate regions are called northers. Local winds blowing in the Arctic and Antarctic regions are called blizzards. In fact the local winds blow in many parts of the world and they are known by different names. Fohn, mistral, sirocco and khamsin are some of the other local winds blowing in various parts of the world. Winds owing their character to the surface features and ascent or descent over them are also called the katabatic winds. Fohn and Chinook are examples of katabatic winds.

Another important group of local winds are the land breeze and sea breeze. They blow in the coastal regions and their direction changes on a daily basis. Due to a higher temperature and lower pressure over the land during the day the winds in the coastal regions blow from sea to land. At night the continent cools rapidly and the oceans is comparatively warmer and has a lower pressure. Therefore the winds blow from land to sea at night. This system of winds is called the system of land and sea breeze. A similar reversal of direction of winds occurs in the mountains also where it produces the valley and mountain winds. The valley winds blow from lower valleys to the upper slopes during the day as the temperature over the upper slopes is higher and the warmer air there rises upwards. At night the rapid cooling of the upper slopes makes the air above them heavier and denser which flows down-slope into the valleys. These winds are called the valley winds.


Submit a Comment

No comments yet.


This website uses cookies

As a user in the EEA, your approval is needed on a few things. To provide a better website experience, uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at:

Show Details
HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
LoginThis is necessary to sign in to the HubPages Service.
Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
AkismetThis is used to detect comment spam. (Privacy Policy)
HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the or domains, for performance and efficiency reasons. (Privacy Policy)
Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
MavenThis supports the Maven widget and search functionality. (Privacy Policy)
Google AdSenseThis is an ad network. (Privacy Policy)
Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
Index ExchangeThis is an ad network. (Privacy Policy)
SovrnThis is an ad network. (Privacy Policy)
Facebook AdsThis is an ad network. (Privacy Policy)
Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
AppNexusThis is an ad network. (Privacy Policy)
OpenxThis is an ad network. (Privacy Policy)
Rubicon ProjectThis is an ad network. (Privacy Policy)
TripleLiftThis is an ad network. (Privacy Policy)
Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)