Thus, such winds are called permanent winds. Since these winds are distributed all over the globe and these are related to thermally and dynamically induced pressure belts and rotation of the earth and hence they are called planetary winds. These winds include trade winds, westerlies and polar winds (fig. 35.7). i. Winds in the Tropics:
Thus, winds blow from polar high pressure to sub-polar low pressure cells. These are called polar winds which are north-easterly in the southern hemisphere and south-easterly in the southern hemisphere.
Global Wind Explained. The rising air creates a circulation cell, called a Hadley Cell, in which the air rises and cools at high altitudes moves outward (towards the poles) and, eventually, descends back to the surface. The continual heating and rise of air at the equator creates low pressure there, which causes air to move (wind)...
In the Southern Hemisphere, this deflection is to the left. The effect is greater with increasing latitude. Unlike winds aloft, which blow nearly parallel to the isobars, surface winds generally cross the isobars. Explain what causes this difference. At the surface, friction affects wind and as a result alters its direction.
The poleward parts of the trade winds or eastern sides of the subtropical anticyclones are dry because of strong subsidence of air currents from above. Because of the dominance of anticyclonic conditions there is strong atmospheric stability, strong inversion of temperature and clear sky.
In this article we will discuss about the classification of planetary winds. The winds blowing almost in the same direction throughout the year are called prevailing or permanent winds. These are also called as invariable or planetary winds because they involve larger areas of the globe.
The equatorial westerlies are associated with strong atmospheric disturbances (cyclonic storms). Flohn has further maintained that south-western monsoons are, infact, equatorial westerlies because these winds are extended upto 30-35°N latitudes over Indian subcontinent due to northward shifting of NITC at the time of summer solstice (fig. 35.9).
Thus, such winds are called permanent winds. Since these winds are distributed all over the globe and these are related to thermally and dynamically induced pressure belts and rotation of the earth and hence they are called planetary winds. These winds include trade winds, westerlies and polar winds (fig. 35.7). i.
These are also called as invariable or planetary winds because they involve larger areas of the globe. On the other hand, winds with seasonal changes in their directions are called seasonal winds (e.g., monsoon winds). On an averages, the location of high and low pressure belts is considered to be stationary on the globe ...
The zone of polar winds shrinks due to northward shifting of pressure belts at the time of northern summer (summer solstice) in the northern hemisphere but it is extended up to 60°N latitude during northern winter (winter solstice). Home ›› Atmospheric Circulation ›› Climatology ›› Geography ›› Planetary Winds ›› Winds.
In fact, the belt of doldrum shifts northward during summer solstice (when the sun is vertical (fig. 35.8) viz.:
The station model shows several weather variables recorded at a particular location. What was the most likely dewpoint at this location?
Clouds usually form on the windward sides of mountains because this is where air
A city located on the coast of North America has warmer winters and cooler summers than a city at the same elevation and latitude located near the center of North America.
A parcel of air has a dry-bulb temperature of 16ºu000e C and a wet-bulb temperature of 10u000eº C. What are the dewpoint and relative humidity readings of the air?
Wind speeds are usually greater over land surfaces than over ocean surfaces.
The c P air mass is warmer and less humid.
Compared to an inland location, a location on an ocean shore at the same elevation and latitude is likely to have
The pressure gradient force and the Coriolis effect at the surface causes air to move across the isobars. Aloft, geostrophic winds lack friction with Earth's surface and can travel more quickly as the Coriolis effect balances the PGF.
The aneroid barometer has a partly evacuated vacuum chamber that compresses as the pressure increases. Levers are connected to the chamber and transmit readings to a pointer on a dial that is calibrated to read the correct atmospheric pressure.
El Niño might cause the southern portion of North America to be wet, with the eastern part also being cool. The northern portion of North America might be warmer. A La Niña might cause the southern portion of North America to be warm and dry and the northern portion to be cool.
In the Northern Hemisphere, the Coriolis effect causes the deflection of the path of a moving object, including moving air, to the right . In the Southern Hemisphere, this deflection is to the left. The effect is greater with increasing latitude.
The Southern Oscillation is a shift in high and low atmospheric pressures in the eastern and western tropical Pacific Ocean. An El Niño is associated with an increase in surface pressure near Australia and a drop in pressure off the coast of Peru. The opposite occurs with La Niña.
The closer together the isobars are, the faster the wind speed.
Describe the formation of a sea breeze. During the summer solar radiation heats the land surface near the sea more quickly than it heats water with its high thermal inertia. A thermal low pressure develops over the land, and air flows onto the land from the sea, which is at a relatively higher pressure.