North American Monsoon

2918 WordsJan 18, 201112 Pages
Monsoon is traditionally defined as a seasonal reversing wind accompanied by corresponding changes in precipitation,[1] but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with the asymmetric heating of land and sea.[2] [3] Usually, the term monsoon is used to refer to the rainy phase of a seasonally-changing pattern, although technically there is also a dry phase. The major monsoon systems of the world consist of the West African and Asia-Australian monsoons. The inclusion of the North and South American monsoons with incomplete wind reversal may be debated. The term was first used in English in British India (now India, Bangladesh and Pakistan) and neighbouring countries to refer to the…show more content…
Additionally, the specific heat capacity of liquid water is significantly higher than that of most materials that make up land. Together, these factors mean that the heat capacity of the layer participating in the seasonal cycle is much larger over the oceans than over land, with the consequence that the air over the land warms faster and reaches a higher temperature than the air over the ocean. The hot air over the land tends to rise, creating an area of low pressure. This creates a steady wind blowing toward the land, bringing the moist near-surface air over the oceans with it.[14] Similar rainfall is caused by the moist ocean air being lifted upwards by mountains,[15] surface heating,[16] convergence at the surface,[17] divergence aloft, or from storm-produced outflows at the surface.[18] However the lifting occurs, the air cools due to expansion in lower pressure, which in turn produces condensation. In winter, the land cools off quickly, but the ocean retains heat longer. The cold air over the land creates a high pressure area which produces a breeze from land to ocean.[14] Monsoons are similar to sea and land breezes, a term usually referring to the localized, diurnal (daily) cycle of circulation near coastlines, but they are much larger in scale, stronger and seasonal.[19] Most summer monsoons
Open Document