METR 212 Class exercise

The way to define a monsoon is via a seasonal change in the prevailing wind direction. The strongest monsoon in the world occurs in Asia, specifically in India. However, the monsoon extends to Indonesia, Viet Nam, and China as well.

Monthly rainfall in cities in Asia will be strongly affected by the monsoon. Southerly winds, especially those coming from over the ocean will be associated with very high average monthly precipitation amounts.

Three cities which see a monsoonal influence on their average monthly precipitation are Beijing (China), Hue (Viet Nam), and Semarang (Indonesia). The locations of these cities are seen as the black dots on the January wind map. from the Earth Systems Research Laboratory of NOAA. On this map and on the loop of months, the low level winds are seen as arrows, not wind flags. So an easterly wind has an arrow which points from east to west. The length of the arrows is proportional to wind speed so longer arrows mean windier conditions.

The full loop of months must also be viewed to see the changes over the course of a year. You may view the loop in any browser. Irfanview will also play loops or you can click on individual months: Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec.

a. Three tabulations of average precipitation are shown for places called Station A, Station B, and Station C ( source: weatherbase.com). Which one is Beijing? Which one is Hue? Which one is Semarang? Hint: Find the three wettest months for each station.

b. Knowing that a change in direction signifies the passage of the monsoon, justify your choices for part a, based on the winds and the effect the wind direction will have on precipitation.

This is due next Tuesday