Please enable JavaScript.
Coggle requires JavaScript to display documents.
1.7 Factors that affect climate: Wind and Oceans (global winds…
1.7 Factors that affect climate:
Wind and Oceans
climate
an area's climate is a measure of two things
-temperature
-humidity and precipitation
the main geographical factors that determine an areas climate are
latitude
altitude
prevailing winds
proximity to the ocean
ocean currents
global winds
why do winds occur?
wind is the movement of air parallel to earth's surface
winds move from areas of high air pressure to areas of low air pressure, until pressure is equalized
winds also move between east and west
the coriolis effect
earth's surface is hotter near the equator
the ground or ocean surface is heated by the sun by radiation
it warms up the air above it by conduction
hot air rises and circulates in the atmosphere by convection
air cools down as it rises and spreads out in the upper atmosphere
cool air is less dense so it sinks back down to the surface
the cool dense air spreads out, especially into areas of lower density- the areas where hot air is rising
hence there is wind from cool, low pressure areas, into hot, low pressure areas
the air convection currents happen on a global scale
prevailing winds: direction of the average wind
local winds are affected by local geographical features and weather
in most areas wind originates from just one direction most of the time and are mainly affected by the global wind currents
prevailing winds affect temperature and humidity
a wind coming from the north or south pole is called polar wind
a wind coming from the equator is called an equatorial wind
seasonal winds
prevailing winds might not come from the same direction all year, making them seasonal
monsoon: winds that bring heavy rains
land and sea breezes
sea breeze: during the day, air over the land is warmer, rises, and creates a low pressure area into which a cool wind blows from the denser air over the sea
land breeze: during the night, the air above the land is now cooler than the air above the sea, so it blows from the land to the sea
ocean currents
surface ocean currents are streams of ocean water that move through the oceans in regular patterns, caused by wind blowing predominantly in the same direction gradually causing momentum in the water
warm currents: some warm currents move from the tropics toward the poles. this warm water warms the air above it. the warmed air then moves over nearby land, affecting its climate
cold currents: cold water comes from the polar zones toward the equator. this cools the air that comes with it
el nino souther oscillation
happens every 2-7 years when trade winds blow warm water from southern north america and central america west cross the pacific
this event can last 9-12 months and can cause flooding, droughts and storms