extreme climates Flashcards
1
Q
formation of a hurricane
A
- evaporation of sea creates a low pressure area
- low pressure area draws in low level winds close to sea surface
- rising air condenses, releasing latent heat, further driving evaporation, condensation and cloud formation (cumulus and cumulonimbus)
- cloud formation not broken up at high altitudes as there is low wind shear
- coriolis force/anticyclone in upper troposphere causes wind to exit and sink, creating hurricane vortex
- hurricane picks up energy as it travels over warm water
- energy dissipates when hurricane makes landfall as there is less energy to absorb from land
2
Q
conditions required for formation of a hurricane
A
- between 30N and 30S of equator, but not at the equator
- sea surface temperature of 26C (top 50m) or above
- low wind shear (directional wind) at high winds
3
Q
tornado formation
A
- ground heated by sun generates upward convection, forcing moist air high into the atmosphere
- meets cool dry air causing rapid cooling, creating clouds (cumulus, cumulonimbus)
- strong wind shear force from opposite direction of convection rotates air
- updraft tilts cylinder of rotating air, tornado touches ground and moves over land
4
Q
tornado alley
A
- tornadoes generally happen in USA
- ideal climatic conditions for tornado formation
- warm moist air moving up from gulf of mexico
- cool westerly wind from pacific ocean
- cool dry air from rock mountains and north Mexican desert
- moves further north over summer
5
Q
Monsoon formation
A
- in summer Asian landmass warms more rapidly than the sea, creating a larger temperature gradient and therefore more convection
- subtropical jet stream weakens and moves north over Himalayas
- tropical easterly jet forms, creating a high pressure system over the Indian ocean
- moist air moves northwards down a pressure gradient and condenses causing large scale rains
6
Q
predictability of monsoons
A
- communities rely on regular annual event for agriculture
- climate change leading to changes in the jet stream may stop or make monsoons more intense
- intense monsoons can trigger cyclones
- can be lethal if unpredictable
7
Q
A