Climate and Weather Flashcards
(41 cards)
Climate
refers to characteristic atmospheric conditions over a long period of time (years or decades)
Weather
refers to atmospheric conditions over short periods of time (days or weeks)
Koppen Climate Classification
Temperature and precipitation to classify climate zones
along with atmospheric pressure, moisture, wind
Climate can be affected
by processes and changes that maintain the climate system:
- ocean currents
- mountain ranges
- plateaus
Earths climate includes interactions of?
atmosphere hydrosphere geosphere biosphere cryosphere - Exchanges energy and moisture between these spheres
Climate imposes major influence on natural processes
- flooding dependent on rainfall amount and intensity
- landslides common in area with rainy climates
- wildfires more likely in dry area
Earths climate system
Natural processes:
- knowing the climate can indicate things about the hazard to expect
- climate classification supplies information about the relationship between climate and vegetation
Permanent gases
Gases whose proportions stay constant
- nitrogen and oxygen
have little effect atmospherically
Variable gases
gases whose proportions vary with time and space
play important roles in atmospheric dynamics
- CO2, water vapour, methane
Aerosols
particles whose proportions vary with time and space
Posotive feedback loops
enhances initial change
- vanishing arctic ice
Negative feedback loops
counteract initial change
- evaporation = cloud formation = cooling = reflectance
Proxy data
indirect evidence using natural recorders of climate variability
- sea floor sediment
- coral deposits
- glacial ice rings
- tree rings
- pollen
Milankovitch theory
- eccentricity of earths orbit (shape)
- obliquity of earths axis (wobble)
- precession of earths axis (angle)
Green Sahara
11,000-5000 years BP (African Humid Period)
controlled position of monsoon rainfall
- increased lake levels
- nike river runoff increased
- period ended when precession shifted and ITCZ migrated back south (removal of moisture)
- return to desert conditions
Solar activity (shorter term controls)
sunspots/solar flares
10’s of years
little ice age/Maunder minimum
medieval warm period
Thermohaline circulation changes
- 100’s to 1000’s of years
Volcanic activity
particulate material in atmosphere
- <10’s or years
Natural Causes of Climate Change
- solar energy changes
- small contribution to overall change
- but make short term hazardous event more likely
- contributor to little ice age initiation
Tipping point
a critical threshold where small change can have significant, long term impact to earths climate
- human or naturally induced
- gradually increasing CO2
Ocean climate patterns
- open oceans climate regions are parallel to latitude lines
- these regions may be modified by surface ocean currents
Ocean’s Climate Zones: Equatorial
- rising air
- weak winds
- doldrums
Ocean’s Climate Zones: Tropical
- north to south equatorial zone
- extend to tropics of Cancer and Capricorn
- strong winds, little precipitation, rough seas
Ocean’s Climate Zones: Subtropical
- high pressure, descending air
- weak winds
- sluggish currents
