2. Atmospheres info

Name the heights of each layer of the atmosphere

Troposphere = 0-10km

Stratosphere= 10-50km

Mesosphere = 50-80km

Thermosphere = 80km +

Explain diurnal energy budget

Types of cloud albedo affect

Cirrus clouds - thin and wispy - low albedo

Cumulonimbus clouds - thick so higher albedo

Stratus = low and thick clouds - highest albedo

Sensible vs latent heat transfer

Sensible = increase in air temp

Latent = energy held in changing of state

Explain this graph

Incoming short wave radiation decreases with latitude due to

• Oblique angle of incidence

• Travels through a longer distance of atmosphere

• Higher albedo

Longwave changes based on insolation as this is what influences temperature of ground.

Dip in longwave near equator due to ITCZ.

What are geostrophic winds

Winds that travel parallel to isobars as the pressure gradient force is balanced with the Coriolis force

Name GAC cells from North to South explaining weather formations and pressure/direction of air

What drives ocean currents - rough model for their movement

Winds, tides, rotations of earth, changes in water pressure
Clockwise in NH, Anti-clockwise in SH in large circles

 

What role does the Great Ocean Conveyor Belt play in the development of heat circulation?

Distributes heat from hotter to colder regions

Define solstice and equinox

Solstice = longest/shortest day in year

Equinox = day and night are approx equal in length

Where and why is the thermal equator?

Usually, around 5N in July, Around equator or just below in January

• Northern Hemisphere has more land

• Land has low specific heat capacity so heats up and loses heat fast

• Therefore, in NH land warms rapidly and surface temperature becomes higher

List all types of air mass and their characteristics

Polar - cold

Tropical - warm

Continental - dry - more extreme

Maritime - moist

Define continentality

Areas in centre of continents experience more extreme temperatures because moderating ocean currents do not reach there

Why does temperature change with altitude

Adiabatic cooling. 1C per 100m dry air, lower for saturated air

What are Rossby waves

Giant meanders in high altitude jet streams/winds

List all forms of cooling/fog

Radiation, advection, orographic, frontal, adiabatic

Explain radiation cooling

• Ground loses heat rapidly by terrestrial long wave radiation - often on cloudless night

• Moist air in contact with ground loses energy due to conduction

• This causes temperature of air mass to drop below dew point

• Excess moisture condenses to form radiation fog, dew and hoar frost

Explain advection cooling

• Warm moist air moves over a cooler land or sea surface

• This causes temperature of air mass to drop below dew point meaning condensation will occur

• This forms advection fog and haar fog

Explain orographic rainfall

• Moist air mass travels into mountain causing vertical movement of air

• As air mass rises it cools due to adiabatic cooling, reaches RH of 100% and condenses

• This forms clouds and precipitation on the windward side of the mountain

• Air is now dry on Leeward side leading to a rain shadow

• Foen Effect - adiabatic lapse rate of dry air is less than saturated air creating high temperatures on leeward side

• 
  

Explain adiabatic cooling

• A parcel of air rises

• Air pressure decreases with elevation

• Parcel of air will expand

• Expansion causes molecules to spread out and cool

Bergeron-Findeisen theory vs Collision and Coalescence theory

BF - supercooled water collides with ice causing ice molecules to grow - when these are heavy enough they fall and melt as rain - cold sub zero conditions

CC - as water droplets move vertically past each other they combine into a larger droplet which eventually falls - tropical conditions

Ways we can record change in temperature of past and how far back can they track and how they work

Instrumental data - 150 yrs

Dendrochronology - 10,000 yrs

Ice cores - 1,000,000 years

Ocean sediment cores and foraminifera - many millions

All forcings for natural climate change

Sun spots - every 11 years - increase earths temp

Milankovic cycles

• Eccentricity - every 100,000 yrs - elliptical orbits - more extremes

• Obliquity - every 41,000 yrs - angle of earths axis changes - more extreme seasons

• Precession - every 26,000 yrs - influences insolation received by each hemisphere over a year

Volcanic eruptions - months/years - reflect insolation causing global temperature drop

Human climate change influence - GHG/aerosols

GHG - enhanced Greenhouse effect as long wave radiation is absorbed and reradiated to earth

Aerosols - reflect insolation reducing temp

Ozone contribution to global warming

Does not contribute to global warming

allows more harmful UV in

What is El Nino

• Weakening trade winds mean that the warm water that usually piles up on the West coast of Australia

• This causes the colder parts of the ocean to warm and spread across the surface

• this increases global temperature and increases risk of floods

• La Nina isi nverse