Atmosphere

Hydrosphere

Air Temperature

Air Pressure controlling

Humidity

MR (mixing ratio) - actual WV in the air
= Mass wv(gm)/Mass air(kg)
not affected by P and T

SMR (saturated mixing ratio) - amount of wv required to saturate 1kg of dry air

AH (absolute humidity)
= Mass wv(gm)/volume of air(m3)
affected by P and T. changing V

RH (relative humidity) = MR/SMR

Weather

Typhoon

Wind

Cloud

Fog

Front

Precipitation

Process

Types:
Rain
Snow
Hail
Sleet
Glaze

Radiation / Valley - Rapid drop if temperature

Advection/ UpSlope - warm humid air to cold air surface

Evaporation / Steam - cold air to warm water surface

Stratus
Stratocumulus
Cumulus
Nimbostratus

Altostrauts
Altoculumus

Cirrostratus
Cirrocumulus
Cirrus

Cumulonimbus

Wind speed <62km/hr = tropical depression


Wind speed >63km/hr = tropical storm


Wind speed >119km/hr = tropical cyclone

Environmental lapse rate

Adiabatic lapse rate - rate at which the air parcel of forced rising air cools adiabatically with height, meaning no addition or removal of heat or energy.

Wet adiabatic rate - above the condensation level, wv condenses, latent heat releases, slower cooling rate of the air.
Rate of cooling is less than dry adiabatic rate.

Dry adiabatic rate - below the condensation level, dry air lifted, temperature cools for every 1000m.

Water vapor

Ocean current

Temperature

Air movement

More WV, density lower, pressure lower.
Because molecular weight of H2O is less than N2 or O2

Convergence aloft = Divergence surface-wind = anticyclone
→ net inflow of sinking air, higher pressure

Divergence aloft = Convergence surface-wind = cyclone
→ net outflow of rising air, lower pressure

Bergeron process: most ppt originate from ice crystal in high attitude, WV attached to ice crystal, grow larger in size and fall

Collision-Coalescence: raindrop coalesces and form large rain droplets, due to high surface tension, droplets breaks and fall as several small droplets

Coriolis Force -
Acts on wind velocity
Modify wind direction
Deflection increases with increasing latitude
Deflection increases with increasing wind speed

Friction -
Wind speed increase with altitude
Frirction decrease with altitude

Pressure gradient movement due to temperature

Horizontal: H → L

Vertical: L → H

Air Uplift

  1. Orthographic uplift - sir forced upwards over a hilly area
  2. Frontal wedging - warm less dense air forced up over a package of cold dense air
  3. Convergence of two air masses
  4. Localized Convective uplifting

Air Stability

Stable - Air parcel colder than surrounding, it resists uplift, tends to return its original position

Unstable - Air parcel warmer than surrounding, it tends to rise

Groundwater & WaterTable

Capillary Fringe - water seep up by capillary action

Saturated Zone (Phreatic)

Unsaturated Zone (Vadose)

Perched Water Tables - GW lies above the regional water table. In lens shape permeable layers with impermeable layer at the bottom.

Water flow

Upward flow

Downward flow

Gravity & Pressure

Pressure differences
from H → L

Artesian well - under enough pressure, water rise above the surface level of the aquifer on its own

Problem

Sea water intrusion

Reverse of flow direction

Over withdrawal - land subsidence, ground collapse

Contamination

Water depletion

Cave formation

  1. Thick limestone bedrock - depth
  2. Significant rainfall - carbonic acid
  3. Water table below ground - dissolve bi-carbonate
  4. Temperature to tropic warmth - fasten dissolution process

Warm front - warm air mass moves over a colder air mass - gentle gradient 1:200, wide spread clouds with light to moderate precipitation

Stationary front - neither advancing nor retreating

Cold front - cold air mass pushes under a warm air mass, steep gradient 1:100, short heavy rain and thunderstorm

Occluded front - cold front advances and overtakes a warm front

Air mass

Continental

Maritime

cP (Polar)

cT (Tropic)

cA (Arctic)

mP

mT

mE (Equatorial)

Thunderstorm - lightning and thunder
1. warm, moist, unstable air
2. upward air movement
3. within ITCZ

Formation:

  1. Warm ocean temperature > 26.5oc - energy source & water vapor - latent heat release during condensation of wv
  2. 10-20 oN/S
  3. Coriolis Force to drive spinning motion - increase due to Conservation of Angular Momentum that rotating speed increases as air moves towards centre
  4. Air pressure > 950 hPa - rising air causes pressure decrease

Air circulation

Scale

Mesoscale (<1000km) min to hr

Macroscale

  1. Synopic (1000-5000km) days to weeks
  2. Plantery (5000-40000km) weeks to more

Microscale (<1km) s to mim

Examples:

  1. Sea land Breeze
  2. Mountain Valley Breeze
  3. Country Breeze
  4. Falling wind

Pressure cells

Weather Observing Tools:

  1. ASOS
  2. Radiosonde
  3. Doppler Weather Radar
  4. Satellite

Thermal Structure

Mesosphere -

  1. coldest place of mesopause, very scarce wv can sublimate into polar nuctilucent clouds
  2. contains little ozone to absorb UV energy
  3. temperature decreases with height

Stratosphere -

  1. ozone layer with peak conc at 25 km
  2. weak vertical motion, free of clouds
  3. less UV energy penetrate deeper due to UV absorption by ozone near the top which cause heating
  4. temperature increases with height

Thermoshpere -

  1. contains little mass
  2. cloudness and no wv
  3. oxygen and nitrogen molecules absorb solar energy cause warming
  4. temperature increases with height
  5. air density is so low that very little heat is transferred, cannot feel heat

Troposphere -

  1. contains 80% of the air mass, wv
  2. strong vertical motion & weather take place
  3. surface heated by solar radiation
  4. temperature decreases with height

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Radiation Budget

Factor affecting


  1. Latitude and seasons
  2. Land and Sea
  3. Altitude
  4. Cloud cover and Albedo
  5. Ocean current
  6. Windward and leeward coast

Factors affecting insolation

  1. Angle of the Sun
    a. Time of day
    b. Latitude
    c. Season
    d. At 0o, 90-λ
    e. At 23.5o N/S = 90-(λ-ψ)
    f. sin ѳ = 1/L
  2. Duration of daylight

  3. Atmosphere

  1. Hadley
  2. Ferrel
  3. Polar
  4. Polar/ Subtropical Jet stream - help balance Earth's heat by bring warm air North and cold air South

Monsoon - particular wind system reverse its direction twice a year

Ocean

Wind effect

Ekman's spiral & transport -

  1. Coriolis force deflect surface currents, increasing deflection with increasing depth
  2. decreasing speed with increasing depth

Ocean current

Gulf stream/
Global Conveyor Belt - transporting water and heat

La Nina

El nino

weaken easterly trade wind, less push for the warm water piling to the western side and to the central and the east, less cold water upwelling in the east.
Thunderstorm in central, west experiences descending air and drought

Dissipation:

  1. Latent heat cut off when moves inland
  2. When large scale flow aloft is unfavorable, diminish intensity

strengthen easterly trade wind, larger push the warm water to far western side, more cold water upwelling in the east. Thunderstorm further west

Southern Oscillation(normal)

easterly trade wind, warm water piling from the coast to the western side, cold water upwelling in the east to replace it. Enhanced easterly trade winds, thunderstorm on the west

Gyres - nearly circular pattern

Driven: Polar oceans, freezing and evaporation of water → increase salinity & density → water sink

Weaken: Polar oceans, melting ices adding fresh water → decrease salinity & density → water upwell

Driven:

  1. surface winds
  2. heat of the sun
  3. Coriolis effect
  4. gravity

Equatorial upwelling

Trade Winds & Coriolis effect - pulls surface water away from the equatorial region, resulted in divergence, causing upwelling of deeper water to replace the surface water.

Tides - generated by gravitational pull of the Moon and Sun on rotating Earth

Spring tide: Earth, Moon, Sun are aligned; highest high and lowest low
Neap tide: Earth, Moon, Sun are at right angle; highest low and lowest high

Begin with the formation of North Atlantic Deep Water

Tide Bulges

Conditions for maximum tide-generating force

  1. Sun is at perihelion
  2. Moon is at perigee
  3. Sun and Moon are aligned, with zero declination
    conditions occur once every 1600 years

Amphidromic Circulation

  1. A tide wave crest enters an ocean basin in the Northern Hemisphere.
  2. The wave trends to the right because of the Coriolis effect, causing a high tide on the basin’s eastern shore.
  3. Unable to continue turning to the right because of the interference of the shore, the crest moves northward, following the shoreline and causing a high tide on the basin’s northern shore.
    4.The wave continues its progress around the basin in a counterclockwise direction, forming a high tide on the western shore and completing the circuit. The point around which the crest moves is an amphidromic point (AP).
  1. The moon’s gravity attracts the ocean toward it.
  2. The motion of Earth around the center of mass of the Earth–moon system throws up a bulge on the side of Earth opposite the moon.
  3. The combination of the two effects creates two tidal bulges.

Types of tide

Diurnal: Moon at angle to the Equator

Mixed: Moon at angle to the Equator, HH,LL,HL,LL

Semi-diurnal: moon in the same plane as the Equator

Pressure Belts

ITCZ - most solar radiation, most ppt, least pressure

Horse latitude

Doldrum