Geo 1 Midterm

Geography
Horse Latitudes
Subtropical Highs (between 30-35 degrees N or S)
STH characterized by absence of wind
Named bc 16th and 17th century sailing ships were sometimes becalmed there and their cargos of horses were thrown overboard to conserve drinking water
albedo
the reflectivity of an object
radiation that is bounced back into space
higher albedo, higher reflectivity
lighter objects have higher albedo (snow)
darker objects have lower albedo (tree cover, soil, deserts)
advection fog
occurs when moist air passes over a cool surface by advection (wind) and is cooled
horizontal movement
example the SF fog/ Warm air from PineApple express from Hawaii moves over cold Pacific water to create advection fog
radiation fog
formed by the cooling of land after sunset by thermal radiation in calm conditions with clear sky
The cool ground produces condensation in the nearby air by heat conduction.
Hawaiian High
subtropical high in North Pacific
dew-point
the atmospheric temperature below chic water vapor begins to condense and form dew (3 degrees C)
Dry Adiabatic Lapse Rate
cools at steady lapse rate (10 C per 1000 meters)
the air is not necessarily dry it is just unsaturated. If the air rises high enough, it cools to the dew point temperature, condensation begins, and clouds form. The altitude at which this occurs is known as the lifting condensation level (LCL).
Environmental Lapse Rate (ELR)
is the rate of decrease of temperature with altitude in the stationary atmosphere at a given time and location
relative humidity
a ratio (expressed as a percentage) that compares the actual amount of water vapor in the air to the water vapor “capacity” of air
Increase temp, Increase water vapor capacity, decrease relative humidity
Decrease temp, decrease water vapor capacity, increase relative humidity
stable air
If a parcel of air resists uplift it is said to be stable. Rise only when acted on by a force such as moving up a mountain. Cold air is beneath warm air. Generally not associated with cloud formation or precipitation. none buoyant. remains immobile unless forced to rise. if clouds develop, tend to be stratiform or cirri form. if precipitation occurs, tends to be drizzly
Aleutian Low
semi-permanent low pressure center located near the Aleutian Islands during the winter. It is one of the main centers of action in the atmospheric circulation of the Northern Hemisphere. The Aleutian Low is characterized by many strong cyclones.
angle of inclination
23.5 degrees
June 20 – Summer Solstice for Northern Hemisphere
December 21 – Winter Solstice for Northern Hemisphere
Equinox (12 hours of day/ 12 hours of night) – March 20 and September 22
Anticyclonic
High pressure system
Northern Hem – clockwise
Southern Hem – counterclockwise
aphelion
away – earth is furthest from sun
Cloud Types
cirriform – thin, wispy
Stratiform – spread out
Cumuliform – mass or pile
“nimb” = rain cloud
cirro = usually high clouds
Conduction
the movement of heat energy from one molecule to another without changes in their relative positions
Continentality
the tendency of land to experience more thermal variation than water
heats and cools more rapidly than water
Convection
Process of convection heat is transfer from one point to another by the predominately vertical circulation of a fluid, such as air or water
Coriolis Force
a force due to the earth’s rotation; acts on a body in motion (airplane or projectile) in a rotating reference frame
to the right in Northern Hem
to the left in Southern Hem
Cyclone
low pressure system
northern hem – counterclockwise
southern hem – clockwise
El Nino/ Southern Oscillation
Walker realized pattern of pressure system
an episodic atmospheric and oceanic phenomenon of the equatorial Pacific Ocean, particularly prominent along the west coast of South America
abnormally warm water appears at the surface of the ocean of the west coast of South America
Normally, dominated by the persistent subtropical high associated with the subsiding air of the Hadley Cell circulation. Trades blow west to east across the Pacific – this tropical airflow drags surface ocean water westward across the Pacific basin in the warm Equatorial Current. Pulls warm water away from South America and cold, nutrient rich water upwells. Darwin – low, tahiti – h. higher water in the Indonesian region

Pressure changes in El Nino. Darwin – high, tahiti – low known as southern oscillation.

ENSO – atmospheric and oceanic

La Nina
usually cooler waters off South America and stronger than usual trade winds
Evaporation
liquid water gains latent heat as it becomes water vapor
Global Winds
N/S Easterlies closest to equator known as the trade winds (0 -30)
N/S Westerlies only winds that blow west (30-60)
Pole Easterlies known as Easterlies (60-90)
latent heat of condensation
the energy released during condensation
high pressure
wind push clouds away
air is falling (H for heavy)
clockwise – northern hem
counterclockwise – southern hem
low pressure
cloudy skys/ heating at surface allows water to evaporate and create water vapor
go up atmosphere it cools and creates clouds
(l for light)
insolation
the solar radiation that reaches the earth’s surface
instability
warm, high humidity, rising air, air close to dew point

when DALR or SALR crosses the ELR

inversion (temperature)
a situation in which temperature in the troposphere increase rather than decreases with increasing altitude
isobars
line connecting points of equal atmospheric pressure
ITCZ
Intertropical Convergence Zone

low pressure zone made up of rising air and a band of clouds that are visible on satellite images from space

jet streams
fast flowing, narrow air currents found in the atmospheres of some planets, including Earth. The main jet streams are located near the tropopause, the transition between the troposphere (where temperature decreases with altitude) and the stratosphere (where temperature increases with altitude). The major jet streams on Earth are westerly winds (flowing east to west). Their paths typically have a meandering shape. strongest jet streams are the Polar jets. weaker Subtropical jets.
North Atlantic Oscillation
irregular “see-saw” multiyear cycles of pressure differences between two regional components of general atmospheric circulation in the North Atlantic ocean basin. The Icelandic low and the Subtropical high
Unstable
buoyant
if clouds develop tend to be cumuliform
if perspiration occurs, tends to be showery
Unstable
buoyant
if clouds develop tend to be cumuliform
if perspiration occurs, tends to be showery
types of rain
rain – widespread form of precipitate consists of liquid forms of water

snow – solid precipitate in form of ice pellets or flakes

sleet – small raindrops that freeze during decent/ reach ground as ice

glaze (freezing rain) – rain turns to ice it collides with a solid object

most complex consists of either small pellets or larger lumps of ice

Pacific Decadal Oscillation
long-term pattern of sea surface temperature change between the northern/west and tropical and eastern tropical Pacific Ocean. Every 20-30 year changes. Influenced by jet streams and El Nino Events. Warmer northern/west temperatures and cooler east temps – current.
Perihelion
proximo/ earth closest to sun
Plane of the ecliptic
the imaginary plane defined by orbital path around the sun
Polar front
the final surface component of the general pattern of atmospheric circulation is a zone of low pressure at about 50-60 degrees latitude of both N and S Hem. (mini ITCZ)
Prime Meridian
where the earth is split in have longitudinally (Greenwich, England)
Stratosphere
above the troposphere/ air increase in temperature with increase in altitude
Tropopause
transition zone between troposphere and stratosphere
Walker Circulation
warm water and persistent low pressure prevail around Northern Australia and Indonesia; local convective thunderstorms develop in the ITCZ producing high annual rainfall in this region of the world. After the air rises in ITCZ, it begins to flow polar ward but is deflected by Coriolis effect into the upper atmosphere westerly antitrade winds. Some of this airflow aloft subsides into the STH on the other side of the Pacific.
Hadley Cell
complete vertical convective circulation cell/ two prominent tropical circulations

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