GEOG 3900 Weeks 5 & 6

Wind and ocean currents result of

Earth’s general circulation (atmosphere and oceans) redistributing a net + radiation (energy) at lower latitudes toward net - radiation at higher latitudes

True

T/F: Atmospheric pressure always decreases non-linearly w/ elevation, while temp may increase or decrease w/ elevation

Inversion

Generally temp decreases as elevation increases in the troposphere, but when temps increase w/ elevation, it is…

Latitude

Insolation varies by

Tilt (earth’s axis)

Seasonal variation by latitude occurs bc of

tropics

Net radiation surplus occurs at the…

poles

Net radiation deficit occurs at the…

redistribute energy (heat)

The atmosphere and ocean circulations…

25

Current solar cycle

Perihelion

7% more insolation (energy)

Some influence on climate, but obvs doesn’t cause seasons

Jan

Aphelion

July

Furthest from sun

Solar altitude/angle

Same sunlight spread over 2x when at 30 degrees

Thus the tropics are the warmest

Annual outgoing radiation

same thickness everywhere

Annual incoming radiation

greater at lower latitudes

Tropical latitudes

The heat engine of the earth system is driven by…

ITCZ

Inter Tropical Convergence Zone

a line of cumulus clouds in the tropics

inter tropical winds from heat

higher, lower

Winds go from ____ to ____ pressure

Temp gradient

Radiation imbalance → __ ______ → Pressure gradient

Global circulation

About transferring heat (energy) from hot tropics to cold poles

land

What heats faster, land or water?

heat capacity

water has a higher….

Evaporation

Liquid to gas

Takes energy

Ex. sweating to cool off

Adiabatic cooling and warming

Derive thermodynamics

No net exchange of heat

Parcels changing volume of pressure

latent heat

heat released or absorbed during a phase change

heat not felt

evaporation, condensation

most common [latent heat] phase changes

general circulation cause

imbalance in net radiation (more to tropics, more from poles)

lower, higher latitudes

Winds and currents redistribute surplus energy from ____ to _____ ______

curvature of the surface → insolation more concentrated at lower latitudes

the Earth’s surface receives dif amounts of radiation from the sun mainly bc of…

pressure

wind is caused by _____ gradient

high, low

wind always flows from regions of relatively ____ pressure to regions of relatively _____ pressure

ITCZ

zone of low pressure around equator

subtropical highs

regions of clear skies + deserts around 30 deg lat

trade winds

easterly winds winds converging on the equator

westerlies

winds predominant in mid-latitudes

polar highs

cold dense air masses predominate

hadley cell

circulation cell between equator + ~30 deg lat

40 deg N

our relative location

net radiation of zero

general circulation

global wind + ocean currents pattern

general circulation cause

imbalance in net radiation (i.e. more incoming energy to tropics; more outgoing at poles)

winds + currents redistribute surplus energy from lower to higher lats

general circulation mechanism

differential isolation → pressure dif → winds (H to L pressure) → ocean currents follow, w/ extra density forcing

atmospheric circulation

low + high surface pressure direct surface winds

coriolis effect deflects winds

circulation cells

ITCZ - convergence + convection

low + high surface pressure

what directs surface winds?

coriolis effect

what deflects winds?

1000x

oceans hold ____ more heat than the atmosphere (90%)

oceans + CO2

contains >50x more than atmosphere

exchanges c w/ atmosphere, absorbing ~30% of our emissions

primary control of atmospheric CO2 levels

water properties

polar

its polarity

why is water such an effect heat source?

polar molecule

ft oxygen bonding w/ hydrogen sharing electrons

”universal solvent”; surface tension → hydrogen bonds

solid less dense than liquid (ice floats)

redistribute heat globally

ocean currents…

current types

surface currents or deeper currents

surface currents

driven by winds

control motion of 10% of ocean’s water

deeper currents

driven by density dif

control motion of 90% of ocean’s water

coriolis effect

makes things (i.e. planes or currents of air) traveling long distances around Earth appear to move at a curve as opposed to a straight line

Gulf Stream

heat pump

sinks

cold, dense water…

rises, energy

warm, salty surface water ____+ transports _____

El Nino

southern oscillation

warm

westerly winds

weaker trade winds

warm ocean temps

walker circulation

normal conditions

typically strong high-pressure systems of the eastern pacific weaken

pacific westerlies bursts of warm, moist air

greatly affected by el nino or la nina

La Nina

cold

strong trade winds

easterly winds

current el nino

record high temps

excess rain

what triggers the shift

what we don’t know about el nino

seasonal temp, precip patterns

El Nino + La Nina known to shift … in many dif regions of the world

teleconnections

the relationships between weather or climate patterns at 2 widely separated locations

shows a dip in the east pacific

During El Nino, the jet stream’s position…

moderate to strong el nino north atlantic basin

substantial reduction in cyclone numbers

60% reduction in numbers of hurricane days

an overall reduction in system intensity

el nino historic imacts

very high rainfall in Peru + California (led to floods + landslides)

forest fires in Indonesia → serious air pollution

crop failures, famine in Africa

collapse of Peruvian anchovetta fisheries

30 degrees

deserts latitude location

subtropical highs

heating

…sets up pressure gradients that drive winds (Coriolis deflection)

tropics

surplus radiation in the…

ferrel cell

the avg motion of air in the mid-latitudes

redistribute heat from the equator toward the poles

water vapor

most potent and abundant greenhouse gas

temperature

water vapor is highly dependent on…

over 800,000 years

atmosphere’s concentrations of CO2 highest level in…

water vapor, CO2

what two greenhouse gases dominate absorption of long wave radiation?

Keeling Curve

Measurement of CO2 levels

Seasonal changes in plants

Why is there an annual cycle w/ the Keeling Curve (ebbs and flows a bit throughout the year)?

northern hemisphere

…sees more variation in keeling curve

due to more land mass, more plants, more industrial activity

wildfires

why is there carbon monoxide in the southern hemisphere?

800,000

ice cores go back _____ years

global circulation

CO2 dispersal determined by…

short, long term

flow of carbon cycles

is sequestered in rocks

most (99.9%) of carbon on or near Earth’s surface…

carbon reservoirs

1) rock reservoir

2) world ocean

4) organic carbon in permafrost (which is thawing!!)

6) living biomass

carbohydrate

CH2O

turn over time/residence time

reservoir / flux out