GEOG 1201 EXAM #1

Cryosphere

Cryosphere

frozen water (part of hydrosphere)

Latitude

specifies north/south position (North Pole: 90 degrees)

Longitude

vertical lines

Prime meridian

Greenwich England (marker for time zones, etc.)

When did Earth’s atmo form?

4.6 billion years ago

Why did atmo form?

outgassing (release of gasses trapped in Earth’s interior, usually through volcanic activity)

1st atmo/primordial atmo

mostly sulfuric (O2 lacking), volcanic eruptions, water vapor, CO2

2nd atmo formation

formed as Earth cooled and water vapor formed clouds

• Ocean formation

• N2 increase

• O2 not present still

3rd atmo

formed as ocean life evolved

• Bacteria began photosynthesis (phytoplankton)

• O2 became significant 2.2 billion years ago

Modern atmo

formed when ozone in stratosphere developed

Atmospheric pressure at sea level

1kg on 1 cm²

Atmo composition

• Heterosphere

• Homosphere

Heterosphere

outer atmo

• Not uniform (gases occur in distinct layers according to atomic weight)

• Hydrogen and helium are lighter, O2 and N2 heavier

Homosphere

fairly uniform blend of gases

• Constant gases

• Variable gases

Constant gases

AMOUNT DOESN’T REALLY CHANGE

N2, O2, Ar (argon), Ne (neon(, He (helium), Kr (krypton), and Xe (xenon)

Variable gases

AMOUNT CHANGES IN ATMOSPHERE

H2O, CO2, CH4, N2O (nitrous oxide), O3

Layers of atmo

Thermosphere

Mesosphere

Stratosphere

Troposphere

Thermosphere

outermost (upper limit = thermopause)

TEMPERATURES RISE - no other layers blocking radiation, takes in lots of solar radiation

Mesosphere

coldest part of atmo, low air pressure (upper limit = mesopause)

TEMPERATURES DECREASE WITH ALTITUDE

Stratosphere

ozone layer converting ultraviolet energy to heat → heating (outer boundary = stratopause)

TEMPERATURES INCREASE WITH ALTITUDE

Troposphere

where weather occurs (outer boundary = tropopause)

TEMPERATURES DECREASE WITH ALTITUDE

Atmo function

• Ionosphere

• Ozonosphere

Ionosphere

outer layer, absorbs cosmic rays, gamma rays, x-rays (etc.) - changes atoms to positively charged ions

Ozonosphere

O3 layer

Ozone depletion

caused by CFCs

UV → CFC = Cl, chlorine breaks down O3

Montreal Protocol

reduced sale and production of CFCs, improved conditions

Effects of O3 depletion

decrease agricultural productivity, alters phytoplankton/plant physiology, skin damage for humans

Natural sources of pollutants

volcanoes, forest fires, pollen, dust storms

Anthropogenic sources of pollution

transportation, burning of fossil fuels, deforestation, etc.

Photochemical smog

mix of UV/NOx/VOCs

UV breaks NO2 into O + NO, NO+O2=O3

Effects of photochemical smog

damage to biological tissues, lung irritation, asthma, increased risk of respiratory illness

NO + VOCS = PANS → eye irritation

Clean Air Act

control pollution on a national level

Industrial pollutants

CO2, pm, sulfuric oxides, SO2 (sulfuric dioxide)+O=SO3 (sulfur trioxide)

Synoptic maps

typically national, air temp,. cloud cover, wind, air pressure, fronts

Isothermal

temp - contours correspond to temp

Isobaric

air pressure - lines called isobars

Radar

precipitation

Satellite imagery

from GOES, cloud formation, eastern and western satellites

Composite satellite image

usually satellite+radar

Atmospheric soundings

by weather balloon, balloon carries radiosonde (measures temp, humidity, pressure, wind), data at specific altitudes

Smog

used to be byproduct of coal and fog (similar to sulfuric acid), engines produce NOX, forms with VOCs, temp inverses and local geo can trap pollutants

Origin of O2

photodissociation (water vapor→2H2O+vis→2H2+O2

photosynthesis (CO2+vis+H2O→CH2O+O2)

Photosynthesis formula

CO2+vis+H2O→CH2O+O2

Ozone formation

photodissociation and recombination of oxygen

O3+UV=2O

O2+O=O3

CO2 sources

decay, volcanoes, burning of fossil fuels, deforestation, weathering of carbonate rocks

Nitrogen sources

volcanoes, industry, vegetation

Argon sources

radioactive decay

Sunspots

sun’s surface disturbances caused by magnetic storms (more=increased radiation)

Solar minimum

period when few sunspots visible

Solar maximum

period with numerous sunspots

Solar wind

sun emitting clouds of electrically charged particles - interacts with Earth’s magnetic field and deflects solar wind towards poles

causes aurora borealis and aurora australis

Radiant energy

sun’s energy, travels in waves

EM spectrum

hotter the object, shorter the wavelength

Insolation

solar energy intercepted by Earth

Solar constant

avg. insolation received at thermopause

Isotope analysis

16O and 18O specifically used to determine climate (more 16O is indicative of warmer climate conditions)

Sediment cores

calcium carbonate shells that build up and become sediment on ocean floor

Rapid warming

56 mya

Paleocene-Eocene Thermal Maximum (PETM) - suddenn increase in CO2 (potentially because of methane release from ocean floor)

Pleistocene

2.5 mya-11,700 years ago

most recent flaciation

Carbon isotope analysis

analyzing ration of 13C/12C - connected to radioactive decay

used for short-term dating

Speleothems

calcium carbonate mineral deposits in caves (stalactites and stalagmites)

similar to tree rings

climate paleontology

Corals

used for climate paleontology

similar to speleothems and tree rings

Transmissivity

radiation goes through substance

Rayleigh scatter

scatter more because shorter wavelength

Mic scatter

even scatter by O2 molecules

Natural climate fluctuation

solar variability - sunspots (not really driver of climate)

orbital cycles - elliptical orbit in 100,000 year cycles

axis wobbles - 26,000 year cycles

axial tilt - 41,000 year cycles

Feedback mechanisms

ice - albedo

water - vapor (increased evap→increased humidity→more evap)

permafrost

wildfire

Carbon budget

exchange of carbon between sources and sinks

largest sink is oceans

IPCC

Intergovernmental Panel on Climate Change

U.N. sponsored

findings: temps increasing globally, ice melt, sea level rise (melting of land mass, thermal expansion)

Kyoto Protocol

legally binding specific emission reductions

COP 21

agreement to reduce greenhouse gas emissions

Ozone hole

50% reduction seasonally, 4-7% depletion per decade

minimum occurs during spring

caused by polar vortex (circulation of cold air)

Polar stratospheric clouds (PSCs)

Cl compounds interacting with cloud particles → increased Cl concentration during winter (UV in spring release Cl, leading to rapid ozone depletion)

Energy

ability to do work (work=force applied over distance)

Power

work over time (measured in watts)

Conduction

transfer between matter in physical contact

Convection

transfer via heating of fluids

Stefan-Boltzmann Law

difference between temp of substance and radiation it gives off

Wien’s Law

wavelength of maximum emission inversely proportional to temp

Direct radiation

direct to ground

Diffuse radiation

passes through clouds to ground

Scattering

deflection and redirection of insolation (the lower the wavelength, greater the scattering)

Refraction

bending of em rays

Reflection

reflecting energy back into space

Absorbtion

assimilation of radiation by molecules of matter

Sensible heat

heat able to be sensed (from kinetic energy)

Latent heat

heat lost/gained when a subject changes states

Highest level of insolation

at tropics

Net radiation

sum of all incoming and outgoing radiation

Terrestrial radiation

about 460 w/m²

10 wavelength of max emission (longwave)

Atmospheric window

no absorption in atmosphere from earth reradiating heat

Revolution

orbit

365.4 days

Rotation

determines day length, deflection of winds, ocean currents, tides

variations in rotational velocity create the Coriolis effect

Axis tilt

about 23.5 degrees

Evidence of climate change

ice cores (isotope ratios, trapped air bubbles)

sea ice

fauna (invertabrae fossils, plankton, dinosaur fossils)

pollen samples (extracted from lake floors, pollen is seasonal)'

tree rings

historical logs and diaries

Diurnal variation

between day and night

Aphelion

Earth’s furthest point from sun (July 4)

Perihelion

Earth closes to the sun (Jan. 3)