ESS 5 Midterm Study Guide

Latent Heat Flux (heat transfer that changes phase of a substance) - i.e. temperature of the substance itself does not change but the temperature of the surrounding environment does. Be able to explain and give examples of how latent heat is important for humans and for our weather/climate

- Humans and animals need to cool down through sweating - Precipitation: formation of clouds and water vapor

5 factors which define 'weather':

- Temperature - Air Pressure - Humidity - Cloud Cover - Wind Speed and Direction

Solar spectrum (blackbody)

Hotter black bodies: 1.Have greater intensities 2.Peak at higher energy wavelengths 3.Emit more energy 4.Color (wavelength) of light can tell us temperature A black body: 1.Absorbs all light shined upon it 2.Emits a spectrum (i.e wavelength) of light that depends upon its temperature

Heat transfer can result in sensible heat flux or latent heat flux

sensible - changes temperature latent- changes phase (energy is stored or released) Specific heat - energy needed to raise 1kg of substance by 1C

Planetary Energy Balance

solar energy absorbed = terrestrial energy emitted BUT solar energy absorbed does NOT equal terrestrial energy emitted over each latitude Energy is transported from the Equator to the poles by winds and ocean currents

Electromagnetic spectrum

the range of wavelengths or frequencies over which electromagnetic radiation extends. - Gamma Rays (highest/shortest) - X-Rays - UV - Visible - Infrared - Radio

Be able to explain what processes converted the 2nd atmosphere into the 3rd atmosphere

Atm. Today: Mostly Nitrogen, Oxygen, and Argon H2O: Earth cooled, atmosphere can only hold so much water vapor emitted by volcanoes, water vapor condensed into cloud and formed oceans O2: Anaerobic bacteria (3.5 Byrs) in oceans, photosynthesis (plants and rocks oxidized), N2: released in small amts by volcanoes (chemically inert/not water soluble), only small amt removed from atmosphere, removal of CO2 - N2 became most abundant. Ar: radioactive decay in rocks, chemically inert and insoluble Lack of CO2: volcanism went down, removed by - dissolution in oceans, biosphere, chemical weathering (acid rain reacts w rock to dissolve) - carbon locked away in minerals and rocks (fossil fuels)

Definition of 'climate'

Avg. weather and variability of atmosphere

Be able to describe which gases made up the second atmosphere and where they came from

Carbon Dioxide and Water Vapor due to Volcanoes and Comets

Be able to identify whether a transfer of heat is by conduction, convection and radiation

Conduction - Energy moving through solid; material does NOT move Convection - energy moving through fluid or gas; material DOES move Radiation - energy moving between two points; does not require any material

Definitions of energy and power

Energy: Ability to do work Potential vs Kinetic Power: How quickly energy is released/used

Composition of the atmosphere today: permanent gases and variable gases (sources and sinks)

Permanent Gases: - 78% Nitrogen - 20% Oxygen - 0.1% Ar Variable Gases: - H2O - CO2 (respiration, volcanoes/dissolution in ocean, photosynthesis) - Methane (agriculture, fossil fuel extraction, decomposition) - Ozone - Nitrous Oxide

Ways of categorizing the vertical structure of the atmosphere: pressure, temperature, chemical composition, electrical conductivity

Pressure increase altitude - pressure and air density decrease Temperature Chemical composition Heterosphere - composition not uniform (thermosphere) Homosphere - composition relatively the same; lower 80 km Electrical Conductivity ionosphere - higher than 60 km; electrified region of upper atmosphere; solar radiation absorption created ions (charged particles) Aurora Borealis

Heat transfer on Earth

Radiation (energy transfer that does not require any material) Conduction (energy moves but the material itself does not) Convection (energy moves with material e.g. forced and free) - Free convection - e.g. the wind - forced convection - energy emitted from equator

Reflection and scattering (specular reflection, Rayleigh and Mie scattering)

Raleigh Scattering - scatters in every direction - by gas molecules - stronger for shorter wavelengths * blue skies and red sunsets Mie Scattering - mainly forward - by particles like aerosols - no strong wavelength preference * grey smog Specular reflection

Be able to use the mechanics of Earth's orbit around the Sun to explain why we get day/night and seasons:

Rotation - Earth spins completely once per day (24 hours) around its axis - reason why we have day and night Revolution - Perihelion (shorter distance) and Aphelion (longer distance); only small influence on seasonal heating; when they occur today? Tilt (23.5) - Principle cause of seasons!!! effects amount of solar energy (solar beam spreading and period of daylight)

Understand and be able to describe/explain/draw diagrams of the different factors which create planetary energy balance and set global temperatures

Solar Constant - suns luminosity (power) - distance from the sun Atmosphere and Albedo - absorption - reflection and scattering - albedo Outgoing long wave radiation - greenhouse effect ***atmosphere, albedo, and outgoing radiation determine temp we feel

Transmission

The amount of solar energy reaching the earth's surface.

Be able to describe and explain how the following factors cause variation in local temperatures:

Time - daily patterns and annual patterns Latitude - absolute v range in temp; e.g. Miami ( higher absolute )v New York (higher range) Altitude - troposphere up to thermosphere Local Features: - aspect, topography, vegetation Warm and cold ocean currents Surface type - heat capacity - albedo Clouds - increase avg temperature

Definition of an 'aerosol' and examples

Tiny liquid droplets or particles that remain suspended in the air. eg. smoke, ice and sea salt crystals, dust, volcanic emissions, pollution

Names and properties of the different layers i.e. troposphere, stratosphere, mesosphere, thermosphere, homosphere, heterosphere

Troposphere - lowest - temp decreases with altitude - 80% of mass - strong vert. motion - Where most weather events occur Stratosphere - most ozone - heated by UV absorption - weak vert. motion Mesosphere - little ozone to absorb UV radiation - temp decreases with altitude Thermosphere - little mass - warm air (O2 absorbs solar radiation) - low density = large temp increase

Gases that made up the first atmosphere and how were they lost

hydrogen and helium (most common in solar system) lost over 50Myrs - H and He not retained by gravity, solar wind, Earth lack of magnetic field, collisions