3.14- Summary of Unit 3

What you did

  • You watched Instructor's Lectures and read the Canvas Content
  • You completed three assignments
  • You took four quizzes

What you learned

You should use this as a Study Guide for the Unit 3 Exam.

  • How to calculate sun angles and to use the analemma to find the declination (be able to estimate declination without an analemma)
  • You learned about the seasons (equinoxes, solstices, length of day - know the dates and the declination of the sun at each of those dates)
  • You learned that the Circle of Illumination divides the Earth into Day and Night and shows the length of day varies with the seasons in each hemisphere as you move from the equator to the poles
  • You learned about the fixed gases and the variable gases of the atmosphere 
  • You learned about solar radiation, the electromagnetic spectrum, wavelengths and frequency
  • You learned about the energy budget (45% strikes the Earth, 33% albedo, 22% absorbed)
  • You learned how the Earth is heated primarily from counter-radiation, long-wave radiation off its surface
  • You learned about albedo (the reflectivity of an object -the earth's albedo is 33%)
  • You learned about conduction (transfer of energy at molecular level: solids/metals-good, air/soil insulators), convection (transfer of energy by the movement of the material itself: liquids/gases) and radiation (transfer of energy by waves: vaccum/space) and in which context each works best
  • You learned about the controls on temperature (latitude, sun angle- higher sun angles more solar energy,  length of day - more consistent length of day more solar energy/great variability at poles none at equator, differential heating of land and water - land heats up and cools off much more quickly than water and to higher and lower temperatures so coldest and hottest temps over land, ocean currents- warm ocean current = mild winter; cold ocean current- mild summer, altitude, continentality)
  • You learned about continentality (continental vs marine locations - continental: hotter summers colder winters less precipitation, maritime - milder summer temperatures, milder winter temperatures wetter usually)
  • You learned about the interrelationship between density, temperature and pressure (affect one, affect all - if temperature rises, pressure rises. If density increases, pressure increase)
  • You learned about isobars and isotherms
  • You learned that in high pressure (anticyclones) air is descending , compressing, warming, causes clear skies, is diverging and moving clockwise in the N. Hemisphere
  • You learned that in low pressure (cyclones) air is rising, expanding, cooling,  causing clouds and precipitation, converging and moving counterclockwise in the N. Hemisphere
  • You learned that wind direction and speed is impacted by the pressure gradient- wind blows from high pressure to low pressure,  the Coriolis Effect - because the earth rotates things appear deflected to the right in the N. Hemisphere and to the left in the S. Hemisphere and friction.
  • You studied the general circulation of the atmosphere, the persistent areas of high and low pressure, the prevailing winds (the subtropical highs, the Intertropical Convergence Zone, the Polar lows, the Polar Highs, the westerlies, the Trade Winds, the Polar Easterlies)
  • You studied regionally important winds such as the monsoons and the Santa Ana winds and locally important winds like sea breezes/land breezes, mountain/valley breezes
  • You learned that all pressure gradients and in turn the wind, is always caused by the unequal heating of the Earth's surface.
  • You learned about evaporation, condensation and saturation (evaporation latent heat stored - cooling process, condensation latent heat released - warming process)
  • You learned about relative humidity and dew point (relative humidity percentage of saturation - 100%RH = saturation, dew point- critical temperature at which relative humidity = 100%)
  • You learned about adiabatic cooling and warming and how to calculate what is happening in rising and descending air (-5.5/1000 feet dry adiabatic lapse rate, -3.3/1000 feet wet adiabatic lapse rate - use after you reach dew point)
  • You learned about the causes of rising air - convective, orographic, frontal, convergent
  • You learned about clouds, fog and dew (advection fog - summer in Sonoma County, radiation fog - winter Sonoma County, Valley fog, evaporation fog, Clouds - stratus, cumulus, cirrus, nimbus means rain producing)
  • You learned about the stability of air (unstable air -hot summer afternoon, stable air - still winter night)
  • You learned about global precipitation - where the wettest and driest areas are

Coming up

  • Air Masses and Fronts
  • Extratropical Cyclones
  • Tropical Cyclones
  • Tornadoes