GEOG 111 1st EditionExam # 1 Study Guide Lectures: 1 - 10“Each test will consist of 40 multiple-choice questions that are drawn from the lecture material, weather quizzes, and in class weather discussions. These questions will be answered on a scantron sheet, which can be obtained from the bookstore.” –from Geography 111 syllabusLecture 1 (August 22)/ Lecture 2 (August 25) Introduction to weather forecasts:- Types of Forecastso Quantitative forecast- a value for the forecast variable is provided (i.e. an inch of rain is expected)o Qualitative forecast- provided only categorical value for the predicted variable (i.e. rain or no rain)o Probability forecast- the chance of some event is stated- 3 resources in making forecasto Weather models- computers that use physics to simulate atmospheric conditions of the futureo Climatology- tell what conditions you would normally expect Usually a good starting point for weather forecasters and may indicate that a weather model needs to be tunedo Forecaster knowledge- something to keep in mind when reading forecasts Pattern recognition- experienced forecasters in an area can recognize patterns and question models- Elements of a forecasto Low/high temperatureo Heat index- what it actually feels like outside (includes humidity)o Precipitation- probability of measureable precipitationo Wind speed- pertains to open landscapeso Wind direction- the direction winds are blowing from Important in air travel and hurricane prediction- Forecasting skillo Accuracy depends on: Proximity to forecasting location Size of the region How well the forecaster knows the climatology and recognizes its patternso Weather models accuracy decrease with time Should be trusted 3-5 days into the future but after that it’s better to rely on climatologyLecture 2 (August 25)/Lecture 3 (August 27)Solar and Terrestrial Radiation:- Radiation comes in many forms through the electromagnetic spectrumo Discriminated on the basis of wave length: gamma xrays UV visible lightinfrared radiation microwaves radio waves Short end- powerful gamma rays that can go through solid materials Long end- microwaves and radio waves that have long wavelengths and are far less powerful - Radiation Laws:o Stefan-Boltzmann Law- the hotter a body is the more radiation it emits Blue is shorter part of the wavelength so it’s the hottest part of the flame E = Stefan-Boltzmann constant * temperature ^4o Weins Law- the wavelength of maximum emission The sun peaks at a shorter wavelength than the Earth which ensures that it’s hotter- Temperatures generally decrease with increasing height above theearth, therefore higher clouds are colder than lower clouds and the earth- Solar Output- relatively constant over timeo Sunspots- storms on the surface of the suno More sunspots  more solar radiation  higher temp. on Earth’s surface- Earth-atmosphere radiation processes Absorption- to assimilate or take in energy- The atmosphere absorbs some of the radiation from the sun- Example: Greenhouse gases such as CO2 and water vapor that are very effective in absorbing infrared (long wave) radiation emitted from the Earth’s surface. This warms the atmosphere up and re-radiates more energy back to the surface Reflection- the temperature of the reflecting object is unchanged- Albedo (A)- describes the overall reflectivity of the Earth’s surfaceo A = (outgoing K/incoming K) x 100%o Where K is reflected radiationo Light colors have high albedos and dark colors have low albedos Scattering- redirecting part of the visible light spectrum- As visible light comes into the atmosphere, blue light is cycling rapidly and reds are cycling slowly- Blues are more likely to collide with an atmospheric particles and be redirected (scattered) so blue light is preferential the sky is blue in an average midday skyo The color of the sky indicates the amount of scattering taking place- Increased volcanic dust increases possibility that warm colors will scatter- Solar radiation can be partitioned into two components:o Direct beam- divided into light and dark, directly from the sun (when clouds block direct beam they create shadows)o Diffuse light- “sky light” from diffused radiation- Inverse relationship between direct beam and diffuse- Less scattering: high direct beam, low diffused light  dark blue sky- More scattering: low direct beam, high diffused light  lighter blue sky Three controlling factors of atmospheric transmissivity (the ease with which radiation is transmitted through the atmosphere; can be visible light or infrared radiation from the Earth):- Clouds: no direct beam, all diffuse- Haze (microscopic particles, aerosols in the sky): direct beam decreases, diffused light increases- Elevation (atmosphere is thinner at higher altitudes so less light gets scattered and the sky is a darker blue): direct beam increases,diffused light decreasesLecture 4 (August 29)/ Lecture 5 (September 3) Earth-Sun Geometry- Seasonal changes in earth-sun geometry controls the intensity of solar radiation and the length of the day- Two independent motions affect earth-sun geometry:o Rotation- counterclockwise (West to East); goes 360 degrees in 24 hours This is why we have time zones We go later in time to the east (Europe is ahead of us) and earlier in time to the west. The sun rises and sets later on the western edge of a time zone region and earlier on the eastern edge of a time zone region. o Revolution- the earth revolving around the sun on the plane of the ecliptic Takes 365.25 days Due to the earth’s elliptical path (not a perfect circle), the distance between the earth and sun varies during the year Perihelion- around January 3- Earth is closest to the sun- 147, 500, 000 km Aphelion- around July 4- Earth is farthest away from sun- 152, 500, 000 km- The Earth’s axis is tilted 23.5 degrees with respect to the plane of the ecliptico This results in seasons Solstice- December 21-22/ June 21-22- Summer: longest day in Northern Hemisphere- SE maxed out in NH- SD= 23.5 degrees north Tropic of Cancer- Latitude increases; day length increases- Winter: shortest day in NH- SE min in NH- SD= 23.5 degrees south Tropic of Capricorn- Latitude increases; day length decreases Equinox- March 21-22/September 22-23- At noon the sun will be hitting the equator