GEOG 1114 1st Edition Lecture 13Outline of Last Lecture -Dew Point and sensible heat-Condensation-Adiabatic Processes-Precipitation-Atmospheric lifting Outline of Current Lecture -Review before Exam 1 -Test strategies Current Lecture Test Strategies: - Remember to read every question- Take your time - Answer every question even when you are unsure- Do your best!Review for test: Four Types of Atmospheric Lifting ConvectiveUnequal heating of surface areas (by conduction) causes a parcel of air near the ground to be warmed more that the surrounding air. Density of the heated air drops, as air expands, and it begins to rise convectively. Uplift is more likely to happen if unstable air is involved. Pressure ofthe unstable airdrops as it rises and it cools adiabatically to the dew point. Condensation and clouds develop. If temp., humidity, and stability conditions are just right the clouds will grow These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.into a cumulonimbus thunderhead and a downpour of showery rains or hail and lightning and thunder will result. OrographicAir is forced to rise over a mountain barrier and it is cooled to the dew point. Windward side: side in which air is forced to rise. Typically WestLeeward side: Side in which air descends. Little PPTN - Rain shadowFrontal LiftingWhen a cool and warm air mass meet, a boundary or front is established between them. The warm air mass is forced to rise above the adjacent cold front. If the warm air is cooled to saturation precipitation can occur along the front. ConvergentWhen air converges there is a general uplift. If lots of crowding occurs get more lift and instability and precipitation can occur. Less common than others, happens in ITCZ, often associated with hurricane formation.Place of the Earth in the solar system:-One of 8 planets, 3rd from the sun- The Sun, a medium sized star that gets its energy from nuclear fusion, is the central body, source of energy-The Solar System is part of the Milky Way galaxy, which is just one of billions of galaxies in our universe-The Universe originated from The Big Bang theory, a cosmic explosion of matter and gases 13.7 million years ago. -Our Solar system originated between 4.5 and 5 billion years ago -A Nebula is a huge cloud of gas that contracted inward (from gravity) to form the sun and the planets-All planets revolve around the sun in an elliptical orbit, counter clockwise to the sun.-There are 150 moons in our solar system. We landed on the Earth’s moon in 1969. Ours revolves around the earth once every 27 days What is a maps purpose? They are used to convey information, they help people understand spatial distributions and identifying patterns, and teach one about size, distance, directions, andunderstanding the layout of our planet.Scale- the mathematical relationship between objects shown on the map and the real world Expression of scale: 1.Fractional Map scale- (Representative Fraction: a.k.a. RF) expressed as a ratio or fraction Ex: 1:24,000 1/24,000 *It is dimensionless meaning you put the units in2.Graphic Map Scale- depicts scale with a bar graph 3. Verbal Map Scale- Ex: 1 inch is equal to 1 mile Large vs. Small Scale Fractional RelationshipSmall Scale- shows a large area with small detail- Smaller Representative Fraction (larger denominator)Large Scale- shows small area with large detail- Large Representative Fraction (smaller denominator)We can make the following generalizations, which help us understand surface pressure conditions:Very warm surface conditions often produce low pressure at the surface (a thermal low). Warm=lowStrongly rising air often produces low pressure at the surface (a dynamic low)Very cold surface conditions often produce high pressure at the surface (a thermal high). Cold=highStrongly descending air often produces high pressure at the surface (a dynamic high)Dew Point: The temperature at which saturation occurs (100% humidity) and condensation begins1.The temperature at which saturation occurs (100 humidity) and condensation begins2. Varies with the moisture content of air 3. High Dew point indicate high moisture content in the air The ProcessRainfall is a rare event because it requires three different things to for rain PPTN (precipitation) =Water + Droplet Formation + UpliftDroplet Formation: Condensation, which produces tiny drops, is not enough to produce precipitation. Two mechanisms are thought to be responsible for droplet formation:Ice-Crystal Formation: Raindrops form as ice crystals found in clouds with temp. Below freezing, grow by attracting water vapor to them. They grow until they are heavy enough to fall. Known as the Bergeron Process. Collision/Coalescence:Raindrops form as small droplets collide and begin to merge and form larger droplets. If large enough they begin to fall and as they do they continue to collide and merge causing larger dropsto form that will eventually fall in the form of rain. Merging only occurs if a positively charged droplet collides with a negatively charged