GEOG 111 1st Edition Lecture 19 Outline of Last Lecture I. Measures of water vapor in the atmosphereII. Conclusion of temperature lectureOutline of Current Lecture I. Temperaturea. Altitudeb. Soil Moisturec. Global temperature patternsII. Vertical air motionsCurrent LectureI. Temperaturea. Altitudei. Generally speaking, the higher the altitude the cooler it getsii. However, the low lying areas of Chapel Hill are usually cooler than the “top of the hill”b. Soil Moisturei. Evaporation- sensible energy to latent energyii. Ex. Sandhills v. Piedmont1. When it rains, large sand grains allow openings for rain water to readily go through the soil2. Sandhills dries out much quicker than clay particles in the Piedmont3. Less evaporation it gets hotterc. Global temperature patternsi. Isotherms- lines of equal temperature1. Lines closer together represent rapid temperature dropsII. Vertical Air Motionsa. Review:i. Wind circulations are driven by the pressure gradient forceii. Differences in air pressure are driven by differences in temperatureb. Responsible for clouds and precipitationi. Upward motion clouds and precipitation1. When air converges it has to lifii. Lots of thunderstorms in equator area1. Many lush rainforests in this areaiii. Mid latitudes- warm winds coming from south and cool fronts from the north; iv. Downward motion clear, dry conditions1. Air sinksThese 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.c. Adiabatic processes- changes in the temperature of the air but no changes in energy/heati. Ex. Inflation and deflation of a tire. Air always feels cool when coming out of the tire because of the instantaneous change from high to low pressure environment ii. In the atmosphere:1. An air parcel is forced upward it expands and cools (no heat has beenremoved) continued lifing, it continues to expand and cool2. When air is lifed in the atmosphere it cools adiabatically3. In contrast, sinking air compressesiii. Why:1. Air pressure decreases with increasing altitudea. Rising air expands due to AP decreaseb. Sinking air compresses due to AP increasec. These changes in volume affect temperatured. Recall the ideal gas law: PV=NRTi. P down, V up, T downii. P up, V down, T upiv. Significance:1. Rising air cools SVP decreases RH increasesa. Eventually, air is saturated, condensation must occur forming a cloud2. Sinking air warming SVP increases RH decreasesd. Lifing condensation level (LCL)-the altitude to which you must lif the air to bring it to saturation; distance from surface to cloudsi. Surface temperature increases, RH decreases, LCL increases1. Example: fog lifing in the morningii. Surface temperature decreases, RH increases, LCL decreases1. Cloud bases lowering during
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