ATMO 336 1st Edition Lecture 1 Outline of Last Lecture I. !st lecture, no material previously coveredOutline of Current Lecture II. Definition of 500mbA. Air pressure vs. water pressureIII.Contour maps and their significanceIV. Relationship between 500mb height patter and air temperaturea. Defining closed lowsb. Defining closed highsc. Warm air in relationship with ridgesd. Cold air in relationship with troughsV. Using atmospheric height to estimate the local temperatureCurrent Lecture- 500mb heighto mb stands for millibars which is a unit for measuring pressureo Air pressure near ground (sea level)=1000mb At sea level, water pressure=0 dive into water; water pressure increases Average air pressure at sea level is approx. 1000 millibars (mb) o Air pressure decreases as you move up in atmosphere (falls to 550mb) caused by weight of air above you Computers calculate forecast models at this height!! At top of atmosphere, air pressure is zeroo At typical 500mb height, this is equal to 4600-6000 meters above sea levelo 500mb height also depends on air temperature- Contour mapso Contours of 500mb heighto Points on earths surface mb determined by these contours by finding which line it is closest to, or averaging between two lines if the point were to be located in the middle (no exact number; estimations accepted)- Relationship between 500mb height pattern and air temperatureo Height of the 500mb surface is related to the temperature of the atmosphere below 500mb (the higher the temp. the higher the height of the 500mb level) Height tells us how hot or cool the surface of earth is in a specific areao In general, warmer than average temps. Can be expected underneath ridges and colder than average temps can be expected underneath troughsThese 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. Warm air expands= ridges Cold air shrinks= troughso Closed low: region of low heights around which one or more closed height contours are drawn (found at base of trougs) Often related with precipitation and change towards colder conditionso Closed highs: centers of high heights surrounded by one or more closed contours( found at apex of ridge) Marked with “H” on maps usually- Hight to estimate local tempo For a iven location and time of year, if the 500mb height on the map is close to average, then the temp is expected to be about averate Above average= higher temps Below average= lower tempso This helps derive the average temperature for the locations and time of
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