PPT-ISOBARS

Familiar idea new focus Isolines review An isoline is a line connecting points of equal value Examples of isolines Contour points of equal altitude Isotherms points of equal temperature. High Low. Thermally Driven Direct Circulation. Low High. Vertical and horizontal motion. Equation of Motion a . = . d. V. /. dt. = . G. + . P. z. . +. . P. n. . + . C . + . “Whirlwind Theory”. Rotation. Coriolis. Espy. Convergence into Low. PGF. 1841. Loomis. Rotation AND Convergence. 1860. Early Maritime Observations (Winds). http://m.nautil.us/issue/25/water/the-dueling-weathermen-of-the-1800s. What . is an . isobar?. How . does wind move? (high to low, low to . high). List . three characteristics of low pressure and three characteristics of high pressure.. Air Movement: Weather. Objective: Understanding how air moves through the atmosphere to affect weather.. The National Weather Service counts on two sources for information:. Radar. Weather Balloon. Data collected from the atmosphere. Data collected from the Earth’s surface . In order to forecast the weather, meteorologists make measurements of:. NGS. How Does Air Pressure Affect Weather?. How much the earth. ’. s atmosphere is pressing down on us. Measured with a . BAROMETER. If it . CHANGES. , then new weather is on the way:. Falling Air Pressure = . What is air pressure?. Air Pressure: the force exerted by the weight of the air above it. Why does the weight of the air not crush you?. The pressure is exerted in all directions, not just down. (Ruler and newspaper demonstration). What air pressure systems are anticyclones associated with?. . What . air pressure systems are cyclones associated with?. Do Now. What air pressure systems are anticyclones associated with? . Highs. WHAT IS A DEPRESSION. WHAT IS AN ANTICYCLONE. WHAT ARE THE EFFECTS OF A DEPRESSION. WHAT ARE THE EFFECTS OF AN ANTICYCLONE. 10 DEPRESSIONS & ANTICYCLONES. THIS IS A WEATHER MAP. DEPRESSIONS AND ANTICYCLONES TELL US WHAT KIND OF WEATHER WE ARE GOING TO HAVE. The National Weather Service counts on two sources for information:. Radar. Weather Balloon. Data collected from the atmosphere. Data collected from the Earth’s surface . In order to forecast the weather, meteorologists make measurements of:. Upward pressure gradient . force (PGF) . is balanced by . gravity (g).. HYDROSTATIC RELATIONSHIP. Despite very strong vertical pressure gradients, vertical. winds (rising and sinking air) are generally weak.. Every 5 hPa: ... 990, 995, 1000, 1005, 1010, .... Tend to be roughly parallel to one another. Isobars can . never. intersect. If . an isobar starts on the map border, then it ends on the map border. 19.1 Understanding Air Pressure. Don’t notice change in your day to day activities. Mostly cause-and-effect relationship. Air pressure causes wind. Wind brings change in temperature/humidity/precipitation. Problem 6.11 (a, b). Mark all centers of High and Low pressure (and 2 locations where it might be off the map). Check surrounding isobars . Find 2 troughs and 2 ridges. Trough:. elongated region of low pressure. REVIEW OF KEY FORCES. Pressure gradient force (PGF). High to Low. Perpendicular to the isobars. Proportional to isobar spacing. Coriolis. force (COR). Acts to . right. of parcel direction in N. Hemisphere.