Mid latitude cyclone worksheet answers

ESS170 Activity #5 [4 pts] Name __________________________ Activity #5 –300-mb Maps and the Jet Stream Part I. Upper-Level Wind Direction Knowing the direction of the upper-level (i.e., 300-mb) winds is critical when it comes to forecasting hurricanes, thunderstorms, even nuclear fallout and volcanic ash. As you learned in Lecture 12, the wind direction in the upper levels runs parallel to the height lines such that relatively colder air (lower heights) is to the left side of an air parcel. You want to imagine you are riding the air parcel (wind vector) like a magic carpet. Using the example below, if warm air is to the north (inferring that cold air must be to the south) the upper-level wind direction must be (from the) east. If you have trouble visualizing this, tilt your head 90° to the left so it is in the same direction as the wind. The cold air then is to the left: WARM AIR (HIGHER HEIGHTS) Height Lines COLD AIR (LOWER HEIGHTS) Practice Problems: 1. What is the upper-level (i.e., 300-mb) wind direction at a location if COLDER air is to its east? [.1] (a) north (b) south (c) west (d) east 2. The figure below shows a nuclear power plant along with 4 surrounding cities (A-D). If there was a meltdown, which city would be most adversely affected by the fallout if HIGHER heights were located to the northwest and LOWER heights to the southeast? [.2] (a) A (b) B (c) C (d) D C A HIGHER B D LOWER 3. If the upper-level (i.e., 300-mb) wind direction is WEST over WCU, where must the relatively WARMER air lie with respect to WCU? [.2] (a) to our north across Canada (b) to our east across New Jersey (c) to our south across Virginia (d) to our west across Ohio 1|Page Part II. Jet Stream Temperature. You ever wonder how cold is it outside the airplane when you’re flying at cruising altitude (i.e., the jet stream level; 300-mb)? You now have the tools to make an estimate! You must show your work for full credit. [.4] Hints: a) Make an estimate of the temperature here at PHL at the ground this time of year. b) Use the lapse rate value from Lecture 7. c) Make a reasonable estimate of the height (in feet) of the jet stream. Part III. Experiment Time! 1. Experiment 1: Share your results of the toilet flushing experiment from the previous activity on Slack. Your deadline is the same as this activity. I will anticipate your results. [.4] 2. Experiment 2: You are going to create an inexpensive, but effective, experiment to demonstrate fluid flow. Water is a fluid. So is air! You will need the following items:     Bowl (approximately 6-12” across and a few inches deep) HOT tap water (enough to fill the bowl) 1 Toothpick ½ cup Instant (not ground!) Coffee (hot cocoa mix is only suitable if in a pinch) Please read the directions before you proceed: a) Fill the bowl with HOT water. b) Dump the instant coffee into the bowl with hot water. c) Wait ~10 seconds until a sheen or film forms on top of the water from the coffee. d) You have anywhere from 10-60 seconds before the film will disappear so immediately move the toothpick randomly, but vigorously, around in the water. e) Occasionally, move the toothpick in a slower, broader clockwise rotation to mimic the Earth’s rotation. f) You should see swirls (eddies) in the water, some going counterclockwise (low pressure/ troughs) and some going clockwise (high pressure/ridges). This is fluid dynamics, folks! To prove you’ve done this experiment, take a cell phone picture of your results and attach it with your Dropbox submission. [.8] 2|Page Part IV. Jet Stream Animations. 1. Watch the following YouTube clip, which shows the forecast volcanic ash plume from the eruption of Mt. Eyjafjallajokull (I’m serious) in Iceland a few years ago: http://www.youtube.com/watch?v=gPcQhbRpI-4 Note the jet stream, denoted by the streamlines, is superimposed on the ash concentration, denoted by the colors. Appreciate the dynamics of the winds 30,000 feet above our heads, ever-changing, and forming clockwise and counterclockwise swirls (ridges and troughs). To prove you watched the video, what is the forecast date, shown in the upper left of the animation, 0:20 into the video? [.2] 2. Here, you will build your own 2-week jet stream loop using again the GFS model forecast: http://mag.ncep.noaa.gov/model-guidance-modelparameter.php?group=Model%20Guidance&model=gfs&area=namer&cycle=20141219%2018%20UT C¶m=300_wnd_ht&fourpan=no&imageSize=M&ps=area a) Scroll down to “Forecast Hours.” Since we want a series of images,