Note: The following changes should be made to the Study Guide, Part B: Applications Activity 5B -
Radiosonde observations at 0000Z 11 OCT 2000 from Chatham, Massachusetts (CHH), and Miami, Florida (MFL) are plotted on Stüve diagrams shown in Images 1 and 2, respectively. They show the vertical variations in temperature in the atmosphere at two sites along the East Coast at that time. As noted in the Monday through Wednesday Daily Summaries for this week, the vast high pressure system that invaded the eastern half of the coterminous US over the past weekend was responsible for record low temperatures across much of the East. Stations from Florida to New England were under the influence of this High.
Each radiosonde report indicates the temperatures measured (in degrees Celsius) and altitudes reached (in meters) for various pressures experienced by the radiosonde as it rises through the atmosphere. (Additional information on the dewpoints and winds given in rawinsonde reports will not be used in this activity.)
Rawinsonde reports for selected stations in tabular text form can be found via the course homepage under "Upper Air Data - Text". The table of Chatham (CHH) rawinsonde data following the questions in this activity includes temperatures and altitudes of several mandatory pressure levels above that station. (Certain pressure values are required to be reported from each radiosonde observation; these are termed "mandatory levels".) Information from the 0000Z 11 OCT 2000 Miami (MFL) sounding is given. Fill in the blanks below with the temperatures (TMPC) and altitudes (HGHT) from the CHH sounding for the same mandatory pressure levels as at MFL. (The surface values for CHH have already been listed as an example.)
Press. MFL Temp. CHH Temp. MFL Alt. CHH Alt. (mb) (C) (C) (m) (m) ------------------------------------------------------ 200 -55.7 ______ 12370 ______ 300 -33.3 ______ 9660 ______ 400 -18.7 ______ 7570 ______ 500 -7.1 ______ 5870 ______ 700 7.2 ______ 3168 ______ 850 10.4 ______ 1551 ______ 1000 22.0 ______ 169 ______ Surface 23.6 6.4 5 16 |
Note: The description of listings found from "Upper Air Data - Text" stations is found in the Homepage User's Guide, available from the homepage. Upper Air Data - Text and Stüves for Selected Cities are both found under the Upper Air section on the Homepage.
Image 1 is the CHH Stüve plotted for 0000Z 11 OCT 2000. Looking at the Chatham Stüve diagram, the altitude at which 500 mb was found over the station was ________ m (values are plotted on the pressure lines at the left edge of the chart). Estimated from the diagram, the temperature at 500 mb over Chatham (recall from Activity 2B, temperature is the heavy, plotted profile to the right in the diagram) was about _______ °C. (The reported temperature is found in the tabular data below.) [Image 2, the MFL Stüve for this time, is also given for comparison.]
Referring to the table of data you completed in Item 17, circle the following pressures which were at higher altitudes over Miami (MFL) than over Chatham (CHH):
1000 mb | 850 mb | 700 mb | 500 mb | 400 mb | 300 mb | 200 mb |
Compare the temperature values for the air columns representing the lower and middle troposphere (from surface to 300 mb) over MFL and CHH. The air column over [(MFL) (CHH)] was warmer. The difference in altitude between the 700- and 500-mb levels at MFL was ______ m while the difference was ______ m at CHH. These differences show that the same pressure decrease (200 mb in this example) occurs through a [(lesser) (greater)] vertical distance in warmer air than in colder air.
Assume you were to fly from Miami to Chatham using your pressure altimeter which was set in Miami to 10,000 feet (approximately 700 mb). As you approached Chatham, your aircraft would actually be at a [(higher) (lower)] altitude than that indicated by your altimeter.
Date: 0000Z 11 OCT 2000 Station: CHH WMO ident: 74494 Latitude: 41.67 Longitude: -69.97 Elevation: 16.00 ---------------------------------------------------- LEVL PRES HGHT TMPC DEWP RELH DIR SPED MIXR mb m C C % deg knt g/kg ---------------------------------------------------- SFC 1011 16 6.4 -3.6 49 290 10 2.9 1 1000 106 6.2 -3.8 49 285 14 2.9 2 976 305 5.3 -4.7 48 275 21 2.8 3 972 338 5.2 -4.8 48 274 22 2.8 4 940 610 2.6 -6.0 53 270 23 2.6 5 925 740 1.4 -6.6 55 265 23 2.5 6 905 914 -0.2 -7.4 58 265 25 2.4 7 871 1219 -2.9 -8.8 64 260 29 2.3 8 850 1413 -4.7 -9.7 68 260 29 2.2 9 805 1829 -7.7 -14.4 59 255 27 1.6 10 774 2134 -9.9 -17.9 52 255 25 1.2 11 744 2438 -12.1 -21.3 46 255 21 0.9 12 726 2632 -13.5 -23.5 43 255 23 0.8 13 718 2716 -13.3 -28.3 27 255 23 0.5 14 715 2743 -13.4 -28.7 26 255 23 0.5 15 700 2909 -14.3 -31.3 22 255 23 0.4 16 633 3658 -19.2 -37.8 18 265 25 0.2 17 615 3879 -20.7 -39.7 17 267 30 0.2 18 583 4267 -22.3 -40.9 17 270 39 0.2 19 537 4877 -24.8 -42.9 17 280 39 0.2 20 531 4956 -25.1 -43.1 17 280 39 0.2 21 500 5390 -28.9 -40.9 30 280 39 0.2 22 472 5799 -32.3 -39.3 50 286 39 0.3 23 452 6096 -34.5 -43.0 42 290 39 0.2 24 447 6179 -35.1 -44.1 39 291 40 0.2 25 411 6762 -35.9 -60.9 6 298 49 0.0 26 400 6950 -37.3 -63.3 5 300 52 0.0 27 397 7010 -37.6 -63.6 5 300 52 0.0 28 379 7321 -39.1 -65.1 5 292 49 0.0 29 363 7620 -39.8 -66.6 4 285 47 0.0 30 342 8024 -40.7 -68.7 3 276 47 0.0 31 325 8372 -39.5 -69.5 3 269 47 0.0 32 317 8534 -39.7 -69.7 3 265 47 0.0 33 300 8920 -40.1 -70.1 3 260 47 0.0 34 290 9144 -40.4 -70.4 3 260 49 0.0 35 250 10150 -41.7 -71.7 2 250 54 0.0 36 232 10668 -42.7 -72.3 2 250 51 0.0 37 200 11660 -44.5 -73.5 3 240 47 0.0 38 185 12192 -45.8 -74.2 3 235 54 0.0 39 150 13560 -49.1 -76.1 3 225 39 0.0 40 140 14021 -50.1 -76.9 3 220 41 0.0 41 116 15240 -52.7 -79.1 3 230 41 0.0 42 102 16053 -54.5 -80.5 3 234 29 0.0 43 100 16154 -54.0 -80.0 3 235 27 0.0 44 100 16180 -53.9 -79.9 3 235 27 0.0 45 96 16459 -53.8 -79.8 3 235 23 0.0 46 94 16566 -53.7 -79.7 3 232 23 0.0 47 79 17678 -55.3 -80.8 3 195 23 0.0 48 70 18470 -56.5 -81.5 3 205 23 0.0 49 59 19507 -56.7 -81.7 3 220 12 0.0 50 50 20610 -56.9 -81.9 3 175 10 0.0 51 45 21336 -58.0 -83.0 3 170 8 0.0 52 41 21842 -58.7 -83.7 3 164 8 0.0 53 37 22538 -55.3 -81.3 3 156 9 0.0 54 30 23840 -54.3 -80.3 3 140 10 0.0 55 20 26440 -53.5 -79.5 3 65 10 0.0 56 19 26908 -52.3 -78.3 3 53 12 0.0 57 17 27432 -53.5 -79.5 3 40 14 0.0 58 16 28038 -54.9 -80.9 3 25 16 0.0 59 16 28042 -54.9 -80.9 3 25 16 0.0 60 12 29870 -51.9 -78.7 3 55 16 0.1 61 11 30230 -51.3 -78.3 3 0.1 TRP 342 8024 -40.7 -68.7 3 276 47 0.0
The DataStreme Homepage shows upper air information for selected stations around the US graphically in Stüve diagrams and in detailed text listings. Actual altitudes of different pressure levels are also found on DataStreme Stüve diagrams to the left, next to the pressure scale. Print out the text data for a reporting station near you and have your students plot these data on a blank Stüve diagram, which you can print from the Homepage Extras section. You can compare your plots to the Homepage version. See if you can find differences for fair and stormy weather situations.
After completing this week's applications, fax the following pages to your LIT mentor by Monday, 16 October 2000:
Return to DataStreme Homepage
URL: datastreme/learn/b_act.html
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