DataStreme Activity 5B:

ATMOSPHERIC PRESSURE IN THE VERTICAL

Note: The following changes should be made to the Study Guide, Part B: Applications Activity 5B -


Do Now:

  1. Print this file.
  2. Print the Wednesday Image 1 and Image 2 Files.
  3. Print (when available) the Thursday, 12 October 2000, Daily Summary File.

To Do Activity:

  1. Read Chapter 5 in STUDY GUIDE, Part A: Narrative.
  2. Go to STUDY GUIDE, Part B: Applications. Start Activity 5B.
  3. Return here (Wednesday Activity B File) when told to do so.

Go To STUDY GUIDE - Activity 5B Now


  1. 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.

  2. 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.]

  3. 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 
  4. 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.

  5. 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.


Faxing Instructions:

After completing this week's applications, fax the following pages to your LIT mentor by Monday, 16 October 2000:

  1. Chapter 5 Progress Response Form
  2. 5A and 5B Activity Response Form
  3. STUDY GUIDE, Part B: Applications, page 5B-4

Return to DataStreme Homepage

URL: datastreme/learn/b_act.html
©Copyright, 2000, American Meteorological Society