Investigation 1B – The Vertical Atmosphere
Collection and Retrieval of Upper-Air Data.
Investigation 1A demonstrated the variation of weather conditions on the surface of the Earth.
However, as we continue in this course, you will also learn that surface weather conditions are
greatly dependent on upper-air weather conditions. As a result, Meteorologists need to make
observations of changes in weather conditions as you rise vertically. To gain context of this
upper-air data, let’s first take a look at the basic structure of the atmosphere:
Figure 1 - Vertical Profile of Temperature in the Atmosphere. From "Essentials of Meteorology" by C. Donald Ahrens. Cengage.
Before answering the questions below, take a moment to investigate this figure, specifically
looking at each of the layers, how temperature (the red line) changes with height in each layer,
and how air pressure (the white numbers) changes with height in each layer. Take a moment and
write down any interesting observations, and also write down any questions you may have. Feel
free to reach out to your instructor if you don’t find the answers to those questions as you move
through this investigation.
1. Air Pressure (the white numbers on the right-axis in mb) ___________________ with
height in the atmosphere:
c. Does not Change
2. However, Air Temperature’s relationship with height (how air temperature changes with
height)_____________________ as you move from one layer to the next layer.
a. Does not Change
3. Specifically, Air Temperature decreases with height in the ______________________
a. Stratosphere and Mesosphere
b. Troposphere and Thermosphere
c. Troposphere and Mesosphere
d. Stratosphere and Thermosphere
4. The top of each layer is called a “pause.” For example, the top of the troposphere is
called the Tropopause. Based on Figure 1, what happens when you reach any of the
“pauses” in the atmosphere:
a. Temperature “levels off” (it stops decreasing or increasing)
b. Temperature suddenly increases drastically
c. Temperature suddenly decreases drastically
5. As a result, an excellent way to identify the tropopause would be to look for:
a. Where temperature stops decreasing
b. Where temperature stops increasing
c. A sudden, sharp decrease in temperature.
While the diagram above is a basic representation of the
“average” atmosphere, the vertical structure of the atmosphere
varies greatly from place to place. Therefore, we cannot rely on
the “average” atmosphere to determine conditions in the upper
atmosphere; instead we must take direct observations. We do this
by collecting Upper-Air Data, which is done through weather
What is a Weather Balloon?
Every day at 0000UTC and 1200UTC, observers across the
United States (the world, in fact), launch weather balloons into the
atmosphere at the same time. Attached to each of these weather
Figure 2 - Meteorology Students Terrence
Mullens and Jeff Forgeron launching a
Weather Balloon at San Jose State
University in 2010.
balloons is an instrument pack called a radiosonde. As the balloon rises, the
radiosonde collects data for many of the weather variables we measure at the
surface (temperature, dew point, air pressure, wind direction, wind speed,
etc.), and relays them to a computer on the ground. These weather balloons
can rise as high as 100,000 feet (about 30,000 meters). If you ever get bored,
check out some of the cool videos that show weather balloon launches with
an onboard camera… some will be posted at the end of this activity.
Figure 3 - A typical radiosonde
As the weather balloon rises in the atmosphere, the radiosonde continuously collects weather
data. This data is then plotted on numerous diagrams for Meteorologists to use to interpret this
data. Throughout this course, we will take a look at much of this data and many of these
diagrams. But for this investigation, we will focus on air temperature. One of the best diagrams
to plot air temperature data is the Stüve Diagram. A blank Stüve Diagram is shown below as
Figure 4. Your instructor should provide a link or file download for the figure below.
Figure 4 - Blank Stüve Diagram
The Weather Data can be plotted on a stuve diagram the same way that you’d plot data on a
simple x-y graph (a plot of radiosonde data is called a Sounding). Temperature would be your
“x” coordinate while Pressure would be your “y” coordinate (we use pressure rather than
elevation because Meteorologists look for certain features at particular pressure levels). For
example, Table 1 below is an abbreviated table of data from a radiosonde launch at Oakland
International Airport on March 28, 2018 while Figure 5 is a sounding of temperature vs. pressure
of the data in Table 1.
Table 1 - Radiosonde Data for Oakland International Airport on March 28, 2018
Figure 5 – Sounding of Radiosonde Data from Oakland International Airport on March 28, 2018. Points are plotted with black
dots, and purple lines drawn to connect the dots.
For additional help on plotting data on a Stuve Diagram, a useful video can be found here:
https://www.youtube.com/watch?v=2zXG3Civ_b8 (note: this video covers both air temperature
and dew point temperature, but we will only use air temperature in this investigation).
6. Temperature increased from the surface to approximately _____________. (Hint: look at
both Table 1 and Figure 5). This phenomenon is called a Surface Inversion, a feature that
is very common near the surface of the Earth.
7. Near the top of Figure 5, a second inversion (layer where temperature increases with
height) is present where temperature stops decreasing at ______________________. This
height is considered the Tropopause, because air temperature stopped decreasing with
height and either leveled off, or began increasing.
Be Careful!!! The surface inversion near the bottom of the diagram is NOT the Tropopause!!!
The tropopause will always be located near the top of the diagram while surface inversions are
only near the surface.
The U.S. Standard Atmosphere
In order to compare radiosonde observations to the “average” condition of the atmosphere, The
US Standard Atmosphere was developed. The US Standard Atmosphere is a simple
representation of the average atmosphere. The lower portion of the US Standard Atmosphere
only has three points: a temperature of +16°C at the surface, -56.5°C at 11km and -56.5°C at
16km. This data is plotted in Figure 6.
Figure 6 - Stuve Diagram with US Standard Atmosphere plotted.
8. The tropopause of the US Standard Atmosphere is at 11km, or a pressure level of
9. From the bottom of the tropopause (the answer to question 8) to the top of figure 6, the
a. Isothermal (no change in temperature with height)
b. An Inversion (temperature increases with height)
10. Comparatively, the tropopause from Oakland’s radiosonde data in Table 1 was
____________________ than the US Standard Atmosphere’s. (HINT: Compare
Oakland’s tropopause height to the US Standard Atmosphere’s and be careful…
remember that lower pressures mean higher elevations).
c. The Same Height As
Comparison of Observed Radiosonde Data to the US Standard
Table 2 is data taken from a radiosonde launch over Brownsville, Texas at 1200 UTC (7am
CDT) on June 4th, 2019.
Pressure (mb) Height (m)
Table 2 - Data from a Radiosonde launch over Brownsville, Texas at 1200 UTC on June 4th, 2019.
Plot this data on a copy of Figure 6 (provided by your teacher or as a file on Canvas) to compare
the data taken at Brownsville to the US Standard Atmosphere. You’ll turn in this plot to your
instructor (unless instructed otherwise). PLEASE USE FIGURE 6. It will make your life easier!!
11. From the data in Table 2 (and plotted by you on Figure 6), a tropopause __________
present between the surface and 100mb over Brownsville
b. Is Not
12. The tropopause over Brownsville is _________________________ than the US Standard
Atmosphere (NOTE: If there is no tropopause between the surface and 100mb, it simply
means that the tropopause is present at an elevation above 100mb pressure level)
b. About the Same Elevation As
13. The atmosphere over Brownsville is warmer than the US Standard Atmosphere from the
surface to a pressure level of approximately _____________________.
14. Sea Level Pressure is approximately 1000mb, so we could say that 100% of the
atmosphere is above 1000mb. Because air pressure is the weight of the air above you, we
could say 90% of the atmosphere’s molecules are above 900mb, 80% above 800mb, and
so on. Therefore, there is still approximately ____________ of the atmosphere’s
molecules at 100mb (the top of the Stuve Diagram provided).
While Stuve Diagrams are relatively convenient to plot, they don’t necessarily provide the best
visual of the layers of the atmosphere as Meteorologists would prefer. As a result, a second
diagram, called a Skew-T Log-p is often used. It is essentially a Stuve Diagram, but the
Temperature axis is skewed. This makes the tropopause much more apparent, but is a pain to
plot. Thankfully, the data collected at Brownsville can be plotted on a Skew-T diagram using
software (a link to the plot is provided below). Figure 7 is a Skew-T of the same radiosonde data
collected at Brownsville and displayed in Table 2.
Figure 7 - Skew T Log P diagram of Data Collected at Brownsville, Texas at 1200 UTC on June 4th, 2019
15. Using the same definition of tropopause (a pressure level well above the surface) where
temperature stops decreasing and starts increasing… even slightly, we ___________ see
a tropopause between the 200mb and 100mb pressure levels
All of the radiosonde data provided in this investigation can be retrieved at the University of
Wyoming Soundings page, which is at http://weather.uwyo.edu/upperair/sounding.html
On the page, you will see several drop-down menus including one that says “Type of Plot.”
Select that menu and scroll down to “GIF Stuve.” Then hover over the map and select a station
(all stations are given a three-letter code… for example, Brownsville’s was BRO). Click on the
three-letter code, and a new tab should open up displaying the latest Stuve Diagram for that
location. Focus on the temperature line (the rightmost thick black line) and answer the questions
1. Is there a surface inversion, and if so, how far does it rise to?
2. Is there a tropopause? If so, is it higher/lower than the US Standard Atmosphere?
3. From what pressure levels is the atmosphere at the location you selected warmer than the
US Standard Atmosphere? Cooler?
4. Print out a copy of the Stuve Diagram you looked at and submit it to your instructor with
the answers to the questions above.
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