GEO165 Meteorology
LAB#1
THE VERTICAL STRUCTURE OF THE ATMOSPHERE:
THE INTERNATIONAL STANDARD ATMOSPHERE -1976
Introduction
The International Standard Atmosphere (ISA) is a model atmosphere, or a standard to
which the real atmosphere can be compared on a given day. It is a meter stick for measuring
and for aircraft operations. The values used in this lab were calculated using this website
http://www.digitaldutch.com/atmoscalc/
ISA – 1976 Sea Level Standards
Standard Sea-Level Pressure 1013.25 hPa = hector Pasals( formerly millibars) which is
defined as 1 atmosphere.
Standard Sea-level Temperature 15°C
Standard Lapse Rate -6.5°C/km
Standard Density 1.225 kg/m3
Standard Speed of Sound 340.294 m/s
In Lab #1 the goal is to explore the vertical temperature and pressure structure of the
atmosphere. We will do this by using Microsoft Excel and creating two graphs one with
three data curves the other with a single curve.
A set of graphs ready for submission includes aesthetic adjustments to enhance
communication. We will label various layers and features and answer the questions that
follow. As in all labs this is a group effort but each student must hand in her/his own
work. If all goes well you will submit your work electronically by emailing the MS Excel
spreadsheet and the MS Word document as atachments.
Materials: This document (lab1.doc) and the Excel spreadsheet (lab1.xls)
Software: MS Excel, MS Word. If you do not have MS Office, download and install the
free Open Office for both MAC and PC. (http://www.openoffice.org/)
Graphing Procedures
A. A First Look at Your Data
1.
Look over your data. There are 4 columns one each for temperatures at various
altitudes at 10°N, 40°N and 70°N. Each column represents the latitudinal average
temperatures around the globe at that latitude.
2. Get a feel for the data. Do you notice anything that stands out?
3. What do you know about the weather differences between the latitudes?
B. The Graphs You Will Create
The graphs we create will be Excel scatter plots. We will go over creating them in class.
There are differences between Excel 2003, Excel 2007, Excel 2010 and Open Office in how
the graphs are created.
Axes – heavier line weight and black with units along the axes and labeled.
Grid – light-weight horizontal and vertical lines at significant values. Not too many or your
graph will look cluttered.
Plot Background – light grey or a gradient to communicate change with height.
Legend – Within a box, darker background strategically placed for visibility.
Title – Either above or within the plot area. If your graph has a great deal of blank space
placing the title high, within the plot area saves space and makes the title more visible.
Data Curves – Different colors and/or weights and or patterns. In this class we will use
color to distinguish between curves. The color should “make sense”. For example for the
10°N graph red is a good choice because the tropical atmosphere is warm. Blue would work
for the 70°N graph and for the 40°N graph an intermediate color.
You will create one graph with three temperature curves and one graph with a single
pressure curve. We will step through the procedures in class.
C. Finishing Touches (Not Optional)
1. Color was long shunned in scientific reporting, but it adds another dimension in visual
communication and scientific papers now often make use of color. We will use color to
enhance how our graphs communicate.
2. Vary line weights and colors to emphasize or de-emphasize an item.
3. San serif fonts look clean and un cluttered. Vary text size and attribute (bold, italic
etc.) to emphasize different text elements.
4. Axes must be labeled and the weight of axis lines should be heavier, while grid lines
should be light in weight and a shade that partially blends into the background.
5. The graph must have a title and legend.
6. Your graph should be clean and uncluttered and it should be easy to quickly see what it
being communicated.
D. Labeling Features
You can use the text box tool in Excel to label features.
Insert Tab >> Text Box
Label the following features – use the world’s greatest information resource – the internet –
do a search and place and/or align the text so it is easy to read.
Troposphere
Tropopause
Stratosphere
Stratopause
Mesosphere
Mesopause
Thermosphere
The two inversions
Ozone Layer
F. Answer the questions.
G. Email your MS Word document and MS Excel spreadsheet
(delete the instruction pages first) to:
steve@shorstmeyer.com
SUBJECT LINE !!! MUST HAVE !!!
geo165
NAME________________________________
We will have an open discussion in class to help answer the questions.
Temperature Graphs
1. A temperature inversion in the atmosphere is when the temperature
INCREASES as altitude INCREASES? In what “spheres” are the two
major inversions.
2. What else is found where the lower inversion is found?
3. What is the importance of this region of the atmosphere?
4. What causes the temperature to increase upwards here?
5. The atmosphere is warmest at the surface of the Earth. What does
this suggest about the source of heat for the lower atmosphere?
6. How does the elevation of the tropopause vary from the tropics to
the polarregions? Why?
Pressure Graph
7. Pressure does not decrease at a constant rate in the atmosphere.
Why?
8. At what approximate altitude are half the air molecules below you?
9. Mt. Everest is the tallest mountain on earth at 8,848 meters. What is
the approximate pressure there according to the standard
atmosphere?
10. What percentage of air molecules are below the summit of Everest?