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Aerographers Mate, Module 05-Basic Meteorology | Next
EARTH-SUN RELATIONSHIP |
CHAPTER 1
FUNDAMENTALS OF METEOROLOGY
Meteorology is the study of atmospheric
phenomena. This study consists of physics, chemistry,
and dynamics of the atmosphere. It also includes many
of the direct effects the atmosphere has upon Earth’s
surface, the oceans, and life in general. In this manual
we will study the overall fundamentals of meteorology,
a thorough description of atmospheric physics and
circulation, air masses, fronts, and meteorological
elements. This information supplies the necessary
background for you to understand chart analysis,
tropical analysis, satellite analysis, and chart
interpretation.
SYSTEM OF MEASUREMENT
LEARNING OBJECTIVE: Recognize the
units of measure used in the Metric System and
the English System and how these systems of
measurement are used in Meteorology.
To work in the field of meteorology, you must have
a basic understanding of the science of measurement
(metrology). When you can measure what you are
talking about and express it in numerical values, you
then have knowledge of your subject. To measure how
far something is moved, or how heavy it is, or how fast
it travels; you may use a specific measurement system.
There are many such systems throughout the world
today.
The
Metric
System
(CGS,
centimeter-gram-second) has been recognized for use
in science and research. Therefore, that system is
discussed in the paragraphs that follow, with brief
points of comparison to the English System (FPS,
foot-pound-second). The metric units measure length,
weight, and time, respectively. The derivation of those
units is described briefly.
LENGTH
To familiarize you with the conventional units of
metric length, start with the meter. The meter is slightly
larger than the English yard (39.36 inches vs. 36
inches). Prefixes are used in conjunction with the meter
to denote smaller or larger units of the meter. Each
larger unit is ten times larger than the next smaller unit.
(See table 1-1.).
Table 1-1.—Common Prefixes in the Metric System
Prefix1
Symbol
Decimal
Value
Scientific Notation
Kilo
K
1000
103
Hecto
H
100
102
Deka
D
10
101
Deci
d
.1
10-1
Centi
c
.01
10-2
Milli
m
.001
10-3
1These prefixes are used with all metric units such as
meters, grams, liters, and seconds (eg., kilometers,
hectometers, centiliters, milliseconds).
Since the C in CGS represents centimeters (cm)
you should see from table 1-1 that the centimeter is
one-hundredth
of
a
meter,
.O1M,
or
10-2
M.
Conversely, 1 M equals 100 cm. To describe a gram,
the G in the CGS system, you must first have a
familiarization with area and volume.
AREA AND VOLUME
A square has four equal sides and it is a one-plane
figure—like a sheet of paper. To determine how much
surface area is enclosed within the square you multiply
the length of one side by the length of the other equal
side. If the sides were 1 centimeter (cm) in length the
area of the square would be 1 cm × 1 cm = 1 square cm,
or 1 cm2. If squares having an area of 1 cm2 were
stacked on top of each other until the stack was 1 cm
tall, you would end up with a cube whose sides were
each 1-cm in length. To determine the volume of the
cube you simply multiply the length by the width and
height. Because each side is 1 cm you end up with a
volume of 1 cubic centimeter (cm3) (1 cm × 1 cm × 1
cm = 1 cm3). More simply stated, multiply the area of
one side of the cube by the height of the cube. Once you
understand how the volume of a cube is determined,
you are now ready to review the G in the CGS system.
1-1
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