Download meteorology

Weather and Climate
Notes and Activities
Name ________________________
Assignment for Vocabulary

On a separate sheet of paper, list the words below 1 to 49 and define them using your textbook, a
dictionary, the Internet, or any other source you choose. Just get it done!!! There are a lot of words here,
do them a little at a time, don’t wait until the last minute.
Once you have defined the words read over each word so that you are able to understand its meaning.
I will collect and grade your completed list or give a matching QUIZ prior to the test on this
information as a homework assignment.
Number each word 1 through 16:
absorption
air mass
climate
clouds
continental air mass convection
duration of insolation evaporation
greenhouse efffect
groundwater
isobars
isotherms
occluded front
polar air mass
psychrometer
radiation
refraction
relative humidity
front
thermometer
tropical air mass
warm front
wet bulb - dry bulb wind speed
windward
anemometer
cold front
Coriolis effect
front
hurricane
leeward
precipitation
rain gauge
station model
thunderstorm
watershed
wind direction
barometer
conduction
dew point
gradient
insolation
maritime
pressure
reflection
stationary
tornado
weather
wind vane
Weather Basics
The energy for weather is supplied by ______________________.
Weather in the United States generally move from _______________ to _______________ at an
approximate rate of ____________________ per day.
Weather in New York State generally moves toward the _______________.
Draw a general weather pattern arrow on each map:
United States
New York State
Weather Variables
Heat and Temperature
Heat and temperature are related but they are not the same thing. Heat is a form of energy that
transfers from one object to another. Temperature is the average kinetic energy (heat) in an object.
Heat transfers can happen in one of three methods:
Method:
Definition:
Examples:
Conduction
Convection
Radiation
Heat can be used to either change the temperature of an object or to change the state of matter. On
page 1 of the ESRT there are data for the phase changes of water. When water melts, it absorbs 334 J
of heat for every gram of material, while freezing gives off the same amount. When water vaporizes,
it absorbs 2260 J of heat for every gram of material, while condensing gives off the same amount.
Sample problems:
1. If 100 g of water freezes to form ice, how much heat was absorbed?
2. If 100 g of ice melts to form water, how much heat was released?
3. If 100 g of water evaporates to form vapor, how much heat was released?
4. If 100 g of water vapor condenses to form water, how much heat was released?
Temperature is measured on three different scales as shown on page 13 of the ESRT. The normal
scale used in the U.S. is Fahrenheit. There are two scales for the metric system; the Celsius scale is
based on water where zero is the freezing point of water and 100 is the boiling point of water. The
Kelvin scale is similar to the Celsius scale in that each degree is the same amount of heat. The zero
point of for the Kelvin scale is Absolute zero, -273ºC. When looking at weather, we usually use ºF
since that is what the National Weather Service uses. Therefore, we sometimes need to convert one
temperature unit to another.
Moisture and Humidity
Moisture in the atmosphere is measured in two ways. It can be measured as Dewpoint or as Relative
Humidity. Both are measured using the wet and dry bulb temperatures on a sling psychrometer and
page 12 in the ESRT. Here are instructions for using a sling psychrometer:
1. wet the wick on the sling psychrometer.
2. spin the psychrometer for 1 minute.
3. read and record the dry bulb and wet bulb temperatures.
4. calculate the difference between the dry bulb and wet bulb temperatures.
5. use the dry bulb temperature and difference with the table on page 12 of the ESRT.
Dewpoint is the temperature at which dew forms. It is measured in ºF or ºC. Being a measure of
moisture, the closer the dewpoint is to the air temperature (dry bulb), the more moisture there is in the
air. Therefore, when the dewpoint is the same as the air temperature, the air is saturated with water, it
is holding all of the water that it can.
Relative humidity is a percent of which the air is saturated. It is also measured with a sling
psychrometer. If the air is holding as much water as it can, it is saturated and the relative humidity is
100%. If the air is completely dry and has no water vapor in it, the relative humidity is 0%.
Dry Bulb (ºC)
Wet Bulb (ºC) Difference (ºC) Dewpoint (ºC)
Relative Humidity (%)
18
13
20
18
10
8
When the air is saturated, water vapor begins to condense. When it condenses, clouds form. Clouds
come in a variety of shapes and sizes but there are three main forms:
Cumulus
Stratus
Cirrus
These forms work together, along with two other prefixes to describe any type of cloud
Nimbus
Alto
Forms of clouds:
Stratocumulus
Cirrostratus
Cumulonimbus
Precipitation
There are 5 main forms of precipitation that happen as water droplets in a cloud become large
and heavy enough fall.
Rain
Snow
Sleet
Hail
Freezing Rain
Air Pressure and Wind
Air Pressure is measured in _______________ by an instrument called a _______________.
It may also be measured in _______________ (but those units are not part of the metric system).
Page 13 of the ESRT has a scale to convert between these units.
As temperatures rise and air becomes warmer, air pressure on the ground _______________.
This is because warmer air _______________. As temperatures drop and air becomes cooler, air
pressure on the ground _______________. This is because cooler air _______________.
Since water vapor is lighter than air, it rises away from Earth’s surface. This causes the
pressure to _______________. Therefore, the greater the amount of water vapor in the air (high
relative humidity or dewpoint close to the air temperature), the _______________ the air pressure.
Similarly, air pressure is affected by altitude. As you increase in altitude, less of the
atmosphere is “piled on top” of you. As altitude increases, air pressure _______________.
As air pressure changes, areas of high pressure and areas of low pressure develop. These
pressure systems each get a swirling of air surrounding them caused by the _______________.
Draw the swirling air around each of the pressure systems below.
L
H
As air moves outward away from the high pressure and inward toward the low pressure, the air will
move from the high pressure area toward the low pressure area. This movement of air is called
_______________.
Wind has both direction and speed. A correctly named wind will include both variables. Wind
speed is measured with an _______________ while wind direction is measured with a
_______________ or wind sock.
Wind direction is stated as the direction the wind is blowing FROM and wind speed is measured in
knots (nautical miles per hour). One knot is equal to 1.15 miles per hour. A 15 knot wind blowing
from the northeast toward the southwest at would be recorded as ____________________________.
Air Masses and Fronts
Air masses are defined by their characteristics of moisture and temperature. Moisture is listed
as continental (c) when the air mass is dry because it formed over land or maritime (m) when the air
mass is moist because it formed over water. Temperature of an air mass is listed as tropical (warm) if
it forms near the equator, polar (cold) if it forms away from the equator, or arctic (frigid) if it forms
near the North Pole. When we put the variables together we get these combinations
Symbol Name
Characteristics
cT
cP
cA
mT
mP
mA
Maritime arctic
Not used- area around North Pole is solid.
Notice that as the symbols for the air masses are written the moisture (c or t) is written in lower case
letter and the temperature (T, P or A) is written in capital letters.
Label the map with the appropriate symbols for the air masses that would originate in each area.
When air masses with different characteristics are in contact with one another there is a definite
boundary that separates them. A boundary between air masses is called a _______________.
As air masses move, one air mass can push another out of the way. Fronts are named for the
air mass that is doing the pushing. If a cold (polar or arctic) air mass is pushing a warm (tropical) air
mass it is called a _______________ front. If a warm (tropical) air mass is pushing a cold (polar or
arctic) air mass it is called a _______________ front.
Cold front-
Notice the steep boundary between the air masses. That means that warm air is rising quickly to form
_______________ clouds that will bring _______________ as the front passes. The map symbol for
a cold front is shown at the bottom of the picture.
Warm front-
Notice the gradual slope of the boundary between the air masses. This makes clouds spread out over
a large distance forming ___________________ clouds and bringing ____________________ as the
front approaches. The map symbol for a warm front is shown at the bottom of the picture.
Stationary front-
A stationary front occurs when a cold air mass and a warm air mass are pushing each other in
opposite directions. The front doesn’t move much until one air mass builds up enough energy to push
the other one out of the way. The symbol for a stationary front is shown on the picture.
Occluded front-
Cold and warm fronts spin counterclockwise around low pressure systems and cold fronts move
faster than warm fronts. An occluded front forms when a cold front catches up to and joins with a
warm front. The two cold air masses meet and force the warm air upward into the atmosphere. The
symbol for an occluded front is shown at the bottom of the picture.
Forming an Occluded Front
Weather Station Models
There are weather stations around the world that are constantly collecting data about the
current condition of the atmosphere by measuring and recording all of the weather variables that were
listed above. These data are then placed in and around a circle that represents the area where the
weather station is located. The diagram below from page 13 of the ESRT shows where each piece of
data belongs and shows a complete sample station model.
The present weather symbols used to the left of the circle on the weather station model are also listed
on page 13 of the ESRT as well as the symbols for air masses, fronts and severe weather.
Draw a sample weather station for the following data:
Temperature= 45ºF
Rain shower, ¼ inch in last 6 hours
Dewpoint= 42ºF
Pressure= 998.2 mb falling steadily 2.4 mb in 3 hrs
Wind from the SW at 15 kts
Partly (75%) cloudy
Weather Forecasting
Weather forecasting is a complicated and difficult process since at tracks so many variables,
each of which can change at any moment. No system for predicting the weather is perfect but in
general, a weather system moves across about 1/3 of the United States in a day. That means that if we
look at the weather in Chicago today, we will see what our weather will be like tomorrow.
The meteorologists who forecast the weather for a living have to take much more information
into account but they have complex data collecting and reporting systems to help them. The National
Weather Service is the branch of the federal government that collects data from across the country
and distributes it. Each meteorological station then has a system of radar and satellite image
capability to help them make predictions.
Severe Weather
Name
Thunderstorms
Tornadoes
Hurricanes
Blizzards
Atmospheric Conditions
Damage/ Danger
Sample Regents Questions
See next page for answer sheet for #70-74.
Answer Sheet for #70-74: