Download File - Mr. Lloyd`s 7th grade science!

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Section 2-4 “Global Heat Balance Review and Weather Analysis”
Part I – “Review on Global Heat Balance”
1.) Due to Earth’s small tilt with respect to its axis of rotation, the tropics receives much more
energy (heat) from the sun than the polar regions.
2.) The role of mid-latitude (where we live) synoptic (broad) weather systems is to remove
temperature and density gradient by transporting (or advecting) warm air poleward and cold air
equatorward.
3.) The temperature and pressure gradients are continuously removed through the interaction of
upper-level waves in the Jetstream with large scale high and low pressure systems near the
surface. Jet Streams steer/intensify High and Low pressure systems at the surface.
4.) Air moves naturally in motion due to different temperature or pressure differences within the
Earth’s atmosphere.
5.) Convective Currents: are produced through
1.) The Heating or cooling of a liquid
2.) Changes in the fluids density
3.) The force of gravity, and convection
6.) Advection of the wind moves cool air below warm air, or warm air above cool air. This is
because warm air is less dense than the cooler air (more water vapor in warm air).
7.) Increase in temperature cause a column of air to expand
8.) When surrounding air cools the air pressure near the surface increases (high pressure)
Part II – “The Movement of Air Masses”
9.) Changing weather conditions are caused by the movement of air masses Air masses form over
large areas of Earth's surface, and take on the general temperature and moisture characteristics of
the area over which they form.
10.) As air masses move, they can collide with one another. The boundary along which two air
masses meet is called a front. Changing weather conditions are common along fronts. Different
types of fronts bring different characteristic weather conditions.
11.) Maritime air masses are air masses that form over large bodies of water.
12.) Continental air masses are air masses that form over large land surfaces.
13.) A high pressure system is a clockwise whirling mass of cool, dry air that generally brings fair
weather and light winds.
14.) A low pressure system is a counter-clockwise whirling mass of warm, moist air that
generally brings stormy weather with strong winds.
15.) Clouds such as cumulonimbus and thunderheads occur within low pressure systems,
tornadoes and lighting can also occur.
16.) A boundary between two air masses of different density, moisture, or temperature is called .
17.) Cold fronts form when a cold air mass moves under a warm air mass, which is less dense,
and pushes air up (produces thunderstorms heavy rain or snow). Cumulus and Cirrus clouds are
most common within this type of front.
18.) Some effects from cold fronts can be cumulus clouds.
19.) A Warm Front is defined as the leading edge of a warm air mass overtaking a cooler, slower
air mass. Stratus Clouds are most common with this type of front.
20.) Some effects from warm fronts can be stratus clouds.
21.) An Occluded Front is formed when a cold front overtakes a warm front and in the process
"cuts off” the warm front from contact with the ground and heat source.
22.) A Stationary Front is a boundary between two different air masses, neither of which is strong
enough to replace the other.
23.) A trough on a weather map is an elongated area of relatively low pressure. Troughs bring
cloudy and rainy weather.
24.) The Norwegian Cyclone Model provides the basic lifecycle of low pressure systems in the
mid-latitudes.
25.) There are 5 stages within the Norwegian cyclone model, which include:
The Stationary Front
Upper Level Jetstream Support
Organization of the Low Pressure System
Maturity Stage
Dissipation Stage
Part III “Cloud Formation”
26.) Clouds are formed when warm, moist air is forced vertically in the atmosphere (by
convection or fronts), cools, and some of the water vapor in the air condenses to form droplets of
liquid water.
27.) Some cloud condensation nuclei consist of particulate matter and aerosols.
28.) Relative Humidity is the amount (percentage) of water vapor the air is holding compared to
the amount it could hold
29.) Dew Point is the temperature at which air is saturated and condensation forms
30.) Cirrus clouds roughly reside above 18,000 feet (usually higher). Are wispy, feathery clouds
made of ice crystals that form at high levels. Usually seen about 24-48 hours before cumulus
cloud formation.
31.) Cumulus Clouds roughly reside at 6,000 feet or above. They are the type of cloud that is
puffy or heaped in appearance and has distinct edges. Can produce severe weather. Linked with
high amounts of water vapor and heat.
32.) Stratus Clouds roughly reside below 6,000 feet. Clouds that form in low, horizontal layers
and blankets the sky. Linked with stationary and warm fronts.
33.) Nimbus = rain clouds
Cumuli= Heaped clouds
Cirri = High Altitude clouds
Alto = Mid – Altitude clouds
Strati = A combining form
34.) Stratocumulus is a cloud of a class characterized by large dark, rounded masses, usually in
groups, lines, or waves, the individual elements being larger than those in altocumulus and the
whole being at a lower altitude, usually below 8000 feet (2400 meters). Strati means a combining
source.
35.) Altocumulus is a middle-level cloud located between 6,500 and 20,00 feet, Altocumulus
clouds are either banded or rounded in formation. Sometimes, they look like balls of cotton stuck
into the blue background of the sky, while other times they look like rows. Often, these clouds
have shadows or dark areas and can sometimes signal bad weather is approaching. They are made
of water whereas high-level clouds are made of ice.
36.) Cirrocumulus is a cirri form cloud of a class characterized by thin, white patches, each of
which is composed of very small granules or ripples: of high altitude, about 20,000–40,000 feet
(6000–12,000 meters). Cirri meaning combining form.
37.) Altostratus is a cloud of a class characterized by a generally uniform gray sheet or layer,
lighter in color than nimbostratus and darker than cirrostratus: of medium altitude, about 8000–
20,000 feet (2450–6100 meters).
38.) Cumulonimbus is a cloud of a class indicative of thunderstorm conditions, characterized by
large, dense towers that often reach altitudes of 30,000 feet (9000 meters) or more, cumuliform
except for their tops, which appear fibrous because of the presence of ice crystals: occurs as a
single cloud or as a group with merged bases and separate tops.
Part IV – “How do Meteorologists Study and Predict Weather”
39.) Meteorologist is an expert in or student of meteorology; a weather forecaster.
40.) Meteorologists use a variety of technologies to study weather including weather satellites,
Doppler radar, weather maps, radiosondes, and aircraft. Meteorologists also use simpler tools,
such as rain gauges, thermometers, barometers and anemometers at ground stations.
41.) Weather forecasting is the application of science and technology to predict the state of the
atmosphere for a given location.
42.) For viewing large weather systems on a worldwide scale, weather satellites are extremely
useful. Weather satellites show cloud formations, large weather events such as hurricanes, and
other global weather systems such as Tornadoes.
43.) Using Doppler Radar, meteorologists can get a picture of precipitation that allows them to
track a storm's progress over time. This is one of the main tools to track and forecast
Tornado/supercell Events.
44.) Radiosondes is an instrument released into the atmosphere that records temperature,
pressure, humidity, wind speed and direction. The Radiosonde measures a vertical profile of the
atmosphere.
45.) Forecasters use weather maps to predict the present and future weather patterns within the
earths Troposphere. Many different levels are used within weather map analysis. Example: 300
mb, 500 mb, 700 mb, 850 mb, 925 mb, and surface.
46.) Isobars and Isotherms are lines on weather maps, which represent patterns of pressure and
temperature, respectively. They show how temperature and pressure are changing over space and
so help describe the large-scale weather patterns across a region in the map.
47.) Aircraft is used to fly into or near hurricanes/tornadoes. Forecasters can drop
dropwindsondes which measure temperature, wind, pressure, and humidity.
***Go to rss.discoveryeducation.com*** Fill out the following essay questions. Hint: Look
under the Explore and Evaluate Tabs!
48.) How do meteorologists study and predict weather?
Meteorologists use tools, such as rain gauges, anemometers, barometers, satellites, and weather
balloons, to gather data about conditions in the atmosphere. They analyze these data to learn
about the locations and movements of air masses, fronts, and other weather patterns. They can
display these patterns using weather maps.
49.) How does the movement of air masses affect weather?
Air masses take on the characteristics of the area where they form. Then they are moved by the
jet stream or prevailing winds. As air masses move they collide with one another. Changing
weather patterns often occur at the boundaries between air masses, called fronts.
50.) How do clouds and rain form?
Clouds form when warm, moist air cools and some of the water vapor in the air condenses to
form droplets of liquid water. As condensation continues, the droplets become larger. When the
water drops inside the cloud become large enough, they fall to Earth’s surface as rain. Often,
raindrops start out as snow crystals which melt as they fall.