science weather Flashcards
(153 cards)
1
Q
Weather
A
atmospheric conditions, along with short-term changes of a certain place at a certain time.
2
Q
Climate
A
The long term average weather conditions that occur in a particular region.
3
Q
Weather describes conditions such as
A
air pressure, wind, temperature, and amount of moisture in the air.
4
Q
How is weather created?
A
energy from the Sun is absorbed by Earth’s surface and heats air above it
5
Q
dew point
A
*The temperature at which air is saturated & condensation forms.
6
Q
Temperature
A
a measure of the average kinetic energy of molecules in the air
7
Q
What happens to the molecules when the temperature is high
A
molecules in air move rapidly , and it feels warm.
8
Q
What happens to the molecules when the temperature is low
A
they move less rapidly, and it feels cold.
9
Q
How is wind caused
A
air flowing from high pressure to low pressure its direction is influenced by the Earth’s rotation
10
Q
isobars
A
lines of equal air pressure on a map, measured in millibars
11
Q
Closer isobars are together means
A
its windier
12
Q
Coriolis Effect
A
Because of the Earth’s rotation, any freely moving object or fluid will appear to:
*Turn to the right of its direction of motion in the Northern Hemisphere
*Turn to the left of its direction of motion in the Southern Hemisphere.
*This is what causes the Westerlies to curve and flow West to East. Otherwise the wind would flow directly South to North.
13
Q
Wind
A
air currents move from high pressure to low pressure this is created
14
Q
Wind direction is measured with what instrument?
A
wind vane
15
Q
Wind speed is measured with what instrument?
A
anemometer
16
Q
Air pressure is measured with what instrument?
A
barometer
17
Q
What is air pressure
A
the pressure exerted by the weight of air (molecules); the force that a column of air applies on the air or a surface below it
18
Q
What is the relationship between density and pressure when the air is warm?
A
warm air = less dense, less pressure
19
Q
What is the relationship between density and pressure when the air is cold?
A
cold air = more dense, more pressure
20
Q
Humididty
A
A measure of the average amount of water vapor (moisture) in the air.
21
Q
what is humidity measured in
A
g/m^3
22
Q
Warm air can hold blank _water vapor than cool/cold air.
A
_more__
23
Q
When the temperature is warm vs cold how do they differ in terms of the rate of speed or movement? Why is this unique?
A
*Warm air can contain more water vapor than cold air. During warm temperatures - water vapor molecules move quickly & don’t easily come together. In cooler temperatures- water vapor molecules move more slowly.
24
Q
When do droplets of liquid stick together?
A
*Slower movement allows water vapor molecules to stick together forming droplets of liquid.
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condensation
*The formation of liquid water from water vapor.
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When air can only hold a certain amount of water vapor in the air for condensation to take place, the air is ...
saturated
27
What is relative humidity?
A measure of the amount of water vapor present in the air compared to the maximum amount of water vapor the air can contain
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Psychrometer
instrument used to measure relative humidity.
29
If air at 25°C contains 11 g of water vapor per cubic meter, the relative humidity is…
50 percent.
30
When water vapor in air condenses it will form what?
*Water droplet liquid or ice.
When air near the ground becomes saturated, the water vapor in air will condense to a liquid. If the temp is above 0 degrees C, dew forms. If the temp is below 0 degrees C, ice crystals/ frost form.
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When temperature decreases, what happens to the amount the air holds ?
*Air can hold less moisture.
32
What is dew point’s relationship with relative humidity?
A high RH indicates dew point is closer to current air temperature.
33
Relative humidity of 100 % indicates
indicates the dew point is equal to the current temperature and the air is maximally saturated with water.
34
When the dew point remains constant and temperature increases, relative humidity will .
decrease
35
When does dew point change
with the amount of water vapor in the air
36
When air near the ground cools to its dew point what happens?
water vapor condenses and forms dew.
37
If the air temperature cools to the dew point, or if the dew point rises to equal the air temperature, then what begins to form?
dew, fog, or clouds
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Frost may form when temperatures are near
0°C.
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Q: What is considered a very uncomfortable dew point?
Dew points above 70°F are considered very uncomfortable because the air feels very humid and sticky.
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Q: At what dew point level does severe weather become more likely?
Dew points near 55°F and higher are often needed for severe weather to develop, because higher moisture levels help fuel storms.
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As the air cools, the amount of water vapor needed for saturation blank and the relative humidity blank.
decreases, increases
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what percent of rh is the air saturated
100
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Water vapor will condense in tiny droplets around
small particles of dust and salt.
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what do billions of water droplets form
clouds
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What must happen for clouds to form ?
For clouds to form air must be lifted. Clouds form as warm air is forced upward, expands, and cools.
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how are clouds classified
shape and hieght
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where are clouds
Some clouds extend high into the sky, and others are low and flat.
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what do dense clouds bring what weather
rain or snow,
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when do thin, wispy clouds appear
mostly sunny days.
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What are the shape and height of clouds vary by
vary with temperature, pressure, and the amount of water vapor in the atmosphere.
51
What are the 3 main types of clouds
stratus, cumulus, and cirrus
52
Stratus clouds- shape
form layers, or smooth, even sheets in the sky.
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When air is cooled to its dew point near the ground, it forms
a stratus cloud called fog.
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Where do stratus clouds usually form
low altitudes and may be associated with fair weather or rain or snow.
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Cumulus clouds- shape
puffy, white clouds, often with flat bases.
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Where r Cumulus clouds found
tower to great heights and can be associated with fair weather or thunderstorms.
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Cirrus clouds look like
Cirrus clouds appear fibrous or curly. They are high, thin, white, and feathery.
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Cirrus clouds made of
ice crystals
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What kind of weather is associated with cirrus clouds?
Cirrus clouds are usually seen during fair weather but can also be a sign that a storm is approaching.
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cirro
describes high cloud
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alto
describes middle elevation clouds
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strato
refers to clouds at low elevation
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Cirrostratus
high clouds.
These clouds usually indicate fair weather, but can also signal an approaching storm.
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Altostratus clouds
form at middle levels.
If the clouds are not too thick, sunlight can filter through them.
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Clouds associated with rain or snow often have the word ____ attached to them.
nimbus
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nimbus is latin for
dark rain cloud
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The water content of these clouds is so high that little sunlight can pass through them. - what cloud
nimbus
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When a cumulus cloud grows into a thunderstorm, it is called a
cumulonimbus cloud
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cumulonimbus are abt blank ft high
18
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Nimbostratus clouds are layered clouds that can bring
long, steady rain or snowfall.
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precipitation
Water falling from clouds. This might be in liquid or solid state.
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how does precipitation work
Cloud droplets combine and grow large enough to fall to Earth. Cloud droplets form around very small solid particles, such as salt and dust. A puff of smoke can contain millions of them.
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Why are raindrops different sizes?
Strong upward winds in a cloud, called updrafts, can hold raindrops in the air. This gives the drops more time to grow before they fall to the ground. Another thing that matters is how dry the air is. If the air is very dry, the raindrops can become smaller or even dry up completely before they reach the ground.
\
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5 main types of precipitation?
rain, snow, sleet, hail, and freezing rain.
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above freezing precipitation
rain
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below freezing precipitation
snow
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how does sleet form
, precipitation needs to pass through the layer of air that is 32 degrees Fahrenheit or colder.
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freezing rain forms when
there is a thick warm layer of air above, but the ground is covered by cold air. The rain falls as liquid, but it freezes as soon as it hits the cold ground.
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What happens when snow falls from cumulonimbus clouds during the colder months?
When snow falls from cumulonimbus clouds, it passes through a warm layer of air and starts to melt.
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What does the quick process of melting and refreezing snow create?
create tiny ice pellets called sleet.
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hail
precipitation in the form of lumps of ice.
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What type of clouds does hail come from and what happens as a result?
Hail forms in cumulonimbus clouds of a thunderstorm when water freezes in layers around a small nucleus of ice
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Surface report-
a description of a set of weather measurements made on Earth’s surface
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upper-air report-
a description of wind, temperature & humidity conditions above Earth’s surface
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Doppler radar-
a specialized type of radar that can detect precipitation as well as the movement of small particles, which can be used to approximate wind speed
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Isobar-
lines that connect all places on a map where pressure has the same value=
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Computer model-
detailed computer programs that solve a set of complex mathematical formulas
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Meteorologist
use information from radar, satellites, computers and other weather instruments to forecast the weather
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Station Model
displays date from many different weather measurements for a certain location; it uses numbers & symbols to display date & observations from surface reports & upper-air reports
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Isotherm-
lines that connect places with the same temperature; show which areas are warm & which are cold
91
warning
severe weather conditions already exist- take immediate action!
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watch
issued when conditions are favorable
93
What is a specific safety measure we can take if there is a blizzard?
Immediate action
stay indoors bc its extremely cold and windy
if you go outside you could get frostbite
94
The National Weather Service classifies a winter storm as a blizzard if:
The winds are 56 km/h.
The temperature is low.
The visibility is less than 400m in falling or blowing snow.
These conditions persist for 3 hrs or more.
95
What is a specific safety measure we can take if there is a tropical cyclone?
Go to the basement/ lowest point in the house/ get away from bodies of water.
96
How are hurricanes classified and named?
Souffrir-Simpsons wind scale- range from category 1-5
Named using a list based on region
Wind speed/ surface damage
97
the structure of a tropical cycle.
Type of pressure and movement:
* low pressure
* counterclockwise
Eye: Center of the hurricane; calm winds
Eyewall: 1st heaviest rain
Spiraling Rainbands: 2nd heaviest rain; extends from the eyewall.
Starts on water but may strike on land
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Where are the weakest and strongest winds in a Hurricane? What is a storm surge?
Weakest- left side of the eye
Strongest- right side of the eye
storm surge- abnormal rise of water along the coast
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What are tropical cyclones?
Uses warm, moist air as fuel
Forms only over warm ocean waters near the equator
100
cyclone season
The Americas/ Caribbean hurricane season runs from June to November 30, peaking in August and September
The cyclone season in south pacific and australia normally runs from November to April
In the bay of Bengal and Arabian Sea, tropical cyclones usually occur from april to June, and september to November.
101
Name four specific safety measures we can take if there is a thunderstorm?
Lightning- lay down in a field/ don't stand under trees/ stay away from pools, metals, go underground
102
Where do tornadoes form?
A: Tornadoes form on land.
103
Q: What causes tornadoes to form?
extremely rapid rotating winds that form at the base of cumulonimbus clouds specifically in a structure called a wall cloud.
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How long do they stay on ground
*Remains on the ground for a few minutes.
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Q: What role do updrafts play in tornado formation?
*Strong, spiraling updrafts of warm, moist air may form in these clouds.
106
Q: How does a tornado form its funnel shape?
*As air spins upward, a low-pressure area forms, and the cloud descends to the ground in a funnel.
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Q: What happens when a tornado moves along the ground?
*Tornadoes suck up debris as it moves along the ground, forming a dust envelope.
108
how are tornadoes classified
the amount of damage they cause
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Q: What scale is used to classify tornadoes?
* Tornado classification using the EF scale, or enhanced fujita scale.
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Q: How is wind speed in a tornado estimated?
A: Wind speed is estimated based on the amount of damage done by the tornado.
111
What causes thunder?
A: Thunder is the result of the rapid heating of air around a bolt of lightning.
112
how hot can lightning get
up to 30,000 degrees Celsius.
113
Q: Where does thunder typically occur?
A: Thunder occurs in warm, moist air masses and along fronts.
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What happens to the air around the lightning?
A: The extreme heat causes the air around the lightning to expand rapidly, then quickly cool and contract.
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Q: What happens as the air cools and contracts?
A: Condensation occurs, forming cumulonimbus clouds that can rise up to 18 km.
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Q: How is the sound of thunder created?
A: The rapid movement of molecules in the air creates sound waves, which we hear as thunder.
117
Lightning
Inside a storms cloud, warm air is filled rapidly as cooler air sinks; when the movement of air can cause different parts of a cloud to become oppositely charged; current flows between regions of opposite electrical charge, lightning flashes; it can occur within a cloud, between clouds or between a cloud and the ground.
118
Hail: From thunderstorms-
can dent card and aluminium sliding on houses flattens and destroys entire crops in minutes.
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Strong Winds:
Generated by thunderstorms, severe thunderstorm - when thunderstorms are accompanied by winds faster than 89m/hr, this is classifies as severe.
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Flash Flooding:
When thunderstorms stall over a region or heavy rain to fall heavily for a period of time. occurs when streams can nor contain all the water running into them.
Flash floods can be dangerous because they occur with little warning.
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Thunderstorms- where
Occurs in warm, moist air masses along fronts.
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Q: What happens to the warm air that leads to a thunderstorm?
A: The warm air is forced upward, where it cools and condenses, forming cumulonimbus clouds.
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Q: What happens to the cool air during a thunderstorm?
A: Cool, dense air sinks and spreads over the Earth’s surface.
124
Q: How do strong winds form during a thunderstorm?
A: The sinking, rain-cooled air and strong updrafts of warmer air cause strong winds associated with thunderstorms.
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Q: Why might hail form during a thunderstorm?
A: Hail may form because of strong updrafts that carry raindrops to higher, colder parts of the storm where they freeze.
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what happens during a cold front
Cold air meets warm air and pushes the warm air upward.
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What kind of weather can a cold front bring?
A: Cold fronts can bring violent storms and thunderstorms.
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What type of weather usually follows a cold front?
A: Fair, cool weather usually follows a cold front.
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What types of clouds are associated with a cold front?
A: Cumulus and cumulonimbus clouds are common with cold fronts.
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what happens during a warm front
Warm air gently rises over a cold air mass and moves over it.
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What kind of weather usually follows a warm front?
A: Rain showers followed by hot, humid weather usually follow a warm front.
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What types of clouds are associated with a warm front?
A: Stratus, nimbostratus, and cirrus clouds are associated with warm fronts.
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What happens during a stationary front
warm air mass meets cold air mass and neither air moves
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What kind of weather can a stationary front cause?
A: A stationary front can cause rain to fall in the same area for several days.
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How many air masses are involved in an occluded front?
A: Three air masses are involved: cold air, cool air, and warm air.
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How does an occluded front form?
A: Cold air moves toward cool air with warm air trapped between them, cutting off the warm air from the surface.
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What type of weather does an occluded front produce?
A: Occluded fronts produce rain, freezing rain, sleet, thunderstorms, and steady periods of precipitation.
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Q: How does the weather from an occluded front compare to other fronts?
A: It usually produces less extreme weather than cold or warm fronts.
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front
A boundary between 2 air masses of different density, moisture, or temperature. Cloudiness, precipitation and storms can occur at the front.
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Maritime
forms over oceans as water evaporates & the air becomes humid; brings wet weather (Moist)
(m)
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Continental
(c) form over land so they are drier
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Tropical ( T):
forms over tropics; brings warm weather
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Polar
( P ): forms over polar region; brings cold weather
A: Arctic/Antarctic M:Monsoon
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Arctic/Antarctic Monsoon
A, M
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Resulting weather comes from these air masses:
1. Maritime Polar mP 2. Continental Polar cP
3. Maritime Tropical mT 4. Continental tropical cT
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cP
continental polar-cold, dry stable
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cT
Continental Tropical- hot, dry, stable air aloft, unstable surface air
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mP
maritime polar- cool, moist, and unstable
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mT
maritime tropical -warm, moist unusually stable
150
Wind blows into low pressure, causing wind to move _____________ in the Northern Hemisphere.
Counter clockwise
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Low pressure systems are called ______________________; associated with what type of weather? __________
Cyclones
stormy weather
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Earth’s rotation causes these winds blow away from high pressure, causing wind to move _____ in the Northern Hemisphere.
clockwise
153
anticyclones- what weather
fair weather
