chapter 16 weather
Terms
undefined, object
copy deck
- Condition of the atmosphere at a particular time and place
- weather
- continuous movement of water from water sources, such as lakes and oceans into the air, onto and over land into the ground and back to the water sources
- Stages of water cycle
- liquid water nchanges into water vapor, which is a gas
- evaporation
- plants release water vapor into the air through their leaves
- transpiration
- water, usually from precipitation what flows across land and collects in rivers, streams and the ocean
- runoff
- when rain, snow, sleet or hail falls from the clouds onto the earthÂ’s surface
- precipitation
- amount of water vapor or moisture in the air.
- humidity
- the amount of moisture the air contains compared with the maximum amount it can hold at a particular temperature.
- relative humidity
- measures relative humity. Consists of two thermometers. One is wet bulb, one is dry bulb. The difference in the two is the relative humidity
- psychometer
- the temperature to which air must cool to be completely saturated.
- dewpoint
- collection of millions of tiny water droplets or ice crystals. The form as warm air rises and cools.
- cloud
- puffy, white with flat bottoms. When warm air rises, indicate fair weather. When they get larger they produce thunderstorms.
- cumulus cloud
- form in layers. Cover large areas of the sky, often blocking out the sun.
- stratus
- dark stratus clouds that produce light to heavy, continuous rain
- nimbostratus clouds
- thin, feathery, white clouds found at high altitudes. Form when wind is strong. Indicate approaching bad weather if they thicken and lower in altitude
- cirrus clouds
- When the water vapor condenses near the ground it forms a stratus cloud called
- fog
- means that precipitation might fall from the cloud cumulus cloud.
- cumulonimbus
- prefix for clouds in high altitude
- cirro made of ice crystals
- Prefix for clouds in middle altitudes:
- Alto can be made up of both water droplets and ice crystals
- Prefix for clouds in low altitudes:
- strato Made up of water droplets
- water, in solid or liquid form that falls from the air to the earth.
- precipitation
- Most common precipitation
- Rain: Liquid water falls from clouds to earth
- Most common solid
- Snow
- 4 types of precipitation
- rain, snow, sleet and hail
- freezing rain. Forms when rain falls through a layer of freezing air. The rain freezes producing falling ice
- sleet
- solid precipitation that falls as balls or lumps of ice. Forms in cumulonimbus clouds
- Hail
- used to measure the amount of rainfall
- rain gauge
- a large body of air that has similar temperature and moisture throughout.
- Air mass
-
Two letters of air mass:
first letter represents what characteristic - moisture
-
Two letters of air mass:
second letter is what characteristic - temperature
-
Explain what the letters mean in relationship describing air mass
m
c
p
t -
m: maritime forms over water wet
C: continental forms over land
dry
p forms over the polar gions Cold
t develops over the tropics warm - the boundary that forms between two different air masses. Weather is usually cloudy and stormy in a front.
- front
- four types of weather fronts
- cold, warm, occluded front, stationary front
- Cold air mass meets and displaces a warm air mass., produces thunderstorms, heavy rain or sonw.
- cold front
- warm air mass meets and overrides a cold air mass. Warm air gradually replaces the cold air.
- warm front
- fast moving cold air mass overtakes a slow moving warm air mass and forces the warm air up. Cool temperatures and large amounts of precipitation
- occluded front
- cold air mass meets a warm air mass and little horizontal movement occurs. Weather is similar to warm front.
- stationary front
- Why do fronts occur in middle latitudes?
- Because there are both cold and warm air masses. In the tropics there is only warm air masses
- weather that can cause property damage and even death.
- Severe weather
- small intense weather systems that produce strong winds, heavy rain, lightning and thunder. Warm moist air rises rapidly in an unstable environment
- thunderstorms
- large electrical discharge that occurs between two oppositely charges surfaces.
- lighteneing
- the sound that results from the rapid expansion of air along the lightning strike
- thunder
- small, rotating column of air that has high wind speeds and low central pressure and that touches the ground.
- tornado
- large rotating tropical weather system with wind speeds of at least 119 km/h
- Hurricane
- Hurricanes turn which way in the northern hemisphere
- counterclockwise
- Hurricanes turn which direction in the southern hemisphere
- clockwise
- Parts of a hurricane
-
eye: center of hurricane, core of warm calm air with low winds
Eye wall: strongest part of the hurricane. Surrounds the eye. Heavy rains and forceful winds up to 300 km
Rain bands beyond the eye wall, spiraling bands of rain and high winds. The winds decrease the further away from eye wall - a wall of water tat builds up over the ocean due to the heavy winds and low atmospheric pressure. Gets bigger and bigger as it nears shore.
- Storm surge
- prediction of weather conditions over the next 3-5 days
- weather forcast
- measures temperature
- thermometer
- measures air pressure
- Barometer
- anemometer
- instrument that measures wind speed
- measures direction of wind
- windsock or windvane
- 3 ways weather is measured in upper atmosphere:
-
weather balloons
radar
weather satellites - lines on a weather map that connect points of equal air pressure. Closed circles mean high or low pressure
- isobars
- isobars
- lines on a weather map that connect points of equal air pressure. Closed circles mean high or low pressure