Ch 13) Weather Lesson 1 Flashcards
prepare for test on friday
What is a hydrometer?
Any instrument used to measure relative humidity.
Hydrometers are essential for determining the moisture content in the air.
What is a psychrometer?
A hygrometer that uses a wet and dry bulb thermometer to measure relative humidity.
Psychrometers are commonly used in meteorology.
What occurs when the atmosphere becomes saturated with water vapor?
Water vapor will condense and form water droplets.
This process is essential for cloud formation and precipitation.
What is the dew point?
The temperature at which air is saturated and condensation can occur.
Understanding dew point is crucial for predicting weather changes.
What are clouds?
Water droplets or ice crystals suspended in the atmosphere.
Clouds form when cooling air reaches the dew point.
Define stratus clouds.
Flat, white, and layered clouds with an altitude up to 2,000 m.
Stratus clouds often cover the sky like a blanket.
What characterizes alto clouds?
Fluffy, heaped, or piled up clouds with an altitude of 2,000 to 6,000 m.
Alto clouds are often associated with changing weather conditions.
Describe cirrus clouds.
Wispy clouds that form at altitudes above 6,000 m.
Cirrus clouds are usually seen in fair weather but can indicate a change.
What is fog?
A cloud that forms near the ground.
Fog can significantly reduce visibility and is important for aviation safety.
What is precipitation?
Water, in liquid or solid form, that falls from the atmosphere.
Precipitation includes rain, snow, sleet, and hail.
Define rain.
Precipitation that reaches Earth’s surface as droplets of water.
Rain is the most common form of precipitation.
What is snow?
Precipitation that reaches Earth’s surface as solid, frozen crystals of water.
Snow can accumulate and significantly alter landscapes.
What is sleet?
Precipitation that usually starts as snow, melts in warm air, and then refreezes in cold air.
Sleet can create hazardous driving conditions.
What is freezing rain?
Rain that freezes when it contacts the ground.
Freezing rain can create dangerous ice layers on roads and power lines.
How does hail form?
Starts as a small piece of ice lifted and dropped in an updraft within a cloud, gaining layers of ice.
Hail can cause significant damage during storms.
What is the water cycle?
A series of natural processes by which water continually moves among oceans, land, and the atmosphere.
The water cycle is essential for regulating Earth’s climate.
What is the typical path of a water molecule in the water cycle?
Water vapor enters the atmosphere from evaporation, cools and condenses, then precipitates back to Earth’s surface.
This cycle maintains the balance of water on Earth.
Define weather.
The atmospheric conditions, along with short-term changes, of a certain place at a certain time.
Weather can change rapidly and affects daily life.
List the weather variables.
- Air temperature
- Wind speed and direction
- Air pressure
- Humidity
- Cloud cover
- Precipitation
These variables are key to understanding weather patterns.
What is air temperature?
The measure of the average kinetic energy of molecules in the atmosphere.
Temperature affects weather conditions and phenomena.
How does air pressure change with altitude?
Air pressure decreases as altitude increases.
This relationship is crucial for weather forecasting.
What instrument measures air pressure?
Barometer.
Barometers are fundamental tools in meteorology.
What unit is used for measuring air pressure?
Millibars (mb).
Understanding air pressure measurements is vital for weather predictions.
What is wind?
Air as it moves from high pressure to low pressure.
Wind is a significant factor in weather systems.
What instrument measures wind speed?
Anemometer.
Anemometers are essential for meteorological studies.
Define humidity.
The amount of water vapor in the air, measured in grams of water per cubic meter of air (g/m³).
Humidity affects comfort levels and weather conditions.
What is relative humidity?
The amount of water vapor present in the air compared to the maximum amount the air could contain at that temperature.
Relative humidity is important for understanding weather patterns.
What does 100% relative humidity indicate?
The air is holding as much water vapor as it can at that temperature and is considered saturated.
This condition can lead to fog or precipitation.
What does 50% relative humidity signify?
The air is holding only half of what it could hold at that temperature.
Relative humidity affects weather perception and comfort.
