Weather and Climate Quiz

Objectives

• Differentiate between weather and climate
• Decode and code station models
• List and describe weather variables

Weather vs. Climate

• Weather: "What you get!"—present atmospheric conditions, constantly updated
• Climate: "What you expect"—average conditions of an area

What Causes Weather?

• Variation in insolation (incoming solar radiation)
• Uneven distribution of heat energy across Earth's surface

Station Models

• Display weather data from a specific location
• Found on Page 13 of the ESRT
• Include information about:
  • Present weather
  • Temperature
  • Visibility
  • Dew point
  • Wind speed and direction
  • Barometric pressure and trend
  • Precipitation
• Symbols represent different weather conditions

Barometric Pressure Conversions

• Locate the coded pressure
• Use a rule:
  • If pressure is less than 1004 add 10 before, if 5 or more add 9 before last digits
  • Always place a decimal between last two digits

Instruments to Acquire Station Model Data

• Temperature: Thermometer
• Dew point: Sling psychrometer or hygrometer
• Wind direction: Wind vane
• Wind speed: Anemometer
• Barometric pressure/trend: Barometer
• Precipitation: Rain gauge

Weather Variables (Temperature)

• Factors influencing temperature:
  • Angle and duration of the sun
  • Color and texture of surfaces
  • Specific heat
  • Altitude

Weather Variables (Pressure)

• Pressure: Weight of the atmosphere, measured with a barometer
• Factors affecting pressure:
  • Temperature and density (warm air is less dense, and therefore has less pressure)
  • Moisture content (more moisture = lower pressure)
  • Altitude (higher altitude = lower pressure)

Weather Variables (Moisture)

• Moisture movement: Water cycle
• Factors affecting evaporation:
  • Temperature (higher temperature = higher evaporation rate)
  • Humidity (higher humidity = lower evaporation rate)
  • Wind (higher wind = higher evaporation rate)
  • Surface area (larger surface area = higher evaporation rate)
• Dew point temperature: Condensation temperature where dew forms, 100% relative humidity
• Wet-bulb depression: difference between dry and wet bulb temperatures, related to moisture content
• Humidity:
  • Absolute humidity: actual amount of water vapor in the air
  • Relative humidity: percentage of water vapor in the air compared to the maximum amount it can hold at a given temperature.

Weather Variables (Wind)

• Wind direction: Named from the direction it comes FROM
• Wind flow: From high pressure to low pressure
• Local winds: Sea breezes and land breezes
• Regional winds: Affected by the Coriolis effect
• Pressure gradient: Close isobars = greater pressure gradient = greater wind speed
• Global winds: Affected by the Coriolis effect; air sinks in high pressure areas, air rises in low pressure areas.

Conditions Needed for Cloud Formation

• Moisture in the air
• Cooling temperature to the dew point
• Condensation nuclei (particles for water vapor to condense around)
• Surface for condensation to occur

Mapping Air Pressure

• Isobars connect areas of equal air pressure (found on Page 13 of the ESRT)
• Isobar interval is 4.0 mb

Summary of Weather Variables

• Describes the different types of weather variables (Temperature, Pressure, Moisture, and Wind) and how they work together in various conditions, by linking them to specific conditions in terms of measurement and interaction with other elements.