Layers if the atmosphere

Layers of the Atmosphere

  • Exosphere

    • The outermost layer of the atmosphere, extending up to approximately 600 km (372 miles) above the Earth's surface.

  • Thermosphere

    • Situated below the exosphere, with a height of about 85 km (53 miles).

  • Mesosphere

    • The layer that lies below the thermosphere, extending up to about 50 km (31 miles).

  • Stratosphere

    • Ranges from the mesosphere up to about 25 km (16 miles).

    • Contains the Ozone Layer, which absorbs and scatters ultraviolet solar radiation.

  • Troposphere

    • The lowest layer of the atmosphere where weather phenomena occur.

Definitions of Weather and Climate

  • Weather

    • Defined as the state of the atmosphere at any given time, encompassing short-term variations.

  • Climate

    • Refers to the average state of the atmosphere over a long period of time, usually taken as 30 years or more.

    • Categories of climate include:

    • Polar

    • Temperate

    • Arid

    • Tropical

    • Mediterranean

    • Mountains

Elements of Weather

  • Weather is assessed using the following elements:

    • Sunshine

    • Cloud Cover

    • Temperature

    • Measures how hot or cold a day is.

    • Rainfall (Precipitation)

    • Refers to the water falling to the Earth.

    • Wind Speed

    • The rate at which the wind is blowing.

    • Wind Direction

    • The origin direction of the wind.

    • Humidity

    • The quantity of water vapor present in the air.

    • Air Pressure

    • The weight of air per unit area.

Instruments of Weather Measurement

  • Various instruments are employed to measure different weather elements:

    • Sunshine: Measured using a Campbell-Stokes sunshine recorder.

    • Cloud Cover: Assessed by the naked eye.

    • Temperature: Measured with a maximum-minimum thermometer.

    • Rainfall: Measured using a rain gauge.

    • Wind Speed: Measured with an anemometer.

    • Wind Direction: Measured using a wind vane.

    • Humidity: Measured with a hygrometer.

    • Air Pressure: Measured using a barometer.

Field of Meteorology

  • Meteorology: The study of weather.

    • Individuals who specialize in meteorology are known as meteorologists.

    • Weather is predominantly studied at the Met Office.

    • Use of computers is the primary method for analyzing and predicting weather conditions, although many instruments must be deployed outdoors.

The Weather Station

  • Weather instruments are housed in a specialized structure known as the Stephenson Screen.

Features of the Stephenson Screen

  • Description of the Stephenson Screen:

    • A white wooden box designed to keep temperature and other measurements accurate.

    • Elevated off the ground to avoid interference from the ground conditions.

    • Located away from trees, buildings, and animals, as well as human interference to ensure accurate data collection.

    • Constructed with slatted sides to promote air circulation.

    • Contains essential instruments such as the maximum-minimum thermometer (also called Six's Thermometer), anemometer, hygrometer, and barometer.

    • Data readings occur every 24 hours.

Specifics on Measuring Weather Elements

  • Sunshine Measurement

    • Recorded in ultraviolet (UV) rays; intensity is captured.

  • Rainfall Measurement

    • Recorded in inches or millimeters using a rain gauge.

  • Wind Speed Measurement

    • Recorded in miles per hour (mph) or kilometers per hour (km/h) using an anemometer.

  • Wind Direction Measurement

    • Measured according to the cardinal directions of the compass using a wind vane.

  • Humidity Measurement

    • Measured using a wet-dry bulb thermometer; represents the amount of moisture in the air.

  • Air Pressure Measurement

    • Measured in millibars using a barometer with readings indicating different weather conditions (e.g., 1010 mbar as a baseline).

  • Temperature Measurement

    • Measured in degrees Celsius (Centigrade) or Fahrenheit, using a maximum-minimum thermometer.