Weather and Climate Notes

Weather vs. Climate

  • Weather: Observed over a short period; can change quickly.

  • Climate: Observed over 30 years; takes a long time to change.

What Constitutes Weather?

  • Temperature: Determined by sunshine; measured by a thermometer.

  • Rainfall: Quantity of rain in a given area over time.

  • Wind Direction: Direction from which wind blows.

  • Cloud Cover: Amount of sky covered by clouds; formed by condensation.

Weather Instruments

  • Thermometer: Measures temperature.

  • Rain Gauge: Measures amount of rain.

  • Wind Vane: Measures wind direction.

  • Anemometer: Measures wind speed.

  • Barometer: Measures atmospheric pressure.

Instrument Placement

  • Thermometer: In a shed.

  • Rain Gauge: Open area, protected from wind.

  • Wind Vane: Highest point on roof.

  • Anemometer: Open space, 10 meters above ground.

  • Barometer: Inside or outside.

Factors Affecting Climate

  • Latitude and sun angle

  • Distance from sea

  • Altitude

  • Prevailing winds

  • Processes leading to rainfall

Latitude and Sun Angle

  • Determines sun exposure duration.

Distance from Sea

  • Water is a heat insulator.

  • Coastal areas: cooler in summer, warmer in winter.

  • Inland locations: greater temperature differences.

Altitude

  • Temperature decreases by 1∘C1^{\circ}C for every 100m increase.

Prevailing Winds

  • Winds from warm grounds bring warm weather.

  • Winds from cold grounds bring cold weather.

Maltese Islands Winds

  • Mostly from Northwest (Majjistral).

  • Westerlies in winter.

  • Sirocco from the South, often with dust.

Processes Leading to Rainfall

  • Relief Rainfall: Warm, moist air over mountains cools, condenses, and forms rain.

  • Frontal Rainfall: Warm, moist air meets cold, dry air, causing condensation.

  • Convectional Rainfall: Ground heats air, causing it to rise, cool, and condense.

Climatic Regions

  • Equatorial/Tropical Climate:

    • Hot and humid with abundant rainfall.

    • Convectional rainfall.

    • Dense, broadleaf rainforests.

  • Mediterranean Climate:

    • Vegetation: Scrubland and moderate-sized trees.

    • Resistant to hot, dry summers, plants may lie dormant.

    • Waxy, hairy, or prickly leaves to reduce moisture loss.

    • Hot dry summers and cold wet winters