Essential Weather and Climate Terms

Basic Weather Concepts

• Isotherms: Lines of equal temperature (℃).
• Frost: Air temperature drops to 0℃.
• Icy Irradiation: Ground cooling causes 0℃ temperature.
• Advection Frost: Cold air mass arrival causes 0℃ temperature.

Humidity and Condensation

• Humidity: Water vapor in the air.
• Relative Humidity: Water vapor percentage relative to saturation.
• Saturation: Maximum water vapor air can hold.
• Fog (Niebla): Water droplets limiting visibility (<1 km).
  • Irradiation Fog: Heat loss from soil.
  • Orographic Fog: Air cooling on slopes.
  • Advection Fog: Warm, humid air mass arrival.
• Dew: Water droplets on surfaces.
• Condensation: Gas to liquid or vapor transition.

Precipitation

• Precipitation: Water falling from clouds.
• Pluviometer: Measures rainfall (mm or L/m²).
• Isohyets (Soyetas): Lines of equal precipitation.
• Orographic Precipitation: Air mass meets a mountain.
• Convective Precipitation: Surface warming heats air mass.
• Frontal Precipitation: Clash of different air masses.

Wind

• Wind (Viento): Horizontal air movement.
• Trade Winds: Winds from subtropical anticyclones.
• Breeze: Wind with alternating direction.

Evaporation and Aridity

• Evaporation: Water turning to steam.
• Evapotranspiration: Moisture loss from plants and soil.
• Actual Evapotranspiration: Actual moisture loss.
• Potential Evapotranspiration: Moisture loss with abundant water.
• Aridity: Temperature-precipitation relationship.
• Gaussen Index: Monthly aridity measure.
• Lautensach Index: Areal aridity measure.

Weather, Climate, and Related Phenomena

• Weather: Atmospheric phenomena.
• Meteorology: Study of weather and atmospheric phenomena.
• Climate: Statistical weather data over time.
• Urban Climate: Urban area weather conditions.
• Climatology: Study of climates and their distribution.

Topographic Influences

• Windward (Barlovento): Mountain slope exposed to wind, causing cooling and precipitation.
• Leeward (Sotavento): Slope sheltered from wind, with warming and drying air.
• Foehn Effect: Air warming on mountain slopes.
• Sun-Exposed Slope (Solana): Valley side receiving direct sunlight.
• Shaded Slope (Umbría): Valley side always in shadow.

Temperature Variations

• Annual Thermal Amplitude: Warmest and coldest month temperature difference.
• Thermal Gradient: Temperature decrease with height.
• Temperature Inversion: Temperature increase with height.

Atmospheric Circulation and Pressure

• Air Circulation: Air mass movement determining weather patterns.
• Jet Stream: High-altitude wind current.
• Cold Drop (Gota Fría): Storm from jet stream troughs.
• Action Centers: High and low-pressure areas.
• Atmospheric Pressure: Weight of air above a surface (mb).
• Barometer: Instrument measuring atmospheric pressure.
• Isobars: Lines of equal atmospheric pressure.
• Millibar: Pressure unit (1/1000 of a bar).
• Isohypses: Lines of equal geopotential height.
• Anticyclone: High-pressure area.
• Cyclone (Borrasca): Low-pressure area.
• Air Masses: Air portions with specific characteristics.
• Weather Front: Boundary between different air masses.
• Polar Front: Boundary between tropical and polar air masses.

Solar Radiation and Clouds

• Insolation: Solar radiation reaching Earth’s surface.
• Clouds: Visible water droplets or ice crystals in the atmosphere.
• Temperature: Degree of heat (℃).