Key Weather Elements Explained

Understanding Weather Elements

These are the components that characterize the climate and interact in the lower layers of the atmosphere. They are modified by various factors.

Temperature: A Key Element

Temperature is the degree or level of heat in the air or environment, measured in degrees Celsius (°C) or Fahrenheit (°F). Average temperature and thermal oscillation (amplitude) can be measured. These can be represented by maps using lines (isotherms) or choropleth maps (using isometric inks).

The incidence of solar radiation (oblique or vertical) determines different thermal zones on the Earth's surface.

Factors Affecting Temperature

Temperature variations are influenced by:

• Proximity to the sea: Moderating effect on coasts, more extreme inland.
• Latitude: Temperatures generally decrease towards the poles.
• Altitude: Temperatures decrease with altitude, approximately 6.5°C per 1 km or 3.6°F per 1,000 ft.
• Frosts: Occur when temperatures drop below 0°C, more commonly inland than on the coast. Frost can be caused by radiation cooling of the ground on clear nights or by cold advection (arrival of a cold air mass).

Atmospheric Moisture: Humidity, Fog, and Haze

a) Humidity: This is the amount of water vapor contained in the air. It depends on factors such as proximity to the sea and temperature (humidity generally decreases with increasing temperature). The absorptive capacity of the air for water vapor depends on temperature; cooling moist air can lead to precipitation. In Spain, humidity often exceeds 70% in coastal areas and the northern sub-plateau, with seasonal differences.

b) Fog: This is a suspension of tiny water droplets in the lower atmosphere, limiting visibility to less than one kilometer. It forms when air in the lower atmosphere cools and condenses. Fog types include radiation fog (caused by nighttime ground heat loss, typical in winter) and advection fog (formed when warm, moist air moves over a cold surface, or cold air moves over a warm, wet surface like the sea, a lake, or a river).

c) Haze: This is a phenomenon that reduces visibility, caused by the presence of fine dust or smoke particles in the lower atmosphere.