Key Meteorological Factors and Climate Definitions in Spain

Factors Shaping Spain's Climate

Geographical Influences

1. Latitude

   The location of Spain in the Northern Hemisphere determines the existence of two distinct transitional periods (spring and autumn).

2. Situation (Crossroads)

   Spain is a crossroads between two continents (Europe and Africa) and two oceans (Atlantic and Mediterranean).

3. Relief Systems

   • The Galician-Cantabrian and Pyrenean systems hinder the entry of air masses.
   • The Central System protects the southern plateau from maritime influence.
   • The Pyrenees and maritime masses (West-Southwest) obstruct penetration.
   • The Iberian continental and polar mass effect is delimited by the Southern Iberian system, separating Atlantic and Mediterranean influences.
   • Coincidence of geographic and climatic areas.

Thermodynamic Factors

High-Level Circulation: The Jet Stream

The Jet Stream shows variations in its speed:

1. Fast Circulation: This is a zonal path (West to East).
2. Slow Circulation: This results in anticyclonic ridges and troughs, leading to storms. A detachment of the jet stream causes a Cold Drop (Gota Fría).

Essential Meteorological Terminology

Temperature Oscillation Amplitude

The difference between the maximum and minimum temperature measured over a specific period (day, month, or year).

Anticyclone

An atmospheric center of high pressure (greater than 1013 millibars), which is the mean pressure at sea level.

Barlovento (Windward)

The slope or region of a relief oriented toward the steering wind.

Cierzo

The local name in the Ebro valley for a cold, dry, and gusty northwest wind.

Continentality

The property of land masses to gain or lose temperature faster than the sea. This effect is greater the larger the land area.

Jet Stream

A strong wind flow that circulates between 7 and 11 km high, flowing from west to east.

Borrasca (Low Pressure System)

A center of action with atmospheric pressure lower than 1013 mbar, which is the mean pressure at sea level.

Polar Front (Frente Polar)

A planar interface between two air masses of different characteristics (warm/cold or dry/humid). It is located in the middle latitudes near the jet stream and undergoes latitudinal displacement.

Cold Drop (Gota Fría)

A cold air mass that slides off the polar front and descends at high speed toward warmer latitudes. It is typically located in the Mediterranean during late summer and early autumn.

Isobar

An imaginary line connecting points of the same temperature. (Note: The standard definition is equal pressure.)

Isohyet

An imaginary line that connects points of equal precipitation on a map.

Bar

A unit of pressure measurement.

Fog

Tiny water droplets suspended in the atmosphere, limiting horizontal visibility to less than 1 km.

Leeward

The sheltered side of a slope or relief, generally drier and wider than the windward (Barlovento) slope.

Umbria (Shade Slope)

The slope of a hill or mountain exposed to the north, where there is mostly shade.