Key Factors Shaping Spain’s Climate and Weather Patterns

Posted on Dec 7, 2024 in Geology

Factors that Influence the Weather

1 – Geographical Factors

Spain’s climate influencing factors:
  • Latitude: Spain is located in the southern half of the northern temperate latitudes, with the exception of the Canary Islands, located in the area near the Tropic of Cancer. Due to its latitude, it experiences four seasons. In general, we can say that greater latitude means a lower temperature, as the sun’s rays impinge less directly with increasing latitude.
  • Status: The Iberian Peninsula is located between two bodies of water with very different thermal characteristics: the Atlantic Ocean and the Mediterranean Sea, and between two continents: Europe and Africa. Therefore, it has a situation at the crossroads of air masses of different origins. The Canary Islands receive different influences due to their location.
  • The influence of the sea: Due to the large width of the peninsula, the sea’s influence is limited and reduced to a narrow coastal strip. The existence of mountain ridges parallel to the coast causes major climatic differences between the narrow peripheral zone and the interior. The sea affects the temperature, softening it. In coastal areas, the winters are much milder and summers a little less hot.
  • The relief: It influences the climate of your choice, for its altitude and orientation.
The provision of mainland relief has several implications:
  • The mountain systems along the coast curb the influence of the sea, which only penetrates clearly through the valley of the Guadalquivir.
  • The east-west position of most of the mountainous landscape makes it difficult for air masses to change from the north or south. It facilitates the entry of air masses from the west, but the massive character of the peninsula makes them lose much of their moisture and extreme temperature as they penetrate into the interior.
  • The basins enclosed by mountains, such as the Douro and the Ebro, have little precipitation because the air masses release their moisture into the mountain ranges that border them.
The altitude temperatures decrease about 0.6 degrees per 100 m of ascent. Height also causes orographic rainfall on the slopes of the ascending air, or windward side, while the leeward slopes are usually much more arid.
The orientation creates strong thermal contrast between the sunny (south-facing slopes), which are warmer, and shady (north-facing slopes), which are cooler.

2. Thermodynamic Factors

They are responsible for air circulation or a succession of air masses that determine the different types of weather and atmospheric climate. The circulation is governed by the current height of the jet or Jet Stream and the size of the centers of action, air masses, and fronts.

A) The Jet Stream:

In the temperate zone, height atmospheric circulation is driven by the jet stream, a strong gust of wind, with a tubular structure, which runs west-east, between 9,000 and 11,000 m altitude. The stream separates the low pressure present on the pole height and left to the left of his career, from tropical high pressure situated to the right. The jet stream is responsible for time on the surface, dependent variations in current velocity and its seasonal displacements. When it runs fast, it has a tubular track with small ripples, under the surface with the polar front and its velocity decreases. When it describes deep undulations: crests or ridges that rise high pressures, and valleys and troughs that cause low pressure. Both are reflected at the surface and give rise to dynamic anticyclones and depressions. The undulations, which may become detached from the main jet, allow air to penetrate far south polar and tropical air moving north, giving great variability at the time of the temperate zone.

B) The center of action, air masses, and fronts.

1. The action centers
They are areas of high or low pressures. Atmospheric pressure is the weight of air at the surface. It is measured in millibars and is represented on maps by lines of time isobars, lines connecting points with the same atmospheric pressure. The normal pressure is 1,013 millibars. When there is more pressure, we are facing anticyclones, and if less than 1,013 mb, we are dealing with storms or depressions.
Anticyclones are responsible for the stable and sunny days, while storms bring unsettled weather and rain.
Air masses are lots of air with specific characteristics of temperature, humidity, and pressure. These properties are acquired in the regions where they originate. Spain, due to its latitude, gets cold arctic air masses and polar and tropical air masses. The three, depending on the surface on which they form, can be wet or inland sea. The fronts are surfaces separating two air masses of different characteristics. Therefore, on both sides of a front is an abrupt change of air properties. In Spain, the most important front is the polar front that separates tropical air masses and polar. Its ripples originate from two fronts storms that cause precipitation
2. The air masses and atmospheric general circulation
Atmospheric pressure is the weight of air above a unit of measure. It is measured with a barometer and in millibars (mb). The pressure on weather maps is represented by isobars lines, which are lines connecting points with the same atmospheric pressure. Normal blood pressure is 1,013.5 mb. When higher pressure we are facing an anticyclone or high-pressure center. Anticyclones always bring stable and sunny weather. When the pressure is less than 1,013.5 mb. we have a storm, cyclone, or depression and the time it is generated is unstable, often cloudy and rainy.
Anticyclones and depressions are air masses of different characteristics, and never mix but are separated by fronts. The fronts can be warm (on maps with time lines and semicircles in red), cold (represented with a line and blue triangles), and occlusal or occluded fronts.
Spain is affected by what is called the Polar Front that separates tropical air masses and polar.
3. Principal Anticyclones Affecting the Peninsula.
  • Azores anticyclone: Part of the subtropical high-pressure belt. It is a maritime tropical air mass, stable and permanent, and that is causing the dry sunny weather and many times occurs in the peninsula. During the summer, the Azores anticyclone is located on the peninsula, moving north to the Atlantic storms. During the winter, the Azores anticyclone moves towards the south, allowing the arrival on the peninsula of the Atlantic storms.
  • Saharan anticyclone: It is a continental tropical air mass that emits winds in all directions. Sometimes these winds reach the peninsula, resulting in dust clouds generated by the so-called red rain or blood (red clay powder dissolved in water vapor).
  • Scandinavian anticyclone: An air mass of polar origin. Produces very low temperatures when it affects the peninsula.
  • Central anticyclone: A seasonal air mass as it appears only in winter. If it extends to the south, it may affect the peninsula in the NE area, causing frosts and cold waves.
  • Plateau anticyclone: A seasonal air mass, as only way for the continental winter in the Central Plateau. Is responsible for dry days, sunny, clear, and very cold.
4. Principal Storms Affecting the Peninsula
  • Depression in Iceland: A permanent low pressure moves to the south in winter and that is tempered by a warm ocean current of the Gulf Stream or Current of the Gulf of Mexico. Brings rain in the north.
  • Depression in the Gulf of Rosas, Lyon, and Genoa: A seasonal air mass (especially active in autumn) due to the high temperature that is at this time the surface water of the sea (the sea takes 5 times longer to warm up and cool down the land). Also due to evaporation over the sea originates. If it matches up cold air is the phenomenon known as a cold drop, which causes intense rainfall with catastrophic effects of floods from rivers and floods that will occur.
  • Depression in the Gulf of Cadiz: This is a seasonal low pressure that forms in winter to ward off the Azores anticyclone and remain empty areas or swamps barometric pressure. Because the winter rains that affect the provinces of Andalusia (in Grazalema (Cádiz) reached its highest rainfall in Spain).
  • Polar Front: the contact zone between tropical air masses and polar air masses. During the summer, located north of the peninsula. In autumn and spring is located between 40 and 55 degrees, and in winter affects more southerly latitudes.
  • The Jet Stream: A stream flowing westerly winds at an altitude between 9,000 and 11,000 meters and at speeds between 150 and 600 km/hour. His direction is west – this determines the general atmospheric circulation in the area. In its progress, it causes the formation of anticyclonic cells to the right and the left cyclonic cells. The polar front is only a reflection of the Jet Stream in height. When Jet velocity decreases, describes deep undulations, which lead to dynamic anticyclones and depressions. The undulations allow air to penetrate into southern latitudes polar and tropical air moving north.