Surely you have heard thousands of times on the news about the Azores anticyclone. It is a meteorological phenomenon that affects the climate of the Iberian Peninsula and that must be understood very well in order to understand the causes and consequences it has on the Spanish climate. Scientists have studied this anticyclone for many years and it has great relevance in weather forecasting.
For this reason, we are going to dedicate this article to telling you what the Azores anticyclone is, what its characteristics, causes and consequences are.
What is an anticyclone
The first thing is to know what an anticyclone is. An anticyclone is an area of high pressure (above 1013 Pa) in which the atmospheric pressure is higher than the surrounding air pressure and increases from the periphery towards the center. It can usually be related to typical stable weather, clear skies, and sunshine.
The anticyclone column is more stable than the surrounding air. In turn, the air that falls downwards creates a phenomenon called sinking, which means that it prevents the formation of precipitation. Of course, it must be taken into account that the way in which the air descends will vary depending on the hemisphere in which it is located.
These anticyclonic airflows are easier to develop in summer, further aggravating the dry season. Unlike cyclones, which are easier to predict, often have an irregular shape and behavior. Broadly speaking, anticyclones can be divided into four groups or categories.
What is the Azores anticyclone
At first glance, becoming a meteorologist in the Azores may seem like an easy task, but all that glitters is not gold. The famous anticyclones do not always translate into stable weather over the archipelago. In our country it usually guarantees us dry and sunny weather in summer, but it also occurs in our winter latitudes. It also does this by stagnating the air and causing the famous winter pollution episodes in big cities. Therefore, it is in charge of marking the time in our latitude. But how was it formed?
Its formation is related to atmospheric circulation and the temperature difference between the equator and the poles. Solar radiation translates into high temperatures in equatorial regions, which causes warm air to rise due to its low density. Warm air rises not only in altitude, but also in latitude.
Up to 30°-40°N. Here, it descends through a sinking process that results in a constant and zero updraft, creating an anticyclone. So this translates into calm and sunny weather.
In summer, it usually approaches Western Europe, blocking the entry of storms from northern latitudes. In winter, however, we are farther away from it because the depression occurs further south. The entry of the storm and the cold air then have a free pass to roam freely at lower latitudes. The weather on the Iberian Peninsula will be affected by the interaction between anticyclones and northern storms.
What is the weather like with the Azores anticyclone?
Although the archipelago is named after this famous anticyclone, the weather on the island is busier than we initially thought. In fact, the weather is very changeable and humid. Of course, if you plan to go this summer, do not do it thinking of sun and beach destinations. Instead, think of these islands as an option to escape the heat. You will find moderate temperatures, but you will almost certainly be surprised if it rains one day.
Depending on the islands we visit, the climate will vary, although it is mostly temperate with no dry season and mild summers. In the central and eastern islands, the climate is temperate, with dry and mild summers.
As a result, summers are milder than winters, with the most rainfall between October and March. In general terms, there is little contrast between one season and another. What there will always be will be a lot of humidity. A meteorological variable linked to the maritime influence that gives the archipelago the greenery and part of the landscape beauty that characterize it.
Difference with storms
It is common to confuse anticyclones with storms, since storms are also called cyclones. However, they are the opposite. To understand the main difference between these two weather phenomena, let's understand what the definition of a storm is.
Storms are slightly diffuse air that tends to rise. It is the area where the atmospheric pressure is lower than the surrounding area. The upward movement of the air favors the formation of clouds, and therefore the production of precipitation. Gusts are essentially fueled by cold air, and their duration depends on the amount of cold air they carry. These types of air masses are very unstable, they form and move quickly.
In the northern hemisphere, the storm rotates counterclockwise. These air masses bring with them unsettled, cloudy, rainy or stormy weather, and sometimes snow in winter.
Azores anticyclone and climate change
Global warming studies suggest that the Azores anticyclone may have intensified in recent years, independent of typical ENSO-type oscillations, leading to more extreme precipitation events in the southeastern United States. There may also be a latitudinal shift of the crest, with some computer models representing a further westward expansion of the future anticyclone. However, during the winter of 2009-2010, the anticyclone became smaller, moved to the northeast, and was weaker than usual, which caused a rapid increase in surface temperatures in the mid-Atlantic.
As you can see, the Azores high is very important for the climate of the peninsula and is very useful for weather prediction. If you want to know more about its impact on rainfall, I recommend reading this article about the high. importance of the anticyclone in rainfallYou may also be interested in learning about other phenomena such as the east and west windsI hope this information helps you learn more about the Azores high and its characteristics.
