Cloud cover means that the sun is hidden behind clouds.
Cloudiness is the condition that implies that the sun appears hidden from an observer's view due to clouds : if the sky is completely covered with clouds, it is said to be cloudy . It should be remembered that a cloud is formed by water droplets or snow crystals found in the atmosphere.
When talking about cloudiness, therefore, reference is made to a fraction of the sky that appears covered in clouds . For example: “They say that, in the coastal region, the cloudiness will increase during the afternoon” , “It doesn't matter how cold or cloudy: I plan to spend the whole day outdoors” , “It dawned with cloudiness, but then it cleared and “The sun began to shine brightly.”
Cloud cover analysis
Each country has entities specialized in the analysis of meteorology . These services are responsible for studying the cloudiness of the atmosphere according to certain regions. To express the cloudiness detected, meteorologists express themselves in octas. What they do is divide the visible spectrum of the sky into eight parts and, depending on the number of these parts that appear covered by clouds, a degree of cloudiness is indicated.
What does this mean? That every expression of cloudiness is associated with a spectrum of observer visibility . Of course, when visibility conditions are altered due to fog or other reasons, it is impossible to qualify cloudiness since the clouds are simply not visible.
The development of meteorological satellites largely solved this problem, offering much more precise measurements. Satellites , however, are not always able to record the thinnest clouds, which makes the measurements not reliable 100% of the time either.
The areas of our planet that are located around the equator tend to be the ones with the highest cloudiness index. At the other extreme , the regions near the poles are those that exhibit less cloudiness.
Cloudiness is studied by meteorology.
Classification according to type
Let's look at the different types of cloudiness that can be seen:
high clouds
- Cirrus clouds: these are white clouds with a certain transparency, which do not have shadows inside and look like long, thin filaments.
- Cirrocumulus : this cloudiness is seen as a layer with certain thin folds and the appearance of small cottony flakes, also white and without internal shadows.
- Cirrostratus : they look like a large veil and it is difficult to notice many of the details in their structure . They have well-defined edges and appreciable regularity, and are characterized by the halo around the sun or moon that they produce.
Medium clouds
- Altocumulus : a type of cloudiness that presents flakes of moderate size and with an irregular structure, with shadows between them, as well as striations or undulations at their base.
- Altostratos : These clouds look like thin layers with a certain density in some parts. In general, they do not prevent the sun from being seen through them.
Low clouds
- Nimbostratus – These look like a grayish-colored layer that shows various levels of opacity and sometimes a slightly striated appearance. They appear mainly with summer and spring rains, as well as during winter snowfalls.
- Stratocumulus : a cloudiness characterized by its broad undulations that can have a truly considerable extent and varying intensities of gray.
- Strata : These clouds look like a bank of grayish fog without a very clear structure.
Vertical development clouds
- Cumulus clouds: large gray clouds with well-defined shadows with a horizontal base and vertical protuberances at the top that show continuous deformation.
- Cumulonimbus: These look like tall, jagged rocks with a top that may look like a mushroom.