Under meteorological conditions, we mean the state of the atmosphere, which is usually characterized by the temperature of the air, its pressure, humidity, speed, as well as the presence or absence of cloudiness. Let us consider in more detail issues related to weather and climate.
General concepts and terms
When talking about weather conditions, terms such as weather or climate are often used. Under the weather understand the current state of the atmosphere, that is, clear or cloudy, cold or hot, the air is moist or dry, a strong wind is blowing, or there is a lull in this particular area. When they talk about climate, they mean a characteristic of atmospheric phenomena over a longer period of time, for example, summer or autumn climate.
Another difference between the concepts of "weather" and "climate" is the territorial factor. The weather can vary from terrain to terrain, for example, in some cities it can pour heavy rain, and clear weather can be 20 km from the city. Climate is a more extended characteristic not only in time, but also in space. So, there are concepts of tropical, continental or polar climate.
Why is there a different climate in different zones of the Earth?
The answer to this question is the spherical shape of our planet. This form leads to the fact that the sun's rays fall at different angles on its surface. The closer the angle of incidence of the rays to 90 o, the more warms up the surface and air. This situation is typical for tropical and subtropical zones. On the contrary, the further the angle of incidence of the rays deviates from the right angle, the less solar energy the soil and air receive, and the colder the climate. A striking example of a cold climate is the state of the atmosphere in Antarctica.
In turn, the difference in temperatures of the polar and equatorial zones of the planet leads to the appearance of winds, and also creates the prerequisites for the formation of rain clouds. Different meteorological conditions in the latitudes of the earth lead to the appearance and disappearance of cyclones (areas of low atmospheric pressure) and anticyclones (areas with high air pressure).
The reason for the existence of the seasons
Every child from an early age knows that there are 4 seasons: winter, autumn, spring and summer. However, all these seasons, each of which is characterized by certain climatic and meteorological conditions, take place only in the middle latitudes of our planet. The strip of our planet, which is located from the 40th parallel of the southern to the 40th parallel of the northern hemisphere, has a tropical and subtropical climate, which is characterized by only 2 times or seasons of the year: wet and dry.
We figured out the cause of the various meteorological conditions in different latitudes. But why is there a change of seasons? The answer to this question lies in the inclination of the earth's axis of rotation relative to the plane of the Earth’s orbit. Our planet revolves around the sun in an almost perfect circle, and if there weren’t a tilt of the Earth’s axis at 23.5 o, then in every latitude the climate would not change during the year. The oblique axis of rotation of the planet provides fluctuations in the amount of solar energy entering the planet’s surface at each point during the year. These energy changes result in fluctuations in air temperature, which are usually ± 40 ° C. The maximum and minimum allowable temperatures are +58 ° C (Al-Aziziya, Libya) and -89.2 ° C (Antarctica), respectively.
Note that the inclination of the axis of rotation of our planet was not constant throughout the entire time of its existence. It is reliably known that during the time of the existence of dinosaurs on Earth, he was definitely different. This tilt can be affected by both external factors associated with different cosmic bodies, as well as internal ones caused by changes in the mass distribution on the surface of our planet.
Favorable and unfavorable weather conditions
Often you can hear the words: “good weather” or “bad weather in this region is expected”. What is the meaning of these phrases? To answer the question, we give below the main parameters that determine the state of the atmosphere (to be precise, we need to say the troposphere, since it is in the lower part of the Earth’s atmosphere that all weather phenomena occur):
- temperature;
- pressure;
- wind speed;
- air humidity;
- the presence or absence of clouds.
The indicators of these five parameters allow us to talk about both favorable and adverse weather conditions (NMU). For example, high temperature and pressure, too bright sun and low humidity or, conversely, low temperatures, rain, high wind speed, low pressure - all these are NMUs. Favorable weather conditions are usually characterized by average values for the above climatic parameters.
The main source of all atmospheric processes
Of course, the engine of all atmospheric (and not only) processes is solar radiation. It is she who causes many chemicals to cycle in nature. With regard to climate and weather, the following can be said: the rays of the sun falling on the Earth do not directly warm the atmosphere, first of all, the temperature of the lithosphere, then the hydrosphere, increases. When cooling, the lithosphere and hydrosphere emit infrared electromagnetic waves, which are simply called "heat". It is these waves that warm the atmosphere of the planet.
An important point in the formation of meteorological environmental conditions is the different heating and cooling rates of the lithosphere and hydrosphere. So, the lithosphere quickly heats up and cools, for the hydrosphere, these processes are much slower. The reason for this different behavior with respect to solar radiation is their different heat capacity, as well as emissivity.
Other energy sources affecting the weather
Solar energy makes the main contribution to all processes occurring in the troposphere. However, there are other sources of energy that can affect the state of the weather in a particular area, and also ensure the stability of these conditions:
- geothermal energy and volcanic processes;
- the process of respiration and waste products of biological organisms that play an important role in maintaining a stable chemical composition of the atmosphere.
Atmospheric processes and their temporal and spatial scales
As noted, any processes in the atmosphere are associated with fluctuations in the amount of solar energy that enters the Earth. Thanks to these fluctuations, heating and cooling of air occurs day and night. This is the daily change in weather. The processes of formation and melting of snow are already annual in nature.
Heating the air in a particular area leads to its expansion, which means a drop in pressure. The change in pressure leads to the formation of winds, which tend to even out the difference. They are of a different nature and in emergency situations can lead to the formation of hurricanes and tornadoes. In the latter case, they speak about very difficult meteorological conditions. In turn, hurricanes are a short-term phenomenon of a certain locality, that is, they are characterized by spatial and long-term time parameters.
Weather forecast
It is difficult to imagine the modern world without weather forecast information in any region of the planet. Thus, aircraft flights, agricultural and commercial activities every year increasingly depend on meteorological data. For example, the flight schedule changes dramatically during adverse weather conditions.
A meteorological forecast is the result of processing a multitude of data using powerful computers that process input information in the framework of some complex empirical model using well-known laws of physics. Data on the meteorological conditions of a particular region are collected using weather stations strategically located on the ground, using satellites and unmanned aerial vehicles.
