Weather 1

This article starts a small series about the weather influences on biathlon shooting. These are to be understood as part or basic knowledge of the biathlon shooting technique. The current article first gives an overview.

Principles

In the outdoor sport of biathlon, the weather has a not inconsiderable influence on the result of the partial performance of biathlon shooting. This fact is not so much based on the possible existence of extreme weather conditions, but rather on the change of external conditions in the course of a competition or even competition day (e.g. the change of conditions from the time of zeroing to the time of shooting in the competition).

The most important factors for the athletes are the wind and visibility/light conditions. Other factors are the air temperature, humidity and air pressure.

Wind

The wind affects the expected shooting result through its speed (or strength) and direction. First of all, it acts with both factors on the bullet after it leaves the barrel. This will be the focus of further considerations in the following articles.

In addition, the wind has an effect on the stability of the shooting position with both factors. Here, the standing position is particularly affected, since it offers more surface area for the wind to "attack" and, on the other hand, is fundamentally not as stable as the prone position. The resulting effects depend on the physical constitution and the basic stability of the shooting position of the respective athlete.

In this context, it can be assumed that when on the prone position, the focus of the effects of the wind is on the bullet trajectory, while when on the standig position, the effects of the wind on the shooting position outweigh those on the bullet trajectory.

Visibility and lighting conditions

The light and visibility conditions are, on the one hand, cloudy and restricted visibility, e.g. due to fog or precipitation (rain and snowfall) or even high cloud cover, which create a diffuse light effect. On the other hand, extremely bright light incidence due to direct sunlight and the possible intensifying reflection in the snow.

The specific effects and possible reactions will be the subject of following articles.

Air temperature

The air temperature has a particular effect on the propellant powder of the cartridge. The warmer it is, the drier/warmer the propellant powder is and the better it burns. This can increase the initial velocity, which stretches the bullet trajectory, which tends to lead to high shots. Conversely, the trajectory curves when the initial velocity decreases due to slower burning of the propellant powder. This then tends to lead to low shots.

However, these temperature-related fluctuations occur more in the course of the season than during a competition day. In the context of a competition day, they are lost in the variation generated by the athlete and are also compensated for before the competition by zeroing. They are therefore negligible in this context.

However, with close observation over the training and competition year, it will be possible to understand quite significant differences in the sighting setting/adjustment.

The air temperature also has an indirect effect via the wind. The colder it is, the greater the air density. This means that the same wind speeds can have a greater effect on the bullet trajectory. Temperature differences of 15° C and above become interesting. This influencing factor is the same as the direct consideration of the temperature, since such temperature differences will hardly occur in the course of a competition or competition day.

today, the rifles and ammunition are adapted to the temperatures to be expected, especially during the competition period in winter,
the possible relevant changes are unlikely to occur/effect in the course of a day,
the effects are lost in the scattering caused by the athlete as well as
be compensated with the zeroing,

the effects of air temperature fluctuations are negligible and do not require any further consideration in athlete education and training.

Humidity

The air humidity has basically the same effect as the air temperature. The higher the humidity, the lower the initial velocity and vice versa. Thus, on the one hand, there is a tendency to shoot low or high. However, these effects (insofar as they occur at all) will disappear in the course of a competition day or competition in the shooter scatter and/or will be compensated by the zeroing.

Air pressure

The air pressure also has an effect on the trajectory of the projectile. The air pressure decreases with increasing altitude above sea level. This stretches the trajectory, resulting in a tendency to shoot high. These factors occur at an altitude change of more than 1000m. But also the influence of the air pressure is compensated by the zeroing. Changes in air pressure in the course of a competition or competition day will not be such that they correspond to a change in altitude of 1000m, so any changes that occur will also be lost in the dispersion caused by the athlete.

The air pressure also affects the wind influence via the change in air density. This means that with increasing altitude and thus decreasing air pressure, the same wind speed has increasingly less influence on the trajectory of the projectile.

Even the potential effects of air pressure (which can be described as theoretical) are therefore negligible for the education and training of athletes.

Summary

After these basic considerations, the following articles will deal in more detail with wind influences and the influences of visibility and light conditions.

ACTS - HE