Basic weather data

2001/03/01 Mendiburu, Joana - Elhuyar Zientziaren Komunikazioa Iturria: Elhuyar aldizkaria

• Klima

Atmospheric pressure is measured with a barometer. At sea level it ranges between 950 and 1,050 millibar, distinguishing between low pressure zones or depression and high pressure zones or anticyclones. These differences have a great importance in meteorology, since they condition the movement of the air masses and therefore the winds.

All weather stations in the world measure the temperature in the same conditions. These conditions are very concrete. The thermometer will be placed in a protected booth located 1.5 m above the ear. In addition, the booth should be well ventilated and painted white. In boats, to achieve the same conditions, the soil must be painted green so that the reflected solar radiation is the same.

To measure solar energy, a pyranometer (or solarmeter) (see photo) is used that reports every 30 seconds of the solar energy it receives. Moisture is the proportion of water in an air mass. By reaching this proportion to 100% a fog forms, small drops of water.

The height of mists and visibility is measured in a given place. That is, with a cloud just above the telemetry you can think that the sky is cloudy, and vice versa, although the sky is cloudy, just above the apparatus if there is no fog, you can think that it is clear. That is why it is important that meteorologists check this data at all times. According to Mr. Laffite, "fully automatic observation is not yet entirely reliable."

Precipitation is measured in a 37 cm diameter container. Every millimeter of rainwater falling into this container indicates a liter of water per square meter. There is also automatic material to measure the amount of rain during night and storm days.

The anemometer is used to measure wind direction and intensity. The intensity is measured by the number of revolutions given by the dynamo, the faster it rotates, the greater the intensity of the wind.