What is meteorological observation?

No matter what nickname people like to use, it is not an easy and satisfactory thing to observe, measure and record the sky in an individual's backyard.

If you have just become a meteorological observer, you must keep in touch with local meteorological service hobby groups, most of which can be searched online. The national meteorological department is also a useful information center for amateur observers.

Although observing the weather is the most economical hobby, when you start observing, you need to buy some basic measuring instruments to measure temperature, pressure and humidity. Good sources of instruments include natural commodity stores, scientific instrument supply companies and museum stores. Contact the local meteorological bureau to discuss where it is best to record readings around your home.

Thermometer is still the most basic instrument in all meteorological equipment. When meteorological observers look at the thermometer, they not only reflect the temperature at that time, but also record the latest maximum and minimum temperatures. Usually, the temperature is the lowest at dawn and the highest at two or three in the afternoon, which changes with the movement of the front. Along the foothills, the collision of air masses or the sinking of foehn (the warm and dry wind on the east side of Rocky Mountain) will make the temperature change all the time.

Volunteer meteorological observers put conventional thermometers and other measuring instruments in wooden boxes, such as shutters with brackets. The temperature measured on the ground is not accurate, and it is more accurate when it is 6 feet (2 meters) from the ground. On sunny days, the temperature there is lower than the grass surface temperature 12 degrees or more. The box protects the internal instruments from direct rain and sunlight, and the box with shutters can circulate the air around the thermometer, so as to obtain accurate temperature readings, rather than shielding them.

Observers without shelter should put the thermometer in a suitable position, away from the top of buildings or chimneys heated by the sun, and away from hot surfaces such as asphalt roads. Using the shade in the north of the house can avoid seasonal differences.

Barometers are more accurate than thermometers. Because the trend of air pressure indicates the direction of storm movement. Absolute pressure is somewhat deceptive, especially for observers living at high latitudes. The global pressure map is compiled after careful measurement by barometer, which shows that the pressure is relatively average in both special altitude areas and sea level areas to achieve consistency. Although some amateur observers use weather barometers, which are characterized by electronic sensors and digital readings, most people prefer to use a standard empty box barometer because it has a vacuum metal chamber with a spring opposite it.

The change of internal space temperature is related to the change of external air pressure and is transmitted to the needle control panel through the lever system. Most meteorological observers prefer empirical accuracy, which can be accurate to 1 "inch" pressure. Or a tenth of a millibar, or even a tenth of a degree. The scope of reading is equally important. Observers living in cold areas are satisfied with the temperature control panel that can't reach-29 F. Meteorological observers don't want to ignore the most important aspects of the weather, namely precipitation and wind. There are several standard measurement methods for rainwater. But the most popular one is the quantity of a sharp bucket (standard quantity), which can be emptied automatically every once in a while, so it can measure rainfall without being full. However, rain, like temperature, is difficult to measure. Because the wind makes the rainfall reaching the top of the bucket inaccurate. Most surveyors try to put the instrument in a relatively open and low position. Similarly, barometers (whether electronic sensors or traditional cup-shaped shafts) will not give accurate wind readings if they are placed near buildings or trees. The standard anemometer must be placed at a height of 35 feet (10 meter).

Observers in the north often boast about the large amount of snow, but the technology there is the highest. A suitable snow detector needs a flat plate, which will regularly sweep away the snow that melts due to weight or ends in heavy snow. On the other hand, some observers are eager to get the record of snowfall, so the results are often high and unreasonable. For this reason, it is best to clean the dishes every 6 hours.

Although it is not as charming as snow, humidity plays an important role in meteorology. Meteorologists used to measure the length of human hair with a hygrometer. Later, observers used hand-cranked hygrometers to do this. There are two thermometers on each side of this instrument, and part of a ball is wrapped in gauze. The observer wets the gauze, turns the thermometer for a few minutes, evaporates and cools the ball to a temperature called wet ball. The temperature difference between the dry bulb thermometer and the wet bulb thermometer can be a measure of atmospheric humidity. At present, electronic sensors for measuring humidity already exist, but they are not very accurate.

Puritans like to use rotating hygrometers, but the dynamic waves of electronic weather stations are compatible with home computers. Some of them appear continuously, and the data provided directly enter the computer, together with software, enabling observers to modernize their weather diaries recorded in words.

Meteorological observers like to compare notes made during observation, and some people find that international network organizations want to mail their data; Others want to take the initiative to observe for the National Weather Service. If the weather above the horizon permits, American observers will become storm trackers in the sky. SKYWARN is a voluntary organization that assists the NWSFO of the National Weather Service.