Basic Geography/Climate/Recording Weather

Recording The Weather Weather conditions are measured at weather stations. These stations contain a variety of instruments to record weather data. The most important instruments of a weather station are: Hydrometer - Are a special type of thermometer that measures the humidity by calculating the water vapour in the air. thumb|right|150px|Standard Rain Gauge Rain Gauge - This is a container that collects precipitation and measured it in millimeters (mm). Barometer - These instruments measures the air pressure. They may be either mercury or aneroid (vacuum) barometers. Often they are attached to a pen that charts movements in pressure on a piece of paper. The resulting chart is called a barograph. thumb|left|sunshine recorder Sunshine Recorder - The recorder is a chart which has the sun's rays focused onto it using a magnifying glass so it burns a record of the hours the sun shone. Maximum and minimum thermometers measure the highest and lowest temperature in degrees Celsius. Wind Vanes show the direction of the wind. Anemometers are used to measure wind speeds, usually in km/h. The wind is caught in small cups and the speed is calculated by measuring how fast the cups rotate. Clouds Recording cloud type and cloud-cover is done manually, using the naked eye. Meteorologists measure cloud-cover in eighths of the sky or oktas. 0 oktas = a completely cloudless sky 4 oktas = half the sky is covered in clouds 8 oktas = the sky is fully clouded-over Mapping weather The internationally agreed way in which to map the weather is by using synoptic charts. Data is collected across a large area from weather stations, balloons, ships, aeroplanes, and satellites. Informations on a synoptic chart is updated at least every six hours. The following information is displayed on a synoptic chart: temperature precipitation atmospheric pressure wind speed direction cloud coverage