What is the wind wind is how form
what is the wind: air movement can be decomposed into vertical and horizontal two component. Vertical component, called the vertical movement of air ( Such as convection movement) 。 The wind is the level of air movement, it is a vector, the movement there are both speed and direction of the wind. Therefore the observation includes two wind direction and wind speed of the wind. 。
with the measured value of the anemometer should include the instantaneous value and the average.
average refers to the average within a certain period of time;
instantaneous value can think in a fairly short sampling period, average value or smooth.
wind speed: refers to the air particle in unit time by moving the horizontal distance of
average wind speed: refers to the average wind speed within a period of time.
maximum wind speed: refers to the average wind speed in a certain period of time of the maximum value.
the instantaneous wind speed, air micelle level of instantaneous speed. In the automatic meteorological station, the instantaneous wind speed refers to the average 3 s wind speed
maximum wind speed: refers to the maximum instantaneous wind speed within a period of time.
how to get the typical data of wind?
the wind is all meteorological elements change over time in one of the most dramatic elements. In order to achieve a certain representative in the observation of wind direction, wind speed data, wind observations are generally within a certain time of the average wind speed and wind direction at most.
experiments show that: take 10 min can reach a certain period of time average representative's request. In the case of most wind gustiness fluctuation is not big, take 1 ~ 2 min in average time end, also can achieve certain representation. Meteorological offices and stations, in observing is generally take 2 min average wind speed and wind direction, most recording instrument is 10 min average wind speed and wind direction at most.
wind ( The gustiness) of the wind Refers to the change of the instantaneous wind speed near the average fluctuation and distribution characteristics.
wind is defined as: in the specified time interval ( 10分钟) , wind speed deviation from the mean value of a positive or negative offset, the duration of less than 2 min.
the gustiness of the wind in the aviation, Marine, atmospheric pollution and the spread of radioactive dust and so on are widely used.
wind observation: there are two main variables of wind speed and direction of the standard deviation, the peak of gust wind.
in what form the wind
anywhere on earth in absorbs the heat of the sun, but due to the nonuniformity of the ground every part is heated, air degree of changes in temperature is different, so the warm air rising inflation after the lighter; Cold air cooling after heavier drops, so warm and cool air flow occurs, the formation of the wind.
the original surface of the earth, all accept the heat of the sun is not the same, in some places to accept more, warming the air. The temperature is rising. Warm air. On the contrary, in some places with less of the sun's heat, the temperature is reduced, the air turned cold, cold air will shrink. Air and water, always by the high temperature air to air flow at low temperature. In this way, the flow of air to form the wind.
due to the rotation of the spin axis and revolves around the sun, the earth between 66. 5° , so the Angle of different locations on earth, the sun Angle is different, and 365 days a year to the same place in this Angle is also changing. Somewhere on earth by the sun radiation energy is and the site is directly proportional to the sine of the Angle of the sun. The earth's poles with less solar radiant energy, so low temperature, high pressure; And the equator receive more calories, high temperature, low air pressure. In addition the earth spin axis and one revolution every 24 h, day and night temperature, barometric pressure changes. Such as in all parts of the earth's surface temperature, air pressure, air flow from high pressure to lower pressure movement, in order to transmit heat from the tropics to the poles, thus forming different direction of the wind, and accompanied by different climate change. Currents in the ocean also plays a similar role. From a global scale, the atmospheric turbulence is a huge amount of energy transmission medium, the earth's rotation to further promote the semi-permanent planetary scale circulation in the atmosphere.
everywhere on earth topography may also affect the formation of the wind, like the sea, because the water heat capacity is big, after accepting the solar radiant energy, surface heating up slowly, the terrestrial heat capacity is small, warming faster. Then during the day, due to high air temperature of the land, the rising air blow to the solar wind of land and sea. Whereas at night, seawater cooling slowly, the surface air temperature is high, the rising air and form the land-sea breeze blew from land to sea.
in the mountains, the air temperature during the day the sun made the mountain, as the hot air rises, valley cold air upward movement, then form the hollow. In contrast to the night, in the air to high heat, gas density increases, the air to move down along the slope, and formed the so-called advantage. Other local factors such as temperature gradient distribution of wind energy change also can make.
on the weather, the wind often refers to the horizontal motion of the air, and wind direction, wind speed, Or wind) To represent. To wind direction refers to the wind, usually represented with 16 bearing or 360 degrees. Said at 360 degrees, the north up measure clockwise