How to describe the change of weather elements? High school geography, answering mode, asking for help, the exam is coming soon, and the teacher asked him to find it, but he couldn't find it.

1. air pressure: the pressure of the atmosphere is the pressure generated by the movement of air molecules on any surface unit area.

2. Temperature: the temperature of the atmosphere, indicating the degree of heat and cold of the atmosphere. It is the average kinetic energy of air molecular motion.

3. Atmospheric humidity (humidity for short): indicates the water vapor content or humidity degree in the air, which can be expressed by physical quantities such as specific humidity (Q), absolute humidity (pv), water pressure (E), dew point and relative humidity (F).

4. Wind: the movement of air relative to the ground. Meteorology often refers to the horizontal movement of air, expressed by wind direction and wind speed.

5. Cloud: A visible polymer consisting of a large number of water droplets and ice crystals suspended in the air. In routine meteorological observation, the shape, height and amount of clouds should be determined.

6. Precipitation: refers to liquid water and solid water falling from the clouds, such as rain, snow and hail.

7. Evaporation: evaporation on the surface of liquid. Meteorology refers to the process of water changing from liquid to gas.

8. Radiation: the process of sending energy or material particles from a radiator to all directions in space. In meteorology, solar radiation is usually called short-wave radiation, while earth surface radiation and atmospheric radiation are long-wave radiation.

9. Sunshine: the time when the sun shines. Meteorology usually provides the observed actual light time.

10. Visibility: the maximum distance that a person can see with normal vision.

1 1. Weather: including current weather and past weather, such as fog, rain, snow, hail, haze, freezing rain, sandstorm, thunder and lightning, etc.

Weather refers to the ever-changing atmospheric state, which is not only the atmospheric state in a certain time and space, but also the continuous change of atmospheric state in a certain time interval. Geographically, weather is the general name of atmospheric conditions (such as cold and warm, wind and rain, dry and wet, sunny and cloudy, etc.). ) and its changes in a short time in a certain area. Weather system usually refers to the atmospheric motion system with typical characteristics, such as high pressure, low pressure, high pressure ridge and low pressure trough, which cause the change and distribution of weather. Factors that affect the weather, such as wind, rain, clouds, fog, frost and snow. The direct cause of wind formation is the uneven distribution of air pressure in the horizontal direction. Wind is affected by many factors, such as atmospheric circulation, topography, waters and so on. Its manifestations are various, such as monsoon, local sea-land wind, valley wind and foehn wind. Wind has a great relationship with air pressure, that is, the pressure exerted by air molecules in a given area. Generally speaking, the more air molecules exist in an area, the greater the air pressure in this area. Rain is water drops falling from the clouds. Water on land and sea surface evaporates into steam. Steam rises to a certain height and turns into water droplets when it is cold. These small water droplets form clouds. They collide with each other in the cloud and merge into large water droplets. When it is too big for the air, it will fall from the clouds and form rain. After the water on the earth is irradiated by sunlight, it becomes water vapor and evaporates into the air. By constantly absorbing the water vapor around the cloud, it condenses and condenses itself, thus making the cloud droplets grow. When the big cloud drops get bigger and bigger, and finally the air can no longer hold them, they fall straight from the clouds to the ground and become our common rain. The formation of clouds is mainly caused by water vapor condensation. After the water vapor enters the lower atmosphere from the evaporation surface, the temperature here is high and there is much water vapor. If the hot and humid air is lifted, the temperature will gradually decrease, and when it reaches a certain height, the water vapor in the air will reach saturation. Water vapor saturation in the air is a necessary condition for cloud formation. If the air continues to rise, excess water vapor will precipitate. When these small water droplets and small ice crystals gradually increase to a level that can be recognized by human eyes, it is a cloud. The process of cloud formation is a process in which water vapor in the air reaches saturation or supersaturation through various reasons and condenses. Fog, fog formation conditions are cooling, humidification and concretion. Increase the water vapor content. This is caused by radiation cooling, which often occurs at night and early morning when the water vapor near the ground is abundant and stable or there is inversion, which is called radiation fog in meteorology; The other is the fog formed by the horizontal movement of warm and humid air and the gradual cooling after passing through the cold ground or water surface, which is called advection fog in meteorology; Sometimes the fog formed by two reasons is called mixed fog frost, which is a kind of white ice crystal and mostly forms at night. In a few cases, it can also begin to form before sunset when the sun is tilted. The formation of frost is not only related to the weather conditions at that time, but also related to the nature of attached objects. When the surface temperature of the object is very low, but the air temperature near the surface of the object is relatively high, there is a temperature difference between the air and the surface of the object. If the temperature difference between the surface of an object and the air is mainly caused by the radiation cooling of the surface of the object, when the warmer air contacts the surface of the object, the air will be cooled, and when the water vapor is supersaturated, the excess water vapor will be precipitated. If the temperature is lower than 0℃, the excess water vapor condenses into ice crystals on the surface of the object, which is frost. Therefore, frost is always formed under weather conditions that are conducive to radiation cooling on the surface of objects. Snow is a natural phenomenon that water or ice condenses in the air and then falls. Snow is the solid form of water. There must be two conditions for the formation of snowfall: one is water vapor saturation, and the other is that there must be condensation nuclei in the air. The maximum amount of water vapor that air can hold at a certain temperature is called saturated water vapor. The temperature at which air reaches saturation is called dew point. When saturated air is cooled to a temperature below the dew point, the excess water vapor in the air becomes water droplets or ice crystals. Condensation nuclei are tiny solid particles suspended in the air. The ideal condensation nuclei are those particles that absorb the most water. If there is no condensation nucleus, the water vapor in the air will condense into water droplets only if it is supersaturated to the degree of relative humidity above 500%. At low temperature, water droplets condense into snow.