IPA

1. Cloud

 The cloud is a visible mass of water droplets or frozen crystals suspended in the atmosphere above the surface of the Earth or another planetary body. The cloud is also visible mass attracted by gravity, such as masses of material in space called interstellar clouds and nebulae. The clouds studied in the science of clouds or cloud physics branch of meteorology.On Earth the substance is usually water vapor condensation. With the help of hygroscopic particles such as dust and salt air from the sea, forming tiny water droplets at low altitudes and ice crystals at high altitude where the air is cooled to saturation by local convective or non-convective lift large scale. In some cases, maybe some high clouds composed of supercooled water droplets. Droplets and crystals are usually about 0.01 mm (0.00039 in) in diameter. The most common agent of lifts including daytime solar heating of the air at the surface, pick up the frontal forcing warmer air mass will rise over the top of a cooler airmass, and orographic lifting air over mountains. When air rises, it expands as the pressure decreases. This process expends energy that causes the cold air. When surrounded by billions of other droplets or crystals they become visible as clouds. In the absence of condensation nuclei, the air becomes saturated and cloud formation is inhibited. in dense clouds exhibit a high reflectance (70% to 95%) throughout the visible range of wavelengths. They thus appear white, at least from the top. Cloud droplets tend to scatter light efficiently, so that the intensity of the solar radiation decreases with depth into the gases, hence the gray or even sometimes dark appearance at the cloud base. Thin clouds may appear to have acquired the color of their environment or background and clouds illuminated by non-white light, such as at sunrise or sunset, may appear colored accordingly. The clouds look darker in the near-infrared because water absorbs solar radiation at those wavelengths.Cloud formationAir always contains water vapor. When this water vapor overflow into water droplets, they form clouds. Peluapan this can happen in two ways:1. If the hot air, the more vapor contained in the air because the water faster menyejat. Hot air laden with water will rise higher, to arrive at a single layer with a lower temperature, it will melt and vapor cloud formed, water molecules point countless.2. The air temperature does not change, but the state of the atmosphere humid. The air will become more and more tepu with water vapor.If the clouds have formed, water droplets in the cloud will be greater and the cloud will become increasingly severe, and slowly force of gravity pulling it down. Up until the point where the water droplets will continue to fall down and the rain descended.If water droplets meets hot air, the dots will evaporate and the clouds disappeared. This is what causes that clouds always changing shape. The water contained in successive clouds of vaporized and melted. This is also why sometimes there is not a rain cloud.