2016年3月9日 · Everyone is exposed to UV radiation from the sun and an increasing number of people are exposed to artificial sources used in industry, commerce and recreation. The sun is by far the strongest source of ultraviolet radiation in our environment. Solar emissions include visible light, heat and ultraviolet (UV) radiation.

Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of the total electromagnetic radiation output from the …

2025年2月19日 · About Ultraviolet (UV) Radiation and Sun Exposure. The sun sends energy to Earth in a few different ways: visible light that you can see, infrared radiation that you feel as heat, and rays of UV radiation that you can’t see or feel. Fortunately, the Earth’s atmosphere protects us from most UV radiation.

2023年8月24日 · UV radiation is a form of electromagnetic energy emitted primarily by the sun and specific artificial sources. It falls just beyond the violet end of the visible light spectrum, making...

UV Index Today provides national and local UV index forecasts for 40,000+ cities in the United States. Our forecasts include the real-time UV index, the hourly UV index, and the UV Index forecast for the next five days. Our forecasts are built using data provided by NOAA.

Ultraviolet (UV) radiation is a form of non-ionizing radiation that is emitted by the sun and artificial sources, such as tanning beds. While it has some benefits for people, including the creation of Vitamin D, it also can cause health risks.

2024年2月20日 · Ultraviolet (UV) radiation is a form of non-ionizing radiation that is emitted by the sun and artificial sources. The beneficial effects of UV radiation include the production of a vital nutrient, vitamin D. However, overexposure may present risks. Sunburn, premature aging, and skin cancer are all risks to overexposure.

2022年6月21日 · Solar UVR levels are influenced by several factors: Sun elevation: the higher the sun in the sky, the higher the UVR level. UVR levels vary with time of day and time of year. Latitude: the closer to the equator, the higher the UVR levels. Altitude: UVR levels increase with altitude as the air is thinner and less UVR is absorbed.

2022年6月20日 · What is the UV index? The UVI is a measure of the level of UV radiation. The values of the index range from zero upward - the higher the UVI, the greater the potential for damage to the skin and eye, and the less time it takes for harm to occur. The UVI is an important vehicle to alert people about the need to use sun protection.

UV is most intense at noon when the sun is at its highest point in the sky, and UV rays have the least distance to travel through the atmosphere.