Climatology higher latitudes. Models can range from relatively simple to quite complex: In contrast to meteorology, which focuses on short term weather systems lasting up to a few weeks, climatology studies the frequency and trends of those systems. It studies the periodicity of weather events over years to millennia, as well as changes in long-term average weather patterns, in relation to atmospheric conditions. study both the nature of climates – local, regional or global – and the natural or human-induced factors that cause climates to change. Climatology considers the past and can help predict future climate change. Phenomena of climatological interest
Short-term exposure limit Short-term exposure limit A short-term exposure limit (STEL) is the acceptable average exposure over a short period of time, usually 15 minutes as long as the time-weighted average is not exceeded. STEL is a term used in occupational health, industrial hygiene and toxicology. The STEL may be a legal limit in the United States for exposure of an employee to a chemical substance. The Occupational Safety and Health Administration (U.S. OSHA) has set OSHA-STELs for 1,3-Butadiene, benzene and ethylene oxide. For chemicals, STEL assessments are usually done for 15 minutes and expressed in parts per million (ppm), or sometimes in