Meteorology

If someone across the country asks you what the weather is like today, you need to consider several factors. Air temperature, humidity, wind speed, the amount and types of clouds, and precipitation are all part of a thorough weather report. It’s also important to consider the difference between weather and climate.

Weather is what is going on in the atmosphere at a particular place at a particular time. Weather is the change we experience from day to day. Weather can change rapidly. A location’s weather depends on air temperature, air pressure, fog, humidity, cloud cover, precipitation, and wind speed and direction. All of these are directly related to the amount of energy that is in the system and where that energy is. The ultimate source of this energy is the Sun. As defined by the National Oceanic and Atmospheric Administration (NOAA), meteorology is the science concerned with the Earth’s atmosphere and its physical processes. A meteorologist is a physical scientist who observes, studies, or forecasts the weather.

Climate is the average of a region’s weather over time. The climate for a particular place is steady and changes only very slowly. Climate is determined by many factors, including the angle of the Sun, the likelihood of cloud cover, topography, and air pressure. These factors are related to the amount of solar energy and precipitation that a region experiences over time. Climate is the long-term average of weather in a particular spot. Although the weather for a particular winter day in Tucson, Arizona, may include snow, the climate of Tucson is generally warm and dry. The chapter discussing climate change describes the Earth systems involved in climate change, the geologic evidence of past climate changes, and the human role in today’s climate change.