Atmospheric scienceAtmospheric science is the study of the Earth's atmosphere and its various inner-working physical processes. Meteorology includes atmospheric chemistry and atmospheric physics with a major focus on weather forecasting. Climatology is the study of atmospheric changes (both long and short-term) that define average climates and their change over time, due to both natural and anthropogenic climate variability. Aeronomy is the study of the upper layers of the atmosphere, where dissociation and ionization are important.
ViscosityThe viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water. Viscosity is defined scientifically as a force multiplied by a time divided by an area. Thus its SI units are newton-seconds per square metre, or pascal-seconds. Viscosity quantifies the internal frictional force between adjacent layers of fluid that are in relative motion.
Commercial areaCommercial areas in a city are areas, districts, or neighborhoods primarily composed of commercial buildings, such as a strip mall, office parks, downtown, central business district, financial district, "Main Street", or shopping centers. Commercial activity within cities includes the buying and selling of goods and services in retail businesses, wholesale buying and selling, financial establishments, and a wide variety of uses that are broadly classified as "business.
Unincorporated areaAn unincorporated area is a region that is not governed by a local municipal corporation. Widespread unincorporated communities and areas are a feature of the United States and Canada. Most other countries of the world either have no unincorporated areas at all or these are very rare. In Argentina, the provinces of Chubut, Córdoba, Entre Ríos, Formosa, Neuquén, Río Negro, San Luis, Santa Cruz, Santiago del Estero, Tierra del Fuego, and Tucumán have areas that are outside any municipality or commune.