Inland Empire in the context of "Metropolitan Statistical Area"

In the United States, a metropolitan statistical area (MSA) is a geographical region with a relatively high population density at its core and close economic ties throughout the region. Such regions are not legally incorporated as a city or town would be and are not legal administrative divisions like counties or separate entities such as states. As a result, sometimes the precise definition of a given metropolitan area will vary between sources. The statistical criteria for a standard metropolitan area were defined in 1949 and redefined as a metropolitan statistical area in 1983.

Due to suburbanization, the typical metropolitan area is polycentric rather than being centered around a large historic core city such as New York City or Chicago. Some metropolitan areas include more than one large historic core city; examples include the Dallas–Fort Worth metroplex, Virginia Beach–Norfolk–Newport News (Hampton Roads), Riverside–San Bernardino (Inland Empire), and Minneapolis–Saint Paul (Twin Cities).

Haze is traditionally an atmospheric phenomenon in which dust, smoke, and other dry particulates suspended in air obscure visibility and the clarity of the sky. The World Meteorological Organization manual of codes includes a classification of particulates causing horizontal obscuration into categories of fog, ice fog, steam fog, mist, haze, smoke, volcanic ash, dust, sand, and snow. Sources for particles that cause haze include farming (stubble burning, ploughing in dry weather), traffic, industry, windy weather, volcanic activity and wildfires.Seen from afar (e.g. an approaching airplane) and depending on the direction of view with respect to the Sun, haze may appear brownish or bluish, while mist tends to be bluish grey instead. Whereas haze often is considered a phenomenon occurring in dry air, mist formation is a phenomenon in saturated, humid air. However, haze particles may act as condensation nuclei that leads to the subsequent vapor condensation and formation of mist droplets; such forms of haze are known as "wet haze".

In meteorological literature, the word haze is generally used to denote visibility-reducing aerosols of the wet type suspended in the atmosphere. Such aerosols commonly arise from complex chemical reactions that occur as sulfur dioxide gases emitted during combustion are converted into small droplets of sulfuric acid when exposed. The reactions are enhanced in the presence of sunlight, high relative humidity, and an absence of air flow (wind). A small component of wet-haze aerosols appear to be derived from compounds released by trees when burning, such as terpenes. For all these reasons, wet haze tends to be primarily a warm-season phenomenon. Large areas of haze covering many thousands of kilometers may be produced under extensive favorable conditions each summer.

San Bernardino County (/sæn ˌbɜːrnəˈdiːnoʊ/ SAN BUR-nə-DEE-noh), officially the County of San Bernardino, is a county located in the southern portion of the U.S. state of California, and is located within the Inland Empire area. As of the 2020 United States census, the population was 2,181,654, making it the fifth-most populous county in California and the 14th-most populous in the United States. The county seat is San Bernardino.

While included within the Greater Los Angeles area, San Bernardino County is included in the Riverside–San Bernardino–Ontario metropolitan statistical area.

San Bernardino (/ˌsæn ˌbɜːrnəˈdiːnoʊ/ SAN BUR-nə-DEE-noh) is a city in and the county seat of San Bernardino County, California, United States. Located in the Inland Empire region of Southern California, the city had a population of 222,101 in the 2020 census, making it the 18th-most populous city in California. The Riverside–San Bernardino metropolitan area at 4.74 million residents is the 12th-largest metropolitan area in the nation. San Bernardino is the economic, cultural, and political hub of the San Bernardino Valley, sharing that distinction for the wider Inland Empire with its twin city of Riverside.

San Bernardino was named in 1810, when Spanish priest Francisco Dumetz led an expedition through the area. In 1839, the Mexican government granted Californio ranchero José del Carmen Lugo the right to settle the area, which was formalized when he was granted Rancho San Bernardino in 1842. Following the American Conquest of California, the largely unsettled rancho was purchased by Mormon settlers who founded the town of San Bernardino in 1851, later incorporated as a city in 1854. After most of the Mormons left in 1857, the city grew significantly in the late 19th century as a commercial hub at the crossroads between Southern California and the American Southwest. Today, San Bernardino is an important hub for the Inland Empire and Southern California. The governments of El Salvador, Guatemala, and Mexico have established the metropolitan area's only consulates in the downtown area. Furthermore, the city's University District serves as a college town, as home to California State University, San Bernardino.

Riverside is a city in and the county seat of Riverside County, California, United States. It is named for its location beside the Santa Ana River in Southern California. It is the most populous city in the Inland Empire and Riverside County, 12th-most populous city in California, and 61st-most populous city in the U.S. with a population of 314,998 at the 2020 census. The Riverside–San Bernardino metropolitan area at 4.74 million residents is the 12th-largest metropolitan area in the nation. Riverside is about 50 miles (80 km) east of downtown Los Angeles and is also part of the Greater Los Angeles area.

Riverside was founded in the early 1870s. It is the birthplace of the California citrus industry and home of the Mission Inn, the nation's largest Mission Revival Style building. It is also home to the Riverside National Cemetery and the Eastern Division of the Federal District Court for the Central District of California.