William Jackson Humphreys (February 3, 1862 – November 10, 1949) was an American physicist and atmospheric researcher.

Biography

Hymphreys was born on February 3, 1862 in Gap Mills, West Virginia

Gap Mills, West Virginia

Gap Mills is an unincorporated community in Monroe County, West Virginia, United States. Gap Mills is located on West Virginia Route 3 east of Union. The community was established in 1775. Gap Mills has a post office with ZIP code 24941....

. He studied physics at Washington & Lee University in Virginia and later at Johns Hopkins University

Johns Hopkins University

The Johns Hopkins University, commonly referred to as Johns Hopkins, JHU, or simply Hopkins, is a private research university based in Baltimore, Maryland, United States...

 in Baltimore, where he earned his Ph.D.

Ph.D.

A Ph.D. is a Doctor of Philosophy, an academic degree.Ph.D. may also refer to:* Ph.D. , a 1980s British group*Piled Higher and Deeper, a web comic strip*PhD: Phantasy Degree, a Korean comic series* PhD Docbook renderer, an XML renderer...

 in 1897, studying under Henry Augustus Rowland

Henry Augustus Rowland

Henry Augustus Rowland was a U.S. physicist. Between 1899 and 1901 he served as the first president of the American Physical Society...

.

He worked in the fields of spectroscopy

Spectroscopy

Spectroscopy is the study of the interaction between matter and radiated energy. Historically, spectroscopy originated through the study of visible light dispersed according to its wavelength, e.g., by a prism. Later the concept was expanded greatly to comprise any interaction with radiative...

, atmospheric physics

Atmospheric physics

Atmospheric physics is the application of physics to the study of the atmosphere. Atmospheric physicists attempt to model Earth's atmosphere and the atmospheres of the other planets using fluid flow equations, chemical models, radiation balancing, and energy transfer processes in the atmosphere...

 and meteorology

Meteorology

Meteorology is the interdisciplinary scientific study of the atmosphere. Studies in the field stretch back millennia, though significant progress in meteorology did not occur until the 18th century. The 19th century saw breakthroughs occur after observing networks developed across several countries...

. In the field of spectroscopy he found the shift of spectral lines under pressure

Pressure

Pressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...

. In atmospheric physics he found a very good model for the stratosphere

Stratosphere

The stratosphere is the second major layer of Earth's atmosphere, just above the troposphere, and below the mesosphere. It is stratified in temperature, with warmer layers higher up and cooler layers farther down. This is in contrast to the troposphere near the Earth's surface, which is cooler...

 in 1909. He wrote numerous books, including a textbook titled Physics of the Air, first published in 1920 and considered a standard work of the time, though it was last published in 1940. He also held some teaching positions at universities.

From 1905 to 1935 he worked as a physicist for the U.S. Weather Bureau, predecessor of the National Weather Service

National Weather Service

The National Weather Service , once known as the Weather Bureau, is one of the six scientific agencies that make up the National Oceanic and Atmospheric Administration of the United States government...

.

He died on November 10, 1949 in Washington, D.C.

Washington, D.C.

Washington, D.C., formally the District of Columbia and commonly referred to as Washington, "the District", or simply D.C., is the capital of the United States. On July 16, 1790, the United States Congress approved the creation of a permanent national capital as permitted by the U.S. Constitution....