Carl-Gustaf Rossby | Biography

Carl-Gustaf Arvid Rossby was one of the greatest organizers and theoreticians in the field of meteorology. He had a keen understanding of the interactive forces in the atmosphere that influence the weather.

Rossby was born in Stockholm, Sweden, in 1898. He studied mathematical physics at the University of Stockholm. His career in meteorology began at the West Norway Weather Office in Bergen in 1918 under the guidance of Norwegian meteorologist Vilhelm Bjerknes. The Bergen Office became the birthplace of modern weather forecasting. It was there that the concept of air masses and frontal systems was first developed.

New data being received from soundings in the upper atmosphere lured Rossby into a desire to resolve the problems and unknown characteristics of this region. During the 1920s, he began taking field trips to such distant places as Greenland and Madeira, making weather observations as he traveled. After obtaining a degree in 1925 from the University of Stockholm, he went to the United States to work at the U.S. Weather Bureau.

The intellectual disparity that existed between his unimaginative American counterparts and the innovative Scandinavian school of meteorologists was a source of disillusion for Rossby. There was no place for him to go and few people in whom he could confide.

Rather than give up on America, Rossby went on to carve a niche for himself from which he could spread his influence. He took up a teaching position at the Massachusetts Institute of Technology (MIT) in 1928, where he found fertile ground for the Bergen ideologies.

At MIT, with the assistance of Rossby-trained collaborators, he investigated and wrote about characteristics of the upper atmosphere in detail never before contemplated. He recognized the existence of pressure ridges (areas of higher pressure) and troughs (lower pressure areas) at the edges of fast-moving air streams, and he noted the instability present in shear zones, or zones of rapid vertical pressure change. He was also interested in the frictional turbulence associated with the interaction of atmosphere and ocean.

The jet streams were perhaps his biggest discovery. These narrow bands of wind, at 7 to 30 miles (11 to 48 km) above the Earth, blow eastward at speeds over 250 miles per hour (400 kph), encircling both hemispheres and having profound effects on the weather.

Another of Rossby's major contributions to meteorology was his development of a formula (called the Rossby equation) to calculate the speed of Rossby waves, that is, waves in the middle and upper layers of the troposphere that have a big impact on conditions in the lower troposphere.

Rossby's organizational abilities led to the revamping of weather stations at the U.S. Weather Bureau and for the military during World War II. In 1945 he established the Journal of Meteorology and later helped reorganize the American Meteorological Society.

He left MIT in 1941 and went to the University of Chicago to chair its new Department of Meteorology. He worked on hydrodynamic experiments and collaborated with John von Neumann in first using machine computation for weather analysis and forecasting.

During the last decade of his life, Rossby re-established his relationship with his Stockholm contacts, commuting between there and Chicago, and keeping active the international lines of communication among meteorologists.

He closed out his career by delving into atmospheric chemistry, a new field for him. As in thermodynamics, he continued, until his death in 1957, to shed light on the balance that exists among the Earth's natural forces.