the science of the atmosphere and the processes occurring in it. The main branch of meteorology is atmospheric physics, which studies physical phenomena and processes. Chemical processes are the concern of atmospheric chemistry, a new and rapidly developing branch of meteorology. Dynamic meteorology is the study of atmospheric processes through the theoretical methods of hydroaeromechanics; one of the important problems of this branch is developing methods of numerical weather prediction. Among the other branches of meteorology are synoptic meteorology, the science of weather and methods of forecasting, and climatology, which has become an independent discipline. These disciplines use both physical and geographic research methods, but physical methods dominate in recent work. Biometeorology is concerned with the influence of atmospheric factors on biological processes; it also includes agricultural meteorology and human biometeorology.
Atmospheric physics deals with the surface air layer and processes in the lowest layer of the atmosphere; aerology, which is concerned with processes in the free atmosphere, where the influence of the earth is less significant; and upper air layers at altitudes of hundreds and thousands of km, where the density of atmospheric gases is very low. Aeronomy deals with the physics and chemistry of the upper air layers. Atmospheric physics also includes actinometry, which studies solar radiation in the atmosphere and the transformations of solar radiation; atmospheric optics, the science of optical phenomena in the atmosphere; atmospheric electricity; and atmospheric acoustics.
The first investigations in meteorology go back to ancient times (Aristotle). Meteorology developed more rapidly in the first half of the 17th century, when the Italian scientists Galileo and E. Torricelli developed the first meteorological instruments, the barometer and thermometer.
The first steps in studying the principles of atmospheric processes were taken in the 17th and 18th centuries. At this time outstanding meteorological research was carried out by M. V. Lomonosov and B. Franklin, both of whom devoted special attention to atmospheric electricity. During the same period instruments for measuring wind speed, amount of precipitation, humidity, and other meteorological elements were invented and perfected. This made it possible to begin systematic observations of the atmosphere using instruments. First, observations were made at individual points, but from the late 18th century on, networks of meteorological stations were employed. The international network of meteorological stations that make surface weather observations over most of the world was established in the mid-19th century.
Observations of the atmosphere at different altitudes were first made in the mountains and, soon after the invention of the aerostat in the late 18th century, in the free atmosphere. Since the late 19th century pilot balloons and sounding balloons with self-registering instruments have been used extensively to observe meteorological elements at varying altitudes. In 1930 the Soviet scientist P. A. Molchanov invented the radiosonde, an instrument that transmits data on the free atmosphere by radio. Radiosonde observation subsequently became the principal method of investigating the atmosphere at aerological stations. In the mid-20th century a world actinometric network was established; its stations conduct observations of solar radiation and its transformations at the earth’s surface. Moreover, methods have been developed for observing ozone content in the atmosphere, elements of atmospheric electricity, the chemical composition of atmospheric air, and the like. Parallel with the expansion of meteorological observations the science of climatology has developed, based on statistical generalization of material from observations. A. I. Voeikov, who studied such atmospheric phenomena as general atmospheric circulation, the hydrologic cycle, and snow cover, made a large contribution to the establishment of climatology as a discipline.
In the 19th century empirical investigations of atmospheric circulation were used to substantiate methods of weather forecasting. The work of W. Ferrel in the United States and H. Helmholtz in Germany marked the beginning of investigations into the dynamics of atmospheric movements; this research was continued in the early 20th century by the Norwegian scientist V. Bjerknes and his students. Further progress in dynamic meteorology was marked by the creation of a method for numerical hydrodynamic weather forecasting, which was worked out by the Soviet scientist I. A. KibeF, and the rapid development of this method that followed.
In the mid-20th century the methods of dynamic meteorology were used extensively in studying general atmospheric circulation. By using these methods the American meteorologists J. Smagorinsky and S. Manabe constructed world charts of air temperature, precipitation, and other meteorological elements. Similar research is underway in many countries; these investigations are closely connected with the International Global Atmospheric Research Program. Modern meteorology devotes considerable attention to studying physical processes in the air layer near the ground. This line of investigation was begun in the 1920’s and 1930’s by the German R. Geiger and other scientists in order to study the microclimate, and it led to the creation of a new branch of meteorology, the physics of the boundary layer of air. Investigations of changes in the climate, in particular, studies of the increasingly noticeable effect of human activity on climate, is important in meteorology.
In Russia meteorology had reached a high level in the 19th century. The Main Physical (today Geophysical) Observatory, which was set up in St. Petersburg in 1849, was one of the first scientific meteorological establishments in the world. In Russia, G. I. Vil’d, who directed the observatory for many years during the second half of the 19th century, created a model system of meteorological observations and a weather service. He was one of the founders of the International Meteorological Organization (1871) and chairman of the international commission for the First International Polar Year (1882–83). During the Soviet period a number of new meteorological establishments have been founded, including the Hydrometeorological Research Center of the USSR (formerly the Central Institute of Forecasts), the Central Aerological Observatory, and the Institute of Atmospheric Physics of the Academy of Sciences of the USSR.
A. A. Fridman was the founder of the Soviet school of dynamic meteorology. His work and the later work of N. E. Kochin, P. la. Kochina, E. N. Blinova, G. I. Marchuk, A. M. Obukhov, A. S. Monin, and M. I. ludin was devoted to the principles of atmospheric movements on various scales and led to the first models of a theory of climate and the development of a theory of atmospheric turbulence. The work of K. la. Kondrat’ev dealt with the principles of radiation processes in the atmosphere.
The climate of the Soviet Union has been studied in detail, and the atmospheric processes that determine it have been investigated in the works of A. A. Kaminskii, E. S. Rubinshtein, B. P. Alisov, O. A. Drozdov, and other Soviet climatologists. In research carried out at the Main Geophysical Observatory, the heat balance of the globe was studied, and atlases with charts of the constituent parts of the balance were prepared. Work in synoptic meteorology (V. A. Bugaev, S. P. Khromov) has significantly increased the accuracy of weather forecasting. The research of Soviet agrometeorologists (G. T. Selianinov, F. F. Davitai) has provided the basis for the optimal placement of crops in the Soviet Union.
Work in the Soviet Union on actively influencing atmospheric processes has led to important results. Experiments on controlling clouds and precipitation, which were begun by V. N. Obolenskii, developed extensively in the postwar years. Research carried out under the direction of E. K. Fedorov resulted in the establishment of the first system that makes it possible to lessen the damage done by hail over a large area.
A typical feature of modern meteorology is use of the latest advances of physics and technology. Thus, the state of the atmosphere is observed by meteorological satellites that make it possible to receive worldwide information on many meteorological elements. Radar is used for ground observation of clouds and precipitation. Automation of meteorological observations and of data processing is steadily increasing. Computers are widely used in research on theoretical meteorology, and their use has been enormously important for improving numerical weather forecasting. The use of quantitative physical methods of investigation is expanding in such areas as climatology, agro-meteorology, and human biometeorology—areas in which these methods were hardly used before.
Meteorology is closely bound up with oceanography and land hydrology. These three sciences study different elements of the same processes of heat exchange and moisture exchange in the earth’s geographic shell. The connection between meteorology and geology and geochemistry is based on the common goals of these sciences in studying the evolution of the atmosphere and changes in the earth’s climates in the geological past. Modern meteorology makes extensive use of the methods of theoretical mechanics, as well as the data and methods of many other physical, chemical, and technical disciplines.
One of the main goals of meteorology is to forecast weather for different periods of time. Short-range forecasts are especially essential for aviation; long-term forecasts are extremely important for agriculture. Data on climatic conditions are vital for the national economy because meteorological factors have a significant effect on many aspects of economic activity. Active influences on atmospheric processes—for example, controlling clouds and precipitation, protecting plants against frosts, and the like—are rapidly growing in practical importance.
Scientific and practical work in meteorology is directed by the Hydrometeorological Service of the USSR, which was established in 1929.
The World Meteorological Organization and other international meteorological organizations bring together the work of different countries. The International Association of Meteorology and Atmospheric Physics, which is part of the International Union of Geodesy and Geophysics, also holds international conferences on various problems of meteorology. The most important conferences on meteorology in the USSR are the All-Union Meteorological Congresses; the last (fifth) congress was held in June 1971 in Leningrad. Work being done in meteorology is published in meteorological journals.
M. I. BUDYKO