Вальтер Мунк: Америкалық мұхитты зерттеуші ғалымның өмірі мен еңбектері

American oceanographer (1917–2019)

Walter Heinrich Munk (October 19, 1917 – February 8, 2019) was an American physical oceanographer. He was one of the first scientists to bring statistical methods to the analysis of oceanographic data. Munk worked on a wide range of topics, including surface waves, geophysical implications of variations in the Earth's rotation, tides, internal waves, deep ocean drilling into the sea floor, acoustical measurements of ocean properties, sea level rise, and climate change. His work won awards including the National Medal of Science, the Kyoto Prize, and induction to the French Legion of Honour. Munk's career began before the outbreak of World War II and ended nearly 80 years later with his death in 2019. The war interrupted his doctoral studies at the Scripps Institution of Oceanography (Scripps), and led to his participation in U. S. military research efforts. Munk and his doctoral advisor Harald Sverdrup developed methods for forecasting wave conditions which were used in support of beach landings in all theaters of the war. He was involved with oceanographic programs during the atomic bomb tests in Bikini Atoll. Beginning in 1975, Munk and Carl Wunsch developed ocean acoustic tomography to exploit the ease with which sound travels in the ocean and use acoustical signals for measurement of broad scale temperature and current. In a 1991 experiment, Munk and his collaborators investigated the ability of underwater sound to propagate from the Southern Indian Ocean across all ocean basins, with the aim of measuring global ocean temperature. The experiment was criticized by environmental groups, who expected that the loud acoustic signals would adversely affect marine life. Munk continued to develop and advocate for acoustical measurements of the ocean throughout his career. For most of his career, he was a professor of geophysics at Scripps at the University of California in La Jolla. Additionally, Munk and his wife Judy were active in developing the Scripps campus and integrating it with the new University of California, San Diego. Munk's career included being a member of the JASON think tank, and holding the Secretary of the Navy/Chief of Naval Operations Oceanography Chair.

In 1917, Munk was born to a Jewish family in Vienna, Austria Hungary. His father, Dr. Hans Munk, and his mother, Rega Brunner, divorced when he was ten years old. In 1932, Munk was performing poorly in school because he was spending too much time skiing, so his family sent him from Austria to a boys' preparatory school in upper New York state. His family envisioned a career for him in finance with a New York bank connected to the family business. Munk earned a B. S. in applied physics in 1939 The master's degree work was based on oceanographic data collected in the Gulf of California by the Norwegian oceanographer Harald Sverdrup, then director of Scripps. After serving 18 months in Field Artillery and the Ski Troops,

Officials at the time estimated that many lives were saved by these predictions. Munk commented in 2009:

text=The Normandy landing is famous because weather conditions were very poor and you may not realize it was postponed by General Eisenhower for 24 hours because of the prevailing wave conditions. And then he did decide, in spite of the fact that conditions were not favorable, it would be better to go in than lose the surprise element, which would have been lost if they waited for the next tidal cycle [in] two weeks.

In 1946, the United States tested two fission nuclear weapons (20 kilotons) at Bikini Atoll in the equatorial Pacific in Operation Crossroads. Munk helped to determine the currents, diffusion, and water exchanges affecting the radiation contamination from the second test, code named Baker. He held a Secretary of the Navy/Chief of Naval Operations Oceanography Chair from 1985 until his death in 2019. but his appointment was at the Institute of Geophysics (IGP) at the University of California, Los Angeles (UCLA). In 1955, Munk took a sabbatical at Cambridge, England. Revelle, its director at the time, was a primary advocate for establishing the La Jolla campus. At this time Munk was considering offers for new positions at the Massachusetts Institute of Technology and Harvard University, but Revelle encouraged Munk to remain in La Jolla. (After planetary physics was added, IGP changed its name to the Institute of Geophysics and Planetary Physics (IGPP). As Carl Wunsch, one of Munk's frequent collaborators, commented: This included two types of friction: horizontal friction between water masses moving at different velocities or between water and the edges of the oceanic basin, and friction from a vertical velocity gradient in the top layer of the ocean (the Ekman layer).

In 1957, Munk and Harry Hess suggested the idea behind Project Mohole: to drill into the Mohorovičić discontinuity and obtain a sample of the Earth's mantle. While such a project was not feasible on land, drilling in the open ocean would be more feasible, because the mantle is much closer to the sea floor. Initially led by the informal group of scientists known as the American Miscellaneous Society (AMSOC), a group that included Hess, Maurice Ewing, and Roger Revelle, However, the project was mismanaged and grew in expense after the construction company Brown and Root won the contract to continue the effort. Toward the end of 1966, Congress discontinued the project. While Project Mohole was not successful, the idea and its innovative initial phase directly led to the successful NSF Deep Sea Drilling Program for obtaining sediment cores.

Starting in the late 1950s, Munk returned to the study of ocean waves. Thanks to his acquaintance with John Tukey, he pioneered the use of power spectra in describing wave behavior. This work culminated with an expedition that he led in 1963 called "Waves Across the Pacific" to observe waves generated by storms in the Southern Indian Ocean. Such waves traveled northward for thousands of miles across the Pacific Ocean. To trace the path and decay of the waves, he established measurement stations on islands and at sea (on R/P FLIP) along a great circle from New Zealand, to the Palmyra Atoll, and finally to Alaska. Munk and his family spent nearly the whole of 1963 on American Samoa for this experiment. Walter and Judith Munk collaborated in making a film to document the experiment. The results show little decay of wave energy with distance traveled. This work, together with the wartime work on wave forecasting, led to the science of surf forecasting, one of Munk's best known accomplishments.

Between 1965 and 1975, Munk turned to investigations of ocean tides, partly motivated by their effects on the Earth's rotation. Modern methods of time series and spectral analysis were brought to bear on tidal analysis, leading to work with David Cartwright developing the "response method" of tidal analysis. With Frank Snodgrass, Munk developed deep ocean pressure sensors that could be used to provide tidal data far from any land. One highlight of this work was the discovery of the semidiurnal amphidrome midway between California and Hawaii.

In the 1990s, Munk returned to the work on the role of tides in producing mixing in the ocean. In a 1966 paper "Abyssal Recipes", Munk was one of the first to assess quantitatively the rate of mixing in the abyssal ocean in maintaining oceanic stratification. At that time, the tidal energy available for mixing was thought to occur by processes near ocean boundaries. According to Sandström's theorem (1908), without the occurrence deep mixing, driven by, e. g., internal tides or tidally driven turbulence in shallow regions, most of the ocean would become cold and stagnant, capped by a thin, warm surface layer. The question of tidal energy available for mixing was reawakened in the 1990s with the discovery, by acoustic tomography and satellite altimetry, of large scale internal tides radiating energy away from the Hawaiian Ridge into the interior of the North Pacific Ocean. Munk recognized that the tidal energy from the scattering and radiation of large scale internal waves from mid ocean ridges was significant, hence it could drive abyssal mixing.

In his later work, Munk focused on the relation between changes in ocean temperature, sea level, and the transfer of mass between continental ice and the ocean. This work described what came to be known as "Munk's enigma", a large discrepancy between observed rate of sea level rise and its expected effects on the earth's rotation.

Munk was elected to the National Academy of Sciences in 1956, the American Academy of Arts and Sciences in 1957, the American Philosophical Society in 1965, and to the Royal Society of London in 1976. He was both a Guggenheim Fellow (1948, 1953, 1962) and a Fulbright Fellow. He was named California Scientist of the Year by the California Museum of Science and Industry in 1969. Munk gave the 1986 Bakerian Lecture at the Royal Society on Ships from Space (paper) and Acoustic monitoring of ocean gyres (lecture). In July 2018 at the age of 100, Munk was appointed a Chevalier of France's Legion of Honour in recognition of his contributions to oceanography. the Arthur L. Day Medal of the Geological Society of America in 1965, the Sverdrup Gold Medal of the American Meteorological Society in 1966, the Gold Medal of the Royal Astronomical Society in 1968, the first Maurice Ewing Medal of the American Geophysical Union and the U. S. Navy in 1976, the Alexander Agassiz Medal of the National Academy of Sciences in 1976, the Captain Robert Dexter Conrad Award of the U. S. Navy in 1978, the National Medal of Science in 1983, the William Bowie Medal of the American Geophysical Union in 1989, the Vetlesen Prize in 1993, the Kyoto Prize in 1999, the first Prince Albert I Medal in 2001, and the Crafoord Prize of the Royal Swedish Academy of Sciences in 2010 "for his pioneering and fundamental contributions to our understanding of ocean circulation, tides and waves, and their role in the Earth's dynamics". This award was given jointly by The Oceanography Society, the Office of Naval Research and the US Department of Defense Naval Oceanographic Office. Two marine species have been named after Munk. One is Sirsoe munki, a deep sea worm. The other is Mobula munkiana, also known as Munk's devil ray, a small relative of giant manta rays living in huge schools, and with a remarkable ability to leap far out of the water. A 2017 documentary, Spirit of Discovery (Documentary), follows Munk in an expedition with the discoverer, his former student Giuseppe Notarbartolo di Sciara, to Cabo Pulmo National Park in Baja Mexico, the place where the species was first found and described.

After Nazi Germany annexed Austria in 1938 during the Anschluss, Munk applied to be a citizen of the United States. In 2011, Munk married La Jolla community leader Mary Coakley. Munk remained actively engaged in scientific endeavors throughout his life, with publications as late as 2016. He turned 100 in October 2017. He died of pneumonia on February 8, 2019, at La Jolla, California, aged 101.

Munk published 181 scientific papers. They were cited over 11,000 times, an average of 63 times each. Some of the most highly cited papers in the Web of Science database are listed below.