Edward Norton Lorenz (May 23, 1917 – April 16, 2008) was an American mathematician and

meteorologist A meteorologist is a scientist who studies and works in the field of meteorology aiming to understand or predict Earth's atmosphere of Earth, atmospheric phenomena including the weather. Those who study meteorological phenomena are meteorologists ...

who established the theoretical basis of weather and climate

predictability Predictability is the degree to which a correct prediction or forecast of a system's state can be made, either qualitatively or quantitatively. Predictability and causality Causal determinism has a strong relationship with predictability. Perfec ...

, as well as the basis for computer-aided atmospheric physics and

meteorology Meteorology is the scientific study of the Earth's atmosphere and short-term atmospheric phenomena (i.e. weather), with a focus on weather forecasting. It has applications in the military, aviation, energy production, transport, agricultur ...

. He is best known as the founder of modern

chaos theory Chaos theory is an interdisciplinary area of Scientific method, scientific study and branch of mathematics. It focuses on underlying patterns and Deterministic system, deterministic Scientific law, laws of dynamical systems that are highly sens ...

, a branch of

mathematics Mathematics is a field of study that discovers and organizes methods, Mathematical theory, theories and theorems that are developed and Mathematical proof, proved for the needs of empirical sciences and mathematics itself. There are many ar ...

focusing on the behavior of

dynamical system In mathematics, a dynamical system is a system in which a Function (mathematics), function describes the time dependence of a Point (geometry), point in an ambient space, such as in a parametric curve. Examples include the mathematical models ...

s that are highly sensitive to

initial conditions In mathematics and particularly in dynamic systems, an initial condition, in some contexts called a seed value, is a value of an evolving variable at some point in time designated as the initial time (typically denoted ''t'' = 0). Fo ...

. His discovery of deterministic chaos "profoundly influenced a wide range of basic sciences and brought about one of the most dramatic changes in mankind's view of nature since Sir Isaac Newton," according to the committee that awarded him the 1991

Kyoto Prize The is Japan's highest private award for lifetime achievement in the arts and sciences. It is given not only to those that are top representatives of their own respective fields, but to "those who have contributed significantly to the scientific, ...

for basic sciences in the field of earth and planetary sciences.

Early life

Lorenz was born in 1917 in

West Hartford, Connecticut West Hartford is a town in Hartford County, Connecticut, United States, west of downtown Hartford, Connecticut, Hartford. The town is part of the Capitol Planning Region, Connecticut, Capitol Planning Region. The population was 64,083 at the 20 ...

. He acquired an early love of science from both sides of his family. His father, Edward Henry Lorenz (1882-1956), majored in mechanical engineering at the

Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a Private university, private research university in Cambridge, Massachusetts, United States. Established in 1861, MIT has played a significant role in the development of many areas of moder ...

, and his maternal grandfather, Lewis M. Norton, developed the first course in chemical engineering at

MIT The Massachusetts Institute of Technology (MIT) is a private research university in Cambridge, Massachusetts, United States. Established in 1861, MIT has played a significant role in the development of many areas of modern technology and sc ...

in 1888. Meanwhile, his mother, Grace Peloubet Norton (1887-1943), instilled in Lorenz a deep interest in games, particularly chess.

Education

Lorenz received a bachelor's degree in mathematics from

Dartmouth College Dartmouth College ( ) is a Private university, private Ivy League research university in Hanover, New Hampshire, United States. Established in 1769 by Eleazar Wheelock, Dartmouth is one of the nine colonial colleges chartered before the America ...

in 1938 and a master's degree in mathematics from

Harvard Harvard University is a private Ivy League research university in Cambridge, Massachusetts, United States. Founded in 1636 and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher lear ...

in 1940. He worked as a weather forecaster for the

United States Army Air Forces The United States Army Air Forces (USAAF or AAF) was the major land-based aerial warfare service component of the United States Army and ''de facto'' aerial warfare service branch of the United States during and immediately after World War II ...

during

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

, leading him to pursue graduate studies in meteorology at the

. He earned both a master's and doctoral degree in

from

in 1943 and 1948. His doctoral dissertation, titled "A Method of Applying the Hydrodynamic and Thermodynamic Equations to Atmospheric Models" and performed under advisor James Murdoch Austin, described an application of fluid dynamical equations to the practical problem of predicting the motion of storms.

Scientific career

Lorenz spent the entirety of his scientific career at the

. In 1948, he joined the MIT Department of Meteorology as a research scientist. In 1955, he became an assistant professor in the department and was promoted to professor in 1962. From 1977 to 1981, Lorenz served as head of the Department of Meteorology at MIT. In 1983, the MIT Department of Meteorology and Physical Oceanography merged with the Department of Geology to become the current MIT Department of Earth, Atmospheric and Planetary Sciences, where Lorenz remained a professor before becoming an emeritus professor in 1987.

Atmospheric circulation

In the late 1940s and early 1950s, Lorenz worked with Victor Starr on the General Circulation Project at MIT to understand the role the weather system played in determining the energetics of the general circulation of the atmosphere. From this work, in 1967, Lorenz published a landmark paper, titled "The Nature and Theory of the General Circulation of the Atmosphere," on

atmospheric circulation Atmospheric circulation is the large-scale movement of Atmosphere of Earth, air and together with ocean circulation is the means by which thermal energy is redistributed on the surface of the Earth. The Earth's atmospheric circulation varies fro ...

from an energetic perspective, which advanced the concept of available potential energy.

Numerical weather prediction

In the 1950s, Lorenz became interested in and started work on

numerical weather prediction Numerical weather prediction (NWP) uses mathematical models of the atmosphere and oceans to weather forecasting, predict the weather based on current weather conditions. Though first attempted in the 1920s, it was not until the advent of comput ...

, which relied on computers to forecast weather by processing observational data on such things as temperature, pressure, and wind. This interest was sparked, in part, after a visit to the

Institute for Advanced Study The Institute for Advanced Study (IAS) is an independent center for theoretical research and intellectual inquiry located in Princeton, New Jersey. It has served as the academic home of internationally preeminent scholars, including Albert Ein ...

in Princeton, New Jersey, where he met Jule Charney, then head of the IAS's Meteorological Research Group and a leading dynamical meteorologist at the time. (Charney would later join Lorenz at

in 1957 as a professor of meteorology.) In 1953, Lorenz took over leadership of a project at MIT that ran complex simulations of weather models that he used to evaluate statistical forecasting techniques. By the late 1950s, Lorenz was skeptical of the appropriateness of the

linear In mathematics, the term ''linear'' is used in two distinct senses for two different properties: * linearity of a '' function'' (or '' mapping''); * linearity of a '' polynomial''. An example of a linear function is the function defined by f(x) ...

statistical models in meteorology, as most atmospheric phenomena involved in weather forecasting are

non-linear In mathematics and science, a nonlinear system (or a non-linear system) is a system in which the change of the output is not proportional to the change of the input. Nonlinear problems are of interest to engineers, biologists, physicists, mathe ...

. It was during this time that his discovery of deterministic chaos came about.

Chaos theory

In 1961, Lorenz was using a simple digital computer, a Royal McBee

LGP-30 The LGP-30, standing for Librascope General Purpose and then Librascope General Precision, is an early off-the-shelf computer. It was manufactured by the Librascope company of Glendale, California (a division of General Precision Inc.), and so ...

, to simulate weather patterns by modeling 12 variables, representing things like temperature and wind speed. He wanted to see a sequence of data again, and to save time he started the simulation in the middle of its course. He did this by entering a printout of the data that corresponded to conditions in the middle of the original simulation. To his surprise, the weather that the machine began to predict was completely different from the previous calculation. The culprit: a rounded decimal number on the computer printout. The computer worked with 6-digit precision, but the printout rounded variables off to a 3-digit number, so a value like 0.506127 printed as 0.506. This difference is tiny, and the consensus at the time would have been that it should have no practical effect. However, Lorenz discovered that small changes in initial conditions produced large changes in long-term results. Lorenz's discovery, which gave its name to Lorenz attractors, showed that even detailed atmospheric modelling cannot, in general, make precise long-term weather predictions. His work on the topic, assisted by Ellen Fetter, culminated in the publication of his 1963 paper "Deterministic Nonperiodic Flow" in '' Journal of the Atmospheric Sciences'', and with it, the foundation of

. He states in that paper: His description of the

butterfly effect In chaos theory, the butterfly effect is the sensitive dependence on initial conditions in which a small change in one state of a deterministic nonlinear system can result in large differences in a later state. The term is closely associated w ...

, the idea that small changes can have large consequences, followed in 1969. In the book "The Essence of Chaos," in the chapter "Our Chaotic Weather" from 1993, authored by Edward Lorenz and Krzysztof Haman, the authors delved into the challenges of weather forecasting. The work discusses the consequences of chaos in the atmosphere and its impact on weather prediction. They describe a scenario in which meteorologists, in the computer age, generate multiple long-term weather forecasts based on different yet similar initial atmospheric conditions. Differences in the forecast results arise due to the sensitivity of the system to initial conditions. Lorenz's insights on deterministic chaos resonated widely starting in the 1970s and 80s, when it spurred new fields of study in virtually every branch of science, from biology to geology to physics. In meteorology, it led to the conclusion that it may be fundamentally impossible to predict weather beyond two or three weeks with a reasonable degree of accuracy. However, the recognition of chaos has led to improvements in

weather forecasting Weather forecasting or weather prediction is the application of science and technology forecasting, to predict the conditions of the Earth's atmosphere, atmosphere for a given location and time. People have attempted to predict the weather info ...

, as now forecasters recognize that measurements are imperfect and thus run many simulations starting from slightly different conditions, called

ensemble forecasting Ensemble forecasting is a method used in or within numerical weather prediction. Instead of making a single forecast of the most likely weather, a set (or ensemble) of forecasts is produced. This set of forecasts aims to give an indication of the ...

. Of the seminal significance of Lorenz's work, Kerry Emanuel, a prominent meteorologist and climate scientist at MIT, has stated: Late in his career, Lorenz began to be recognized with international accolades for the importance of his work on deterministic chaos. In 1983, along with colleague Henry Stommel, he was awarded the

Crafoord Prize The Crafoord Prize () is an annual science prize established in 1980 by Holger Crafoord, a Swedish industrialist, and his wife Anna-Greta Crafoord following a donation to the Royal Swedish Academy of Sciences. It is awarded jointly by the Acade ...

from the Swedish Academy of Sciences, considered to be nearly equal to a

Nobel Prize The Nobel Prizes ( ; ; ) are awards administered by the Nobel Foundation and granted in accordance with the principle of "for the greatest benefit to humankind". The prizes were first awarded in 1901, marking the fifth anniversary of Alfred N ...

. He was also awarded the

for basic sciences in the field of earth and planetary sciences in 1991, the Buys Ballot Award in 2004, and the Tomassoni Award in 2008. In 2018, a short documentary was made about Lorenz's immense scientific legacy on everything from how we predict weather to our understanding of the universe. A reprint book containing invited papers on butterfly effects was published to celebrate the 50th anniversary of the metaphorical butterfly effect.

Personal life and death

Later in life, Lorenz lived in

Cambridge, Massachusetts Cambridge ( ) is a city in Middlesex County, Massachusetts, United States. It is a suburb in the Greater Boston metropolitan area, located directly across the Charles River from Boston. The city's population as of the 2020 United States census, ...

with his wife, Jane Loban (1919–2001), and their three children, Nancy, Cheryl, and Edward. He was an avid outdoorsman, who enjoyed hiking, climbing, and cross-country skiing. He kept up with these pursuits until very late in his life. On April 16, 2008, Lorenz died at his home in Cambridge from cancer at the age of 90.

Legacy

Lorenz is remembered by colleagues and friends for his quiet demeanor, gentle humility, and love of nature. He was described as "a genius with a soul of an artist" by his close friend and collaborator Jule Charney.

The Lorenz Center

In 2011, The Lorenz Center, a climate think tank devoted to fundamental scientific inquiry, was founded at

in honor of Lorenz and his pioneering work on

and

climate science Climatology (from Greek , ''klima'', "slope"; and , '' -logia'') or climate science is the scientific study of Earth's climate, typically defined as weather conditions averaged over a period of at least 30 years. Climate concerns the atmospher ...

Centenary celebration

In February 2018, The Edward Lorenz Center and Henry Houghton Fund hosted a symposium, named MIT on Chaos and Climate, in honor of the 100th anniversary of the birth of Lorenz and Charney. The two-day event featured presentations from world-renowned experts on the many scientific contributions that the two pioneers made on the fields of

physical oceanography Physical oceanography is the study of physical conditions and physical processes within the ocean, especially the motions and physical properties of ocean waters. Physical oceanography is one of several sub-domains into which oceanography is div ...

atmospheric dynamics Meteorology is the scientific study of the Earth's atmosphere and short-term atmospheric phenomena (i.e. weather), with a focus on weather forecasting. It has applications in the military, aviation, energy production, transport, agriculture, ...

, and experimental fluid dynamics, as well as the personal legacy they left behind of integrity, optimism, and collaboration. A video produced for the event highlights the indelible mark made by Charney and Lorenz on MIT and the field of meteorology as a whole.

Publications

Lorenz published many books and articles, a selection of which can be found below. A more complete list can be found on the Lorenz Center website
link
* 1955 Available potential energy and the maintenance of the general circulation. ''Tellus''. Vol. 7; 2
Link
* 1963 Deterministic nonperiodic flow. ''Journal of the Atmospheric Sciences''. Vol. 20: 130–141.
Link
* 1967 The nature and theory of the general circulation of atmosphere. ''World Meteorological Organization''. Vol. 218
Link
* 1969 Three approaches to atmospheric predictability. ''Bulletin of the American Meteorological Society''. Vol. 50; 345–349
Link
* 1972 Predictability: Does the Flap of a Butterfly's Wings in Brazil Set Off a Tornado in Texas? ''American Association for the Advancement of Sciences;'' 139th meeting
Link
* 1976 Nondeterministic theories of

climate change Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...

. ''Quaternary Research''. Vol. 6
Link
* 1990 Can chaos and intransitivity lead to interannual variability? ''Tellus''. Vol. 42A
Link
* 2005 Designing Chaotic Models. ''Journal of the Atmospheric Sciences''. Vol. 62, No. 5: 1574–1587
Link

Awards

* 1969 Carl-Gustaf Rossby Research Medal,

American Meteorological Society The American Meteorological Society (AMS) is a scientific and professional organization in the United States promoting and disseminating information about the atmospheric, oceanic, and hydrologic sciences. Its mission is to advance the atmosph ...

. * 1973

Symons Gold Medal The Symons Gold Medal is awarded biennially by the Royal Meteorological Society for distinguished work in the field of meteorological science. It was established in 1901 in memory of George James Symons, a notable British meteorologist. Recipient ...

Royal Meteorological Society The Royal Meteorological Society is an organization that promotes academic and public engagement in weather and climate science. Fellows of the Society must possess relevant qualifications, but Members can be lay enthusiasts. It publishes vari ...

. * 1975 Fellow,

National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, NGO, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the ...

(U.S.A.). * 1981 Member,

Norwegian Academy of Science and Letters The Norwegian Academy of Science and Letters (, DNVA) is a learned society based in Oslo, Norway. Its purpose is to support the advancement of science and scholarship in Norway. History The Royal Frederick University in Christiania was establis ...

. * 1983

Royal Swedish Academy of Sciences The Royal Swedish Academy of Sciences () is one of the Swedish Royal Academies, royal academies of Sweden. Founded on 2 June 1739, it is an independent, non-governmental scientific organization that takes special responsibility for promoting nat ...

. * 1984 Honorary Member,

. * 1989

Elliott Cresson Medal The Elliott Cresson Medal, also known as the Elliott Cresson Gold Medal, was the highest award given by the Franklin Institute. The award was established by Elliott Cresson, life member of the Franklin Institute, with $1,000 granted in 1848. Th ...

The Franklin Institute The Franklin Institute is a science museum and a center of science education and research in Philadelphia, Pennsylvania. It is named after the American scientist and wikt:statesman, statesman Benjamin Franklin. It houses the Benjamin Franklin ...

* 1991

for ... his boldest scientific achievement in discovering "deterministic chaos". * 1992 Roger Revelle Medal * 2000 International Meteorological Organization Prize from

World Meteorological Organization The World Meteorological Organization (WMO) is a List of specialized agencies of the United Nations, specialized agency of the United Nations responsible for promoting international cooperation on atmospheric science, climatology, hydrology an ...

* 2004 Buys Ballot Medal of the

Royal Netherlands Academy of Arts and Sciences The Royal Netherlands Academy of Arts and Sciences (, KNAW) is an organization dedicated to the advancement of science and literature in the Netherlands. The academy is housed in the Trippenhuis in Amsterdam. In addition to various advisory a ...

. * 2004 Lomonosov Gold Medal of the

Russian Academy of Sciences The Russian Academy of Sciences (RAS; ''Rossíyskaya akadémiya naúk'') consists of the national academy of Russia; a network of scientific research institutes from across the Russian Federation; and additional scientific and social units such ...

* 2008 Felice Pietro Chisesi e Caterina Tomassoni award

References

External links

"Weather and Chaos: The Work of Edward N. Lorenz," 2018
* ttps://www.telegraph.co.uk/news/obituaries/1895916/Professor-Edward-Lorenz.html Obituary ''

The Daily Telegraph ''The Daily Telegraph'', known online and elsewhere as ''The Telegraph'', is a British daily broadsheet conservative newspaper published in London by Telegraph Media Group and distributed in the United Kingdom and internationally. It was found ...

'', 18 April 2008.
Kerry Emanuel, "Edward Norton Lorenz", Biographical Memoirs of the National Academy of Sciences (2011)
{{DEFAULTSORT:Lorenz, Edward 1917 births 2008 deaths 20th-century American mathematicians 21st-century American mathematicians American meteorologists United States Army Air Forces personnel of World War II Carl-Gustaf Rossby Research Medal recipients Chaos theorists Dartmouth College alumni Foreign members of the Royal Society Foreign members of the USSR Academy of Sciences Foreign members of the Russian Academy of Sciences Harvard University alumni Kyoto laureates in Basic Sciences Massachusetts Institute of Technology School of Science alumni Massachusetts Institute of Technology School of Science faculty Members of the Norwegian Academy of Science and Letters Members of the United States National Academy of Sciences People from West Hartford, Connecticut Recipients of the Buys Ballot Medal (Netherlands) United States Army Air Forces soldiers Recipients of the Lomonosov Gold Medal