Dezső Dévényi, meteorologist, friend, and colleague, passed away suddenly of a heart attack, Thanksgiving Day, 26 November 2009.


He was born in Keszthely, Hungary, on 4 June 1948 of Dezső (he was named after his father) and Anna Dévényi.  In his youth he and his brother, László, were accomplished soccer players, but Dezső’s soccer career ended with an ankle injury in college.   Dezső attended Eötvös Loránd University in Budapest.  For his graduate work, he developed a new version of optimum interpolation, a statistical/mathematical tool for assimilating weather data into prediction models, based on the simplex method.  In 1973, he received an MSc degree in meteorology and mathematics/physics teacher [sic] and was soon employed by the Hungarian Meteorological Service as a Junior Research Scientist.  For a year, beginning in March 1975, he studied with Lev S. Gandin, considered by many to be the father of statistical methods of meteorological data assimilation, at the Main Geophysical Observatory in St. Petersburg (then called Leningrad).


Upon his return to Budapest, Dezső had a long and distinguished career with the Hungarian Met Service.  He served as its Scientific Secretary from 1979 to 1984 and then, from 1985 through 1991, filled a number of supervisory positions.  In chronological order, he was Chief of the Hydrology Branch, the Numerical Forecasting Branch, the Long-Range Forecasting Division, and the Weather Forecasting Division.  During this time, he never lost his appetite for meteorological data assimilation and its application to numerical weather prediction.  In fact, he made groundbreaking contributions toward improving the Met Service’s operational capability.  In 1988 he published a book with Ottó Gulyás, Mathematical Statistical Methods in Meteorology (in Hungarian).  It may not be widely known, but in March 1991 Dezső, along with R. Bubnova from Czechoslovakia and V. Ivanovici from Romania visited Météo France to help initiate a project later known as ALADIN, which became a cornerstone of regional numerical weather prediction in Central Europe.


In 1991 Dezső received his doctoral degree in geosciences from Eötvös Loránd University.  His thesis title was “The Application of Satellite Data in the Objective Analysis of Meteorological Fields.”  In 1996, after additional examinations, the University awarded him a Doctor Habilitationis Degree in earth sciences, essentially qualifying him to be a teaching professor.


Perhaps because he wanted to spend more time on data assimilation research, Dezső accepted an appointment as National Research Council Visiting Scientist at NOAA’s Forecast Systems Laboratory (FSL) in Boulder, Colorado, USA.  At FSL from October 1991 until April 1993, Dezső assisted with the early development of the Rapid Update Cycle (RUC), a system still operational at the National Centers for Environmental Prediction, that generates hourly analyses of U.S. weather data and initializes short-term mesoscale forecasts every hour.


Upon his return to the Hungarian Met Service, Dezső again headed the Weather Forecasting Division until January 1994, when he became Vice President of the Service.


The allure of research again beckoned in January 1995, when Dezső returned to Boulder, Colorado.  His employer was the Cooperative Institute for Research in Environmental Sciences at the University of Colorado, but he worked again with many of the same colleagues at NOAA/FSL on the assimilation of a variety of meteorological observations into the prediction model for the RUC.


For awhile, it appeared that academia might draw Dezső permanently back to Hungary.  He left in July 1999 for an Associate Professorship at Eötvös Loránd University in Budapest and taught there during the fall semester.  But he returned to Boulder for good early in 2000 to continue work on a three-dimensional variational analysis code, the data assimilation part of the RUC.  In recent years, he worked to adapt code from the Gridpoint Statistical Interpolation Analysis at the National Centers for Environmental Prediction for use in the Rapid Refresh, a successor hourly update cycle to the RUC.


Dezső joined the Hungarian Meteorological Society in 1971; he became a Board Member in 1978.  He joined the Mathematical Society of Hungary in 1978 and the American Meteorological Society in 2008.  He was an Editorial Board Member of Időjárás, the quarterly journal of the Hungarian Meteorological Service since 1982.  A member of the Committee on Meteorology of the Hungarian Academy of Sciences since 1986, he headed the Subcommittee on Observations and Data Assimilation, 1999-2002. He became a member of the Committee on Atmospheric Dynamics in 2002 and of the Committee on Climate in 2008.


Dezső was teacher and mentor to a generation of Hungarian meteorologists.  His grasp of mathematics was beyond that of most of his colleagues, but he was always willing to explain things in as much depth as he thought they could handle, and he had an uncanny knack for finding quickly the perfect reference for any scientific discussion.  He was fond of books.  His library was so large, nearly 5,000 volumes, that much of it had to remain in Hungary when he came to the U.S.  He visited Barnes and Noble weekly.  The story is told that he was sent out to buy a new pair of jeans, but came back instead with a new book….three times.  He was a voracious reader; he reserved early mornings for technical reading and think work, and evenings for recreational reading, especially science fiction. 


He maintained close ties with his Hungarian colleagues and meteorologists elsewhere in Europe.  He was an excellent source on the latest developments in data assimilation and numerical weather predication throughout the world.


In the late 1970s, Dezső sometimes visited a pharmacy where his uncle’s wife worked.  At one point, she was planning a birthday party for her husband and invited Dezső along with another employee of the pharmacy, Mary.  Dezső was one year ahead of Mary in high school, but they had never been well acquainted―until the birthday party.  That is how Dezső met the love of his life.  Working in Budapest, Dezső was soon traveling on weekends to Hévíz, where Mary lived, 200 km away.  They were engaged at Christmas 1978 and married the following March.  Their daughter, Patricia, was born during their first year of marriage.  On their 25th wedding anniversary, Dezső gave Mary a Westie puppy, Zseni, to keep her company during the day while he worked at the lab.  Before long, Dezső was as eager to walk the puppy as Mary.


Dezső was fluent in Hungarian, English and Russian and could get along in German as well.  He maintained a lively interest in world affairs, history, and the arts.    He was, above all, a gentle man with a friendly and unflappable disposition.  His dry sense of humor was much appreciated.  When asked “How are you doing,” he would reply more often than not, “Not too bad, yet.”  He would probably answer the question now “Very well, thank you,” but we who are left behind sorely miss him.  


Dezső was preceded in death by his brother, László, in 1993.  He is survived by his wife, Mary Dévényi, daughter Patricia Dévényi, and a rambunctious but beloved dog, Zseni.­­­­­­­­­­­­­­­­­­­­­



Thomas W. Schlatter and Stanley G. Benjamin, with contributions from Mary and Patricia Dévényi, Gábor Radnóti and András Horányi