Masao Kanamitsu, whose pioneering efforts transformed the ability of scientists to detect climate patterns over the course of decades, died of cancer Aug. 17 at his home in Del Mar, Calif. He was 67.
The researcher known to friends and family simply as "Kana" was well known nationally and internationally. Kanamitsu helped develop the framework for numerical modeling - the numerical representation of the atmosphere formed by coding the essential equations that govern its state and how it evolves with time.
Thousands of climate scientists benefitted from his contributions to a research project called "Reanalysis," begun while he was a scientist at the National Weather Service (NWS). The comprehensive, dynamically consistent reanalysis of historical meteorological data dating back to the 1940s gave the field a new means for studying and predicting climate behavior.
The 1996 reanalysis paper published in the Bulletin of the American Meteorological Society that he co-authored has been called the most cited paper in the history of geosciences, having been referenced in nearly 8,000 papers to date since its publication.
"It provided researchers for the first time with a long and internally consistent historical data set, one which authoritatively integrates many kinds of observational data and can be used to study the recent past record of weather and climate change," said Scripps Distinguished Professor Emeritus Richard Somerville, a colleague of Kanamitsu's.
Kanamitsu's work at Scripps was aimed at improving extended range prediction-forecasting the atmosphere at time leads from a few weeks to decades in advance. This led him to explore new ways to model influences upon the atmosphere by processes operating at its lower boundary, involving both the ocean and the land surface.
"Kana was one of the world's leading developers and experimenters involved with numerical weather and climate prediction, which is the primary means to predict and explore future climate," said Scripps climate scientist Dan Cayan.
By his key contributions to the Reanalysis project, Kanamitsu firmly established himself as a leading climate expert, said Somerville.
He subsequently became one of the world's most eminent leaders in the science of seasonal climate modeling. His work is recognized for major contributions in several areas of climate science, including downscaling from global-scale to regional-scale climate simulations, the impact of soil moisture and the predictability issues of seasonal climate.
University of Maryland Distinguished University Professor Eugenia Kalnay was lead author of the 1996 Reanalysis paper and Kanamitsu's division chief at the NWS' National Center for Environmental Prediction (NCEP) in Camp Springs, Md., at the time of its publication. Kanamitsu was the Branch Chief of the Global Modeling Branch at NCEP.
He led the effort to implement advances in the NCEP global spectral model that resulted in significant improvements in the operational forecast skill, said Kalnay, who described him as a natural to lead the effort.
"I respected Kana enormously: he gave all he had to the work he did, was courageous both in his scientific work and in his dealing with health problems that would have been daunting for somebody less strong," Kalnay said. "He was an inspiration for all of us who had the privilege of interacting with him."
Scripps climate researcher Alexander Gershunov is co-author of an upcoming study of recent temperature extremes that relied on the reanalysis Kanamitsu helped develop. Gershunov, whose Scripps Oceanography office was next door to Kana's, credited Kanamitsu's work with giving scientists a way to analyze climate to an extent never before possible.
"He was a hugely accomplished climate scientist," Gershunov said. "He was a world traveler and a very gentle person who was quick to see the humor in life. I loved to interact with him because of that. He was always quick to laugh."
Kanamitsu came to Scripps in 2001. Previously he had joined the National Meteorological Center in 1985 and was a senior scientist at the center - which later became the National Center for Environmental Prediction - before becoming a research meteorologist at Scripps. Earlier in his career, Kanamitsu had worked at the European Centre for Medium-Range Weather Forecasts and the Numerical Weather Prediction Division of the Japan Meteorological Agency.
Kanamitsu was born in Kumamoto, Japan, on November 6, 1943, and was raised in Sapporo, Japan. He received B.S. and M.S. degrees in geophysics from Hokkaido University in his native Japan before receiving his Ph.D. in meteorology from Florida State University in 1975. Cayan noted that Kanamitsu was already a veteran researcher with several published papers when the 1996 reanalysis study was released. He had an immediate effect in attracting young researchers when he made the move to Scripps, and also made important advances in understanding the regional climate here.
Recently, Kanamitsu had completed California Reanalysis Downscaling at 10 km (CaRD10), a project that used supercomputers in Japan and the United States to crunch several terabytes of data to create a climate history of California, downscaled to resolve hourly structure at a scale of 10 kilometer (6.2 mile) grid cells. The most recent revision of the CaRD10 analysis extends from 1948 to 2011.
"His impact upon the climate community has been multi-generational," said Cayan. "He was extremely modest and always gentle but a very persistent person. He had great integrity, professionally and personally."
Kanamitsu enjoyed hiking in various mountain ranges around Japan, the United States and Europe, according to wife Mariko and daughter Tomoko.
"He loved dogs, taking photographs, was an expert at making soba noodles, and most of all, he loved to eat. Kana had an optimistic, bright demeanor and a wonderful sense of humor. He always gave his all to every pursuit; his attitude was to 'never give up!' A loving husband and father, he had a warm and generous spirit," they wrote in a letter to friends.
At Kanamitsu's request there will be no funeral or memorial service. He is survived by his wife Mariko, daughter Tomoko and sister Yoko Okuyama.