Roger Willis Daley, UCAR Distinguished Scientific Visitor at the Naval Research Lab in Monterey, died at his home in Carmel Valley, California, August 29, 2001. Daley was born in Purley, England on January 25, 1943. He moved with his parents at an early age to West Vancouver, British Columbia, Canada. He studied at the University of British Columbia graduating with a B. S. in mathematics and physics in 1964. He completed a M. S. in Meteorology at McGill University in 1966 with a thesis on the topic of large-scale rainfall prediction. After two years as a professional weather forecaster in Goose Bay, Labrador and Montreal, Quebec, he began PhD studies at McGill, graduating in 1971. His PhD thesis was on the simulation of convection using the spectral method.
 

Daley spent two years of post-doctoral studies at the Institute for Theoretical Meteorology in Copenhagen before returning to Canada to a research scientist position with the Meteorological Service of Canada (MSC) in Montréal. From 1973 to 1977, he carried out research and development on numerical weather prediction (NWP) systems that were implemented at the Canadian Meteorological Centre (CMC). He was the team leader for the world's first operational spectral forecast model, which was implemented in 1976. The spectral approach is now used in most operational global NWP centres and forms the dynamical basis for most climate models presently in use. He also was a co-developer of the variable resolution finite element model that was used for regional forecasting applications in Canada for many years.

In 1977, Daley accepted a position at the National Center for Atmospheric Research (NCAR) in Boulder, Colorado where he carried out research on non-linear normal mode initialization and other outstanding problems in the dynamics of large-scale atmospheric flow particularly as they related to global NWP. He also became much more interested in the science of data assimilation. During this period, Daley was author or co-author on some 16 publications in the refereed literature and was honoured by receiving the NCAR outstanding publication award. Nevertheless, he did not neglect his interest in operational applications. He was involved in implementation of nonlinear normal mode initialization for baroclinic models at CMC in Canada and at Météo-France in Paris; and implemented an innovative error covariance formulation at the European Centre for Medium Range Weather Forecasts.

In 1985, Daley returned to Canada to take up the position of Chief Scientist in the Canadian Climate Centre. He was an integral part of the development of the research agenda for the Canadian Climate Program that was ultimately a major initiative of Canada's Green Plan. This program supported the development of a vigorous climate research capability in Canada that thrives to this day. His personal scientific work was consumed with the production of a book entitled "Atmospheric Data Assimilation", which was published in 1991. This book is now a classic. In writing the book, Daley encountered many vexing difficulties and inconsistencies with the approaches used in operational data assimilation. He proceeded to tackle and resolve these questions. These investigations led to an explosion of publications by Daley in the refereed literature during the period 1985 to 1995. By the time he left the MSC he was firmly established as a world leader in data assimilation through his comprehensive book, but also in terms of creative new developments in the theory and practice of data assimilation. Some scientists believe that Daley was largely responsible for elevating data assimilation to be a prestigious field of scientific enquiry.

In 1995, Daley accepted a position as a UCAR Distinguished Scientific Visitor at the Marine Meteorology Division, Naval Research Laboratory, in Monterey, California, and moved his family to the Carmel Valley. Daley took on the job of the design and construction of a new three-dimensional variational data assimilation system specifically meant to serve the needs of the US Navy. This system is now known as the NRL Atmospheric Variational Data Assimilation System, or NAVDAS. It was put in operation at Fleet Numerical Oceanography and Meteorology Center and Navy regional centres in 2003. NAVDAS is designed to meet data assimilation needs of both global models and regional nested models. Daley continued to innovate as he continued to implement. His colleagues at NRL Monterey greatly admired his ability to be equally productive in the "nitty-gritty" computer programming of components of NAVDAS as he was in the abstract matrix algebra of data assimilation theory. Daley was full of ideas and very active in research on an accelerated cycling representor method as a new approach to four-dimensional data assimilation.

Throughout his career, Daley was in demand as a consultant, as a scientific visitor and adjunct professor. He held visiting appointments at ECMWF; Météo-France; Florida State University and The Meteorological Institute of Stockholm University. He was an adjunct professor at McGill University, Colorado State University and the Naval Postgraduate School and a Scientist Emeritus with the Meteorological Service of Canada. He also lectured extensively throughout the world including a series of lectures in Beijing, China; as a principal lecturer at the 1990 Summer Colloquium at NCAR and at the University of Toulon in France. He also gave unstintingly of his time and energy to professional activities serving on many important international scientific committees, carrying out scientific reviews and serving as member of journal editorial boards of the AMS and the Swedish Geophysical Society. He was Editor for the CMOS journal Atmosphere-Ocean from 1989-1992.

Daley received many honours during his career. From the Canadian Meteorological and Oceanographic Society (CMOS) he received the Prize in Applied Meteorology in 1975 and the President's Prize in 1982. He was elected a Fellow of the Royal Society of Canada in 1993 and a Fellow of the American Meteorological Society (AMS) in 1997. In January 2001, he was awarded the prestigious Jules Charney Medal of the AMS for a lifetime of outstanding scientific achievement.

In 2005, the Canadian Meteorological and Oceanographic Society inaugurated the Roger Daley Post-Doctoral Publication Award in his homour. The prize for exclllence of a publication in the fields of meteorology or oceanography is funded from contributions from his family, friends and CMOS members.

Daley was an avid mountaineer and very interested in the history of polar exploration. He is survived by his wife of 33 years, Lucia; a daughter, Kate Daley of Victoria , B. C.; a son, Charlie Daley of Arcata, California; a brother Andrew Daley of Kelowna, B. C.; two nephews and a niece.

Philip Merilees, Superintendent, Marine Meteorology Division Naval Research Laboratory