Roger Daley Atmospheric Science

Principal constructor of the Canadian numerical weather forecasting system

"Don’t worry if you have not made a choice of career. It can come anytime from grade school to graduate school. But for a career in the natural sciences get a good foundation in math."

The Story

It’s 1966. Roger Daley is working at the United States Air Force base in Goose Bay, Labrador, on apprenticeship for the Canadian Weather Service. Daley is lonely, spending a lot of time by himself in his humble room in the barracks. It’s cold and there’s not much to do. The smell of jet fuel is everywhere and the Delta Dagger Interceptors and KC-135 tankers that refuel B-52 bombers in flight roar overhead at all hours of the day and night.

Daley decides to try an experiment. Working alone in his room at night, he makes up little blue cards for all the American pilots to fill out while flying missions in the area. The pilots have to write down things like dates, times, temperatures, altitudes, wind directions, wind velocities and their own general impression of the “bumpiness” of the flight. To Daley, the air is like an ocean of flowing currents and bubbles of different gasses constantly jostling about. It’s a fluid like water, but much thinner.

When the cards start coming in, he spends a lot of time poring over maps spread out on his bed late at night, entering the information from the cards onto the maps to get a picture of this ocean of air around him — the atmosphere. Partly out of curiosity and partly just to have something to do, he takes the information and works out some mathematical formulas that relate the complicated interactions of winds, temperatures, altitudes and other factors that create atmospheric turbulence, the “bumpy” feeling you get in airplanes sometimes.

The pilots are very interested and cooperative because they “live” in this ocean of air, and knowing the patterns of upper-level turbulence along the Labrador coast will help them fly more safely.

They start hanging around Daley’s room and talking about the air in which they fly. He realizes he loves this research and, though he never publishes these results, he decides to go back to university to get a degree in meteorology, the science of weather. But the government of Canada had paid for Daley’s training as a weather forecaster and in return he had to go wherever the government sent him. That’s how he ended up in Goose Bay, and he had to work as a weather forecaster for two years.


Then he attended McGill University in Montreal to get a doctorate (PhD) in meteorology. After that he spent some time in Copenhagen, Denmark, doing more research on the mathematics of wind patterns. From 1972 to 1978 he worked at the Canadian Meteorological Centre in Montreal. While there, he headed a research group that developed mathematical techniques called spectral transforms, using them to create computer programs that could predict the weather for about three days ahead. Launched in 1976, it was the first operational global computer weather-modelling system in the world.

These numerical descriptions of the atmosphere (or variations of them) form the basis of virtually all forecasting and long-term climate simulations in use everywhere in the world to this day, including at the United States Navy’s Fleet Numerical Meteorological and Oceanographic Center (FNMOC) in Monterey, California.


In 1978 Daley took on the job of senior scientist at the U.S. National Center for Atmospheric Research in Boulder, Colorado, perhaps the world’s leading atmospheric research centre. There he worked on numerous outstanding and difficult problems in global weather modelling, using mathematics and computers. In 1985 he went back to Canada to become chief scientist at the Canadian Climate Centre in Downsview, Ontario, where he worked for 10 years. In 1991 he wrote a book on atmospheric data analysis, which is considered by many to be the classic book on atmospheric modelling. Daley’s last project in Canada involved the estimation of atmospheric wind fields based on satellite measurements of minor atmospheric chemical constituents; in other words, he was using information from satellites to track winds in the upper atmosphere.

Throughout his life, Daley was in great demand all over the world and contributed to weather forecasting projects in France, Sweden and China. He was a member of the Intergovernmental Panel on Climate Change (IPCC), the group of scientists who in 1991 issued a cautious warning about global warming as a result of rising carbon dioxide emissions from the use of fossil fuels.

In 1995 Daley accepted a position in Monterey, California, at the Marine Meteorology Division of the U.S. Naval Research Laboratory, to help develop an advanced shipboard forecasting system for United States Navy ships. The system, called the Navy Atmospheric Variational Data Assimilation System, or NAVDAS, became operational at Monterey for testing purposes around 1998, but Daley died of a heart attack in 2001 before he could see it implemented fleetwide.

As A Young Scientist...


Daley’s family moved to Canada while he was young, and he grew up in West Vancouver with the Coast Mountains as his backyard. He climbed and skied and at one point his family lived on a small island just offshore from West Vancouver, so he spent a lot of time by the sea and in the family boat. His best subject in high school was history, but he was always good at mathematics. He never wanted to be a research scientist. He wanted to do something useful that related to “normal” life. In grade 12 he had no intention of studying science.


The Science

Meteorology is the study of Earth’s atmosphere and weather. If you ever listen to a weather forecast, chances are that you are enjoying the results of Roger Daley’s research. Among many other accomplishments, he developed a mathematical technique called spherical harmonic expansion that is now used worldwide in computerized global atmospheric simulation models to predict the weather.

Just as people make small plastic or wooden models of cars or airplanes, meteorologists make models of how the temperature, wind, rain and other things in the atmosphere change over time and space. Instead of plastic and wood, meteorologists use numbers and equations inside a computer to model the real atmosphere. It’s very similar to a car-racing video game. The simulated cars and the feeling of racing them can be very detailed and intense, but it’s not a real car in a real race. In fact, it’s just a bunch of mathematical calculations done by the computer and displayed on a screen. Yet by playing the game a person can get an idea of what it would be like to drive a real race car. In the same way, the atmospheric models used by meteorologists are not real, but they give an idea of what the real atmosphere might be like under certain conditions. Daley’s models are used every day to collect weather data and predict the weather all over the world. Good weather forecasts are essential for agriculture and all forms of transportation, among many other human endeavours.

Daley’s models are also used in studies of global warming — the conjecture that burning coal, oil and gas might generate a large enough increase in carbon dioxide over the next 100 years to cause a greenhouse effect, warming the planet by a few degrees Centigrade. Ice caps would melt and the ocean would rise, drastically changing the world as we know it. Although he served on the IPCC, Daley remained somewhat skeptical about the potential for global warming. He felt there were too many unknown variables and many questions that had not been considered. He was surprised by the amount of public attention the IPCC report generated when it warned about global warming, and he felt it was an overreaction. He was cynical about the many world governments who made a big show of reducing greenhouse emissions while, for economic reasons, they had no intention of ever doing so. He was also critical of the huge number of pseudo-scientists who suddenly became “experts” on global warming after the release of the IPCC report. For this reason, Daley resigned from the IPCC and dissociated himself from global-warming research.

He said, in his very well-educated opinion as the scientist who created global atmospheric modelling: “Our systems cannot predict weather much beyond four days, so attempting to predict global changes 100 years from now seems questionable at best.”


Weather satellite. Click to enlarge.

1. Real Earth Earth’s weather is a very complex system affected by ocean currents, temperature, pressure, wind and many other factors.

2. Weather satellite Several hundred weather and remote sensing satellites currently orbit Earth, detecting many of the factors that create weather. They send this information back to base stations that relay it to weather computers.

3. Supercomputer A supercomputer in a central location records and interprets information from satellites and other sources, updating itself continuously as more and more data come in.

4. Model Earth The weather computer constructs a model of Earth based on very complicated mathematical formulas. This model is updated all the time and is used to generate maps that are sent to weather forecasters. They use these maps to help predict the weather.

The process of combining data in the model with data from real-world observations is called data assimilation, and this was Daley’s specialty. According to his colleagues in Monterey, he was equally productive and comfortable writing low-level computer code components of weather-modelling systems or working out the abstract matrix algebra of data assimilation theory.


Daley hoped future generations would develop a huge computer system that would be able to model all the geophysical systems in the world. (Geophysical systems are the forces and motions that affect Earth’s air, lakes and oceans and even continents through earthquakes and volcanoes.) Among other things, such a system would allow us to accurately predict trends in global warming and the formation of ozone holes, gaps in the upper atmosphere that appear seasonally over the North and South Polar ice caps.

Explore Further

Roger Daley, Atmospheric Data Analysis, Cambridge University Press, 1991.

Daley Memorial web page at the U.S. Naval Research Laboratory.

Environment Canada radar and satellite images:

U.S. National Weather Service. Click on tabs for satellite and radar images

Weather Underground has international weather maps and data.


Career Advice

So You Want to Be a Meteorologist

Daley decided to become a weather forecaster because, he said, “I wanted to do something practical with my education, something that would help people in ordinary life.” The physics of weather seemed more practical to him than nuclear physics, for instance.

Daley liked to remind people, “Scientists don’t say ‘I.’” Science is a group effort. Ideas evolve and are always based on the thinking of those who came before. Every scientist has colleagues, and virtually all scientific papers have multiple authors. When referring to the global forecasting system he worked on, Daley always used to say, “We did this,” or “We implemented that.” Yet in his obituary, one of his colleagues at the U.S. Naval Research Laboratory said, “Having Roger on your science team is like having Michael Jordan on your high school basketball team.”

Daley felt that for a career in the natural sciences one ought to make an extra effort to get a good foundation in mathematics, because mathematics opens many doorways to countless research and job opportunities.


The Person

January 25, 1943
London, England
Date of Death
August 29, 2001
Place of Death
Monterey, CA
Family Members
  • Spouse: Lucia Tudor Daley
  • Mother: Mary Daley
  • Father: Eric Daley
  • Children: Kate, Charlie
Curious, hard-working
Favorite Music
Handel’s Water Music
Other Interests
History, family, travel
University Corporation for Atmospheric Research distinguished visitor
  • BSc (hon.) 1964, UBC in Honours Physics;
  • MSc 1966, McGill, Training as weather forecaster
  • PhD 1971, McGill, Modeling convective clouds
  • Fellow of the Royal Society of Canada (1993),
  • Outstanding Scientist (National Centre for Atmospheric Research, Boulder, Colorado) 1994
Professor Robert Stewart
Last Updated
November 21, 2010

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Using coffee and cream to demonstrate the principles used by meteorologists to track the weather.

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