In response, Bruce told the guests that he was 'very proud to have been honoured with this award . . . for the majority of my career, I have been a measurement scientist, a so-called metrologist, within the atmospheric science community. Sometimes, in the darker moments of my working life, I have felt that as a metrologist, working in a meteorologist's domain, something was missing apart from the letters 'e' and 'o' in the career discipline label. But I have always returned to the light of day and the joy of trying to assist in making better instruments and better measurements for a better climate record.

Better instruments and observations are a priceless investment.

A better climate record is the first and fundamental step for a better future for us all. I have always enjoyed the chase in trying to improve measurements by using the fundamental forms of physics

A flight of serendipity

As serendipity would have it, in early 1994 I was returning on a Qantas red-eye special from LA to Melbourne when I came up with the idea for the calibration. I had a spare blank A4 book for notes and observations, and I went to christen it. In my high school years at a Catholic Marist school in Adelaide, one used to write religiously in red 'JMJ', for Jesus, Mary and Joseph, on the top of each new page. That faded after high school, but from the time of my initial study during my Ph.D. at Flinders Uni, I always christened a new research workbook on the first page with the basic global irradiance equation. This time, exhausted, having recently been robbed, and after one or two glasses of Australian wine, I made a mistake writing the equation—so I wrote it again underneath. And as I looked down on the beautiful symmetry and simplicity of the two equations, the idea of the alternate calibration method stared out. While not in the league of Archimedes, the thrill of discovery was there. For my own record I noted in the book that I didn't shout 'Eureka' but whispered an unprintable invective. I then asked for another glass of wine!'

(Two pyranometers are usually placed side by side—one measuring global irradiance (direct and indirect sunlight), the other diffuse irradiance (reflected or indirect sunlight). Bruce's leap of inspiration, triggered by the juxtaposition of the two near-identical equations, recognised that if the pyranometers were swapped during the weeks of observing the only unknowns are their calibration factors; 'high school arithmetic' provided a calibration.

Before Bruce's 'alternate method', pyranometers were lucky to be returned to Head Office for calibration every two or three years. Now all routine measurements in clear sun can be used, and calibrations are done on the spot.)

Bureau of Meteorology