BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20250828T171808EDT-15160pi14h@132.216.98.100 DTSTAMP:20250828T211808Z DESCRIPTION:Atmospheric and Oceanic Sciences Departmental Seminar Series\n \npresents\n\nWeather\, Macroweather\, Climate: reuniting Richardson's str ands\n\na talk by\n\nShaun Lovejoy\n Professor\, \n Department of Physics\, \n şÚÁĎÉç\n\nA hundred years ago\, Lewis Fry Richardson made the first numerical weather forecast\, founding the field of numerical weathe r prediction (NWP). Based on deterministic continuum mechanics\, today it is not only ubiquitous in daily weather forecasts\, but has been extended to seasonal predictions through to multidecadal climate projections\n\nBut Richardson also pioneered the development of high level turbulent laws. I n 1926 he proposed the “Richardson 4/3 law” of turbulent diffusion\, a law that wasn’t vindicated until 2013. Whereas NWP attempts to account for ev ery whirl\, cloud\, eddy\, structure\, the 4/3 law exploits the idea of sc aling to statistically account for the collective outcome of billions upon billions of structures jointly acting from millimetres up to the size of the planet.\n\nThe idea that high-level statistical laws could explain the actions of myriads of vortices\, cells and structures was shared by succe ssive generations of turbulence scientists. Unfortunately\, they faced mon umental mathematical difficulties largely connected to turbulent intermitt ency: the fact that most of the activity (e.g. energy flux) is inside tiny \, violently active regions\, themselves buried in a hierarchy of structur es within structures. The application of turbulence theory to the atmosphe re\, encounters an additional obstacle: stratification that depends on sca le.\n\nThe 1980’s marked a turning point when Richardson’s deterministic a nd statistical strands parted company\, the unity of the atmospheric scien ces was broken. On the one hand\, computers revolutionized NWP\, on the ot her hand\, the nonlinear revolution promised to tame chaos itself\, includ ing turbulent chaos with its fractal structures within structures.\n\nIn t his talk\, I summarize four decades of work attempting to understand atmos pheric variability that occurs over an astonishing range of scales: from m illimetres to the size of the planet\, from milliseconds to billions of ye ars. The variability is so large that standard ways of dealing with it are utterly inadequate: in 2015\, it was found that classical approaches had underestimated the variability by the astronomical factor of a quadrillion . The new understanding allows us to finally reunite Richardson’s strands. \n\nFor example\, I show that the deterministic weather models respect the stochastic scaling laws very well. I explain “macroweather” and how it si ts in between the weather and climate\, finally settling the question: “Wh at is Climate”? I answer the question “how big is a cloud?” and show that Mars is our statistical twin and why this shouldn’t surprise us. I explain how the multifractal butterfly effect gives rise to events that are so ex treme that they have been called “black swans”.\n\nBy using data from the real world – not model – climate\, and with the help of the Fractional Ene rgy Balance Equation (FEBE)\, I explain how the emergent scaling laws can make accurate monthly to decadal (macroweather) forecasts by exploiting an unsuspected but huge memory in the atmosphere-ocean system itself. I show how the FEBE can help to significantly reduce the large uncertainties in our current climate projections to 2050 and 2100.\n\nMonday Dec 02/ 3:30 P M/ Burnside Hall/ Room 934\n DTSTART:20191202T203000Z DTEND:20191202T220000Z LOCATION:Room 934 SUMMARY:Weather\, Macroweather\, Climate: reuniting Richardson's strands URL:/meteo/channels/event/weather-macroweather-climate -reuniting-richardsons-strands-302737 END:VEVENT END:VCALENDAR