In mid March the BCCR celebrated the 150 aniversary of Vilhelm Bjerknes. In this context Professor Sir Brian Hoskins held his guest lecture “The fingerprints of Vilhelm Bjerknes on modern climate science”.
In his excellent overview of climate science, one of Hoskins' key points was that Vilhelm Bjerknes' circulation teorem can become more central in future climate research. Hoskins emphasised the need to evaluate the structures of phenomena such as blocking patterns in the atmosphere in order to improve predictive skill. He indicated that Bjerknes' circulation concept could be a central tool in this connection.
”Thermodynamics has dominated climate science over fluid mechanics. In my opinion we should emphasize both fluid mechanics as well as thermodynamics”, Sir Brian Hoskins said.
Eystein Jansen, sir Brian Hoskins og Nils Gunnar Kvamstø. Photo: Gudrun Sylte
Eystein Jansen paid particular attention to how Hoskins removed the divide between weather forecasting and climate research.
"Hoskins claimed that in the future one will have a more seamless transition between alerts on shorter time scales such as days and weeks, to seasonal and climate warning notices that are several decades into the future. This applies in particular to climate forecasts in smaller regions where it is important to understand the systematics and the structure of weather phenomena to understand how climate change will play out in the future". Jansen says.
Nils Gunnar Kvamstø, Head of the Geophysical Institute, focused on how Hoskins emphasized the importance of improving the climate models.
”This work should be organised in such a way that it to a larger extent than in the past integrates process knowledge. He clearly illustrated though that there is much valuable information in the climate models although they have systematic errors.” Nils Gunnar Kvamstø says.
In conclusion, Sir Brian Hoskins summarized what we can learn from Vilhelm Bjerknes:
Vilhelm Bjerknes qualities & gifts to our science, according to sir Brian Hoskins
• Need to use both hydrodynamic and thermodynamic equations
- the circulation theorem
- complete set of equations, leading to possibility of prognosis
• Need for diagnosis of initial state
• Need to seek structure that may help diagnosis and prognosis.
• vision for weather and seasonal forecasting (need to predict ocean)
• Appreciation of societal driver for weather & climate prediction
• Ability to convince funders
• Selection, simulation and oganisation of excellent youg scientists
• Optimism & determination!