Driving upwelling by heating the lower stratosphere

Add to your list(s) Download to your calendar using vCal

• Alison Ming (DAMTP)
• Friday 12 May 2017, 16:00-17:00
• MR2, Centre for Mathematical Sciences, Wilberforce Road, Cambridge.

If you have a question about this talk, please contact Doris Allen.

A feature of the time averaged tropical lower stratospheric upwelling is the double peak structures centred near 70 hPa and 20° N-S which have previously been noted in observational datasets. However, the corresponding structures in diabatic heating rates are not related to local temperature anomalies as would be the case if they were relaxational in nature. We will first demonstrate that the enhanced diabatic heating near the centre of these peaks relative to the Equator arises predominantly from the meridional structure in ozone concentrations. We then suggest that the primary cause of the peaks in upwelling is the externally imposed part of the radiative heating field which is able to change the wave field. This motivates the second part of this study in which a scaling argument shows that an externally imposed zonally symmetric heating can indeed drive steady-state upwelling provided that the wave force (required to satisfy angular momentum constraints) is sufficiently sensitive to changes in the mean flow. The applicability of this regime to the observed double peak structure is confirmed by experiments in a dry dynamical circulation model. Similar arguments are then be applied to problem of the recently identified compensation between the driving of the Brewer-Dobson circulation by resolved and parameterized waves.

This talk is part of the Fluid Mechanics (DAMTP) series.

This talk is included in these lists:

• All CMS events
• All Talks (aka the CURE list)
• CMS Events
• CamBridgeSens
• Cambridge talks
• Combined External Astrophysics Talks DAMTP
• Cosmology, Astrophysics and General Relativity
• DAMTP Fluids Talks
• DAMTP info aggregator
• Fluid Mechanics (DAMTP)
• Interested Talks
• Life Science Interface Seminars
• MR2, Centre for Mathematical Sciences, Wilberforce Road, Cambridge
• SJC Regular Seminars
• School of Physical Sciences
• Talks related to atmosphere and ocean dynamics and climate science
• Trust & Technology Initiative - interesting events
• bld31

Note that ex-directory lists are not shown.