OxTalks will soon move to the new Halo platform and will become 'Oxford Events.' There will be a need for an OxTalks freeze. This was previously planned for Friday 14th November – a new date will be shared as soon as it is available (full details will be available on the Staff Gateway).
In the meantime, the OxTalks site will remain active and events will continue to be published.
If staff have any questions about the Oxford Events launch, please contact halo@digital.ox.ac.uk
Intermittency is a core characteristic of precipitation, not well described by data and very poorly modeled. There is a need to properly represent the phenomena and processes responsible for precipitation either explicitly or implicitly (parameterized). Detailed analyses are made of near-global gridded (about 1°) hourly or 3-hourly precipitation rates from two observational datasets (TRMM 3B42v7 3-hourly, and CMORPH (v1.0 CRT) hourly both of which have been revised and bias corrected, and from special runs of the CESM model from January 1998 to December 2013 to obtain hourly values to explore the intermittency of precipitation: the frequency, intensity, duration and amounts, and compare with observed estimates. The latter differ somewhat but both are considerably different from the model, which has too much precipitation overall, and it precipitates far too often at low rates and not enough for intense rates, with the divide about 2 mm/h. A focus is on the duration of events, and a new metric is proposed based upon the ratio of the frequency of precipitation at certain rates (0.1 to 2 mm/h) for hourly vs 3-hourly vs daily amounts. A comparison is made for all products of the conditional probability of precipitation (given previous precipitation) for various thresholds. There is a need to properly represent the phenomena and processes responsible for precipitation either explicitly or implicitly (parameterized).