Matthias Zahn, University of Reading, ESSC

Estimation of past and future polar low frequency over the North Atlantic 

Polar lows are maritime small scale storms beyond the size properly resolved by global reanalysis and global model data.  In my talk I will show that by means of dynamical downscaling it is possible to simulate these storms with as regional climate model (RCM).  These results are used to develop an automated detection procedure for polar lows, which then is applied to the output fields of longterm RCM simulations driven by NCEP reanalysis data on the one hand side and to global data of IPCC future projections on the other.  While there could not be found any systematic changes of polar low frequency for the past, a significant decrease was found associated to projected atmospheric warming.   

The results constitute my PhD work plus some additional work and have recently been published in series of papers.   


http://www.nerc-essc.ac.uk/~maz/