Open AccessImproved predictability of stratospheric sudden warming events in an atmospheric general circulation model with enhanced stratospheric resolution
Author(s) -
Marshall Andrew G.,
Scaife Adam A.
Publication year - 2010
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2009jd012643
Subject(s) - predictability , environmental science , climatology , stratosphere , initialization , atmospheric sciences , climate model , atmospheric model , altitude (triangle) , ozone layer , general circulation model , meteorology , climate change , physics , geology , oceanography , geometry , mathematics , quantum mechanics , computer science , programming language
The impact of stratospheric resolution on the predictability of stratospheric sudden warming (SSW) events and their effect on European climate is cleanly assessed in two versions of the Hadley Center's atmospheric climate model, Hadley Center global environmental model. The standard 38‐level version of the model extends to an altitude of 39 km (∼3 mbar) while the extended 60‐level version has enhanced stratospheric resolution and reaches 84 km altitude (∼0.004 mbar). We show that the L60 model captures SSW events earlier than the L38 model (12 days before an event compared with 8 days) and influences the simulation of European surface winter cold spells at seasonal time scales, highlighting the benefit of high vertical resolution and daily initialization for seasonal forecasting. This is likely due to earlier initialization of the downward‐propagating SSW signal in the higher‐top L60 model. We suggest however that the increased lead time for predicting SSW events is unlikely to be improved much further by raising the model lid above the L60 model domain.