BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Talks.cam//talks.cam.ac.uk// X-WR-CALNAME:Talks.cam BEGIN:VEVENT SUMMARY:Using Arctic ice mass balance buoys for model evaluation - Alex We st (Met Office) DTSTART:20170915T152000Z DTEND:20170915T154000Z UID:TALK79491@talks.cam.ac.uk CONTACT:INI IT DESCRIPTION:Since 1993 the Arctic Ocean has seen the deployment of over 10 0 ice mass balance buoys (IMBs)\, devices which measure elevation of the s ea ice surface and base\, as well as internal ice temperatures at a vertic al resolution of 10cm. \; Here the thermodynamic data provided by the IMBs is used to evaluate the sea ice simulation of the CMIP5 model HadGEM2 -ES\, which simulates anomalously high summer melting and winter freezing in the recent historical period. \; Monthly mean fluxes of topmelt\, s nowfall\, conduction\, basal growth and ocean-to-ice heat are calculated f or the entire IMB network\, giving a distribution of around 500 data point s for each variable. Model evaluation is concentrated in two regions of th e Arctic that are particularly densely sampled by the IMBs\, the North Pol e and the Beaufort Sea. Distributions of modelled and observed fluxes in t hese regions are compared\, and severe biases in June top melting fluxes a nd winter conductive fluxes are identified which are too large to be attri buted to sampling biases in the IMBs. \; Consistent with previously id entified biases in the Arctic climate simulation of HadGEM2-ES\, the resul ts allow detailed attribution of the sea ice simulation biases to particul ar drivers in the atmosphere and sea ice. LOCATION:Seminar Room 1\, Newton Institute END:VEVENT END:VCALENDAR