Giovanni Sgubin, Didier Swingedouw, Sybren Drijfhout, Yannick Mary & Amine Bennab (2017), Abrupt cooling over the North Atlantic in modern climate models, NATURE COMMUNICATIONS | 8:14375 | DOI: 10.1038/ncomms14375 |www.nature.com/naturecommunications
Kolstad, E. W. (2017), Higher ocean wind speeds during marine cold air outbreaks. Q.J.R. Meteorol. Soc.. doi:10.1002/qj.3068
Marine cold air outbreaks (MCAOs) are large-scale events in which cold air masses are advected over open ocean. It is well-known that these events are linked to the formation of polar lows and other mesoscale phenomena associated with high wind speeds, and that they therefore in some cases represent a hazard to maritime activities. However, it is still unknown whether MCAOs are generally conducive to higher wind speeds than normal. Here this is investigated by comparing ocean near-surface wind speeds during MCAOs in atmospheric reanalysis products with different horizontal grid spacings, along with two case-studies using a convection-permitting numerical weather prediction model. The study regions are the Labrador Sea and the Greenland–Iceland–Norwegian (GIN) Seas, where MCAOs have been shown to be important for air–sea interaction and deep water formation. One of the main findings is that wind speeds during the strongest MCAO events are higher than normal and higher than wind speeds during less severe events. Limited evidence from the case-studies suggests that reanalyses with grid spacings of more than 50 km underestimate winds driven by the large ocean–atmosphere energy fluxes during MCAOs. The peak times of MCAOs usually occur when baroclinic waves pass over the regions. Therefore, the strong wind episodes during MCAOs generally last for just a few days. However, MCAOs as defined here can persist for 50 days or more....
Årthun, M. et al. Skillful prediction of northern climate provided by the ocean. Nat. Commun. 8, 15875 doi: 10.1038/ncomms15875 (2017).
It is commonly understood that a potential for skillful climate prediction resides in the ocean. It nevertheless remains unresolved to what extent variable ocean heat is imprinted on the atmosphere to realize its predictive potential over land. Here we assess from observations whether anomalous heat in the Gulf Stream's northern extension provides predictability of northwestern European and Arctic climate. We show that variations in ocean temperature in the high latitude North Atlantic and Nordic Seas are reflected in the climate of northwestern Europe and in winter Arctic sea ice extent. Statistical regression models show that a significant part of northern climate variability thus can be skillfully predicted up to a decade in advance based on the state of the ocean. Particularly, we predict that Norwegian air temperature will decrease over the coming years, although staying above the long-term (1981–2010) average. Winter Arctic sea ice extent will remain low but with a general increase towards 2020....
(Paper) On model differences and skill in predicting sea surface temperature in the Nordic and Barents Seas
Langehaug, H.R., Matei, D., Eldevik, T. et al. Clim Dyn (2017) 48: 913. doi:10.1007/s00382-016-3118-3
The Nordic Seas and the Barents Sea is the Atlantic Ocean’s gateway to the Arctic Ocean, and the Gulf Stream’s northern extension brings large amounts of heat into this region and modulates climate in northwestern Europe. We have investigated the predictive skill of initialized hindcast simulations performed with three state-of-the-art climate prediction models within the CMIP5-framework, focusing on sea surface temperature (SST) in the Nordic Seas and Barents Sea, but also on sea ice extent, and the subpolar North Atlantic upstream. The hindcasts are compared with observation-based SST for the period 1961–2010. All models have significant predictive skill in specific regions at certain lead times. However, among the three models there is little consistency concerning which regions that display predictive skill and at what lead times. For instance, in the eastern Nordic Seas, only one model has significant skill in predicting observed SST variability at longer lead times (7–10 years). This region is of particular promise in terms of predictability, as observed thermohaline anomalies progress from the subpolar North Atlantic to the Fram Strait within the time frame of a couple of years. In the same model, predictive skill appears to move northward along a similar route as forecast time progresses. We attribute this to the northward advection of SST anomalies, contributing to skill at longer lead times in the eastern Nordic Seas. The skill at these lead times in particular beats that of persistence forecast, again indicating the potential role of ocean circulation as a source for skill. Furthermore, we discuss possible explanations for the difference in skill among models, such as different model resolutions, initialization techniques, and model climatologies and variance....
Suo, L., Gao, Y., Guo, D., and Bethke, I. Sea-ice free Arctic contributes to the projected warming minimum in North Atlantic. Environ Res Lett (at press).
Projected global warming is not spatially uniform and one of the minima in warming occurs in the North Atlantic (NA). Several models from the Coupled Model Intercomparison Project Phase 5 even projected a slight NA cooling in 2081-2100 relative to 1986-2005. Here we show that, by our simulations performed with Bergen Climate Model (BCM), an autumn (September to November) sea-ice free Arctic (SIF) contributes to the NA warming minimum by weakening the Atlantic meridional overturning circulation (AMOC). The role of the air-sea interaction in the response to the SIF, which has not been widely discussed in the literature, has been highlighted by the results presented in this study....
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Author/Participant: Daniela Matei (MPI)
Topic: Presentation of Blue-Action
Disseminated materials: Presentation
Date and Location: APPLICATE project Kickoff, 8-9 February 2017, Bremerhaven (DE)
Audience: Scientific community, Higher education, other EU projects
Talk regarding WP2 activities
23-24 May 2017 Evaluating climate and Earth system models at the process level, Brussels
Clustering workshop for the EU Horizon 2020 projects APPLICATE, Blue-Action, PRIMAVERA and CRESCENDO
European Commission, Attilio Gambardella
The Workshop was organized in two parts:
- First, a session to showcase projects and initiatives taking place in Canada, Europe, the
United States, which are relevant to the development of an integrated Arctic observing
Author/Participant: Joan Ballester (ISGlobal)
Topic: Forecast scheme of temperature-related mortality for decision-making in European regions and cities
Disseminated materials: Poster
Date and Location: Fifth International Conference on Climate Services 28 February – 2 March 2017 | Cape Town, South Africa http://www.climate-services.org/iccs/iccs5/conference-programme/
Vilena Valeeva, International Conference on Arctic Science: Bringing Knowledge to Action, Reston, Virginia (USA), 24-27 April 2017
Author/participant Representative Blue-Action: Vilena Valeeva (IASS)
Organisers: Arctic Monitoring and Assessment Programme (AMAP), whose work is conducted according to a mandate determined by the Arctic Council Ministers and Senior Arctic Officials & EU-PolarNet http://www.amap.no/about
Author: Raeanne Miller/SRSL)
Due by 1 March 2017- Uploaded 1 March 2017
Authors: Chiara Bearzotti/DMI & Euan Paterson/SAMS)
Due by January 2017- Closed on 14 February 2017
Due by January 2017 - Uploaded 23 February 2017
Description of tasks and duties of the project office at the coordinating institution (DMI)
Author: Chiara Bearzotti/DMI
Due by February 2017, Uploaded 16 March 2017
Author: Chiara Bearzotti (DMI)
Due by 1 March 2017, Uploaded 3 March 2017
Authors: Christine Valentin, Julia Tasse/WOC & Chiara Bearzotti/DMI
Due by December 2016 - Uploeaded 17 March 2017
Author: Raeanne Miller (SRSL)
Due by June 2017, uploaded on 15 June 2017
Author: Thomas Dale (CKIC) and many others contribubtors
Due by June 2017, uploaded on 15 June 2017
About this document
Work package in charge: WP7 Management
Lead author: Danish Meteorological Institute: Chiara Bearzotti
Reviewer: Alfred-Wegener-Institut: Luisa Cristini