The fourth day of the IMSC 2019 was the day when the heat wave finally hit Toulouse with full force. Around 40 deg C was what the temperature measurements told us and it felt a bit overwhelming. The morning started again with plenary sessions and talks about uncertainty separation and down-scaling. Afterwards followed the poster session in a tent outside, and it got warmer and warmer over time as the wind was not as strong as in the last days.
After lunch the parallel sessions for the day started and I chose the one on forecast evaluation. The first part was reserved for the development of new verification procedures and I had my own talk in this section. It went alright, I presented two new skill scores basing on the EMD and demonstrated it at different seasonal prediction applications. The second half of the session was on the application of verification procedures and showed many different fields.
With the end of the talks it was time for the social events. The choice was either a wine tasting on a ship or a walking tour through town. I chose the latter one and it was a challenge to always find shade to get not too warm in the sunshine. Tomorrow will be the last day and the weather will still be warm enough to be a challenge.
A new year has started and in the recent month three new papers have been published, which have my name in the author list. In all three cases my contributions were more in the sense of statistical assistance, so I will just briefly introduce the topics.
Skilful Seasonal Prediction of Ocean Surface Waves in the Atlantic Ocean
This paper predicts ocean surface waves on the seasonal scale. It uses enhanced prediction of the NAO with the sub-sampling algorithm to generate prediction skill for wave height in the North Atlantic. As the prediction enhances not only wind waves, but also the swell it is a consistent prediction enhancement for the total wave height.
Dobrynin, M.; Kleine, T.; Düsterhus, A.; Baehr, J: Skilful Seasonal Prediction of Ocean Surface Waves in the Atlantic Ocean, GRL, 46, 1731–1739
Seasonal predictability of European summer climate re-assessed
The second paper investigates the predictability of European summer climate by a physics-based sub-sampling. It uses for this a connection from tropical Atlantic SST anomalies over a wave train in the upper troposphere to the second mode of North Atlantic surface pressure. Unlike European winter’s, the second mode is as important as the first mode for European summer climate. As a consequence the predictability of surface temperature and other atmospheric variables over Europe are enhanced.
Neddermann, N.-C.; Müller, W. A.; Dobrynin, M.; Düsterhus, A.; Baehr, J. (2019): Seasonal predictability of European summer climate re-assessed, Climate Dynamics
Atlantic Inflow to the North Sea Modulated by the Subpolar Gyre in a Historical Simulation With MPI‐ESM
This study uses a global model to show that the strength of the subpolar gyre (SPG) has a profound influence on North Sea water properties. Up to now regional models showed that most of the modulation happens due to Atmospheric influence. The modulations by the SPG happen on a decadal scale and can be followed on their way from the Atlantic to the North Sea.
Koul V.; Schrum, C.; Düsterhus, A.; Baehr, J.: Atlantic Inflow to the North Sea Modulated by the Subpolar Gyre in a Historical Simulation With MPI‐ESM, JGR Oceans
Last week NCAR in Boulder (Colorado) hosted the second edition of the International Conference on Subseasonal to Decadal prediction. It covered the climate prediction from a few weeks up to a few years and hosted with around 350 scientists a good representation of the community in this field. During most of the days the conferences was split into a subseasonal to seasonal (S2S) and a seasonal to decadal (S2D) session.
The International Conference on S2S2D poster
I personally visited only the S2D part, as my current work focuses on this topic. The first day looked into the mechanisms of predictability and the typical candidates, like ocean, soil moisture and stratosphere, were discussed. The second day shifted then more to the modelling of these phenomena. The weather services presented their new prediction systems and new approaches to modelling were discussed. As a third topic covered the handling of the predictions. It looked at calibration and other technique to make the prediction really useful. This lead to the fourth topic, which discussed the decision-making process basing on the prediction. Here, the applications were the main focus points and many different phenomena and their predictability were shown. Topic number five looked at the statistical verification. It presented new approaches to access the skill of the models. The final session of the S2D session looked at the frontiers of earth system prediction and therein especially at the handling of carbon within the models. Afterwards in a combined session of both parts many different aspects on the future of research in this field were brought up. Among others the topics of temporal dependence of forecast skill and the so-called ‘signal to noise paradox’ lead to a lively discussion.
My personal contributions were threefold. I showed on a poster in the first session how the Summer NAO can be predicted using ensemble sub-sampling. In the second session I presented a poster on the view that sub-sampling can be viewed as a post processing procedure and can so explain why it works. The talk in the fifth session then covered the 2D categorical EMD score.
All in all it was a great conference, with many interesting discussions and a great overview over this interesting field. Certainly many impulses will come from this and will give not only my own research a new push.
Last week I attended the European Climate Observations, Modelling and Services (ECOMS) at the MetOffice in Exeter. The conference itself lasted three days and for me personally it was the first time to pay Exeter a visit. The event was the last meeting for three EU projects, which in the days before had meetings on their own. All three projects are involved around seasonal and decadal climate predictions and cover different aspects of it. The projects were NACLIM, concentrating on the physical mechanisms and observations, SPECS, focussing on the modelling, and EUPORIAS, looking for the establishing of climate services. As such the topics and the background of the attending scientists were quite diverse, leading to interesting talks and conversations.
MetOffice in Exeter