Just after I have attended a conference on seasonal and decadal prediction at NCAR in Boulder/Colorado, my next stop was at the PALSEA and QUIGS meeting in Galloway/New Jersey. It was the third time that I attended a PALSEA and as the other two times it was a great opportunity for me. The main topic of the conference was the sea-level and climate change during the last and other interglacials.
Many talks surrounded the available data and their interpretation. In this context it is a very complex task to bring together on the one side the many different proxies and evidences of sea-level height during that period and on the other side to explain their causes by the changes of ice-sheets in the higher latitudes and the reaction on them by the Earth. As a consequence there were many interesting discussions surrounding this field and many different viewpoints were heard. Specific questions around when the last interglacial exactly started, how high the sea-level was during that period and how the exact evolution of sea-level happened during that time were often discussed during this week. Most discussions were evidence driven, trying to make sense of the sometimes contradicting results and their uncertainties.
Also the understanding of the consequences of these results played an important role, as sea-level change is not happening isolated. It requires the build up or melting of ice shoot and with it a change in climate. In a climate system, as we know from looking around us today, that is highly connected all the climate sub-components, especially atmosphere, cryosphere and ocean have to tell the same story.
Myself have presented a poster on the last interglacial sea-level evolution and had several interesting discussions on this topic. Also the field trip, which showed us the study fields of salt marches, which are used to investigate Holocene sea-level change at the East American coast was very informative. Seeing the data collection first hand always helps to understand the topic better and getting better results at the computer in your own office. All in all it was a great opportunity for me, which was made possible by the financial contribution by the organisers, which allowed me to attend.
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.