H2020Индивидуална стипендия2021–2023

DivPredSkill · Climate model diversity in the North Atlantic and its impact on prediction skill on interannual-to-decadal timescales

„Хоризонт 2020“ — Действия „Мария Склодовска-Кюри“

Период: 2021-07-19 → 2023-07-18
Финансиране от ЕС: 212 934 €
Участници: 1
Схема: MSCA-IF

Линиите свързват координатора с партньорите.

Накратко на български

Взаимодействието между океанските течения (AMOC) и атмосферното налягане (NAO) в Северния атлантик се анализира чрез сравнение на различни климатични модели. Това помага за по-доброто разбиране на температурните промени и валежите в Европа, което е важно за земеделието и икономиката.

Този кратък обзор е генериран от изкуствен интелект

Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.

Резултати накратко

Climate model diversity in the North Atlantic and its impact on prediction skill on interannual-to-decadal timescales

The Atlantic Meridional Overturning Circulation (AMOC) is an important component of the climate system. It transports heat from the equatorial Atlantic to the higher latitudes of the North Atlantic, which contributes to the mild winters in Europe. Another component relevant for the weather and climate in Europe is the North Atlantic Oscillation (NAO). The NAO describes atmospheric pressure differences over the Atlantic which affect temperature and precipitation over Europe, especially in winter. Thus, understanding the interaction of the AMOC and the NAO is of interest for the political, economic, and agricultural sectors. One problem though is that observational records for the AMOC are too short in time to learn more about its interaction with the NAO. Therefore, climate models have to be used to study this topic. Still, climate models are subject to uncertainties and systematic errors. In this project, we focus on the differences across a large number of climate models. We compare them in terms of their AMOC and NAO variability and interaction, to learn more about the effect of model uncertainties. We conclude that the AMOC-NAO interaction of a model is very sensitive to its tendency to be, on average, rather warm and salty or cold and fresh in the subpolar region of the North Atlantic. Models that fall into the warm-salty category, show a stronger and longer-lasting response of the AMOC to the NAO compared to the cold-fresh models. This is linked to the models' sea ice cover and the stability of the water column in the Labrador Sea. Furthermore, it was found that the potential to make skillful decadal climate predictions, is higher for the models categorised as cold-fresh. These results stress that climate model behaviour is very diverse suggesting that research findings related to North Atlantic climate should not rely only on a single model result or the multi-model mean. Moreover, this project's results identify key elements in the models that lead to uncertainty in the North Atlantic climate variability, which is highly valuable for future model improvement enabling also better climate predictions.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз

Цел на проекта

Europe is vulnerable to climate extremes and climate change, making predictions valuable to political and economic stakeholders. The European winter climate depends a lot on sea level pressure differences between Iceland and the Azores, described by the North Atlantic Oscillation (NAO). Thus, many modelling centres working on predictions, focus on improving NAO predictions. Recent studies find the NAO could be highly predictable, much higher than suggested by individual models - calling for a better process understanding to improve models and predictions. The major source of our ability to make predictions for years and beyond are slow ocean processes, e.g. linked to the Atlantic Meridional Overturning Circulation (AMOC). Both, AMOC and NAO are considered key for North Atlantic decadal variability and predictability. They interact, especially via the NAO driving AMOC, but also vice versa. Consequently, prediction skill is reduced by uncertainties in the NAO-AMOC relationship, but also by severe mean state biases common among models. As of yet, not much effort has been made to understand skill difference across models - motivating the proposed research: The overarching research objective is to understand the causes for inter-model differences in interannual-to-decadal prediction skill - with a focus on the role of the model-dependent NAO-AMOC relationship and mean state biases. Specific objectives are to: (i) identify model differences in the NAO-AMOC interaction and their effect on differences of the potential to predict the North Atlantic; (ii) assess the role of mean state biases for model differences; (iii) link these findings with North Atlantic forecast skill. The proposed research comprises: the novel idea to relate predictability to model biases via NAO-AMOC interaction; and the innovative approach to link findings from long, uninitialised simulations to initialised predictions, enabling new insights valuable to the climate modelling and prediction community.

Оригинален текст от CORDIS (на английски).

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