To cite this article: Ronan Connolly, Michael Connolly & Willie Soon (2017) Re-calibration of Arctic sea ice extent data sets using Arctic surface air temperature records, Hydrological Sciences Journal, 62:8, 1317-1340

[[ ABSTRACT : A new seasonal and annual dataset describing Arctic sea ice extents for 1901–2015 was constructed by individually re-calibrating sea ice data sources from the three Arctic regions (NorthAmerican, Nordic and Siberian) using the corresponding surface air temperature trends for the pre-satellite era (1901–1978), so that the strong relationship between seasonal sea ice extent and surface air temperature observed for the satellite era (1979-present) also applies to the pre-satellite era. According to this new dataset, the recent period of Arctic sea ice retreat since the1970s followed a period of sea ice growth after the mid-1940s, which in turn followed a period of sea ice retreat after the 1910s. Arctic sea ice is a key component of the Arctic hydrological cycle, through both its freshwater storage role and its influence on oceanic and atmospheric circulation. Therefore, these new insights have significance for our understanding of Arctic hydrology. ]]

Qui mène à leur chapitre 6 ‘Conclusions’ :
[[ This late-1970s reversal in sea ice trends was not captured by the hindcasts of the recent CMIP5 climate models used for the latest IPCC reports, which suggests that current climate models are still quite poor at modelling past sea ice trends. Nor is it described in previous Arctic sea ice reconstructions such as the Walsh datasetor the widely used HadISST sea ice dataset, although some recent studies have noted similar reversals, e.g.Pirón and Pasalodos (2016) and Alekseevet al.(2016). As we saw from Figure 1, and Tables 1and2, Arctic sea ice is a key component of the Arctic hydrological cycle. So, this new dataset should be of use for improving our understanding of Arctic hydrology. ]]

Reste donc de la place pour expliciter plus rigoureusement la complexité des phénomènes… dont les médias ne pointent que les derniers temps !

L’actualisation des données du DMI pour mai 2021 est enfin apparue.

Non pas de différence, hormis dans la présentation des données. Les deux sites donnent la même pente de décroissance de l’extension à savoir 2,7%/décennie pour le mois de mai. En reprenant NSIDC on voit donc que l’extension poursuit un léger accroissement par rapport aux années précédentes (2018, 2019 et 2020) pour atteindre une valeur quasi-équivalente (même un peu supérieure) à celle de 2017. En l’absence de données actualisées de DMI nous mettrons celles du NSDIC suite à votre remarque.