Postponed: Impact of the North Atlantic Atmospheric Variability on the Northern European Sea Level

Speaker: 
Fabio Mangini (Ocean and Sea Ice Remote Sensing)
Seminar Date: 
17. March 2020 - 11:15 - 11:45
Location: 
Lecture room, Ground Floor, NERSC

In this project, we analyze the contribution of the winds to the winter-time sea level variability over the Northern European continental shelf at intra-seasonal timescale. Using daily gridded sea level anomaly from altimetry, we relate anomalously high and anomalously low sea level events to the daily winter-time jet clusters. The jet clusters are persistent and recurrent states of the atmospheric circulation in the North Atlantic. They are four in number and capture different configurations of the eddy-driven jet stream. Following this approach, we find two main results. At first, more than one large-scale atmospheric pattern might cause particularly high and low sea level values on the shelf. Secondly, the atmospheric patterns responsible for anomalously high and for anomalously low sea level events might not be symmetric or, in other words, have the same spatial pattern, but opposite sign. Interestingly, these results do not well agree with the ones we obtain when we apply a composite analysis to the same problem. Notably, at any one location, the composite analysis returns only two atmospheric patterns, one associated with anomalously high and one associated with anomalously low sea level events. Moreover, we find that these two patterns are symmetric. This comparison suggests that the composite analysis approach might not be able to well describe the contribution of the winds to the Northern European sea level variability at the timescales here of interest.