Can Seismic Stations be Used to Better Understand Variations in Storm Patterns in the North Atlantic?

Nonlinear interaction of ocean waves during pelagic storms excites secondary microseisms with periodicity from 4-10 s [Longuet-Higgins, 1950]. Due to favorable atmospheric-oceanic conditions that generate strong opposing winds and interacting ocean waves of significant wave height at the appropriate acoustic resonating depth, the region SE of Greenland has been recognized as the major source of secondary microseisms in northern hemisphere [e.g. Kedar et al., 2008]. This study investigates how variations in energy of secondary microseisms (ESM) recorded at station SFJD in southern Greenland compare to variations in significant wave height (SWH) and wind speed SE of Greenland using records from October 1997 until December 2016. We find high correlation between EMS and average SWH as well as wind speed over the area of interest, with correlation coefficients of 0.84 and 0.65, respectively. In addition, the variations in ESM greatly overlap with fluctuations in North Atlantic Oscillation (NAO) over the past two decades. The positive NAO phase overlaps with increased ESM, with maximum values in both NAO and ESM during winter 2014/2015. High ESM during positive NAO phase reflects more intense storms SE of Greenland. Similarly, decreases of microseismic energy correspond to years with negative NAO phase, with minimum values during 2010. Our result suggests that seismic stations can improve long-term monitoring of different climate indices and augment satellite and in-situ measurements, which suffer from limited spatial and temporal resolution.