  Atmospheric transient eddies and low-frequency flow contribution to the ocean
surface wave climate in the North Atlantic during boreal winter is investigated
(1980 - 2016). We conduct a set of numerical simulations with a
state-of-the-art spectral wave model Wavewatch III forced by decomposed wind
fields derived from the ERA-Interim reanalysis (0.7{\deg} horizontal
resolution). Synoptic-scale processes (2-10 day bandpassed winds) are found to
have the largest impact on the formation of wind waves in the western
mid-latitude North Atlantic along the North American and western Greenland
coasts. The eastern North Atlantic is found to be influenced by the combination
of low-frequency forcing (>10 day bandpassed winds) contributing up to 60% and
synoptic processes contributing up to 30% to mean wave heights. Mid-latitude
storm track variability is found to have a direct relationship with wave height
variability on the eastern and western margins of the North Atlantic in
particular implying an association between cyclone formation over the North
American Eastern Seaboard and wave heights anomalies in the eastern North
Atlantic. A shift in wave height regimes defined using an EOF analysis is
reflected in the occurrence anomalies in their distribution. Results highlight
the dominant role of transient eddies on the ocean surface wave climatology in
the mid-latitude eastern North Atlantic both locally and through association
with cyclone formation in the western part of the basin. These conclusions are
presented and discussed particularly within the context of long-term
storm-track shifts projected as a possible response to climate warming over the
coming century.
