Remote and Local Forcing in the Brazil–Malvinas Region

Abstract

Abstract Origins of the seasonal variability observed in current meter data from the Malvinas (Falkland) Current are sought in the wind field on both a regional and circumpolar scale. A singular value decomposition of the covariance of the fields makes it possible to distinguish between a local and a remote source of variability. The local mode is the result of changes in the wind stress curl around 40°S causing an annual modulation transverse to the mean path of the current, and thus contributes little to the variability in transport. It seems likely that the wind stress curl drives the annual excursions of the Brazil–Malvinas Front and forces the retroflection of the Malvinas Current. The remote mode features increased transport trailing negative wind stress curl anomalies at Drake Passage with a lag of 20–30 days. Repeating this analysis with the winds on a circumpolar domain suggests that this might be the regional manifestation of a more global feature, associating globally negative wind stress curl ...