Pressure Gauges and Satellite Altimetry Ensure the Continuity of Florida Current Transport Observations

Abstract

The Florida Current (FC), the initial segment of the Gulf Stream, is a key component of both the meridional overturning and horizontal gyre circulations in the subtropical North Atlantic. The four-decade-long record of the FC volume transport derived from submarine cable measurements constitutes the longest quasi-continuous climate record of any boundary current. Unfortunately, data collection ceased in November 2023 due to a mechanical failure of the cable. While efforts are underway to restore the cable system, alternative methods for estimating the FC transport are urgently needed. Here, we combine data from a pair of pressure gauges deployed on either side of the FC at 27°N with satellite altimetry to extend daily transport estimates and fill gaps in the cable record. We demonstrate that transport estimates based on cross-stream pressure differences represent a suitable interim substitute for cable-based measurements, although they are limited by the vertical incoherence of the flow.