Capturing the Loop Current by its Ends – Part I: A Volume-Conserving Objective Mapping of the Canek Velocity Database

We present a high-resolution gridded velocity database derived from moored observations in the Yucatan Channel and Florida Straits during 2012–2020 (~8.4 years), monitoring the inflow and outflow boundaries of the Loop Current system in the Gulf of Mexico. These observations provide key insights into the connection between regional circulation and larger-scale processes, including the North Atlantic subtropical gyre and the upper limb of the Atlantic meridional overturning circulation. Velocity fields were constructed using objective mapping with volume conservation, achieved by tuning spatial decorrelation scales to ensure minimal time-mean net transport through the Gulf. Mapping uncertainty reflected changes in array coverage, with the highest values during early deployments lacking deep sampling. Uncertainty decreased substantially following the addition of deep instruments in the second half of the record, especially near the Yucatan sill. The volume-conserving scheme, based on a weighted mean transport, yielded mean (± standard error of the mean) values of 27.6±1.0 and 27.6±0.9 Sv for the Yucatan and Florida sections, respectively. Improved sampling significantly reduced transport uncertainty—particularly in the Yucatan Channel, from ~4.3 to 1.6 Sv. Cross-validation revealed contrasting sensitivities: transport in the Yucatan section was relatively robust to mooring removal, whereas transport in the Florida section was more sensitive to array coverage. Despite limitations in resolving deep flow structure, simulated early campaigns captured most transport variability, supporting viable monitoring strategies with reduced sampling density.