by Feili Li
It seems to be a quiet year for OSNAP – just one OSNAP cruise took place last summer and so most of the moorings have stayed in the water for a year and a half. But OSNAP scientists have been working intensively on analyzing the first two years of data and we have started to obtain some very interesting results based on measurements from individual arrays. Some of those results were presented and discussed at a workshop held in Southampton, UK in early November (blog post). Much more is coming and will be presented at the Ocean Sciences Meeting 2018 in Portland, OR. Please stay tuned as we will soon publish a dedicated blog post with a list of all OSNAP-related presentations at OSM 2018.
In addition to analyses by individual groups, all OSNAP scientists have been working closely on the first data products from the full array. We are now in the process analyzing preliminary results and finalizing the flux estimates. Final products are expected to be delivered in spring of 2018. These final products include the overturning volume and associated heat and freshwater transport time series along with the cross-sections of velocity, temperature, and salinity (Figure 1 below shows the mean velocity and property fields at OSNAP). It is always worth mentioning that OSNAP is not an isolated program as our results are based on many existing observational efforts in the region (e.g., Argo, AVISO) and the results will be analyzed in coordination with ongoing programs (e.g., OVIDE, RAPID).
During the first two years of the OSNAP deployment, the subpolar North Atlantic experienced a widespread cooling with two successive intense winters (2014/15 and 2015/16). Strong air-sea heat fluxes during those two winters led to intensified deep convection with an enormously large production of Labrador Sea Water. All the changes make us wonder about any concurrent changes in circulations (overturning and gyre) at the subpolar latitudes. Once we have firmed up the flux estimates at OSNAP, we will soon begin the task of investigating those observed changes in the region and linking them to local and/or remote forcing mechanisms.
Next year sure will be a productive year for OSNAP – be prepared for exciting news!