The Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) program
The Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) program started in September 2014 as a six-year initiative funded by the NSF’s Division of Polar Programs, with additional support from NOAA and NASA. The program, with its headquarters at Princeton University, has been extended for another five years. SOCCOM’s mission is to drive a transformative shift in understanding of the role of the Southern Ocean in climate change and biogeochemistry. SOCCOM is deploying ~200 ice-capable biogeochemical profiling floats throughout the Southern Ocean, contributing to the core Argo program with additional floats and sensors. The floats provide a profile every 10 days of temperature, salinity, nitrate, oxygen, pH, optical backscatter, and chlorophyll fluorescence to 2000 m depth. These observations are being assimilated in an ocean model, the Southern Ocean State Estimate, which provides high quality air-sea flux “reanalysis” specific to the Southern Ocean, and dynamically consistent interpolation of the observations. Using this observational data and the state estimate output, high resolution earth system models are being improved to both increase our understanding of the Southern Ocean’s current workings and make better projections of the future trajectory of the Earth’s climate and biogeochemistry.
Arctic floats north of Lomonosov Ridge
A research initiative called SODA (Stratified Ocean Dynamics in the Arctic) is aiming to deploy ~20 floats in the area of the Beaufort Gyre. It has been implemented recently in 2016 and is planned for a 5 year period until 2015. A persistent loss of sea ice volume can be anticipated from the observed decrease in sea-ice extent and decreasing ages of the ice. The aim of SODA is therefore to understand these changes and their impact on arctic stratification and circulation, sea ice evolution, and the acoustic environment.
The trajectory of one of the floats deployed in 2016 is shown in the figure. Although the float was deployed in rather shallow water initially, and worked in an ice pack for a decent amount of time it has operated for 147 cycles and monitored the multi-layer structure of temperature field in the Arctic over the shelf as well as the shelf break.
Arctic floats in the Baffin Bay
Baffin Bay has been selected as a preferred area for studying ice-edge phyto-plankton blooms in high latitudes. Climate change seems to affect these blooms and observations by Ocean Remote Sensing show that the spring blooms occur now 50 days earlier than in 1997. Deployment of PRO-ICE floats in the Baffin Bay has started in 2015 and will continue until 2020 as a cooperation between the French program NAOS and the Canadian program FCI. Altogether 19 floats are planned with funding for 10 floats from France and 9 floats from Canada. The floats carry a bio-geochemical payload including sensors for oxygen, nitrates, light measurements at different wavelength, chlorophyll-a, CDOM and backscattering.
The first field tests have demonstrated the challenges of having a float surface under these environmental conditions. An ice layer as thin as 2 cm can prevent the float from surfacing, since it only has a pull of ~ 500-600 g when ascending.
The adaption of the ice-sensing algorithm (ISA) developed by Klatt et al (2007) to the hydrographic conditions of the Baffin Bay has resulted in an appropriate choice of a temperature threshold which differs from the one selected for the Southern Ocean.
In the summer 2016, 5 PRO-Ice were deployed during the cruise “Greenedge” onboard the Canadian icebreaker Amundsen. 4 floats were deployed in Baffin Bay and the 5th in the Labrador Sea.
Deployment of the four Pro-Ice floats on July 9th 2016:
takapm009B (WMO 6902667), lat 69°30.062’N / Long 60°08.815’W
takapm013B (WMO 4901802), lat 69°30.029’N / Long 61°00.658’W
takapm05B (WMO 4901803), lat 69°19.341’N / Long 60°58.997’W
takapm014B (WMO 6902668), lat 69°20.209’N / Long 60°13.251’W
Routes of the 4 floats in Baffin Bay since their deployment until 2016, November 1st were they navigate in a winter pattern (profile down to 1000m and rise to 15m under the surface). On the map, the shape of the floats represents the position where the floats were deployed in Summer 2016.