Presenter: Sarah Purkey (Scripps Institution of Oceanography, UCSD)

Description:
The implementation of a 1000 biogeochemical (BGC) Argo array is underway, offering, for the first time, a systematic continuous global view of the ocean’s chemical and biological processes on seasonal to decadal time scales. The long-term sustainability of the array is contingent on the longevity, reliability and availability of the ocean technology that supports it.  Here we present on the design of, development of, and data from a new model of BGC Argo float based on the existing Scripps Institution of Oceanography (SIO) Core Argo model, the SOLO-II. The BGC SOLO measures the full suite of 6 required BGC parameters including pH, nitrate, dissolved oxygen (with in-air sampling capability), downwelling irradiance, backscatter, chlorophyll fluorescence, temperature, salinity and pressure.  Using a high vertical sampling scheme for all sensors, the float is estimated to use less than 20 kJ of energy per profile, allowing for over 300 profiles before the battery’s life is exhausted.   Data is efficiently transmitted via a compressed data structure across the RUDICS two-way iridium communication system. The buoyancy system utilizes the reliable SOLO-II reciprocating hydraulic pump technology, allowing the float to profile from the surface to 2000 dbar anywhere in the global ocean without special ballasting. Finally, the scientific value of the BGC SOLO will be illustrated using data from the first BGC SOLO deployed in the the California Current in Febuary of 2022. Plans are underway to transfer this technology to MRV Systems by early 2022 for commercial sale.