3:35 PM - 3:55 PM
[AOS16-02] Biogeochemical Argo: Significances and Challenges
★Invited Papers
Keywords:BGC Argo, GO-SHIP, ocean acidification, oxygen decline, ocean observing network
Since 1980s, high-quality data of ocean carbon and biogeochemistry (BGC) have been acquired globally from the ocean interior in ship-based hydrographic programs such as WOCE/JGOFS and GO-SHIP and at time-series sites such as those at 137°E, station ALOHA near Hawaii and BATS near Bermuda. These datasets have been quality-controlled and are freely available from the database GLODAPv2, helping constrain the global budget of anthropogenic carbon and documenting the progress of ocean acidification and oxygen decline that are endangering the marine ecosystems worldwide and thus our societies. However, we still have large data gaps particularly in time for most of the ocean regions. The measurements with low time frequency in global oceans, typically once in several years to a decade in GO-SHIP, prevent from resolving seasonality in upper layers as well as distinguishing between the impact of human-induced forcing and that of ocean internal variability on ocean carbon and BGC.
On October 29, 2020, NSF announced a $53 million grant to build a global network of BGC-Argo (GO-BGC) (~500 floats). In Japan, several Argo floats installed with O2 and pH sensors are to be deployed in the region of North Pacific Subtropical Mode Water in February 2021 as a part of Kakenhi project “Hybrid ocean observations” in “Hotspot 2”. A sustained observing network of BGC-Argo is expected to help fill in the large data gaps in the ocean carbon and BGC and greatly improve our understanding of their change and variability, thus understand and project impacts of climate change and variability as well as the changes in anthropogenic CO2 emission on BGC and carbon-climate feedback. Massive data from BGC-Argo are also potentially to be critical in measuring the effectiveness of our policy and efforts to reduce CO2 emission on the changes in ocean and its health on which our society depends.
However, collecting climate-quality data of BGC from sustained BGC-Argo network well enough to quantify the trends of, e.g., acidification and oxygen decline is still a challenge. It is required to establish a network of in-situ ocean observing networks which enables to provide high-quality reference data for calibration and validation of data from sensors, in addition to further improving the performance of sensors for BGC in terms of precision, stability, cost and so on.
On October 29, 2020, NSF announced a $53 million grant to build a global network of BGC-Argo (GO-BGC) (~500 floats). In Japan, several Argo floats installed with O2 and pH sensors are to be deployed in the region of North Pacific Subtropical Mode Water in February 2021 as a part of Kakenhi project “Hybrid ocean observations” in “Hotspot 2”. A sustained observing network of BGC-Argo is expected to help fill in the large data gaps in the ocean carbon and BGC and greatly improve our understanding of their change and variability, thus understand and project impacts of climate change and variability as well as the changes in anthropogenic CO2 emission on BGC and carbon-climate feedback. Massive data from BGC-Argo are also potentially to be critical in measuring the effectiveness of our policy and efforts to reduce CO2 emission on the changes in ocean and its health on which our society depends.
However, collecting climate-quality data of BGC from sustained BGC-Argo network well enough to quantify the trends of, e.g., acidification and oxygen decline is still a challenge. It is required to establish a network of in-situ ocean observing networks which enables to provide high-quality reference data for calibration and validation of data from sensors, in addition to further improving the performance of sensors for BGC in terms of precision, stability, cost and so on.