Tropical Atlantic Observing System (TAOS) Review Report

Abstract

The Tropical Atlantic Observing System (TAOS) review was proposed by the CLIVAR Atlantic Region Panel (ARP) and has been organized by the CLIVAR ARP in close cooperation with the PIRATA consortium. The review is intended to evaluate scientific progress since the last review and recommend actions to advance sustained observing efforts in the tropical Atlantic. The structure of the report is organized with an executive summary that introduces the main societal drivers and provides a summary of the recommendations and where in the report these are more thoroughly discussed. The core text of the report then proceeds in the following order: (1) a concise review of TAOS societal, scientific and operational drivers; (2) a summary of the current TAOS observing network; (3) recommendations on the evolution of the TAOS; (4) information on the actual TAOS data flow and products and recommendations for their evolution; and (5) recommendations on the future governance of the TAOS. More detailed information on the scientific and operational drivers are provided in the Appendices as well as a rationalization of all observing requirements in terms of Essential Ocean and Climate Variables.

Global Ocean Monitoring and Prediction at NOAA Climate Prediction Center: 15 Years of Operations

“…For these reasons, monitoring of the availability of the ocean build a robust and sustainable observing system to meet existing and evolving observational requirements. Similar reviews for the Atlantic (Johns et al 2021) and Indian (Beal et al 2020) Oceans have also been completed. As the ocean observing system evolves in near future, a continuous need for monitoring ocean observations becomes even more critical.…”

Contrasting Sea‐Air CO2 Exchanges in the Western Tropical Atlantic Ocean

“…This sub‐region is homogeneously a CO 2 source to the atmosphere throughout the year, which becomes more intense near the Brazilian coast, where the NBC flow is intensified (e.g., Johns et al., 1998; Salisbury et al., 2011). Such CO 2 outgassing behavior is associated with warmer tropical waters (Figure S6 in Supporting Information S1) (Azar et al., 2021; Johns et al., 2021) coupled with equatorial upwelling (Landschützer et al., 2014; Takahashi et al., 2009). Moreover, the influence of CO 2 ‐enriched waters from the Indian Ocean (Orselli, Goyet, et al., 2019; Orselli, Kerr, et al., 2019), which are advected by mesoscale structures along the South Atlantic Ocean (Azar et al., 2021; Souza et al., 2018), may strengthen the seawater CO 2 supersaturation in this sub‐region.…”

Contrasting sea-air CO2 exchanges in the western Tropical Atlantic Ocean

“…The North Equatorial Current (NEC) flows westwards in the northern hemisphere, carrying relatively cold waters from the North Atlantic to the western Tropical Atlantic Ocean (Fig. 1c) (Johns et al, 2021). On the other hand, the North Brazil Current (NBC) flows northwest along the Brazilian coast (Stramma et al, 1995;Rodrigues et al, 2007;Silva et al, 2009), carrying warm and more saline waters (Fig.…”

“…This is particularly true because the spreading area of the Amazon River plume, as well as the period of maximum freshwater discharge, vary seasonally and interannually (Liang et al, 2020). Furthermore, the surface current system (e.g., Johns et al, 1998;Salisbury et al, 2011;Johns et al, 2021) and the ocean-atmosphere-land coupling (Utida et al, 2019;Johns et al, 2021;Louchard et al, 2021) make it difficult to build an overall picture of sea-air CO2 exchanges in this region from spatial and temporal snapshots.…”

“…However, the Tropical Atlantic Ocean is the second largest source of CO2 from the ocean to the atmosphere, mainly due to equatorial upwelling and warm waters (Landschützer et al, 2014, Takahashi et al, 2009. The ocean dynamics of the surface current system (e.g., Johns et al, 1998;Salisbury, et al, 2011;Johns et al, 2021) and the large freshwater input from the Amazon River (Liang et al, 2020), coupled with precipitation dynamics (Ibánhez et al, 2015;Utida et al, 2019), also add a biogeochemical complexity to the western Tropical Atlantic Ocean (da Cunha & Buitenhuis, 2013). Such complexity is reflected in the pronounced spatial and temporal variability of the marine carbonate system and particularly in the sea-air CO2 exchanges (Körtzinger, 2003;Cooley et al, 2007;Lefèvre et al, 2010;Valerio et al, 2021;Louchard et al, 2021;Mu et al, 2021).…”