Direct observational evidence of strong CO uptake in the Southern Ocean.

The Southern Ocean is the primary region for the uptake of anthropogenic carbon dioxide (CO) and is, therefore, crucial for Earth's climate. However, the Southern Ocean CO flux estimates reveal substantial uncertainties and lack direct validation. Using seven independent and directly measured air-sea CO flux datasets, we identify a 25% stronger CO uptake in the Southern Ocean than shipboard dataset-based flux estimates.

Biogenic carbon pool production maintains the Southern Ocean carbon sink.

Through biological activity, marine dissolved inorganic carbon (DIC) is transformed into different types of biogenic carbon available for export to the ocean interior, including particulate organic carbon (POC), dissolved organic carbon (DOC), and particulate inorganic carbon (PIC). Each biogenic carbon pool has a different export efficiency that impacts the vertical ocean carbon gradient and drives natural air-sea carbon dioxide gas (CO) exchange. In the Southern Ocean (SO), which presently accounts for ~40% of the anthropogenic ocean carbon sink, it is unclear how the production of each biogenic carbon pool contributes to the contemporary air-sea CO exchange.

Reassessing Southern Ocean Air-Sea CO Flux Estimates With the Addition of Biogeochemical Float Observations.

New estimates of CO from profiling floats deployed by the Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) project have demonstrated the importance of wintertime outgassing south of the Polar Front, challenging the accepted magnitude of Southern Ocean carbon uptake (Gray et al., 2018, https://doi:10.1029/2018GL078013).

Observing Changes in Ocean Carbonate Chemistry: Our Autonomous Future.

Purpose Of Review: We summarize recent progress on autonomous observations of ocean carbonate chemistry and the development of a network of sensors capable of observing carbonate processes at multiple temporal and spatial scales.

Recent Findings: The development of versatile pH sensors suitable for both deployment on autonomous vehicles and in compact, fixed ecosystem observatories has been a major development in the field. The initial large-scale deployment of profiling floats equipped with these new pH sensors in the Southern Ocean has demonstrated the feasibility of a global autonomous open-ocean carbonate observing system.

Differential induction of apoptosis by cigarette smoke extract in primary human lung fibroblast strains: implications for emphysema.

Cigarette smoke is the principal cause of emphysema. Recent attention has focused on the loss of alveolar fibroblasts in the development of emphysema. Fibroblasts may become damaged by oxidative stress and undergo apoptosis as a result of cigarette smoke exposure.