One-third of Southern Ocean productivity is supported by dust deposition.
Nature
; 629(8012): 603-608, 2024 May.
Article
in En
| MEDLINE
| ID: mdl-38750234
ABSTRACT
Natural iron fertilization of the Southern Ocean by windblown dust has been suggested to enhance biological productivity and modulate the climate1-3. Yet, this process has never been quantified across the Southern Ocean and at annual timescales4,5. Here we combined 11 years of nitrate observations from autonomous biogeochemical ocean profiling floats with a Southern Hemisphere dust simulation to empirically derive the relationship between dust-iron deposition and annual net community production (ANCP) in the iron-limited Southern Ocean. Using this relationship, we determined the biological response to dust-iron in the pelagic perennially ice-free Southern Ocean at present and during the last glacial maximum (LGM). We estimate that dust-iron now supports 33% ± 15% of Southern Ocean ANCP. During the LGM, when dust deposition was 5-40-fold higher than today, the contribution of dust to Southern Ocean ANCP was much greater, estimated at 64% ± 13%. We provide quantitative evidence of basin-wide dust-iron fertilization of the Southern Ocean and the potential magnitude of its impact on glacial-interglacial timescales, supporting the idea of the important role of dust in the global carbon cycle and climate6-8.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Seawater
/
Oceans and Seas
/
Climate
/
Dust
/
Carbon Cycle
/
Iron
Language:
En
Journal:
Nature
Year:
2024
Type:
Article
Affiliation country:
Australia