07 Mar 2023
 | 07 Mar 2023
Status: this preprint is currently under review for the journal ESD.

The Indonesian Throughflow Circulation Under Solar Geoengineering

Chencheng Shen, John C. Moore, Heri Kuswanto, and Liyun Zhao

Abstract. The Indonesia Throughflow (ITF) is the only low-latitude channel between the Pacific and Indian oceans, and its variability has important effects on global climate and biogeochemical cycles. Climate models consistently predict a decline in ITF transport under global warming, but it has not yet been examined under solar geoengineering scenarios. We use standard parameterized methods for estimating ITF: the Amended Island Rule and Buoyancy Forcing, to investigate ITF under the SSP2-4.5 and SSP5-8.5 greenhouse gas scenarios, and the geoengineering experiments G6solar and G6sulfur that reduce net global mean radiative forcing from SSP5-8.5 levels to SSP2-4.5 levels using solar diming and sulfate aerosol injection strategies. Six model ensemble mean projections for 2080–2100 relative to historical ITF are reductions of 19 % under the G6solar scenario and 28 % under the G6sulfur scenario which compare with reductions of 23 % and 27 % under SSP2-4.5 and SSP5-8.5. Thus, significant weakening of the ITF occurs under all scenarios, but G6solar closer approximates SSP2-4.5 than does G6sulfur. In contrast with the other three scenarios which show only reductions in forcing due to ocean upwelling, the G6sulfur experiment shows a large reduction in ocean surface wind stress forcing accounting for 47 % (38 %~65 % across model range) of the decline of total ITF transport. There are also reductions in deep-sea upwelling in extratropical western boundary currents.

Chencheng Shen et al.

Status: open (until 26 Apr 2023)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on esd-2023-6', Anonymous Referee #1, 27 Mar 2023 reply

Chencheng Shen et al.

Chencheng Shen et al.


Total article views: 278 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
241 30 7 278 13 3 3
  • HTML: 241
  • PDF: 30
  • XML: 7
  • Total: 278
  • Supplement: 13
  • BibTeX: 3
  • EndNote: 3
Views and downloads (calculated since 07 Mar 2023)
Cumulative views and downloads (calculated since 07 Mar 2023)

Viewed (geographical distribution)

Total article views: 269 (including HTML, PDF, and XML) Thereof 269 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
Latest update: 28 Mar 2023
Short summary
The Indonesian Throughflow is an important pathway connecting the Pacific and Indian Oceans. Solar dimming and sulfate aerosol injection geoengineering will affect the water volumes transported in future – but so will increasing greenhouse gases. Geoengineering with sulfate aerosols affects winds more than simply “shading the sun” and reduces the water transport more – similar as we simulate for unabated greenhouse gas emissions.