Work

Imprint of Indian Ocean Dipole on nitrous oxide dynamics

Year: 2025

Type: article

Abstract: The northern Indian Ocean is a hotspot of nitrous oxide (N 2 O) emissions, with strong seasonal monsoons and interannual Indian Ocean Dipole (IOD) variability. We examine the IOD influence on N 2 O seasonality using a regional ocean model covering 1981–2020, with a focus on the coastal ocean where ∆ p N 2 O variability is more than threefold greater than in the open ocean. Positive IOD amplifies ∆ p N 2 O seasonality by a factor 2 to 5 in the east and dampens it by ∼ 30% in the west. Negative IOD reverses this pattern but changes are weaker (< 10%). This east/west contrast and asymmetry between positive and negative IOD arise from changes in transport of N 2 O produced in subsurface by nitrification and denitrification, and significantly modulate local N 2 O emissions (−40% to +130%). Sparse N 2 O observations and systematic biases in IOD phase sampling compound seasonal and interannual variability, likely leading to underestimation of N 2 O seasonality and emissions in observation‐based reconstructions.

Source: Limnology and Oceanography Letters

DOI: 10.1002/lol2.70086

Authors: Yangyang Zhao, Laure Resplandy, Fan Yang, Xianhui Sean Wan, Calla M. Marchetti, Bess Ward

Institutions: Princeton University, High Meadows Environmental Institute, Xiamen University, State Key Laboratory of Marine Environmental Science

Language: English

Topic: Marine and coastal ecosystems

Subfield: Oceanography

Field: Earth and Planetary Sciences

Domain: Physical Sciences

SDGs: Climate action, Life below water

Open Access status: gold

Estimated APC paid: $3,700