TY - JOUR

T1 - Fate of Methane from the Nord Stream Pipeline Leaks

AU - Dissanayake, Anusha L.

AU - Gros, Jonas

AU - Drews, Henning Johannes

AU - Nielsen, Jacob Woge

AU - Drews, Annika

N1 - Publisher Copyright: © 2023 The Authors. Published by American Chemical Society.

PY - 2023

Y1 - 2023

N2 - In September 2022, three major subsea leaks occurred in the Nord Stream pipelines, releasing an estimated 225 kt of natural gas into the Baltic Sea. To explain its behavior in the water column, we developed a combined model to simulate the near-field buoyant bubble plumes and the far-field advection, dispersion, volatilization, and biodegradation of the dissolved methane fraction. According to these simulations, 94.9% of the leaked methane was emitted to the atmosphere immediately above the leaks by ascending gas bubble plumes. The remaining 5.1% of the methane (11 kt) initially dissolved, leading to concentrations of up to 625,000 nM or 5 orders of magnitude above the local Baltic Sea natural background. The modeling suggests that within 35 days, 71.4% of the dissolved methane volatilized and 26.0% biodegraded, and the maximum water column concentration decreased to 70 nM. We find that up to 409 km3 of seawater experienced concentrations greater than 10 times above the natural background. The modeling shows that more than 10 marine protected areas in the Baltic Sea were exposed to elevated dissolved methane concentrations.

AB - In September 2022, three major subsea leaks occurred in the Nord Stream pipelines, releasing an estimated 225 kt of natural gas into the Baltic Sea. To explain its behavior in the water column, we developed a combined model to simulate the near-field buoyant bubble plumes and the far-field advection, dispersion, volatilization, and biodegradation of the dissolved methane fraction. According to these simulations, 94.9% of the leaked methane was emitted to the atmosphere immediately above the leaks by ascending gas bubble plumes. The remaining 5.1% of the methane (11 kt) initially dissolved, leading to concentrations of up to 625,000 nM or 5 orders of magnitude above the local Baltic Sea natural background. The modeling suggests that within 35 days, 71.4% of the dissolved methane volatilized and 26.0% biodegraded, and the maximum water column concentration decreased to 70 nM. We find that up to 409 km3 of seawater experienced concentrations greater than 10 times above the natural background. The modeling shows that more than 10 marine protected areas in the Baltic Sea were exposed to elevated dissolved methane concentrations.

KW - Baltic Sea

KW - buoyant bubble plume model

KW - dissolved methane

KW - natural gas

KW - pipeline blowouts

KW - subsea

U2 - 10.1021/acs.estlett.3c00493

DO - 10.1021/acs.estlett.3c00493

M3 - Journal article

AN - SCOPUS:85173160653

VL - 10

SP - 903

EP - 908

JO - Environmental Science & Technology Letters

JF - Environmental Science & Technology Letters

SN - 2328-8930

IS - 10

ER -