Improved subseasonal prediction of Atmospheric Energy Transport over the Northwest Pacific using an atmosphere-ocean coupled model

Kyungmin Kwak a Department of Atmospheric Sciences, Yonsei University, Seoul, Republic of Korea

Search for other papers by Kyungmin Kwak in
Current site
Google Scholar
PubMed
Close
,
Hajoon Song a Department of Atmospheric Sciences, Yonsei University, Seoul, Republic of Korea
b Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea

Search for other papers by Hajoon Song in
Current site
Google Scholar
PubMed
Close
,
Namgu Yeo c Department of Atmospheric Science, Kongju National University, Gongju, Republic of Korea

Search for other papers by Namgu Yeo in
Current site
Google Scholar
PubMed
Close
,
Eun-Chul Chang c Department of Atmospheric Science, Kongju National University, Gongju, Republic of Korea

Search for other papers by Eun-Chul Chang in
Current site
Google Scholar
PubMed
Close
,
Myung-Seo Koo d Numerical Modeling Group, Korea Institute of Atmospheric Prediction Systems, Seoul, Republic of Korea

Search for other papers by Myung-Seo Koo in
Current site
Google Scholar
PubMed
Close
,
Eunjeong Lee d Numerical Modeling Group, Korea Institute of Atmospheric Prediction Systems, Seoul, Republic of Korea

Search for other papers by Eunjeong Lee in
Current site
Google Scholar
PubMed
Close
, and
Junseong Park d Numerical Modeling Group, Korea Institute of Atmospheric Prediction Systems, Seoul, Republic of Korea

Search for other papers by Junseong Park in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

Poleward transport of energy is essential for reducing the Earth’s energy imbalance. During boreal summer, equatorward dry static energy transport (DSET) and poleward latent heat transport (LHT) are located in the upper and lower tropical atmosphere, respectively. This study investigates changes in meridional atmospheric energy transport and their underlying mechanisms using a global coupled atmosphere-ocean model. In the July 2017 simulations, the coupled model better captures the phase variation of DSET and exhibits a small LHT at 20°N (approximately 1 PW) compared with the standalone atmospheric model. Ocean coupling decreases meridional gradient of ocean skin temperature, which mitigates the poleward propagation of convection. Consequently, the well-established meridional circulation not only increases low-level divergence but is also linked to changes in the spatial distribution of moisture. Our results show that ignoring the seasonal variability in ocean temperature can accelerate the hemispheric energy imbalance through the northwest Pacific region.

© 2025 American Meteorological Society. This is an Author Accepted Manuscript distributed under the terms of the default AMS reuse license. For information regarding reuse and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Hajoon Song, hajsong@yonsei.ac.kr

Abstract

Poleward transport of energy is essential for reducing the Earth’s energy imbalance. During boreal summer, equatorward dry static energy transport (DSET) and poleward latent heat transport (LHT) are located in the upper and lower tropical atmosphere, respectively. This study investigates changes in meridional atmospheric energy transport and their underlying mechanisms using a global coupled atmosphere-ocean model. In the July 2017 simulations, the coupled model better captures the phase variation of DSET and exhibits a small LHT at 20°N (approximately 1 PW) compared with the standalone atmospheric model. Ocean coupling decreases meridional gradient of ocean skin temperature, which mitigates the poleward propagation of convection. Consequently, the well-established meridional circulation not only increases low-level divergence but is also linked to changes in the spatial distribution of moisture. Our results show that ignoring the seasonal variability in ocean temperature can accelerate the hemispheric energy imbalance through the northwest Pacific region.

© 2025 American Meteorological Society. This is an Author Accepted Manuscript distributed under the terms of the default AMS reuse license. For information regarding reuse and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).

Corresponding author: Hajoon Song, hajsong@yonsei.ac.kr
Save