Dominant Processes for Dependence of Boreal Summer Intraseasonal Oscillation on El Niño Phases
Abstract Boreal summer intraseasonal oscillation (BSISO) strongly interacts with background mean fields and tends to be stronger and longer in its northward propagation during La Niña than El Niño summers. However, BSISO dependence on El Niño‐Southern Oscillation phase has not been well understood....
Saved in:
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Wiley
2022-07-01
|
| Series: | Geophysical Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1029/2022GL098669 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850183373833633792 |
|---|---|
| author | Doo Young Lee June‐Yi Lee Young‐Min Yang Pang‐Chi Hsu Ji‐Eun Kim |
| author_facet | Doo Young Lee June‐Yi Lee Young‐Min Yang Pang‐Chi Hsu Ji‐Eun Kim |
| author_sort | Doo Young Lee |
| collection | DOAJ |
| description | Abstract Boreal summer intraseasonal oscillation (BSISO) strongly interacts with background mean fields and tends to be stronger and longer in its northward propagation during La Niña than El Niño summers. However, BSISO dependence on El Niño‐Southern Oscillation phase has not been well understood. Here, we show that BSISO‐related convections are stronger and more organized with northward propagation on 30–60‐day timescales during El Niño developing (E‐DV) than decaying (E‐DC) summers over the western Pacific. The easterly vertical shear, responsible for the next vorticity generation north of the BSISO convection, in the E‐DV (E‐DC) remarkably increases (decreases) due to the enhanced (weakened) upper‐level easterly anomaly. The air‐sea interaction in E‐DV gets stronger due to the larger meridional gradient of sea surface temperature, amplifying northward propagation than in E‐DC. |
| format | Article |
| id | doaj-art-84510511c6534e7ebdb0ef212fef3b7a |
| institution | OA Journals |
| issn | 0094-8276 1944-8007 |
| language | English |
| publishDate | 2022-07-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geophysical Research Letters |
| spelling | doaj-art-84510511c6534e7ebdb0ef212fef3b7a2025-08-20T02:17:21ZengWileyGeophysical Research Letters0094-82761944-80072022-07-014914n/an/a10.1029/2022GL098669Dominant Processes for Dependence of Boreal Summer Intraseasonal Oscillation on El Niño PhasesDoo Young Lee0June‐Yi Lee1Young‐Min Yang2Pang‐Chi Hsu3Ji‐Eun Kim4Research Center for Climate Sciences Pusan National University Busan South KoreaResearch Center for Climate Sciences Pusan National University Busan South KoreaKey Laboratory of Meteorological Disaster Ministry of Education/International Joint Research Laboratory on Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and Technology Nanjing ChinaKey Laboratory of Meteorological Disaster Ministry of Education/International Joint Research Laboratory on Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and Technology Nanjing ChinaCenter for Climate Physics Institute for Basic Science Busan South KoreaAbstract Boreal summer intraseasonal oscillation (BSISO) strongly interacts with background mean fields and tends to be stronger and longer in its northward propagation during La Niña than El Niño summers. However, BSISO dependence on El Niño‐Southern Oscillation phase has not been well understood. Here, we show that BSISO‐related convections are stronger and more organized with northward propagation on 30–60‐day timescales during El Niño developing (E‐DV) than decaying (E‐DC) summers over the western Pacific. The easterly vertical shear, responsible for the next vorticity generation north of the BSISO convection, in the E‐DV (E‐DC) remarkably increases (decreases) due to the enhanced (weakened) upper‐level easterly anomaly. The air‐sea interaction in E‐DV gets stronger due to the larger meridional gradient of sea surface temperature, amplifying northward propagation than in E‐DC.https://doi.org/10.1029/2022GL098669boreal summer intraseasonal oscillation30‐60‐day oscillationnorthward propagationEl Niñoeasterly vertical shearair‐sea interaction |
| spellingShingle | Doo Young Lee June‐Yi Lee Young‐Min Yang Pang‐Chi Hsu Ji‐Eun Kim Dominant Processes for Dependence of Boreal Summer Intraseasonal Oscillation on El Niño Phases Geophysical Research Letters boreal summer intraseasonal oscillation 30‐60‐day oscillation northward propagation El Niño easterly vertical shear air‐sea interaction |
| title | Dominant Processes for Dependence of Boreal Summer Intraseasonal Oscillation on El Niño Phases |
| title_full | Dominant Processes for Dependence of Boreal Summer Intraseasonal Oscillation on El Niño Phases |
| title_fullStr | Dominant Processes for Dependence of Boreal Summer Intraseasonal Oscillation on El Niño Phases |
| title_full_unstemmed | Dominant Processes for Dependence of Boreal Summer Intraseasonal Oscillation on El Niño Phases |
| title_short | Dominant Processes for Dependence of Boreal Summer Intraseasonal Oscillation on El Niño Phases |
| title_sort | dominant processes for dependence of boreal summer intraseasonal oscillation on el nino phases |
| topic | boreal summer intraseasonal oscillation 30‐60‐day oscillation northward propagation El Niño easterly vertical shear air‐sea interaction |
| url | https://doi.org/10.1029/2022GL098669 |
| work_keys_str_mv | AT dooyounglee dominantprocessesfordependenceofborealsummerintraseasonaloscillationonelninophases AT juneyilee dominantprocessesfordependenceofborealsummerintraseasonaloscillationonelninophases AT youngminyang dominantprocessesfordependenceofborealsummerintraseasonaloscillationonelninophases AT pangchihsu dominantprocessesfordependenceofborealsummerintraseasonaloscillationonelninophases AT jieunkim dominantprocessesfordependenceofborealsummerintraseasonaloscillationonelninophases |