Affiliation:
1. Key Laboratory of Western China's Environmental Systems of the Ministry of Education College of Earth and Environmental Sciences Lanzhou University Lanzhou China
2. Academy of Plateau Science and Sustainability Qinghai Normal University Xining China
3. Key Laboratory for Semi‐Arid Climate Change of the Ministry of Education College of Atmospheric Sciences Lanzhou University Lanzhou China
4. School of Systems Science Beijing Normal University Beijing China
Abstract
AbstractIn this study, we obtained the first leading mode and principal component 1 (PC1) of North Pacific sea surface temperature (SST). The PC1‐related SST anomalies, located relatively north/south, are referred to as North/South PC1 events. Model outputs, observations, reanalysis datasets and sensitivity experiments show that during the North PC1 events, an enhanced Aleutian low occurs and is located relatively north, favoring anomalous southerlies over western North America. The anomalous southerlies induce a strong warming anomaly over North America via warm advection of the anomalous southerlies and temperature advection of the climatological westerlies over North America. However, the Aleutian low anomaly and corresponding southerly anomaly associated with South PC1 events shift southward, favoring weakened effects of South PC1 events on atmospheric circulations and surface temperatures over North America. The meridional position of PC1 events deserves to be considered in the studies of the PC1 and its related climate changes.
Funder
Natural Science Foundation of Gansu Province
National Natural Science Foundation of China
Higher Education Discipline Innovation Project
Publisher
American Geophysical Union (AGU)
Subject
General Earth and Planetary Sciences,Geophysics