The diversity of the boreal spring North Atlantic sea surface temperature tripole pattern and corresponding Northern Hemispheric surface air temperature anomalies

Abstract The North Atlantic sea surface temperature tripole (NAT) is a predominant boreal spring oceanic mode, which notably influences Northern Hemispheric climates. However, the NAT pattern and its corresponding Northern Hemispheric surface air temperature (SAT) anomalies exhibit large year-to-year disparities. Here, we identified three types of NAT pattern based on the relative significance of sea surface temperature anomaly (SSTA) among the three poles. The first type is characterized by more dominant SSTA at the southern pole, which corresponds to the pronounced positive SAT anomalies over North America and negative SAT anomalies over the Ural Mountain regions. The second type features more intensive SSTA at the central pole, which is linked with more zonally oriented barotropic low-pressure anomalies and negative SAT anomalies stretching from western Europe to Northeast Asia. The third type exhibits more significant SSTA over the northern pole, which corresponds to the high-pressure anomalies and positive SAT anomalies over the Turan Plain.