Cold Springs Over Mid-Latitude North America Induced by Tropical Atlantic Warming

In recent decades, severe cold winters and springs have frequently occurred over mid-latitude North America, despite the anthropogenic global warming trend. In this study, we reveal a possible mechanism by investigating the teleconnection between tropical oceans and North America. Through observational analysis and numerical experiments, we reveal that an anomalous tropical Atlantic warming can trigger a cold spring over central-western mid-latitude North America. The tropical Atlantic warming intensifies regional deep atmospheric convection and generates a stationary Rossby wave train propagating poleward, forming an anomalous low pressure center over the mid-latitude North Atlantic. This low-level circulation adjustment further intensifies the cold advection and increases the cloud cover over central-western North America, cooling the surface through cloud radiative feedback. The mechanisms revealed in this study may contribute to the improvement of predictability of cold springs over North America, and have broad implications for agriculture production, power supply, and public health.