Distinct Impacts of the Central and Eastern Atlantic Niño on the European Climate

The Atlantic Nino is the primary interannual variability mode in the tropical Atlantic, with far-reaching impacts on global climate. A recent study identified two types of the Atlantic Nino, each with its maximum warming centered in the central and eastern equatorial Atlantic, respectively. Through analysis of observational data and numerical model experiments, we find that the two Atlantic Nino types have distinct climatic impacts on Europe. This is because the central Atlantic Nino is associated with a pronounced increase in precipitation in the western tropical Atlantic, while the positive precipitation anomalies during the eastern type are mainly located in the eastern basin with weaker amplitudes. Consequently, compared to the eastern Atlantic Nino, the extra-tropical atmospheric waves and the associated precipitation and temperature anomalies in Europe during the central type are stronger and shifted westward. Therefore, distinguishing between the two Atlantic Nino types may help improve seasonal climate predictions in Europe. The Atlantic Nino is the primary climate phenomenon in the tropical Atlantic that can influence global climate systems and human livelihoods through atmospheric teleconnections. A recent study suggests that the Atlantic Nino can be categorized into two types: the CAN and the EAN, based on the location of the maximum sea surface temperature warming center. It is demonstrated here that these two types of the Atlantic Nino have distinct impacts on the European climate during boreal summer. This discrepancy arises from differences in the associated precipitation increase between the two Atlantic Nino types. Consequently, the changes in atmospheric circulation and climate anomalies in Europe associated with the CAN are stronger and shifted westward compared to those during the EAN. Hence, it is important to distinguish between the two Atlantic Nino types, as this may help improve seasonal climate predictions for European countries. Central Atlantic Nino (CAN) and eastern Atlantic Nino (EAN) generate atmospheric waves that result in distinct impacts on the European climateAtmospheric wave train over Europe excited by the CAN is stronger and shifted westward compared to that by the EANLinear baroclinic model can effectively replicate the atmospheric circulation excited by the CAN and EAN observed over Europe