Research on the Propagation Characteristics of Temperature Anomaly in the Intermediate and Deep Ocean Layers

Abstract Due to the lack of observational data, the understanding of propagation characteristics of temperature anomaly is mainly concentrated in the sea surface and the waters above thermocline. Little is known about the propagation characteristics of temperature anomaly in the middle and deep oceans. Based on the gridded Argo data, we analyze the propagation characteristics of temperature anomaly along the isodensity. We found that the temperature anomalies in the middle and deep ocean layers propagate westward at most latitudes, which is the same direction as the propagation of the surface temperature anomaly caused by oceanic Rossby waves. Through the Radon transform, we determined the propagation speeds on different isodensities and explored the relationship of propagation speeds and latitudes and water depth. To the best of our knowledge, this study is the first to explore the propagation characteristics of mid-deep temperature anomalies at the ocean basin scale.