The Atlantic Meridional Overturning Circulation (AMOC) at 26.5°N exhibits significant seasonal variability, with a mean strength of 18.7 ± 2.1 Sv (1 Sv = 10⁶ m³/s) over 48 months from April 2004 to April 2008. The seasonal cycle of the AMOC has a peak-to-peak amplitude of 6.7 Sv, with maximum strength in autumn and minimum in spring. While the northward Ekman transport was previously thought to dominate the seasonal cycle, this study shows that geostrophic midocean and Gulf Stream transports (2.2 and 1.7 Sv rms, respectively) are substantially larger than the Ekman component (1.2 Sv rms). A simple model based on linear dynamics suggests that the seasonal cycle is dominated by wind stress curl forcing at the eastern boundary of the Atlantic. Seasonal geostrophic AMOC anomalies may represent an important and previously underestimated component of meridional transport and storage of heat in the subtropical North Atlantic. The study also suggests that aliasing of seasonal AMOC anomalies might have accounted for a large part of the inferred slowdown of the AMOC over the past several decades. The AMOC is visualized as the meridional overturning streamfunction Ψ(y,z,t) at any given latitude y, which is calculated from the northward velocity integrated over the Atlantic. The study presents a dataset and methodology for computing the strength and structure of the AMOC, and discusses the temporal variability and vertical structure of the AMOC, with a focus on seasonal anomalies. A forcing mechanism is proposed that accounts for a large fraction of the seasonal AMOC anomalies. The study also discusses the implications of the results and concludes that the seasonal cycle of the AMOC is dominated by wind stress curl forcing at the eastern boundary of the Atlantic. The study also highlights the importance of the seasonal cycle of the AMOC in the context of ocean heat storage and meridional heat transport. The study also discusses the limitations of the model and the need for further research to better understand the seasonal variability of the AMOC.The Atlantic Meridional Overturning Circulation (AMOC) at 26.5°N exhibits significant seasonal variability, with a mean strength of 18.7 ± 2.1 Sv (1 Sv = 10⁶ m³/s) over 48 months from April 2004 to April 2008. The seasonal cycle of the AMOC has a peak-to-peak amplitude of 6.7 Sv, with maximum strength in autumn and minimum in spring. While the northward Ekman transport was previously thought to dominate the seasonal cycle, this study shows that geostrophic midocean and Gulf Stream transports (2.2 and 1.7 Sv rms, respectively) are substantially larger than the Ekman component (1.2 Sv rms). A simple model based on linear dynamics suggests that the seasonal cycle is dominated by wind stress curl forcing at the eastern boundary of the Atlantic. Seasonal geostrophic AMOC anomalies may represent an important and previously underestimated component of meridional transport and storage of heat in the subtropical North Atlantic. The study also suggests that aliasing of seasonal AMOC anomalies might have accounted for a large part of the inferred slowdown of the AMOC over the past several decades. The AMOC is visualized as the meridional overturning streamfunction Ψ(y,z,t) at any given latitude y, which is calculated from the northward velocity integrated over the Atlantic. The study presents a dataset and methodology for computing the strength and structure of the AMOC, and discusses the temporal variability and vertical structure of the AMOC, with a focus on seasonal anomalies. A forcing mechanism is proposed that accounts for a large fraction of the seasonal AMOC anomalies. The study also discusses the implications of the results and concludes that the seasonal cycle of the AMOC is dominated by wind stress curl forcing at the eastern boundary of the Atlantic. The study also highlights the importance of the seasonal cycle of the AMOC in the context of ocean heat storage and meridional heat transport. The study also discusses the limitations of the model and the need for further research to better understand the seasonal variability of the AMOC.