Geophysical Research Letters, 27, 1739-1742.

Effect of ENSO and the MJO on Western North Pacific Tropical Cyclones

Adam H. Sobel
Department of Applied Physics and Applied Mathematics and Department of Earth and Environmental Sciences, Columbia University, New York, NY.

Eric D. Maloney
Department of Atmospheric Sciences, University of Washington, Seattle, Washington


Prior work has suggested that Rossby wave accumulation in the lower troposphere may be an important mechanism for the development of synoptic-scale disturbances in the western north Pacific in northern summer. This work examines the intraseasonal and interannual variability of wave accumulation by computing the barotropic wave activity flux divergence at 850 hPa for different phases of the Madden-Julian oscillation (MJO) and El Ni\~{n}o/southern oscillation (ENSO). Indirectly, and without ruling out other influences, the results suggest a physical mechanism behind previously identified relationships between tropical cyclogenesis statistics and these two modes of variability (MJO and ENSO).