The MJO's Impacts on Global Tropical Cyclone Activity Using an Extended MJO Index (1905-2011)

While the impacts of the MJO on tropical cyclone activity for various basins around the globe have been well established, these relationships are typically only documented back to the mid 1970s, when outgoing longwave radiation became available. This study utilizes an extended reconstruction of the MJO back to 1905 using surface pressure data from the 20th Century Reanalysis to evaluate the stability of TC/MJO relationships for each of the global basins further back in time than has been done before. While there is increased uncertainty in both MJO position/amplitude as well as tropical cyclone data in the first part of the 20th century, in general, TC/MJO relationships demonstrated since the mid 1970s hold true since 1905. In addition, given the longer period of data examined here, we also evaluate the combined effects of El Nino-Southern Oscillation and the MJO on global TCs.