The role of storm-relative advection of absolute angular momentum in strengthening of Atlantic tropical cyclones

Abstract

[1] This study examined absolute angular momentum tendency in Atlantic tropical cyclones. Each advective and torque term in the storm-relative Eulerian absolute angular momentum tendency equation was calculated in a storm relative reference frame using modeled and observational data. 18 storms between 2004 and 2006 were simulated using the hurricane weather research and forecast model. In addition, the storm-relative advection of absolute angular momentum was calculated using reconnaissance aircraft wind data from 12 Atlantic hurricanes which occurred between 2003 and 2007. Through methods of statistical correlation, categorical composition and linear regression, it was found that mid-level horizontal advection of relative angular momentum was most relevant to 12 hour strength change in the modeled tropical cyclones. Mid-level horizontal advection of relative angular momentum was most relevant to intensity change in the observed hurricanes, while mid-level advection of Earth's angular momentum was found to be most closely related to strength change in observed hurricanes.