Analysis and High-Resolution Modeling of Tropical Cyclogenesis during the TCS-08 and TPARC Field Campaign

The accurate prediction of tropical cyclone (TC) genesis, structure, and intensity changes is critical to Navy missions and civilian activities in coastal areas. Significant gains have been made in TC track prediction over the past decades. However, genesis and intensity forecasts have shown very little progress during the same time period. A primary contributing factor to our lack of skill in the prediction of TC genesis and intensity is our lack of observations prior to and during TC genesis and intensification periods, and an inadequate understanding of the physical mechanisms that control cyclogenesis and intensity changes. The TCS-08 and TPARC field campaign provide an unprecedented opportunity for us to gain first-hand observations of TC genesis in the western Pacific, and to compare them with high-resolution model simulations. By analyzing and assimilating these observation data, we intend to better understand the physical mechanisms involved in TC internal dynamic and thermodynamic processes, external forcing, and scale interactions. Only after thoroughly understanding these processes can one tackle the weaknesses in current state-of-the-art weather forecast models. The objective of this project is to investigate the synoptic and climatic aspects of TC genesis in the western North Pacific. We will investigate the specific synoptic and dynamic processes through which an initial weak vortex (either mid-level or near-bottom vortex) develops into a TC using a cloud-resolving model. We also will examine the large-scale control of the Madden-Julian Oscillation (MJO) and the El Nino-Southern Oscillation (ENSO) on TC genesis in the western North Pacific. In addition, we will conduct data assimilation using data collected from the TCS-08 observational campaign. We will examine how the cyclogenesis forecast may be significantly improved with a better description of the dynamic and thermodynamic precursor signals.