Special satellite data analysis and NWP impact studies during TPARC

For the Thorpex-Pacific Regional Campaign (TPARC) and the Tropical Cyclone Structure (TCS) field experiments conducted over the western North Pacific in 2008, special high-resolution (space and time) MTSAT atmospheric motion vector (AMV) datasets and derived diagnostics were routinely created at UWisc.-CIMSS during the two month experiment period, with enhanced datasets from MTSAT rapid-scan imagery during selected TC events. The AMVs capture crucial storm and environmental flow characteristics that are important to the diagnosis of structure/intensity changes, as well as initialization data for NWP forecasting of track and intensity. The derived products include storm canopy-level divergence and vorticity, and deep-layer environmental shear, which are used to investigate TC genesis, development, and intensity change.

During TPARC/TCS, CIMSS produced the AMV datasets every hour, appreciably increasing the temporal coverage over routinely available operational AMVs (6-hourly). These hourly AMVs are being tested in data denial experiments within a 4D-VAR version of the Navy Operational Global Atmospheric Prediction System (NOGAPS). The experiments are focusing on Typhoons Nuri and Sinlaku, two storms that were sampled extensively during the TPARC/TCS field exercise. In addition to the hourly AMVs, CIMSS also derived AMVs during special MTSAT rapid-scans for TCs Sinlaku and Jangmi during the experiment. The more frequent satellite images produce AMVs that can more coherently track cloud motions, and better capture mesoscale flows that may be important scales to capture for process studies involving TC intensity change dynamics.

This talk will summarize the preliminary results from the NOGAPS data impact experiments. It will also describe some of the TC diagnostic studies being conducted using the AMV datasets.