Reanalysis of western Pacific typhoons in 2004 with multi-satellite observations

18 A pilot tropical cyclone reanalysis project was conducted 19 to construct a reliable, high temporal and spatial resolu20 tion tropical cyclone dataset for selected western Pacific 21 typhoons in summer 2004, with the application of the latest 22 satellite observations and a 4-dimensional variational data 23 assimilation method. Primary data used for the reanalysis 24 include SSM=I rain rate, GOES-retrieved upper-level wind, 25 QuikSCAT surface wind, Aqua AIRS=AMSU retrieved 26 temperature and moisture profiles, and JTWC best track 27 data. A regular reanalysis procedure was established and 28 up to 12 western Pacific typhoons have been reanalyzed. 29 The reanalysis period covers the entire life cycle of a 30 tropical cyclone, from a few days prior to its genesis to 31 its final decay stage. A preliminary analysis shows that the 32 reanalysis product significantly improves typhoon in33 tensity, structure, and track, compared to the NCEP op34 erational final analysis. The validation of the TC structure 35 against independent observations shows that the reanaly36 sis reproduces well the asymmetric characteristics of TC 37 rain bands and cloud bands. A further modeling experiment 38 with an initial condition from the reanalysis product reveals 39 a significant improvement in typhoon intensity forecast 40 compared to a parallel experiment with an initial condition 41 from the NCEP final analysis, which provides a further 42 indication of quality of the tropical cyclone reanalysis. 43 The reanalysis product and the raw observational data will 44 soon be posted on the data server of the IPRC Asia-Pacific 45 Data-Research Center (http:==apdrc.soest.hawaii.edu=) for 46 public use. 47 48