| To analyze ATMS data characteristics and compare these with AMSUA/MHS, NPP-ATMS and NOAA-18 AMSUA/MHS from 8.1-8.30 in 2012 is used in the frame of WRFDA. Trials of bias correction and cloud detection of ATMS are conducted.Besides, the impact of assimilation of ATMS data on typhoon tracks forecasts are demonstrated.Conclusions are as follows:ATMS and AMSUA/MHS are obviously different in channel number, center frequency and polarization. ATMS has a broader range of the coverage and observation density, so that it can provide more information. The deviations of most ATMS sounding channels especially for midlevel temperature sounding channels, are less than corresponding AMSUA/MHS channels, except for some window channels and humidity channels. Attention should be paid as ATMS channel 3 has larger deviations than corresponding AMSUA/MHS channel 1.For ATMS own channels, deviations of window channels are the largest, the deviation of midlevel temperature channel is the least, the sizes of deviations of high level temperature channel and humidity channel are close. ATMS window channels have strong "limb effect", especially channel 1-2 and channel 16-17, and the characteristics of deviations vary with scan position are similar with corresponding AMSUA/MHS channels. The midlevel temperature channels of ATMS have least "limb effect". High-level temperature sounding channels have "limb effect’ while the effect is smaller than corresponding AMSUA/MHS channels. The corresponding channels biases of ATMS and AMSUA/MHS have similar variability with scan position although the latter one has a smoother result. After bias correction using coefficients derived from ATMS microwave data, it can reduce OMB bias, make bias to a Gaussian distribution and improving results of numerical prediction. Using a new cloud detecting scheme can improve numerical prediction effectively. The studies of individual cases show that assimilation of ATMS satellite microwave data can improve the prediction of typhoon tracks. |
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