Abstract
The near real-time NRL global tropical cyclone (TC) monitoring system based on multiple satellite passive microwave (PMW) sensors is improved with a new inter-sensor calibration scheme to correct the biases caused by differences in these sensor’s high frequency channels. Since the PMW sensor 89 GHz channel is used in multiple current and near future operational and research satellites, a unified scheme to calibrate all satellite PMW sensor’s ice scattering channels to a common 89 GHz is created so that their brightness temperatures (TBs) will be consistent and permit more accurate manual and automated analyses. In order to develop a physically consistent calibration scheme, cloud resolving model simulations of a squall line system over the west Pacific coast and hurricane Bonnie in the Atlantic Ocean are applied to simulate the views from different PMW sensors. To clarify the complicated TB biases due to the competing nature of scattering and emission effects, a four-cloud based calibration scheme is developed (rain, non-rain, light rain, and cloudy). This new physically consistent inter-sensor calibration scheme is then evaluated with the synthetic TBs of hurricane Bonnie and a squall line as well as observed TCs. Results demonstrate the large TB biases up to 13 K for heavy rain situations before calibration between TMI and AMSR-E are reduced to less than 3 K after calibration. The comparison stats show that the overall bias and RMSE are reduced by 74% and 66% for hurricane Bonnie, and 98% and 85% for squall lines, respectively. For the observed hurricane Igor, the bias and RMSE decrease 41% and 25% respectively. This study demonstrates the importance of TB calibrations between PMW sensors in order to systematically monitor the global TC life cycles in terms of intensity, inner core structure and convective organization. A physics-based calibration scheme on TC’s TB corrections developed in this study is able to significantly reduce the biases between different PMW sensors.
Highlights
Severe weather phenomena such as tropic cyclones (TC), especially intense TCs, can bring dramatic damages to societies, properties and human lives
The large brightness temperature (TB) depressions caused by ice scattering at 85–91 GHz (40–60 K) provides excellent all-weather views of storm rainband organization and inner core structure that is highly correlated with storm intensity [3,4,5]
Similar results are found for the squall line case except with a small value of TB corrections because the convection intensity of the squall line is much weaker than hurricane Bonnie (Figure 4b)
Summary
Severe weather phenomena such as tropic cyclones (TC), especially intense TCs, can bring dramatic damages to societies, properties and human lives. The passive microwave (PMW) imager channels onboard low earth orbiting (LEO) satellites observe radiances from both the Earth’s surface and cloud emissions as well as scattering by ice particles associated with intense convection (eyewall and rainbands). The high frequency (85–91 GHz) PMW sensor channels are a suitable choice for monitoring TC location, structure, and intensity because of their ability to penetrate clouds and mitigate VIS/IR deficiencies and their modest spatial resolution (5–13 km). By using a combination of both operational and research satellite PMW sensors available in near real-time, we are able to globally track the life cycles of TCs in terms of location, intensity, structure, movement, and aspects of rapid intensification (Kieper and Jiang, 2012 [11]). Mission (TRMM) microwave imager (TMI), Special Sensor Microwave/Imager (SSM/I), and Special Sensor Microwave Imager Sounder (SSMIS) for tropical cyclone Jasmine on
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
