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Journal of Meteorological Research 2016年第3期30卷 356-370页

作者：张堃吴春强李俊 Chinese Academy of Meteorological Sciences Beijing 100081China National Satellite Meteorological Center Beijing 100081China Cooperative Institute for Meteorological Satellite Studies University of Wisconsin-MadisonMadisonWI 53706USA

Considering the characteristics of nonlinear problems,a new method based on the L-curve method and including the concept of entropy was designed to select the regularization parameter in the one-dimensional variational analysis-based sounding retrieval *** the first iteration,this method uses an empirical regularization parameter derived by minimizing the entropy of *** subsequent iterations,it uses the L-curve method to select the regularization parameter in the vicinity of the regularization parameter selected in the last *** new method was employed to select the regularization parameter in retrieving atmospheric temperature and moisture profiles from atmospheric infrared sounder radiance measurements selected from the first day of each month in *** results show that compared with the original L-curve method,the new method yields 5.5%and 2.5%improvements on temperature and relative humidity profiles,*** with the discrepancy principle method,the improvements on temperature and relative humidity profiles are 1.6%and 2.0%,respectively.

关键词： atmospheric infrared sounder retrieval entropy L-curve regularization parameter

Influence of the Saharan Air Layer on Atlantic Tropical Cyclone Formation during the Period 1-12 September 2003

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Advances in atmospheric Sciences 2011年第1期28卷 16-32页

作者：潘维玉吴立广 Key Laboratory of Mesoscale Severe Weather of Ministry of Education School of Atmospheric SciencesNanjing University Key Laboratory of Meteorological Disaster of Ministry of Education Nanjing University of Information Science and Technology

atmospheric infrared sounder （AIRS） data show that the Saharan air layer （SAL） is a dry, warm, and well-mixed layer between 950 and 500 hPa over the tropical Atlantic, extending westward from the African coast to the Caribbean Sea. The formations of both Hurricane Isabel and Tropical Depression 14 （TD14） were accompanied with outbreaks of SAL air during the period 1-12 September 2003, although TD14 failed to develop into a named tropical cyclone. The influence of the SAL on their formations is investigated by examining data from satellite observations and numerical simulations, in which AIRS data are incorporated into the MM5 model through the nudging technique. Analyses of the AIRS and simulation data suggest that the SAL may have played two roles in the formation of tropical cyclones during the period 1-12 September 2003. First, the outbreaks of SAL air on 3 and 8 September enhanced the transverse-vertical circulation with the rising motion along the southern edge of the SAL and the sinking motion inside the SAL, triggering the development of two tropical disturbances associated with Hurricane Isabel and TD14. Second, in addition to the reduced environmental humidity and enhanced static stability in the lower troposphere, the SAL dry air intruded into the inner region of these tropical disturbances as their cyclonic ？ows became strong. This effect may have slowed down the formation of Isabel and inhibited TD14 becoming a named tropical cyclone, while the enhanced vertical shear contributed little to tropical cyclone formation during this period. The 48-h trajectory calculations confirm that the parcels from the SAL can be transported into the inner region of an incipient tropical cyclone.

关键词： tropical cyclone Saharan Air Layer atmospheric infrared sounder

Moisture Structure of the Quasi-biweekly Mode Revealed by AIRS in Western Pacific

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Advances in atmospheric Sciences 2009年第3期26卷 513-522页

作者：陶丽 Xiouhua FU 陆维松 Key Laboratory of Meteorological Disaster of Ministry of Education~Nanjing University of Information Science ＆ Technology Nanjing 210044 International Pacific Research Center School of Ocean Science and Technology University of Hawaii Honolulu HI 96822

Using atmospheric infrared sounder （AIRS） humidity profiles, rainfall from the Tropical Rainfall Measuring Mission （TRMM） Global Precipitation Index （GPI）, Quick Seatterometer （QSCAT） satellite-observed surface winds, and SST from the Advanced Microwave Scanning Radiometer for NASA＇s Earth Observing System （AMSR_E）, we analyzed the structure of the summer quasi-biweekly mode （QBM） over the western Pacific in 2003-2004. We find that the signal of 10 20-day oscillations in the western Pacific originates from the Philippine Sea, and propagates northwestward toward South China. The AIRS data reveal that the boundary-layer moisture provides preconditioning for QBM propagation, and leads the mid-troposphere moisture during the entire QBM cycle. The positive SST anomaly leads or is in-phase with the boundary- layer moistening, and may be a major contributor. Most likely, the 10 20-day SST anomaly positively feeds back to the atmosphere by moistening the boundary layer, destabilizing the troposphere, and leading the QBM to propagate northwestward in the western North Pacific. However, the ECMWF/TOGA （Tropical Ocean and Global Atmosphere） analysis does not display boundary-layer （BL） moisture anomalies leading the mid-troposphere moisture.

关键词： quasi-biweekly mode moisture structure atmospheric infrared sounder

A Solely Radiance-based Spectral Angular Distribution Model and Its Application in Deriving Clear-Sky Spectral Fluxes over Tropical Oceans

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Advances in atmospheric Sciences 2016年第2期33卷 259-268页

作者： Lei SONG Yinan WANG Institute of atmospheric Physics Chinese Academy of Sciences

The radiation budget at the top of the atmosphere plays a critical role in climate research. Compared to the broadband flux, the spectrally resolved outgoing longwave radiation or flux （OLR）, with rich atmospheric information in different bands, has obvious advantages in the evaluation of GCMs. Unlike methods that need auxiliary measurements and information, here we take atmospheric infrared sounder （AIRS） observations as an example to build a self-consistent algorithm by an angular distribution model （ADM）, based solely on radiance observations, to estimate clear-sky spectrally resolved fluxes over tropical oceans. As the key step for such an ADM, scene type estimations are obtained from radiance and brightness temperature in selected AIRS channels. Then, broadband OLR as well as synthetic spectral fluxes are derived by the spectral ADM and validated using both synthetic spectra and CERES （Clouds and the Earth＇s Radiant Energy System） observations. In most situations, the mean OLR differences between the spectral ADM products and the CERES observations are within -4-2 W m-2, which is less than 1% of the typical mean clear-sky OLR over tropical oceans. The whole algorithm described in this study can be easily extended to other similar hyperspectral radiance measurements.

关键词： hyperspectral radiance spectral angular distribution model scene type atmospheric infrared sounder