The inflow angle of tropical cyclones （TC） is generally neglected in numerical studies of ocean surface waves induced by TC. In this study, the impacts of TC inflow angle on ocean surface waves were investigated usi...The inflow angle of tropical cyclones （TC） is generally neglected in numerical studies of ocean surface waves induced by TC. In this study, the impacts of TC inflow angle on ocean surface waves were investigated using a high-resolution wave model. Six numerical experiments were conducted to examine, in detail, thc effects of inflow angle on mean wave parameters and the spectrum of wave directions. A comparison of the waves simulated in these experiments shows that inflow angle significantly modifies TC-induced ocean surface waves. As the inflow angle increases, the asymmetric axis of the significant wave height （SWH） field shifts 30° clockwise, and the maximum SWH moves from the front-right to the rear-right quadrant. Inflow angle also affects other mean wave parameters, especially in the rear-left quadrant, such as the mean wave direction, the mean wavelength, and the peak direction. Inflow angle is a key factor in wave models for the reproduction of double-peak or multi-peak patterns in the spectrum of wave directions. Sensitivity experiments also show that the simulation with a 40° inflow angle is the closest to that of the NOAA statistical SLOSH inflow angle. This suggests that 40° can be used as the inflow angle in future TC-induced ocean surface wave simulations when SLOSH or observed inflow angles are not available.展开更多
Simulated outgoing longwave radiation （OLR） outputs by two versions of the grid-point atmospheric general circulation model （GAMIL） were analyzed to assess the influences of improvements in cloud microphysics and ...Simulated outgoing longwave radiation （OLR） outputs by two versions of the grid-point atmospheric general circulation model （GAMIL） were analyzed to assess the influences of improvements in cloud microphysics and convective parameterization schemes on the simulation of the Madden-Julian oscillation （MJO） and other tropical waves. The wavenumber-frequency spectral analysis was applied to isolate dominant modes of convectively coupled equatorial waves, including the M30, Kelvin, equatorial Rossby （ER）, mixed Rossby-gravity （MRG）, and inertio-gravity （1G） waves. The performances of different versions of the GAMIL model （version 1.0 （GAMIL1.0） and version 2.0 （GAMIL2.0）） were evalu- ated by comparing the power spectrum distributions of these waves among GAMIL 1.0, GAMIL2.0, and observational data. GAMIL1.0 shows a weak MJO signal, with the maximum variability occurring separately at wavenumbers 1 and 4 rather than being concentrated on wavenumbers 1-3, suggesting that GAMILI.0 could not effectively capture the intraseasonal variability. However, GAMIL2.0 is able to effectively reproduce both the symmetric and anti-symmetric waves, and the significant spectra of the MJO, Kelvin, and MRG waves are in agreement with observational data, indicating that the ability of GAMIL2.0 to simulate the MJO and other tropical waves is enhanced by improving the cloud microphysics and convective parameterization schemes and implying that such improvements are crucial to further improving this model＇s performance.展开更多
Peristaltic flow of magnetohydrodynamic （MHD） Williamson fluid in a symmetric chan- nel is addressed. Modeling is given with Sorer and Dufour effects. Channel walls have compliant properties. Analysis has been carri...Peristaltic flow of magnetohydrodynamic （MHD） Williamson fluid in a symmetric chan- nel is addressed. Modeling is given with Sorer and Dufour effects. Channel walls have compliant properties. Analysis has been carried out through long wavelength and low Reynolds number approach. The obtained series solutions for small Weissenberg number are developed. Impact of variables reflecting the salient features of wall properties, Blot numbers and Soret and Dufour on the velocity, temperature and concentration has been point out. Trapping phenomenon is also analyzed.展开更多
基金Supported by the National Natural Science Foundation of China(No. 40706008)the Open Research Program of the Chinese Academy Sciences Key Laboratory of Tropical Marine Environmental Dynamics (No. LED0606)+1 种基金the Shandong Province Natural Science Foundation (No. Z2008E02)the National High Technology Research and Development Program of China (863 Program) (No.2008AA09A402)
文摘The inflow angle of tropical cyclones （TC） is generally neglected in numerical studies of ocean surface waves induced by TC. In this study, the impacts of TC inflow angle on ocean surface waves were investigated using a high-resolution wave model. Six numerical experiments were conducted to examine, in detail, thc effects of inflow angle on mean wave parameters and the spectrum of wave directions. A comparison of the waves simulated in these experiments shows that inflow angle significantly modifies TC-induced ocean surface waves. As the inflow angle increases, the asymmetric axis of the significant wave height （SWH） field shifts 30° clockwise, and the maximum SWH moves from the front-right to the rear-right quadrant. Inflow angle also affects other mean wave parameters, especially in the rear-left quadrant, such as the mean wave direction, the mean wavelength, and the peak direction. Inflow angle is a key factor in wave models for the reproduction of double-peak or multi-peak patterns in the spectrum of wave directions. Sensitivity experiments also show that the simulation with a 40° inflow angle is the closest to that of the NOAA statistical SLOSH inflow angle. This suggests that 40° can be used as the inflow angle in future TC-induced ocean surface wave simulations when SLOSH or observed inflow angles are not available.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (KZCX2-YW- Q11-04)the National Basic Research Program of China (2011 CB403505 and 2010CB950402)the National Natural Science Foundation of China (40975052)
文摘Simulated outgoing longwave radiation （OLR） outputs by two versions of the grid-point atmospheric general circulation model （GAMIL） were analyzed to assess the influences of improvements in cloud microphysics and convective parameterization schemes on the simulation of the Madden-Julian oscillation （MJO） and other tropical waves. The wavenumber-frequency spectral analysis was applied to isolate dominant modes of convectively coupled equatorial waves, including the M30, Kelvin, equatorial Rossby （ER）, mixed Rossby-gravity （MRG）, and inertio-gravity （1G） waves. The performances of different versions of the GAMIL model （version 1.0 （GAMIL1.0） and version 2.0 （GAMIL2.0）） were evalu- ated by comparing the power spectrum distributions of these waves among GAMIL 1.0, GAMIL2.0, and observational data. GAMIL1.0 shows a weak MJO signal, with the maximum variability occurring separately at wavenumbers 1 and 4 rather than being concentrated on wavenumbers 1-3, suggesting that GAMILI.0 could not effectively capture the intraseasonal variability. However, GAMIL2.0 is able to effectively reproduce both the symmetric and anti-symmetric waves, and the significant spectra of the MJO, Kelvin, and MRG waves are in agreement with observational data, indicating that the ability of GAMIL2.0 to simulate the MJO and other tropical waves is enhanced by improving the cloud microphysics and convective parameterization schemes and implying that such improvements are crucial to further improving this model＇s performance.
文摘Peristaltic flow of magnetohydrodynamic （MHD） Williamson fluid in a symmetric chan- nel is addressed. Modeling is given with Sorer and Dufour effects. Channel walls have compliant properties. Analysis has been carried out through long wavelength and low Reynolds number approach. The obtained series solutions for small Weissenberg number are developed. Impact of variables reflecting the salient features of wall properties, Blot numbers and Soret and Dufour on the velocity, temperature and concentration has been point out. Trapping phenomenon is also analyzed.
