The vertical resolution of LICOM1.0 (LASG/IAP Climate System Ocean Model, version 1.0) is adjusted by increasing the level amount within the upper 150 m while keeping the total of levels. It is found that the eastern ...The vertical resolution of LICOM1.0 (LASG/IAP Climate System Ocean Model, version 1.0) is adjusted by increasing the level amount within the upper 150 m while keeping the total of levels. It is found that the eastern equatorial Pacific cold tongue is sensitive to the adjustment. Compared with the simulation of the original level scheme, the adjusting yields a more realistic structure of cold tongue extending from the coast of Peru to the equator, as well as a temperature minimum at Costa Rica coast, north of the cold tongue. In the original scheme experiment, the sharp heating by net surface heat flux at the beginning of spin-up leads to a great warm- ing in the eastern equatorial Pacific Ocean. The weak vertical advection due to a too thick mixed layer in the coarse vertical structure also accounts for the warm bias. The fact that most significant improvements of the upper 50 m temperature appear at the region of the thinnest mixed layer indicates the necessity of fine vertical resolution for the eastern equatorial Pacific Ocean. However, the westward extension of equatorial cold tongue, a defect in the original scheme, gets even more serious in the adjusting scheme due to the intensi- fied vertical velocity and hence vertical advection in the central-eastern equatorial Pacific Ocean.展开更多
In this paper, a difference scheme with energy dynamic equilibrium (DS-EDE) is presented, which can be used for the simulation of long-term atmosphere and sea motion. Based on three dimensional nonlinear evolution equ...In this paper, a difference scheme with energy dynamic equilibrium (DS-EDE) is presented, which can be used for the simulation of long-term atmosphere and sea motion. Based on three dimensional nonlinear evolution equations for atmosphere and sea motion, a three dimensional compact upwind scheme (CUWS) is constructed, as the basis of the DS-EDE. The DS-EDE satisfies the following condition of energy dynamic equilibrium (EDE): the total work of external forces on the region boundary is equal to the sum of the total effective variation of the kinetic energy and the energy dissipation in the average flow motion and the effective variation of the potential energy per unit time within the region of interest. It really reflects the basic mechanism of the action of external forces and dissipation in atmosphere and sea movement. Therefore, the DS-EDE developed in this paper is a suitable model for simulating long-term atmosphere and sea movement with forcing and dissipation.展开更多
An eddy-permitting quasi-global oceanic GCM was driven by wind stresses from reanalysis data for the pe- riod of 1958—2001 to get the time series of the upper circula- tion in the Indonesian Sea. The model represents...An eddy-permitting quasi-global oceanic GCM was driven by wind stresses from reanalysis data for the pe- riod of 1958—2001 to get the time series of the upper circula- tion in the Indonesian Sea. The model represents a reason- able pathway of Indonesian Throughflow (ITF) with Makas- sar Strait making the major passage transfer the North Pa- cific water southward. The simulated annual mean ITF transport is 14.5 Sv, with 13.2 Sv in the upper 700 m. Annual cycle is the dominant signal for the seasonal climatology of the upper layer transport. Both the annual mean and sea- sonal cycle agree well with the observation. The overall cor- relation between the interannual anomaly of the ITF trans- port and Ni?o 3.4 index reaches ?0.65 in the simulation, which indicates that ENSO-related interannual variability in the Pacific is dominant in controlling the ITF transport. The relationship between the interannual anomalies of ITF and sea surface temperature in the Pacific, the Indian Ocean is not fixed in the simulation. In 1994, for instance, the intensive Indian Ocean sea surface temperature anomaly plays a dominant role in the formation of an impressive large transport of ITF.展开更多
An optical model accounting for the East Asian dust is proposed as a result of theory calculation and compo-sition analysis of the aerosol samples collected in China de-sert during the international project, Studies o...An optical model accounting for the East Asian dust is proposed as a result of theory calculation and compo-sition analysis of the aerosol samples collected in China de-sert during the international project, Studies on the Origin and Transport of Aeolian Dust and its Effects on Climate (ADEC). Study indicates that dust aerosols emitting from China deserts have smaller imaginary parts of refractive indices, therefore absorb less and scatter more solar radia-tion than the most dust optical models published so far. Fur-thermore, the forward fraction of scattering is less and the backscattering is stronger than those of the other models. The seasonal averaged radiative forcing in spring, 2001 over east Asia-north Pacific region is simulated employing the new dust optical model. The net forcing at the top of atmos-phere (TOA) is estimated as -0.943 W·m-2 for regional and seasonal mean, with shortwave and longwave contributions of -1.700 and 0.759 W·m-2, respectively. The surface net forcing is calculated to be -5.445 W·m-2, and made up of shortwave component of -6.250 W·m-2 and longwave component of +0.759 W·m-2. The distributions of TOA and surface net forcing over this region are also analyzed in this study.展开更多
The linear barotropic vorticity equation describing wind-driven oceancirculation is considered as a convection-diffusion equation that can be numerically solved bylattice Boltzmann method. Numerical experiments are ca...The linear barotropic vorticity equation describing wind-driven oceancirculation is considered as a convection-diffusion equation that can be numerically solved bylattice Boltzmann method. Numerical experiments are carried out to examine the validity of the modelfor the wind-driven circulation. When horizontal viscosity is constant and spatially uniform, allnumerical solutions for different parameters approach analytical solutions well. The spatiallyvarying horizontal viscosity is also included in this model. It is shown that the variant horizontalviscosity increases the meridional transport significantly in west boundary current. By theinvestigation of numerical results, it was concluded that this model is competent for simulatingwestern boundary current.展开更多
文摘The vertical resolution of LICOM1.0 (LASG/IAP Climate System Ocean Model, version 1.0) is adjusted by increasing the level amount within the upper 150 m while keeping the total of levels. It is found that the eastern equatorial Pacific cold tongue is sensitive to the adjustment. Compared with the simulation of the original level scheme, the adjusting yields a more realistic structure of cold tongue extending from the coast of Peru to the equator, as well as a temperature minimum at Costa Rica coast, north of the cold tongue. In the original scheme experiment, the sharp heating by net surface heat flux at the beginning of spin-up leads to a great warm- ing in the eastern equatorial Pacific Ocean. The weak vertical advection due to a too thick mixed layer in the coarse vertical structure also accounts for the warm bias. The fact that most significant improvements of the upper 50 m temperature appear at the region of the thinnest mixed layer indicates the necessity of fine vertical resolution for the eastern equatorial Pacific Ocean. However, the westward extension of equatorial cold tongue, a defect in the original scheme, gets even more serious in the adjusting scheme due to the intensi- fied vertical velocity and hence vertical advection in the central-eastern equatorial Pacific Ocean.
基金This study was supported by China Institute for Radiation Protection,partly by State Key Laboratory of Numerical Modeling for Atmosphenc Sciences and Geophysical Fluid Dynamics.
文摘In this paper, a difference scheme with energy dynamic equilibrium (DS-EDE) is presented, which can be used for the simulation of long-term atmosphere and sea motion. Based on three dimensional nonlinear evolution equations for atmosphere and sea motion, a three dimensional compact upwind scheme (CUWS) is constructed, as the basis of the DS-EDE. The DS-EDE satisfies the following condition of energy dynamic equilibrium (EDE): the total work of external forces on the region boundary is equal to the sum of the total effective variation of the kinetic energy and the energy dissipation in the average flow motion and the effective variation of the potential energy per unit time within the region of interest. It really reflects the basic mechanism of the action of external forces and dissipation in atmosphere and sea movement. Therefore, the DS-EDE developed in this paper is a suitable model for simulating long-term atmosphere and sea movement with forcing and dissipation.
文摘An eddy-permitting quasi-global oceanic GCM was driven by wind stresses from reanalysis data for the pe- riod of 1958—2001 to get the time series of the upper circula- tion in the Indonesian Sea. The model represents a reason- able pathway of Indonesian Throughflow (ITF) with Makas- sar Strait making the major passage transfer the North Pa- cific water southward. The simulated annual mean ITF transport is 14.5 Sv, with 13.2 Sv in the upper 700 m. Annual cycle is the dominant signal for the seasonal climatology of the upper layer transport. Both the annual mean and sea- sonal cycle agree well with the observation. The overall cor- relation between the interannual anomaly of the ITF trans- port and Ni?o 3.4 index reaches ?0.65 in the simulation, which indicates that ENSO-related interannual variability in the Pacific is dominant in controlling the ITF transport. The relationship between the interannual anomalies of ITF and sea surface temperature in the Pacific, the Indian Ocean is not fixed in the simulation. In 1994, for instance, the intensive Indian Ocean sea surface temperature anomaly plays a dominant role in the formation of an impressive large transport of ITF.
文摘An optical model accounting for the East Asian dust is proposed as a result of theory calculation and compo-sition analysis of the aerosol samples collected in China de-sert during the international project, Studies on the Origin and Transport of Aeolian Dust and its Effects on Climate (ADEC). Study indicates that dust aerosols emitting from China deserts have smaller imaginary parts of refractive indices, therefore absorb less and scatter more solar radia-tion than the most dust optical models published so far. Fur-thermore, the forward fraction of scattering is less and the backscattering is stronger than those of the other models. The seasonal averaged radiative forcing in spring, 2001 over east Asia-north Pacific region is simulated employing the new dust optical model. The net forcing at the top of atmos-phere (TOA) is estimated as -0.943 W·m-2 for regional and seasonal mean, with shortwave and longwave contributions of -1.700 and 0.759 W·m-2, respectively. The surface net forcing is calculated to be -5.445 W·m-2, and made up of shortwave component of -6.250 W·m-2 and longwave component of +0.759 W·m-2. The distributions of TOA and surface net forcing over this region are also analyzed in this study.
文摘The linear barotropic vorticity equation describing wind-driven oceancirculation is considered as a convection-diffusion equation that can be numerically solved bylattice Boltzmann method. Numerical experiments are carried out to examine the validity of the modelfor the wind-driven circulation. When horizontal viscosity is constant and spatially uniform, allnumerical solutions for different parameters approach analytical solutions well. The spatiallyvarying horizontal viscosity is also included in this model. It is shown that the variant horizontalviscosity increases the meridional transport significantly in west boundary current. By theinvestigation of numerical results, it was concluded that this model is competent for simulatingwestern boundary current.
