The normal mode method is adopted to decompose the differences between simulations with SST(sea surface temperature)anomahes over centra-eastern Pacific and normal SST by use of a nine-layer global spec- tral model in...The normal mode method is adopted to decompose the differences between simulations with SST(sea surface temperature)anomahes over centra-eastern Pacific and normal SST by use of a nine-layer global spec- tral model in order to investigate short-range climatic oscillation with various time scales forced by El Nino during the northern summer.Investigation shows that El Nino may have the following influence on atmosphere on various space-time scales.Extra-long wave components of Rossby mode forced by convective anomaly over equatorial western Pacific resulting from El Nino produce climatic oscillation on monthly(sea- sonal)time scale in middle-high latitudes of Southern and Northern Hemispheres;extra-long wave components of Kelvin mode forced by SST anomalies propagate along the equator,resulting in 30—60 day oscillation of tropical and subtropical atmosphere;and its long waves move eastward with westerly,resulting in quasi-biweek oscillation.展开更多
This paper discusses the stability structure and the bifurcation of phase path characteristics of synoptic scale system.The analytic results show that the catastrophe of the synoptic scale disturbance may be caused by...This paper discusses the stability structure and the bifurcation of phase path characteristics of synoptic scale system.The analytic results show that the catastrophe of the synoptic scale disturbance may be caused by the nonlinear effects of barotropic and baroclinic instability and advection of ambient large-scale flow.Also, foregoing nonlinear effects on the speed of development and decay of the system are presented in the processes deviating from or approaching to equilibrium state.It has been found that there is a resonance phenomenon between the time-oscillation of heat source and the atmospheric disturbance.展开更多
The combination of preozonation and subsequent biological granular activated carbon （O3/BAC） filtration is well known as a promising method for the removal of many pollutants. Temperature and nutrients are the domin...The combination of preozonation and subsequent biological granular activated carbon （O3/BAC） filtration is well known as a promising method for the removal of many pollutants. Temperature and nutrients are the dominant factors in external conditions to influence the biological communities. To explore the influence of preozonation under low temperature, the factors such as dissolved oxygen （DO）, dissolved organic carbon （DOC） and NH4^＋-N were analyzed from the sampling ports every week; triphenyl tetrazolium ehloride-dehydrogenase activity （TTC-DHA） and the nitrifying activity were detected along the bed height ofbiofilter at four levels （10. 40. 70 and i 10 cm） on the 90th, 110th, and 130th day; ~nicrobial community, based on 16S rRNA gene-denaturing gradient gel electrophoresis （DGGE）, was monitored on the 130th day of the operation. The observed microbial property showed that preozonation had a positive influence on bioactivity, biomass and nitrifying activity. Community analysis showed no significant difference on the biodiversity of nitrifying bacteria between the parallel filters in the inlet end based on the method employed. This result showed that biofilters＇ performance is not correlated well with microbial biodiversity. The elevated functionality in O3/BAC filters can be a result of increased microbial activity, which was promoted by preozonation.展开更多
文摘The normal mode method is adopted to decompose the differences between simulations with SST(sea surface temperature)anomahes over centra-eastern Pacific and normal SST by use of a nine-layer global spec- tral model in order to investigate short-range climatic oscillation with various time scales forced by El Nino during the northern summer.Investigation shows that El Nino may have the following influence on atmosphere on various space-time scales.Extra-long wave components of Rossby mode forced by convective anomaly over equatorial western Pacific resulting from El Nino produce climatic oscillation on monthly(sea- sonal)time scale in middle-high latitudes of Southern and Northern Hemispheres;extra-long wave components of Kelvin mode forced by SST anomalies propagate along the equator,resulting in 30—60 day oscillation of tropical and subtropical atmosphere;and its long waves move eastward with westerly,resulting in quasi-biweek oscillation.
文摘This paper discusses the stability structure and the bifurcation of phase path characteristics of synoptic scale system.The analytic results show that the catastrophe of the synoptic scale disturbance may be caused by the nonlinear effects of barotropic and baroclinic instability and advection of ambient large-scale flow.Also, foregoing nonlinear effects on the speed of development and decay of the system are presented in the processes deviating from or approaching to equilibrium state.It has been found that there is a resonance phenomenon between the time-oscillation of heat source and the atmospheric disturbance.
文摘The combination of preozonation and subsequent biological granular activated carbon （O3/BAC） filtration is well known as a promising method for the removal of many pollutants. Temperature and nutrients are the dominant factors in external conditions to influence the biological communities. To explore the influence of preozonation under low temperature, the factors such as dissolved oxygen （DO）, dissolved organic carbon （DOC） and NH4^＋-N were analyzed from the sampling ports every week; triphenyl tetrazolium ehloride-dehydrogenase activity （TTC-DHA） and the nitrifying activity were detected along the bed height ofbiofilter at four levels （10. 40. 70 and i 10 cm） on the 90th, 110th, and 130th day; ~nicrobial community, based on 16S rRNA gene-denaturing gradient gel electrophoresis （DGGE）, was monitored on the 130th day of the operation. The observed microbial property showed that preozonation had a positive influence on bioactivity, biomass and nitrifying activity. Community analysis showed no significant difference on the biodiversity of nitrifying bacteria between the parallel filters in the inlet end based on the method employed. This result showed that biofilters＇ performance is not correlated well with microbial biodiversity. The elevated functionality in O3/BAC filters can be a result of increased microbial activity, which was promoted by preozonation.
