1986 Vol. 3, No. 2
Display Method:
1986, 3(2): 139-149.
doi: 10.1007/BF02682548
Abstract:
Case experiments of monthly predictions of eight winter months during 1976－1977 and 1982－1983 El Nino events are performed by using a three-layer anomalous filtered model (AFM), in which transient Rossby waves are filtered. The results show that this model predicts successfully the large-scale patterns of the monthly mean surface temperature anomalies. The correlation coefficients between observations and predic-tions are basically higher than those of persistence predictions. By comparison with the anomalous general circulation model (AGCM) the AFM gives almost the identical results, but the computation time required for running the AFM is nearly 100 times less than that required for running the AGCM. It is also shown that the results of the three-layer model are better than those of the one-layer model. In the meanwhile, four seasonal forecasts are also earned out by using the same model. It seems that the AFM possesses potential ability in predicting large-scale circulation anomalies.On the basis of the works done during the last decade and of the results in this paper, the predicting ability of the AFM is summed up in the last section.
Case experiments of monthly predictions of eight winter months during 1976－1977 and 1982－1983 El Nino events are performed by using a three-layer anomalous filtered model (AFM), in which transient Rossby waves are filtered. The results show that this model predicts successfully the large-scale patterns of the monthly mean surface temperature anomalies. The correlation coefficients between observations and predic-tions are basically higher than those of persistence predictions. By comparison with the anomalous general circulation model (AGCM) the AFM gives almost the identical results, but the computation time required for running the AFM is nearly 100 times less than that required for running the AGCM. It is also shown that the results of the three-layer model are better than those of the one-layer model. In the meanwhile, four seasonal forecasts are also earned out by using the same model. It seems that the AFM possesses potential ability in predicting large-scale circulation anomalies.On the basis of the works done during the last decade and of the results in this paper, the predicting ability of the AFM is summed up in the last section.
1986, 3(2): 150-161.
doi: 10.1007/BF02682549
Abstract:
In older to calculate updated coefficients for atmospheric temperature retrieval from satellite sounding data and radiosonde data, it is necessary to form statistical samples of real radiance and radiosonde data match-ups. A procedure is presented here for the data matchups. And a method of eigenvectors of statistical covariance matrices is used to produce updated coefficients for atmospheric temperature retrieval. The updated coefficients produced are tested using radiance observations from NOAA-7 satellite. Comparisons of these real-time retrieved data with radiosonde data show that the atmospheric temperature profiles retrieved have an accu-racy of RMS 2－3 degrees (oC). In addition, the error sources are also discussed.
In older to calculate updated coefficients for atmospheric temperature retrieval from satellite sounding data and radiosonde data, it is necessary to form statistical samples of real radiance and radiosonde data match-ups. A procedure is presented here for the data matchups. And a method of eigenvectors of statistical covariance matrices is used to produce updated coefficients for atmospheric temperature retrieval. The updated coefficients produced are tested using radiance observations from NOAA-7 satellite. Comparisons of these real-time retrieved data with radiosonde data show that the atmospheric temperature profiles retrieved have an accu-racy of RMS 2－3 degrees (oC). In addition, the error sources are also discussed.
1986, 3(2): 162-171.
doi: 10.1007/BF02682550
Abstract:
Analyzing in detail the dependence of sky radiance on aerosol optical property and surface albedo, we present a new method for simultaneous determination of aerosol size distribution, its wavelength-dependent refractive index and surface albedo. The aerosol scattering phase function near 10o, its weighted phase function near 40o introduced in this paper, which can be inferred from sky radiance data, and the radiance near 90o are respectively used in retrieving the real part of refractive index, its imaginary part and surface albedo. Results in numerical experiments are satisfactory under different given conditions.
Analyzing in detail the dependence of sky radiance on aerosol optical property and surface albedo, we present a new method for simultaneous determination of aerosol size distribution, its wavelength-dependent refractive index and surface albedo. The aerosol scattering phase function near 10o, its weighted phase function near 40o introduced in this paper, which can be inferred from sky radiance data, and the radiance near 90o are respectively used in retrieving the real part of refractive index, its imaginary part and surface albedo. Results in numerical experiments are satisfactory under different given conditions.
1986, 3(2): 172-188.
doi: 10.1007/BF02680044
Abstract:
In part I of this paper, we have discussed two problems: the general properties of two-dimensional baro-tropic motion and the evolution and structure of both Rossby wave packet and inertio-gravity wave packet. In this part, we shall continue our discussion. Third, normal modes and continuous spectra of both quasi-geostrophic and non-geostrophic models, their different behaviour, and the comparison of normal mode approach to the wave packet approach. Fourth, weakly nonlinear theory of interaction based on the analysis of eddy transports. A nonzonal basic flow as well as non-geostroptaic model is also included in the consideration. The last, the fully nonlinear theory, making emphasis on the conditions for the maintenance of nonzonal disturbances and the conditions for their continuous and complete absorption by the zonal flow. A comparison of Rossby wave absorption to energy cascade in the two-dimensional turbulence is also given.
In part I of this paper, we have discussed two problems: the general properties of two-dimensional baro-tropic motion and the evolution and structure of both Rossby wave packet and inertio-gravity wave packet. In this part, we shall continue our discussion. Third, normal modes and continuous spectra of both quasi-geostrophic and non-geostrophic models, their different behaviour, and the comparison of normal mode approach to the wave packet approach. Fourth, weakly nonlinear theory of interaction based on the analysis of eddy transports. A nonzonal basic flow as well as non-geostroptaic model is also included in the consideration. The last, the fully nonlinear theory, making emphasis on the conditions for the maintenance of nonzonal disturbances and the conditions for their continuous and complete absorption by the zonal flow. A comparison of Rossby wave absorption to energy cascade in the two-dimensional turbulence is also given.
1986, 3(2): 189-198.
doi: 10.1007/BF02682552
Abstract:
The three stairstep output of the video amplifier has now been designed for the NOAA/WPL dual-channel radiometer in order to provide an analog input to one A/D converter instead of to two phase-detectors, and the synchronous detection for data and AGC is done in software. We put the new system into the dual-channel radiometer which was set in Boulder Atmospheric Observatory (BAO) to make experiments for three weeks and found the processor reliable and flexible.
The three stairstep output of the video amplifier has now been designed for the NOAA/WPL dual-channel radiometer in order to provide an analog input to one A/D converter instead of to two phase-detectors, and the synchronous detection for data and AGC is done in software. We put the new system into the dual-channel radiometer which was set in Boulder Atmospheric Observatory (BAO) to make experiments for three weeks and found the processor reliable and flexible.
1986, 3(2): 199-207.
doi: 10.1007/BF02682553
Abstract:
Aerosol sampling was carried out at a city centre site and a suburb site in Beijing in January 1983. PIXE (Proton Induced X-ray Emission) compatible cascade impactors were employed. The samples were analysed for 20 elements by PIXE in Fudan University. It has been found that most of the elements have bi-mode size distributions with a gradual progression from mainly coarse mode Ca, Ti and Al to mainly fine mode Zn, As and Pb. Elements Cl, K, S and Si show most obvious bi-mode, of which Si and S are particularly interesting. The concentrations of coarse mode aerosol in the city centre are about 1.4 times as large as that in the suburb for most of the elements, while the concentrations of fine mode aerosol in the city centre differ greatly from that in the suburb and vary significantly among elements, indicating some industrial sources. The enrichment factors of elements indicate that the coal smoke has a large-scale influ-ence in North China.
Aerosol sampling was carried out at a city centre site and a suburb site in Beijing in January 1983. PIXE (Proton Induced X-ray Emission) compatible cascade impactors were employed. The samples were analysed for 20 elements by PIXE in Fudan University. It has been found that most of the elements have bi-mode size distributions with a gradual progression from mainly coarse mode Ca, Ti and Al to mainly fine mode Zn, As and Pb. Elements Cl, K, S and Si show most obvious bi-mode, of which Si and S are particularly interesting. The concentrations of coarse mode aerosol in the city centre are about 1.4 times as large as that in the suburb for most of the elements, while the concentrations of fine mode aerosol in the city centre differ greatly from that in the suburb and vary significantly among elements, indicating some industrial sources. The enrichment factors of elements indicate that the coal smoke has a large-scale influ-ence in North China.
1986, 3(2): 208-214.
doi: 10.1007/BF02682554
Abstract:
Analyses are made of all terms in the vorticity equation for the atmosphere at low latitudes by using the scale analysis theory, with the result that for synotic-scale motion the baroclinic term, i. e. the twisting term and the vorticity vertical-transport term, approximates in order to the relative-vorticity advection, divergence and β term. With intensified atmospheric disturbance ratios of the β term to others become smaller while the others stay in more or less fixed proportions between them. This statement has been confirmed by the results of 22 typhoons calculated covering a large area in low latitudes. Besides, the baroclinic term for the genesis and development of 6 typhoons over 1979－1980 is calculated and the results ob-tained show that it has significant effect. Finally, the baroclinicity is shown not to be ignored in dealing with synoptics and dynamics of synoptic-scale systems such as typhoons and easterly waves.
Analyses are made of all terms in the vorticity equation for the atmosphere at low latitudes by using the scale analysis theory, with the result that for synotic-scale motion the baroclinic term, i. e. the twisting term and the vorticity vertical-transport term, approximates in order to the relative-vorticity advection, divergence and β term. With intensified atmospheric disturbance ratios of the β term to others become smaller while the others stay in more or less fixed proportions between them. This statement has been confirmed by the results of 22 typhoons calculated covering a large area in low latitudes. Besides, the baroclinic term for the genesis and development of 6 typhoons over 1979－1980 is calculated and the results ob-tained show that it has significant effect. Finally, the baroclinicity is shown not to be ignored in dealing with synoptics and dynamics of synoptic-scale systems such as typhoons and easterly waves.
1986, 3(2): 215-226.
doi: 10.1007/BF02682555
Abstract:
China is situated in the region of the prevailing East Asian monsoon, which has obvious seasonal varia-tion. There exists a close relation between the long-distance northward and southward movement of arrayworms and the seasonal variation of the general circulation in the lower atmosphere over East Asia. So accord-ing to the data of moths and the notes of meteorological observation, we put emphasis on analysing the problems of the transmigration direction, height, limits, ascending and descending condition of armyworms and moths base in this country, and then draw the transmigration route diagram.
China is situated in the region of the prevailing East Asian monsoon, which has obvious seasonal varia-tion. There exists a close relation between the long-distance northward and southward movement of arrayworms and the seasonal variation of the general circulation in the lower atmosphere over East Asia. So accord-ing to the data of moths and the notes of meteorological observation, we put emphasis on analysing the problems of the transmigration direction, height, limits, ascending and descending condition of armyworms and moths base in this country, and then draw the transmigration route diagram.
1986, 3(2): 227-237.
doi: 10.1007/BF02682556
Abstract:
Effects of various radiation models and spectral data on the calculation of the atmospheric infrared cool-ing rates (IRCR) have been systematically investigated by contrasting with a model, whose accuracy of IR transmission function is comparable to that of exact line-by-line integration, as a reference model.
Effects of various radiation models and spectral data on the calculation of the atmospheric infrared cool-ing rates (IRCR) have been systematically investigated by contrasting with a model, whose accuracy of IR transmission function is comparable to that of exact line-by-line integration, as a reference model.
1986, 3(2): 238-244.
doi: 10.1007/BF02682557
Abstract:
By using a linear oceanic mixed layer model, the long period waves in the tropical ocean are investi-gated numerically. Due to the inhomogeneity of the large-scale average sea temperature field of the ocean in tropical regions, besides the westward propagating equatorial Rossby wave to be modified, there will be a kind of long period thermal wave which propagates eastward under certain oceanic background conditions. Under the influences of these two kinds of waves, the propagating and evolving processes of the sea surface temperature anomalies (SSTA) are dearly shown by numerical experiments. The results of numerical ex-periments are consistent with the ones obtained by the theoretical analysis in Part I. The possible relation-ship between these two kinds of waves and El Nino events is also discussed indirectly.
By using a linear oceanic mixed layer model, the long period waves in the tropical ocean are investi-gated numerically. Due to the inhomogeneity of the large-scale average sea temperature field of the ocean in tropical regions, besides the westward propagating equatorial Rossby wave to be modified, there will be a kind of long period thermal wave which propagates eastward under certain oceanic background conditions. Under the influences of these two kinds of waves, the propagating and evolving processes of the sea surface temperature anomalies (SSTA) are dearly shown by numerical experiments. The results of numerical ex-periments are consistent with the ones obtained by the theoretical analysis in Part I. The possible relation-ship between these two kinds of waves and El Nino events is also discussed indirectly.
1986, 3(2): 245-251.
doi: 10.1007/BF02682558
Abstract:
It is verified that there is δ-phase function characteristic in both of TS and SW simplified models, and on the basis of TS model, a more accurate model calculating the albedo and transmissivity of cloud layers is derived.
It is verified that there is δ-phase function characteristic in both of TS and SW simplified models, and on the basis of TS model, a more accurate model calculating the albedo and transmissivity of cloud layers is derived.
1986, 3(2): 252-261.
doi: 10.1007/BF02682559
Abstract:
Criteria of the free meandering tracks of typhoons are derived from the general solutions of typhoon motion equations. It is suggested that the meandering motion of a typhoon is caused by the combination of the internal force, the initial speed of the typhoon and the average pressure gradient force of the typhoon volume affected by the environmental pressure field. It is also revealed that under specified circumstances, the meandering may be caused only by the typhoon's internal force. Finally two examples of fitting cal-culation are given for illustration.
Criteria of the free meandering tracks of typhoons are derived from the general solutions of typhoon motion equations. It is suggested that the meandering motion of a typhoon is caused by the combination of the internal force, the initial speed of the typhoon and the average pressure gradient force of the typhoon volume affected by the environmental pressure field. It is also revealed that under specified circumstances, the meandering may be caused only by the typhoon's internal force. Finally two examples of fitting cal-culation are given for illustration.
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