The synthetic tidal parameters with high spatial resolution for gravity over China and its neighbor area are constructed with Earth＇s tidal model and ocean tide loading calculated using TPXO7 global ocean tide model ...The synthetic tidal parameters with high spatial resolution for gravity over China and its neighbor area are constructed with Earth＇s tidal model and ocean tide loading calculated using TPXO7 global ocean tide model as well as tidal data over China seas. The comparison between synthetic parameters and ones observed by spring gravimeters at some seismic network stations and Hong Kong station and one observed by super-conducting gravimeter at Wuhan station shows that the average differences in amplitude factors and phases are smaller than 0.005 and 0.5° respectively; and that the discrepancies between observational and synthetic parameters are dependent on gravimetric technique in that the synthetic parameters are in well agreement with the superconducting gravimetric observations. This also indicates that the synthetic result is a good estimation for tidal gravity, and the numerical results in the present paper not only can provide ground and space gravimetry such as absolute gravimetry with correction model of tidal gravity, but also provide effective tidal parameters over areas where no observation is carried out.展开更多
The scale factor accuracy of superconducting gravimeters （SG） can be largely improved by a high repetition rate of calibration experiments. At stations where the availability of absolute gravimeters is limited, care...The scale factor accuracy of superconducting gravimeters （SG） can be largely improved by a high repetition rate of calibration experiments. At stations where the availability of absolute gravimeters is limited, carefully calibrated spring gravimeters can be used for providing the reference signal assuming the irregular drift is properly adjusted. The temporal stability of the SG scale factor is assessable by comparing the temporal variations of M2 tidal parameters observed at neighboring SG sites or from synthetic tide models. Combining these methods reduces the SG scale factor error to a few 0.1%0. The paper addresses the particular procedure required for evaluating the calibration experiments based on spring gravimeters and presents results obtained at Conrad observatory （Austria）. Comparing the M2 amplitude factor modulation helped to reveal a SG scale factor offset of about 0.2%0 due to re-installation.展开更多
Tidal stream energy is a type of marine renewable energy which is close to commercial-scale production. Tidal stream turbine arrays are considered as the one of the most promising exploitation methods. However, compar...Tidal stream energy is a type of marine renewable energy which is close to commercial-scale production. Tidal stream turbine arrays are considered as the one of the most promising exploitation methods. However, compared to the relatively mature technology of single turbine design and installation, the current knowledge on the hydrodynamic processes of tidal stream turbine arrays is still limited. Coastal models with simplified turbine representations based on the shallow water equation are among the most favorable methods for studying the tidal stream energy extraction processes in realistic sites. This paper presents a review of the progress and challenges in assessing the tidal stream energy.展开更多
基金The Knowledge Innovation Program of the Chinese Academy of Sciences (KZCX2-YW-133)National Nature Science Foundation of China (40730316, 40574034).
文摘The synthetic tidal parameters with high spatial resolution for gravity over China and its neighbor area are constructed with Earth＇s tidal model and ocean tide loading calculated using TPXO7 global ocean tide model as well as tidal data over China seas. The comparison between synthetic parameters and ones observed by spring gravimeters at some seismic network stations and Hong Kong station and one observed by super-conducting gravimeter at Wuhan station shows that the average differences in amplitude factors and phases are smaller than 0.005 and 0.5° respectively; and that the discrepancies between observational and synthetic parameters are dependent on gravimetric technique in that the synthetic parameters are in well agreement with the superconducting gravimetric observations. This also indicates that the synthetic result is a good estimation for tidal gravity, and the numerical results in the present paper not only can provide ground and space gravimetry such as absolute gravimetry with correction model of tidal gravity, but also provide effective tidal parameters over areas where no observation is carried out.
文摘The scale factor accuracy of superconducting gravimeters （SG） can be largely improved by a high repetition rate of calibration experiments. At stations where the availability of absolute gravimeters is limited, carefully calibrated spring gravimeters can be used for providing the reference signal assuming the irregular drift is properly adjusted. The temporal stability of the SG scale factor is assessable by comparing the temporal variations of M2 tidal parameters observed at neighboring SG sites or from synthetic tide models. Combining these methods reduces the SG scale factor error to a few 0.1%0. The paper addresses the particular procedure required for evaluating the calibration experiments based on spring gravimeters and presents results obtained at Conrad observatory （Austria）. Comparing the M2 amplitude factor modulation helped to reveal a SG scale factor offset of about 0.2%0 due to re-installation.
基金Project supported by the National High-Technology Research and Development Program of China(863 Program,Grant No.2012AA052602)
文摘Tidal stream energy is a type of marine renewable energy which is close to commercial-scale production. Tidal stream turbine arrays are considered as the one of the most promising exploitation methods. However, compared to the relatively mature technology of single turbine design and installation, the current knowledge on the hydrodynamic processes of tidal stream turbine arrays is still limited. Coastal models with simplified turbine representations based on the shallow water equation are among the most favorable methods for studying the tidal stream energy extraction processes in realistic sites. This paper presents a review of the progress and challenges in assessing the tidal stream energy.
