From May to July, 1985, foulers on eleven navigation buoys have been surveyed in Shuidongand Bohe Harbours of Dianbai, Guangdong. Foulers on different parts of buoys (side, bottom and in-side tail tube) were sampled. ...From May to July, 1985, foulers on eleven navigation buoys have been surveyed in Shuidongand Bohe Harbours of Dianbai, Guangdong. Foulers on different parts of buoys (side, bottom and in-side tail tube) were sampled. The thickness and cover area of foulers were measured in the field andall the foulers on an area of 30×30 cm~2 were taken back for lab. identification. Thirty-four quatita-tive samples and several qualitative samples have been got and five hundred and twenty-four sampleshave been classified.展开更多
Significant wave height（SWH） can be computed from the returning waveform of radar altimeter, this parameter is only raw estimates if it does not calibrate. But accurate calibration is important for all applications,...Significant wave height（SWH） can be computed from the returning waveform of radar altimeter, this parameter is only raw estimates if it does not calibrate. But accurate calibration is important for all applications, especially for climate studies. HY-2a altimeter has been operational since April 2012 and its products are available to the scientific community. In this work, SWH data from HY-2A altimeters are calibrated against in situ buoy data from the National Data Buoy Center（NDBC）, Distinguished from previous calibration studies which generally regarded buoy data as ＂truth＂, the work of calibration for HY-2A altimeter wave data against in situ buoys was applied a more sophisticated statistical technique-the total least squares（TLS） method which can take into account errors in both variables. We present calibration results for HY-2A radar altimeter measurement of wave height against NDBC buoys. In addition, cross-calibration for HY-2A and Jason-2 wave data are talked over and the result is given.展开更多
Complementarities between wind and wave energies have many signifcant advantages that are unavailable with the sole deployment of either.Using all available wind speed,signifcant wave height,and wave period buoy obser...Complementarities between wind and wave energies have many signifcant advantages that are unavailable with the sole deployment of either.Using all available wind speed,signifcant wave height,and wave period buoy observations over a 10-year period(i.e.,2009–2019),colocated wind and wave energy resources are estimated.Although buoy records are imper-fect,results show that the inner Caribbean Sea(CS)under the infuence of the Caribbean low-level jet has the highest wind energy resource at~1500 W/m^(2),followed by the outer CS at~600 W/m^(2) and Atlantic Ocean(AO)at~550–600 W/m^(2) at a 100 m height.Wave energy was most abundant in the AO at 14 kW/m,followed by the inner CS at 13 kW/m and outer CS at 5 kW/m.The average and dominant wave energies can reach a maximum of 10 and 14 kW/m,respectively.Asymmetry between wind and wave energy resources is observed in the AO,where wave energy is higher than the low wind speed/energy would suggest.Swell is responsible for this discrepancy;thus,it must be considered not only for wave energy extraction but also for wind turbine fatigue,stability,and power extraction efciency.展开更多
Malaysian Airlines Flight MH370 disappeared on 8 March 2014, while flying from Kuala Lumpur to Beijing. A flaperon from the flight was found on Reunion Island in July 2015. Two more confirmed pieces of debris were fou...Malaysian Airlines Flight MH370 disappeared on 8 March 2014, while flying from Kuala Lumpur to Beijing. A flaperon from the flight was found on Reunion Island in July 2015. Two more confirmed pieces of debris were found in Mauritius and Tanzania, and 19 unconfirmed items were found off Mozambique, South Africa, and Madagascar. Drift buoys originating from the designated underwater search area arrived in Reunion Island, Mauritius, and Tanzania. Some of these buoys took a similarly long time as did real debris to reach these destinations, following a heading northeast and then west. For the present study, a maritime object drift prediction model was developed. ＂High resolution surface currents, Stokes drift, and winds＂ were processed, and a series of model experiments were constructed. The predicted trajectories of the modeled objects were similar to the observed trajectories of the drift buoys. Many modeled objects drifted northward then westward, ending up in Reunion Island, Mauritius, and Tanzania with probabilities of 5%0, 5%0, and 19%o, respectively. At the end of the simulation, most objects were located near 10~S in the western Indian Ocean. There were significant differences between experiments with different leeway factors, possibly because of the influence of southeast trade winds. The north part of the underwater search area is most likely to be the crash site, because the predicted trajectories of objects originating here are consistent with the many pieces of debris found along the east coast of Africa and the absence of such findings on the west coast of Australia.展开更多
The vertical thermohaline structure in the western equatorial Pacific is examined with a Gravest Empirical Mode(GEM)diagnosis of in-situ mooring measurements. The poor GEM performance in estimating deep thermohaline v...The vertical thermohaline structure in the western equatorial Pacific is examined with a Gravest Empirical Mode(GEM)diagnosis of in-situ mooring measurements. The poor GEM performance in estimating deep thermohaline variability from satellite altimetry confirms a lack of vertical coherence in the equatorial ocean. Mooring observation reveals layered equatorial water with phase difference up to 6 months between thermocline and sub-thermocline variations. The disjointed layers reflect weak geostrophy and resemble pancake structures in non-rotating stratified turbulence. A coherency theorem is then proved, stating that traditional stationary GEM represents in-phase coherent structure and can not describe vertically out-of-phase variability. The fact that stationary GEM holds both spatial and temporal coherence makes it a unique tool to diagnose vertical coherent structure in geophysical flows. The study also develops a non-stationary GEM projection that captures more than 40% of the thermohaline variance in the equatorial deep water.展开更多
文摘From May to July, 1985, foulers on eleven navigation buoys have been surveyed in Shuidongand Bohe Harbours of Dianbai, Guangdong. Foulers on different parts of buoys (side, bottom and in-side tail tube) were sampled. The thickness and cover area of foulers were measured in the field andall the foulers on an area of 30×30 cm~2 were taken back for lab. identification. Thirty-four quatita-tive samples and several qualitative samples have been got and five hundred and twenty-four sampleshave been classified.
基金The Marine Public Welfare Project of China under contract No.201305032
文摘Significant wave height（SWH） can be computed from the returning waveform of radar altimeter, this parameter is only raw estimates if it does not calibrate. But accurate calibration is important for all applications, especially for climate studies. HY-2a altimeter has been operational since April 2012 and its products are available to the scientific community. In this work, SWH data from HY-2A altimeters are calibrated against in situ buoy data from the National Data Buoy Center（NDBC）, Distinguished from previous calibration studies which generally regarded buoy data as ＂truth＂, the work of calibration for HY-2A altimeter wave data against in situ buoys was applied a more sophisticated statistical technique-the total least squares（TLS） method which can take into account errors in both variables. We present calibration results for HY-2A radar altimeter measurement of wave height against NDBC buoys. In addition, cross-calibration for HY-2A and Jason-2 wave data are talked over and the result is given.
文摘Complementarities between wind and wave energies have many signifcant advantages that are unavailable with the sole deployment of either.Using all available wind speed,signifcant wave height,and wave period buoy observations over a 10-year period(i.e.,2009–2019),colocated wind and wave energy resources are estimated.Although buoy records are imper-fect,results show that the inner Caribbean Sea(CS)under the infuence of the Caribbean low-level jet has the highest wind energy resource at~1500 W/m^(2),followed by the outer CS at~600 W/m^(2) and Atlantic Ocean(AO)at~550–600 W/m^(2) at a 100 m height.Wave energy was most abundant in the AO at 14 kW/m,followed by the inner CS at 13 kW/m and outer CS at 5 kW/m.The average and dominant wave energies can reach a maximum of 10 and 14 kW/m,respectively.Asymmetry between wind and wave energy resources is observed in the AO,where wave energy is higher than the low wind speed/energy would suggest.Swell is responsible for this discrepancy;thus,it must be considered not only for wave energy extraction but also for wind turbine fatigue,stability,and power extraction efciency.
基金Acknowledgements This work is supported by the National Key Research and Development Program of China （No. 2017YFC1404700） the National Natural Science Foundation of China （Grant Nos. 41430963 and 41606005） the Fundamental Research Funds for the Central Universities （No. 201713023）. Surface drifter data were provided by the Global Drifter Program. Surface currents data were from Hybrid Coordinate Ocean Model developed by Florida State University （HYCOM）. Wave data were provided by the European Centre for Medium-Range Weather Forecasts （ECMWF）. Wind data were provided by NOAA＇s National Centers for Environmental Prediction （NCEP）.
文摘Malaysian Airlines Flight MH370 disappeared on 8 March 2014, while flying from Kuala Lumpur to Beijing. A flaperon from the flight was found on Reunion Island in July 2015. Two more confirmed pieces of debris were found in Mauritius and Tanzania, and 19 unconfirmed items were found off Mozambique, South Africa, and Madagascar. Drift buoys originating from the designated underwater search area arrived in Reunion Island, Mauritius, and Tanzania. Some of these buoys took a similarly long time as did real debris to reach these destinations, following a heading northeast and then west. For the present study, a maritime object drift prediction model was developed. ＂High resolution surface currents, Stokes drift, and winds＂ were processed, and a series of model experiments were constructed. The predicted trajectories of the modeled objects were similar to the observed trajectories of the drift buoys. Many modeled objects drifted northward then westward, ending up in Reunion Island, Mauritius, and Tanzania with probabilities of 5%0, 5%0, and 19%o, respectively. At the end of the simulation, most objects were located near 10~S in the western Indian Ocean. There were significant differences between experiments with different leeway factors, possibly because of the influence of southeast trade winds. The north part of the underwater search area is most likely to be the crash site, because the predicted trajectories of objects originating here are consistent with the many pieces of debris found along the east coast of Africa and the absence of such findings on the west coast of Australia.
基金supported by the National Basic Research Program of China (Grant No.2012CB417400)the National Natural Science Foundation of China (Grant Nos. 41576017 & U1406401)
文摘The vertical thermohaline structure in the western equatorial Pacific is examined with a Gravest Empirical Mode(GEM)diagnosis of in-situ mooring measurements. The poor GEM performance in estimating deep thermohaline variability from satellite altimetry confirms a lack of vertical coherence in the equatorial ocean. Mooring observation reveals layered equatorial water with phase difference up to 6 months between thermocline and sub-thermocline variations. The disjointed layers reflect weak geostrophy and resemble pancake structures in non-rotating stratified turbulence. A coherency theorem is then proved, stating that traditional stationary GEM represents in-phase coherent structure and can not describe vertically out-of-phase variability. The fact that stationary GEM holds both spatial and temporal coherence makes it a unique tool to diagnose vertical coherent structure in geophysical flows. The study also develops a non-stationary GEM projection that captures more than 40% of the thermohaline variance in the equatorial deep water.
