The emulsification of crude oil is caused by the oil flowing into the water,resulting in the increase of oil film tension,viscosity,water content,and volume,which brings great harm to the marine ecological environment...The emulsification of crude oil is caused by the oil flowing into the water,resulting in the increase of oil film tension,viscosity,water content,and volume,which brings great harm to the marine ecological environment and difficulties for the cleanup of marine emergency equipment.The realization observation of emulsification crude oil will increase the response speed of marine emergency response.Therefore,we set up crude oil emulsification samples to study the physical property in laboratory and conducted radar measurements at different incidence angles in outdoor.The radar is C band in resolution of 0.7 m by 0.7 m.A fully polarimetric scatterometer(HH,VV,and VH/HV)is mounted at 1.66 m(minimum altitude)height at an incidence angle between 35°and 60°.An asphalt content of less than 3%crude oil and the filtered seawater were used to the outdoor emulsification scattering experiment.The measurement results are as follows.The water content can be used to describe the process of emulsification and it is easy to measure.Wind speed,asphalt content,seawater temperature,and photo-oxidation affect the emulsifying process of crude oil,and affects the normalized radar cross section(NRCS)of oil film but wind is not the dominant factor.It is the first time to find that the emulsification of crude oil results in an increase of NRCS.展开更多
Surface Water and Ocean Topography(SWOT)is a next-generation radar altimeter that offers high resolution,wide swath,imaging capabilities.It has provided free public data worldwide since December 2023.This paper aims t...Surface Water and Ocean Topography(SWOT)is a next-generation radar altimeter that offers high resolution,wide swath,imaging capabilities.It has provided free public data worldwide since December 2023.This paper aims to preliminarily analyze the detection capabilities of the Ka-band radar interferometer(KaRIn)and Nadir altimeter(NALT),which are carried out by SWOT for internal solitary waves(ISWs),and to gather other remote sensing images to validate SWOT observations.KaRIn effectively detects ISW surface features and generates surface height variation maps reflecting the modulations induced by ISWs.However,its swath width does not completely cover the entire wave packet,and the resolution of L2/L3 level products(about 2 km)cannot be used to identify ISWs with smaller wavelengths.Additionally,significant wave height(SWH)images exhibit blocky structures that are not suitable for ISW studies;sea surface height anomaly(SSHA)images display systematic leftright banding.We optimize this imbalance using detrending methods;however,more precise treatment should commence with L1-level data.Quantitative analysis based on L3-level SSHA data indicates that the average SSHA variation induced by ISWs ranges from 10 cm to 20 cm.NALTs disturbed by ISWs record unusually elevated SWH and SSHA values,rendering the data unsuitable for analysis and necessitating targeted corrections in future retracking algorithms.For the normalized radar cross section,Ku-band and four-parameter maximum likelihood estimation retracking demonstrated greater sensitivity to minor changes in the sea surface,making them more suitable for ISW detection.In conclusion,SWOT demonstrates outstanding capabilities in ISW detection,significantly advancing research on the modulation of the sea surface by ISWs and remote sensing imaging mechanisms.展开更多
For open sea conditions the sea surface roughness is described as a function of surface stress and wind speed over sea surface by Charnock relation. The sea surface roughnessn in the North-west Pacific Ocean is derive...For open sea conditions the sea surface roughness is described as a function of surface stress and wind speed over sea surface by Charnock relation. The sea surface roughnessn in the North-west Pacific Ocean is derived successfully using wind speed data estimated by the TOPEX satellite altimeter. From the results we find that： （1） the mean sea surface roughness in winter is greater than in summer; （2） compared with other sea areas, the sea surface roughness in the sea area east of Japan （ N30°- 40°, E135°- 150°） is larger than in other sea areas; （3） sea surface roughness in the South China Sea changes more greatly than that in the Bohai Sea, Yellow Sea and East China Sea.展开更多
基金Supported by the National Natural Science Foundation of China(No.41576032)the Major Program for the International Cooperation of the Chinese Academy of Sciences,China(No.133337KYSB20160002)partially supported by the National Natural Science Foundation of China(Nos.41576170,61371189)
文摘The emulsification of crude oil is caused by the oil flowing into the water,resulting in the increase of oil film tension,viscosity,water content,and volume,which brings great harm to the marine ecological environment and difficulties for the cleanup of marine emergency equipment.The realization observation of emulsification crude oil will increase the response speed of marine emergency response.Therefore,we set up crude oil emulsification samples to study the physical property in laboratory and conducted radar measurements at different incidence angles in outdoor.The radar is C band in resolution of 0.7 m by 0.7 m.A fully polarimetric scatterometer(HH,VV,and VH/HV)is mounted at 1.66 m(minimum altitude)height at an incidence angle between 35°and 60°.An asphalt content of less than 3%crude oil and the filtered seawater were used to the outdoor emulsification scattering experiment.The measurement results are as follows.The water content can be used to describe the process of emulsification and it is easy to measure.Wind speed,asphalt content,seawater temperature,and photo-oxidation affect the emulsifying process of crude oil,and affects the normalized radar cross section(NRCS)of oil film but wind is not the dominant factor.It is the first time to find that the emulsification of crude oil results in an increase of NRCS.
基金The National Natural Science Foundation of China under contract Nos U2006207 and 42006164.
文摘Surface Water and Ocean Topography(SWOT)is a next-generation radar altimeter that offers high resolution,wide swath,imaging capabilities.It has provided free public data worldwide since December 2023.This paper aims to preliminarily analyze the detection capabilities of the Ka-band radar interferometer(KaRIn)and Nadir altimeter(NALT),which are carried out by SWOT for internal solitary waves(ISWs),and to gather other remote sensing images to validate SWOT observations.KaRIn effectively detects ISW surface features and generates surface height variation maps reflecting the modulations induced by ISWs.However,its swath width does not completely cover the entire wave packet,and the resolution of L2/L3 level products(about 2 km)cannot be used to identify ISWs with smaller wavelengths.Additionally,significant wave height(SWH)images exhibit blocky structures that are not suitable for ISW studies;sea surface height anomaly(SSHA)images display systematic leftright banding.We optimize this imbalance using detrending methods;however,more precise treatment should commence with L1-level data.Quantitative analysis based on L3-level SSHA data indicates that the average SSHA variation induced by ISWs ranges from 10 cm to 20 cm.NALTs disturbed by ISWs record unusually elevated SWH and SSHA values,rendering the data unsuitable for analysis and necessitating targeted corrections in future retracking algorithms.For the normalized radar cross section,Ku-band and four-parameter maximum likelihood estimation retracking demonstrated greater sensitivity to minor changes in the sea surface,making them more suitable for ISW detection.In conclusion,SWOT demonstrates outstanding capabilities in ISW detection,significantly advancing research on the modulation of the sea surface by ISWs and remote sensing imaging mechanisms.
文摘For open sea conditions the sea surface roughness is described as a function of surface stress and wind speed over sea surface by Charnock relation. The sea surface roughnessn in the North-west Pacific Ocean is derived successfully using wind speed data estimated by the TOPEX satellite altimeter. From the results we find that： （1） the mean sea surface roughness in winter is greater than in summer; （2） compared with other sea areas, the sea surface roughness in the sea area east of Japan （ N30°- 40°, E135°- 150°） is larger than in other sea areas; （3） sea surface roughness in the South China Sea changes more greatly than that in the Bohai Sea, Yellow Sea and East China Sea.
