Over the past decades,sea ice in the polar regions has been significantly affecting local and even hemispheric climate through a positive ice albedo feedback mechanism.The role of fast ice,as opposed to drift ice,has ...Over the past decades,sea ice in the polar regions has been significantly affecting local and even hemispheric climate through a positive ice albedo feedback mechanism.The role of fast ice,as opposed to drift ice,has not been well-studied due to its relatively small coverage over the earth.In this paper,the optical properties and surface energy balance of land fast ice in spring are studied using in situ observations in Barrow,Alaska.The results show that the albedo of the fast ice varied between 0.57 and 0.85 while the transmittance increased from 1.3×10-3 to 4.1×10-3 during the observation period.Snowfall and air temperature affected the albedo and absorbance of sea ice,but the transmittance had no obvious relationship with precipitation or snow cover.Net solar shortwave radiation contributes to the surface energy balance with a positive 99.2%of the incident flux,with sensible heat flux for the remaining 0.8%.Meanwhile,the ice surface loses energy through the net longwave radiation by 18.7%of the total emission,while the latent heat flux accounts for only 0.1%.Heat conduction is also an important factor in the overall energy budget of sea ice,contributing 81.2%of the energy loss.Results of the radiative transfer model reveal that the spectral transmittance of the fast ice is determined by the thickness of snow and sea ice as well as the amount of inclusions.As major inclusions,the ice biota and particulates have a significant influence on the magnitude and distribution of the spectral transmittance.Based on the radiative transfer model,concentrations of chlorophyll and particulate in the fast ice are estimated at 5.51 mg/m^(2)and 95.79 g/m^(2),which are typical values in the spring in Barrow.展开更多
The sensing characteristics of irradiated fiber Bragg gratings(FBGs)and Fabry-Perot interferometers(FPIs)were investigated under a 2MGy dose of gamma radiation.The study found that the pressure sensitivity of FP senso...The sensing characteristics of irradiated fiber Bragg gratings(FBGs)and Fabry-Perot interferometers(FPIs)were investigated under a 2MGy dose of gamma radiation.The study found that the pressure sensitivity of FP sensors after irradiation was stable,while the temperature sensitivity of FBG sensors was unstable,and both wavelengths displayed a shift.These findings offer the possibility for the application of FP pressure sensors in the gamma radiation environments,and FBG sensors require further research to be suitable for application in the nuclear radiation environments.展开更多
A length-matched micro Fabry-Perot(FP)interferometer is proposed for strain measurement under irradiation environment.Theoretical simulation shows that a well length-matched FP sensor can achieve a very low drift of t...A length-matched micro Fabry-Perot(FP)interferometer is proposed for strain measurement under irradiation environment.Theoretical simulation shows that a well length-matched FP sensor can achieve a very low drift of the cavity length and strain sensitivity in irradiation environment.In experiment,such an FP cavity is realized by laser micromachining.It shows a low cavity length drift of−0.037μm and a strain sensitivity deviation of 0.52%,respectively,under gamma irradiation.Meanwhile,the intensity of interference fringes is also stable.As a result,such a length-matched FP cavity is a very promising candidate for strain sensing in radiative environments.展开更多
基金The National Major Research High Resolution Sea Ice Model Development Program of China under contract No.2018YFA0605903the National Natural Science Foundation of China under contract No.41776192the Fundamental Research Funds for the Central Universities under contract No.202165005。
文摘Over the past decades,sea ice in the polar regions has been significantly affecting local and even hemispheric climate through a positive ice albedo feedback mechanism.The role of fast ice,as opposed to drift ice,has not been well-studied due to its relatively small coverage over the earth.In this paper,the optical properties and surface energy balance of land fast ice in spring are studied using in situ observations in Barrow,Alaska.The results show that the albedo of the fast ice varied between 0.57 and 0.85 while the transmittance increased from 1.3×10-3 to 4.1×10-3 during the observation period.Snowfall and air temperature affected the albedo and absorbance of sea ice,but the transmittance had no obvious relationship with precipitation or snow cover.Net solar shortwave radiation contributes to the surface energy balance with a positive 99.2%of the incident flux,with sensible heat flux for the remaining 0.8%.Meanwhile,the ice surface loses energy through the net longwave radiation by 18.7%of the total emission,while the latent heat flux accounts for only 0.1%.Heat conduction is also an important factor in the overall energy budget of sea ice,contributing 81.2%of the energy loss.Results of the radiative transfer model reveal that the spectral transmittance of the fast ice is determined by the thickness of snow and sea ice as well as the amount of inclusions.As major inclusions,the ice biota and particulates have a significant influence on the magnitude and distribution of the spectral transmittance.Based on the radiative transfer model,concentrations of chlorophyll and particulate in the fast ice are estimated at 5.51 mg/m^(2)and 95.79 g/m^(2),which are typical values in the spring in Barrow.
基金This work was funded by the National Science Foundation of China(NCSF)(Grant No.51875091)the Study and Application of Full-model Impact Dynamic Fretting Damage Test System in the Extreme Environment(Grant No.51627806)+3 种基金Research on Application of Optical Fiber Sensing in Nuclear Power(Grant No.180046)Optical Fiber Sensing and Processing Prototype for Nuclear Field Key Parameter Measurement(Grant No.191091)Data Acquisition and Post-processing Software Development for Integrated Fiber Optic Sensors(Grant No.190167)the State 111 Project(Grant No.B14039).
文摘The sensing characteristics of irradiated fiber Bragg gratings(FBGs)and Fabry-Perot interferometers(FPIs)were investigated under a 2MGy dose of gamma radiation.The study found that the pressure sensitivity of FP sensors after irradiation was stable,while the temperature sensitivity of FBG sensors was unstable,and both wavelengths displayed a shift.These findings offer the possibility for the application of FP pressure sensors in the gamma radiation environments,and FBG sensors require further research to be suitable for application in the nuclear radiation environments.
基金This work was funded by the National Natural Science Foundation of China(Grant No.51875091)the Study and Application of Full-Model Impact Dynamic Fretting Damage Test System in the Extreme Environment(Grant No.51627806)+2 种基金Optical Fiber Sensing and Processing Prototype for Nuclear Field Key Parameter Measurement(Grant No.191091)Data Acquisition and Post-Processing Software Development for Integrated Fiber Optic Sensors(Grant No.190167)the State 111 Project(Grant No.B14039).
文摘A length-matched micro Fabry-Perot(FP)interferometer is proposed for strain measurement under irradiation environment.Theoretical simulation shows that a well length-matched FP sensor can achieve a very low drift of the cavity length and strain sensitivity in irradiation environment.In experiment,such an FP cavity is realized by laser micromachining.It shows a low cavity length drift of−0.037μm and a strain sensitivity deviation of 0.52%,respectively,under gamma irradiation.Meanwhile,the intensity of interference fringes is also stable.As a result,such a length-matched FP cavity is a very promising candidate for strain sensing in radiative environments.
