Melt pond is a distinctive characteristic of the summer Arctic,which affects energy balance in the Arctic system.The Delta-Eddington model(BL)and Two-strEam rAdiative transfer model(TEA)are employed to retrieving pond...Melt pond is a distinctive characteristic of the summer Arctic,which affects energy balance in the Arctic system.The Delta-Eddington model(BL)and Two-strEam rAdiative transfer model(TEA)are employed to retrieving pond depth Hpand underlying ice thickness Hi according to the ratio X of the melt-pond albedo in two bands.Results showed that whenλ1=359 nm andλ2=605 nm,the Pearson’s correlation coefficient r between X and Hp is 0.99 for the BL model.The result of TEA model was similar to the BL model.The retrievals of Hp for the two models agreed well with field observations.For Hi,the highest r(0.99)was obtained whenλ1=447 nm andλ2=470 nm for the BL model,λ1=447 nm andλ2=451 nm for the TEA model.Furthermore,the BL model was more suitable for the retrieval of thick ice(0<Hi<3.5 m,R2=0.632),while the TEA model is on the contrary(Hi<1 m,R2=0.842).The present results provide a potential method for the remote sensing on melt pond and ice in the Arctic summer.展开更多
The dynamic model of two-flexible-arm mechanism with elastic joints is studied.The transmission problem of the joint which connects two flexible links is successfully solved. The mechanical model is proposed for the j...The dynamic model of two-flexible-arm mechanism with elastic joints is studied.The transmission problem of the joint which connects two flexible links is successfully solved. The mechanical model is proposed for the joint, and a practical vibration analysis method of lumped parameter transfer matrix modal analysis is developed for two flexible arms with an elastic joint.展开更多
基金the National Key R&D Program of China(Grant no.2018YFA0605901)the National Natural Science Foundation of China(Grant nos.41922045,41676187).
文摘Melt pond is a distinctive characteristic of the summer Arctic,which affects energy balance in the Arctic system.The Delta-Eddington model(BL)and Two-strEam rAdiative transfer model(TEA)are employed to retrieving pond depth Hpand underlying ice thickness Hi according to the ratio X of the melt-pond albedo in two bands.Results showed that whenλ1=359 nm andλ2=605 nm,the Pearson’s correlation coefficient r between X and Hp is 0.99 for the BL model.The result of TEA model was similar to the BL model.The retrievals of Hp for the two models agreed well with field observations.For Hi,the highest r(0.99)was obtained whenλ1=447 nm andλ2=470 nm for the BL model,λ1=447 nm andλ2=451 nm for the TEA model.Furthermore,the BL model was more suitable for the retrieval of thick ice(0<Hi<3.5 m,R2=0.632),while the TEA model is on the contrary(Hi<1 m,R2=0.842).The present results provide a potential method for the remote sensing on melt pond and ice in the Arctic summer.
文摘The dynamic model of two-flexible-arm mechanism with elastic joints is studied.The transmission problem of the joint which connects two flexible links is successfully solved. The mechanical model is proposed for the joint, and a practical vibration analysis method of lumped parameter transfer matrix modal analysis is developed for two flexible arms with an elastic joint.
