Aerosol layer height(ALH)is an important but uncertain parameter for evaluating the impact of aerosols on weather and climate and for accurate atmospheric correction.This study aims to assess the potential for measuri...Aerosol layer height(ALH)is an important but uncertain parameter for evaluating the impact of aerosols on weather and climate and for accurate atmospheric correction.This study aims to assess the potential for measuring ALH by the Ocean Color Instrument(OCI)on NASA’s Plankton,Aerosol,Cloud,ocean Ecosystem satellite.OCI measures Earth-reflected solar spectrum including reflectance in the oxygen(O_(2))A and B absorption bands that are invaluable for determining ALH.We assessed the sensitivity and information contained therein in retrieving ALH over the ocean surface by using the radiative transfer simulation of OCI observations in the O_(2) bands.The capabilities were also demonstrated using hyperspectral data measured by the TROPOspheric Monitoring Instrument(TROPOMI),as spectrally convolved into the OCI bands.Our results indicate that(a)OCI observations in the O_(2) A band are sensitive to ALH,whereas those around the O_(2) B band have relatively reduced sensitivity;(b)the most pronounced sensitivity to ALH is found in the 762.5 nm(and 690 nm)around the oxygen A(and B)bands,which are selected for ALH retrievals in this study;and(c)the ALH retrieved from OCI proxy data is in good agreement with the aerosol profile probed by CALIOP lidar.Overall,the ALH retrievals for both smoke and dust events exhibit a root mean square error of 0.49 km and 0.31 km,respectively,for the smoke and dust cases,aligning with the uncertainties of ALH as measured from the concurrent TROPOMI and the Earth Polychromatic Imaging Camera instruments.Therefore,this study suggests from OCI observations that we can generate ALH products with a well-characterized uncertainty.The technique and results presented in this study are suitable to develop a simple but robust ALH algorithm for OCI observations when the data become available.展开更多
One of the essential controls on the microwave thermal emissions(MTE) of the lunar regolith is the abundance of Fe O and TiO_2, known as the(Fe O+Ti O_2) abundance(FTA). In this paper, a radiative transfer simulation ...One of the essential controls on the microwave thermal emissions(MTE) of the lunar regolith is the abundance of Fe O and TiO_2, known as the(Fe O+Ti O_2) abundance(FTA). In this paper, a radiative transfer simulation is employed first to study the change in the brightness temperature(T_B) with FTA under a range of frequencies and surface temperatures. Then, we analyze the influence of FTA on the MTE of the lunar regolith using microwave sounder(CELMS) data from the Chang'E-2 lunar orbiter, Clementine UV-VIS data, and lunar samples recovered from the Apollo and Surveyor projects. We conclude that:(1) FTA strongly influences the MTE of the lunar regolith, but it is not the decisive control, and(2) FTA decreases slightly with depth. This research plays an essential role in appropriately inverting CELMS data to obtain lunar regolith parameters.展开更多
基金support of this study from the PACE Science Project Team and valuable interaction with the PACE Science and Application Science Teamsupport was received for the research,authorship,and/or publication of this article+2 种基金funded by the NASA Remote Sensing Theory program(Grant No.80NSSC20K1747)the DSCOVR program(Grant No.80NSSC22K0503)the UMBC START and CIDER awards.
文摘Aerosol layer height(ALH)is an important but uncertain parameter for evaluating the impact of aerosols on weather and climate and for accurate atmospheric correction.This study aims to assess the potential for measuring ALH by the Ocean Color Instrument(OCI)on NASA’s Plankton,Aerosol,Cloud,ocean Ecosystem satellite.OCI measures Earth-reflected solar spectrum including reflectance in the oxygen(O_(2))A and B absorption bands that are invaluable for determining ALH.We assessed the sensitivity and information contained therein in retrieving ALH over the ocean surface by using the radiative transfer simulation of OCI observations in the O_(2) bands.The capabilities were also demonstrated using hyperspectral data measured by the TROPOspheric Monitoring Instrument(TROPOMI),as spectrally convolved into the OCI bands.Our results indicate that(a)OCI observations in the O_(2) A band are sensitive to ALH,whereas those around the O_(2) B band have relatively reduced sensitivity;(b)the most pronounced sensitivity to ALH is found in the 762.5 nm(and 690 nm)around the oxygen A(and B)bands,which are selected for ALH retrievals in this study;and(c)the ALH retrieved from OCI proxy data is in good agreement with the aerosol profile probed by CALIOP lidar.Overall,the ALH retrievals for both smoke and dust events exhibit a root mean square error of 0.49 km and 0.31 km,respectively,for the smoke and dust cases,aligning with the uncertainties of ALH as measured from the concurrent TROPOMI and the Earth Polychromatic Imaging Camera instruments.Therefore,this study suggests from OCI observations that we can generate ALH products with a well-characterized uncertainty.The technique and results presented in this study are suitable to develop a simple but robust ALH algorithm for OCI observations when the data become available.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41371332 & 41590851)the Fundamental Research Funds for the Central Universities (Grant No. JCKY-QKJC23)the Science and Technology Development Fund of Macao (Grant No. 110/2014/A3)
文摘One of the essential controls on the microwave thermal emissions(MTE) of the lunar regolith is the abundance of Fe O and TiO_2, known as the(Fe O+Ti O_2) abundance(FTA). In this paper, a radiative transfer simulation is employed first to study the change in the brightness temperature(T_B) with FTA under a range of frequencies and surface temperatures. Then, we analyze the influence of FTA on the MTE of the lunar regolith using microwave sounder(CELMS) data from the Chang'E-2 lunar orbiter, Clementine UV-VIS data, and lunar samples recovered from the Apollo and Surveyor projects. We conclude that:(1) FTA strongly influences the MTE of the lunar regolith, but it is not the decisive control, and(2) FTA decreases slightly with depth. This research plays an essential role in appropriately inverting CELMS data to obtain lunar regolith parameters.
