SICEv3.0 Severnaya Zemlya snow and ice broadband albedo and surface optical properties from Sentinel-3’s OLCI at 500 m resolution, Near Real Time (NRT)

SICE v3.0. 0.5 km Arctic land ice SSA, broadband albedo and spectral reflectance for 2017 to 2023 Timespan 1 April, to 31 September for each year 2017 to 2023 and is being updated starting ~April each year Description For Greenland, 0.5km daily data (Table 1) from the pySICE v2.1 algorithm, see Bahbah et al (2023) and Kokhanovsky et al (2023) for details. Broadband albedo "albedo_bb_planar_sw" is after Kokhanovsky et al (2019). "BBA_combination" is albedo_bb_planar_sw for albedo_bb_planar_sw values above 0.565 and is combined with an ampirical albedo for albedo_bb_planar_sw below or equal to 0.565, see Wehrlé et al (2021). Data format is GeoTiff in the EPSG:3413 - WGS 84 / NSIDC Sea Ice Polar Stereographic North. We suggest using rasterio to read the data files. The data are also available from https://thredds.geus.dk/ Data Format Data format is GeoTiff in the EPSG:3413 - WGS 84 / NSIDC Sea Ice Polar Stereographic North projection.   Table 1, SICE v3.0 data, alphabetical name, description ANG, Angström parameter for atmospheric aerosol correction AOD_550, aerosol optical depth at 550 nm from CAMS, m units al, effective absorption length, mm units albedo_bb_spherical_sw, albedo under isotropic radiation albedo_bb_planar_sw, broadband albedo albedo_spectral_planar_NN, multispectral albedo_spectral_planar, where NN is a number for bands 01-21 diagnostic_retrieval, per pixel diagnostic info cloud_mask,SCDA cloud mask cloud_mask, SCDA cloud mask cv1, quality check 1 (see ATBD) cv2, quality check 2 (see ATBD) factor<,snow covered fraction within mixed pixels grain_diameter, effective optical snow grain diameter isnow, See Table 2 lat, decimal latitude lon, decimal longitude O3_SICE, OLCI total ozone retrieval corrected for ozone scattering after Kokhanovsky et al 2020 r0, reflectance of a semi-infinite non-absorbing snow layer r_TOA_NN, multispectral TOA reflectance, where NN is a number for bands 01-21 r_BRR_NN, multispectral botttom of atmosphere reflectance, where NN is a number for bands 01-21 snow_specific_surface_area, SSA saa, solar azimuth angle sza, solar zenith angle vaa, viewing azimuth angle vza, viewing zenith angle Table 2, Diagnostic codes Diagnostic Code, Description 0, clean snow 1, polluted snow 6, polluted snow for which r0 was calculated and not derived from observations 7, polluted snow of calculated spherical albedo in bands 1 and 2 greater than 0.98 reprocessed as clean snow 100, sza exceeding 75, no retrival albedo 102, TOA reflectance at band 21 less than 0.1, no retrieval 104, grain_diameter less than 0.1, no retrieval, potential cloud flag -N, impossible to solve polluted snow albedo equation at band N See also related information below Reference Publications Kokhanovsky, A., Vandecrux, B., Wehrlé, A., Danne, O., Brockmann, C., and Box, J. E.: An improved retrieval of snow and Ice properties using spaceborne OLCI/S-3 spectral reflectance measurements: Updated atmospheric correction and snow impurity load estimation, Remote Sens. (Basel), 15, 77, https://doi.org/10.3390/rs15010077, 2022 Kokhanovsky A.A., Lamare, M. and Rozanov, V. (2020) Retrieval of the total ozone over Antarctica using Sentinel-3 ocean and land colour instrument. Journal of Quantitative Spectroscopy and Radiative Transfer 251, 107045 https://doi.org/10.1016/j.jqsrt.2020.107045 Code Bahbah, R., Wehrlé, A., Mankoff, K., Vandecrux, B., and Box, J. E.: Sentinel-3 snow and ice optical properties retrieval (SICE) version 3.0, https://doi.org/10.5281/zenodo.10058790, 2023. How to gather and read the data see https://github.com/GEUS-SICE/SICE_gather and raise any issues there. Acknowledgements SICE has been supported by the following contracts to the European Space Agency (ESA): Dec. 2016 – Jan. 2019 SEOM S34Sci Land Study 1: Snow, ESRIN Contract 4000118926/16/I-NB Dec. 2018 – Jul. 2020 EO Science For Society, ESA/Contract 4000125043/18/I-NB – ESA/AO/1-9101/17/I-NB EO SCIENCE FOR SOCIETY, Pre-operational Sentinel-3 Snow and Ice Products (SICE) Jan. 2019 – Dec. 2020 ESA PRODEX, An operational service of new Sentinel-3 algorithms for climate monitoring of the Greenland Cryosphere within the CryoClim network May 2021 – June 2023 ESA PRODEX, Seamless Integration of Sentinel-3 Albedos in a Weather-modelling System (SISAWS) Feb 2022 – Oct. 2023 ESA EO Science For Society, Snow and ICE optical and physical properties from Sentinel-3 (SICE), ESA CCN contract 4000125043/18/I-NB and the ESA Network of Resources, Related Information description of variables, inputs and outputs https://github.com/GEUS-SICE/pySICE/tree/pySICEv2.1 https://snow.geus.dk/ Questions? contact Jason Box, [e-mail]

SICE v3.0. 0.5 km 冰原陆冰地表反照率与光谱反射率数据集，时间范围为2017年至2023年，每年4月1日至9月30日，数据每年大约从4月开始更新。对于格陵兰岛，提供由pySICE v2.1算法生成的0.5公里每日数据（见表1），详细信息可参见Bahbah等（2023年）及Kokhanovsky等（2023年）。宽带反照率“albedo_bb_planar_sw”参考Kokhanovsky等（2019年）。“BBA_combination”为当albedo_bb_planar_sw值大于0.565时的albedo_bb_planar_sw，对于albedo_bb_planar_sw值小于或等于0.565的情况，则与经验反照率相结合，详细信息可参见Wehrlé等（2021年）。数据格式为EPSG:3413 - WGS 84 / NSIDC 海冰极地正射投影的GeoTiff格式。建议使用rasterio读取数据文件。数据也可从https://thredds.geus.dk/获取。数据格式为EPSG:3413 - WGS 84 / NSIDC 海冰极地正射投影的GeoTiff格式。 表1，SICE v3.0数据，按字母顺序排列的名称，描述：ANG，大气气溶胶校正的Angström参数；AOD_550，来自CAMS的550 nm气溶胶光学厚度，单位为m；al，有效吸收长度，单位为mm；albedo_bb_spherical_sw，各向同性辐射下的反照率；albedo_bb_planar_sw，宽带反照率；albedo_spectral_planar_NN，多光谱反照率，其中NN为01-21波段的编号；diagnostic_retrieval，每个像素的诊断信息；cloud_mask，SCDA云掩膜；cv1，质量检查1（见技术手册）；cv2，质量检查2（见技术手册）；factor<，混合像素内的积雪覆盖分数；grain_diameter，有效光学雪粒直径；isnow，见表2；lat，十进制度纬度；lon，十进制度经度；O3_SICE，经Kokhanovsky等（2020年）校正的OLCI总臭氧提取；r0，半无限非吸收雪层的反射率；r_TOA_NN，多光谱TOA反射率，其中NN为01-21波段的编号；r_BRR_NN，多光谱大气底层反射率，其中NN为01-21波段的编号；snow_specific_surface_area，特定表面面积；saa，太阳方位角；sza，太阳天顶角；vaa，观测方位角；vza，观测天顶角。 表2，诊断代码 诊断代码，描述：0，纯净雪；1，污染雪；6，已计算r0但非源自观测的污染雪；7，波段1和2中计算出的球形反照率大于0.98的污染雪，经重新处理视为纯净雪；100， sza超过75，无法提取反照率；102，TOA在21波段小于0.1，无法提取；104，粒度小于0.1，无法提取，潜在的云标志-N，无法在波段N求解污染雪反照率方程。 参考文献出版物：Kokhanovsky等（2022年）：使用卫星OLCI/S-3光谱反射率测量改进雪和冰性质的反演：更新大气校正和雪杂质负荷估计，Remote Sens. (Basel)，15，77；Kokhanovsky等（2020年）：使用Sentinel-3海洋和陆地色彩仪器反演南极洲总臭氧，Journal of Quantitative Spectroscopy and Radiative Transfer，251，107045；Bahbah等（2023年）：Sentinel-3雪和冰光学性质提取（SICE）版本3.0。有关数据收集和读取方法，请参阅https://github.com/GEUS-SICE/SICE_gather，并在那里提出任何问题。致谢：SICE项目得到了以下欧洲航天局（ESA）合同的资助：2016年12月-2019年1月 SEOM S34Sci Land Study 1：雪，ESRIN合同4000118926/16/I-NB；2018年12月-2020年7月 EO Science For Society，ESA/Contract 4000125043/18/I-NB – ESA/AO/1-9101/17/I-NB；2019年1月-2020年12月 ESA PRODEX，CryoClim网络内格陵兰冰冻圈气候监测的新Sentinel-3算法的运行服务；2021年5月-2023年6月 ESA PRODEX，无缝集成Sentinel-3反照率到天气模型系统中（SISAWS）；2022年2月-2023年10月 ESA EO Science For Society，Sentinel-3雪和冰的光学和物理性质（SICE），ESA CCN合同4000125043/18/I-NB和ESA资源网络。变量、输入和输出的描述及相关信息请参阅https://github.com/GEUS-SICE/pySICE/tree/pySICEv2.1和https://snow.geus.dk/。如有疑问，请联系Jason Box，[e-mail]。