1993-2020年全球海洋0.25度海平面逐月数据

数据基本信息数据时间：1993.1-2020.12空间位置：全球海洋数据条目：336 条数据分辨率：0.25度数据类型：除原始遥感影像外的栅格数据数据摘要海平面高度指的是去除海洋潮汐后的海面相对于平均海面的高度，海平面产品是逐年月均的海平面高度网格数据。海平面产品是全球气候变化的重要参考指标之一，准确了解全球海平面变化，是全球气候变化研究必不可少的。 基于T/P、Jason-1/2/3、ERS-1/2、ENVISAT、GFO、Cryosat-2、SARAL、Sentinel-3和 HY-2等长时序多源卫星高度计数据，通过数据预处理与统一，采用时空客观分析方法，生成了1993-2020年0.25°月均全球海平面高度数据产品。数据作者（联系人）信息姓名：张杰联系人电话：[phone]邮编：266061联系人邮箱：[e-mail]单位：自然资源部第一海洋研究所地址：青岛市崂山区仙霞岭路6号数据引用方式及申明申明方式：1993-2020年全球海洋0.25度海平面逐月数据来源于国家重点研发计划项目“全球气候数据集生成及气候变化关键过程和要素监测（2016YFA0600100）”引用方式：张杰. 自然资源部第一海洋研究所. 1993-2020年全球海洋0.25度海平面逐月数据.2021数据溯源信息数据来源描述：本研究使用的卫星高度计数据从ftp:// ftp-access.aviso.altimetry.fr、ftp:// osdds-ftp.nsoas.org.cn和https://coda.eumetsat.int/#/home下载获取。数据生成过程描述：高度计数据预处理与质量控制的目的是基于卫星高度计自身的数据编辑准则，筛选过滤掉不满足数据质量要求的数据，然后针对筛选后的数据计算出沿轨海面高度（Sea Surface Hight，SSH）观测值。针对多源卫星高度计数据，利用各自数据编辑准则进行数据质量控制，读取生成质量控制后的卫星高度计的海面高度数据。具体采用的数据编辑准则如下： 按照下列条件移除陆地、海冰、丢失以及被污染的数据：surface_type = 0；alt_echo_type=0；rad_surf_type=0；qual_1hz_alt_data=0；qual_1hz_alt_instr_corr = 0；qual_1hz_rad_data = 0；orb_state_flag = 3；rain_flag = 0；ecmwf_meteo_map_avail = 0；ice_flag = 0；每秒平均测距可靠观测点数在10个以上；海面高观测值标准差大于0mm 小于200mm； 卫星轨道高与测距值之差大于-130m小于100m；干对流层改正值大于-2500mm小于-1900mm；湿对流层改正值大于-500mm小于1mm；电离层改正值大于-400mm小于40mm；海况偏差改正值大于-500mm小于0mm；海洋潮汐改正绝对值小于5000mm；固体地球潮改正绝对值小于1000mm；极潮改正绝对值小于150mm；有效波高大于0m小于11m；Ku波段后向散射系数大于7dB小于30dB；高度计测量风速大于0m/s小于30m/s；星下点偏离平台姿态角大于-0.2°小于0.64°； Ku波段后巷散射系数的均方根小于1.0 dB；后向散射系数的可靠观测点数大于10个；各校正项不等于其默认值。数据质量信息：利用验潮站数据及国外同类数据对海平面产品进行了精度检验，基于本产品数据得到的海平面上升速度小于0.2 mm/a，达到项目技术指标的要求。

Basic Data Information
Data Time Span: 1993.1–2020.12
Spatial Coverage: Global Oceans
Number of Data Entries: 336
Data Resolution: 0.25°
Data Type: Grid data excluding original remote sensing images

Data Abstract: Sea level height refers to the height of the sea surface relative to the mean sea level after removing ocean tides. The sea level product is monthly mean sea level height grid data. As one of the important reference indicators for global climate change, accurately understanding global sea level change is essential for global climate change research.
Based on long-term time-series multi-satellite altimeter data including T/P, Jason-1/2/3, ERS-1/2, ENVISAT, GFO, Cryosat-2, SARAL, Sentinel-3 and HY-2, through data preprocessing and unification, and using spatio-temporal objective analysis methods, the 0.25° monthly mean global sea level height data product for 1993–2020 was generated.

Data Author (Contact Person) Information
Name: Zhang Jie
Contact Phone: [phone]
Postal Code: 266061
Contact Email: [e-mail]
Affiliation: First Institute of Oceanography, Ministry of Natural Resources of the People's Republic of China
Address: No. 6, Xianxia Ling Road, Laoshan District, Qingdao City

Data Citation and Declaration
Declaration: The 1993–2020 global ocean 0.25° monthly mean sea level data is derived from the National Key R&D Program of China "Generation of Global Climate Datasets and Monitoring of Key Climate Change Processes and Elements (2016YFA0600100)".
Citation: Zhang Jie. First Institute of Oceanography, Ministry of Natural Resources. 1993–2020 Global Ocean 0.25° Monthly Mean Sea Level Data. 2021

Data Provenance
Data Source Description: The satellite altimeter data used in this study was downloaded from ftp://ftp-access.aviso.altimetry.fr, ftp://osdds-ftp.nsoas.org.cn and https://coda.eumetsat.int/#/home.
Data Generation Process Description: The purpose of altimeter data preprocessing and quality control is to filter out data that does not meet the data quality requirements based on the satellite altimeter's own data editing criteria, then calculate the along-track Sea Surface Height (SSH) observations from the filtered data. For multi-source satellite altimeter data, data quality control is carried out using their respective data editing criteria, and quality-controlled sea level height data from satellite altimeters is generated. The specific data editing criteria are as follows:
Remove land, sea ice, missing and contaminated data according to the following conditions: surface_type = 0; alt_echo_type=0; rad_surf_type=0; qual_1hz_alt_data=0; qual_1hz_alt_instr_corr = 0; qual_1hz_rad_data = 0; orb_state_flag = 3; rain_flag = 0; ecmwf_meteo_map_avail = 0; ice_flag = 0; the number of reliable range-averaged observations per second is more than 10; the standard deviation of sea level height observations is greater than 0 mm and less than 200 mm; the difference between satellite orbit height and range measurement value is greater than -130 m and less than 100 m; the dry tropospheric correction value is greater than -2500 mm and less than -1900 mm; the wet tropospheric correction value is greater than -500 mm and less than 1 mm; the ionospheric correction value is greater than -400 mm and less than 40 mm; the sea state bias correction value is greater than -500 mm and less than 0 mm; the absolute value of ocean tidal correction is less than 5000 mm; the absolute value of solid Earth tide correction is less than 1000 mm; the absolute value of polar tide correction is less than 150 mm; significant wave height is greater than 0 m and less than 11 m; Ku-band backscatter coefficient is greater than 7 dB and less than 30 dB; altimeter-measured wind speed is greater than 0 m/s and less than 30 m/s; the sub-satellite point deviation from the platform attitude angle is greater than -0.2° and less than 0.64°; the root mean square of Ku-band backscatter coefficient is less than 1.0 dB; the number of reliable observations of backscatter coefficient is more than 10; each correction term is not equal to its default value.

Data Quality Information: Accuracy tests were conducted on the sea level product using tide gauge data and foreign similar datasets. The sea level rise rate obtained based on this product is less than 0.2 mm/a, which meets the technical indicators of the project.