ESA Biomass Climate Change Initiative (Biomass_cci): Global datasets of forest above-ground biomass for the years 2010, 2017, 2018, 2019 and 2020, v4

This dataset comprises estimates of forest above-ground biomass for the years 2010, 2017, 2018, 2019 and 2020. They are derived from a combination of Earth observation data, depending on the year, from the Copernicus Sentinel-1 mission, Envisat’s ASAR instrument and JAXA’s Advanced Land Observing Satellite (ALOS-1 and ALOS-2), along with additional information from Earth observation sources. The data has been produced as part of the European Space Agency's (ESA's) Climate Change Initiative (CCI) programme by the Biomass CCI team. This release of the data is version 4. Compared to version 3, version 4 consists of an update of the three maps of AGB for the years 2010, 2017 and 2018 and new AGB maps for 2019 and 2020. New AGB change maps have been created for consecutive years (2018-2017, 2019-2018 and 2020-2019) and for a decadal interval (2020-2010). The pool of remote sensing data now includes multi-temporal observations at L-band for all biomes and for all years. The AGB maps rely on revised allometries which are now based on a longer record of spaceborne LiDAR data from the GEDI and ICESat-2 missions. Temporal information is now implemented in the retrieval algorithm to preserve biomass dynamics as expressed in the remote sensing data. Biases between 2010 and more recent years have been reduced. The data products consist of two (2) global layers that include estimates of: 1) above ground biomass (AGB, unit: tons/ha i.e., Mg/ha) (raster dataset). This is defined as the mass, expressed as oven-dry weight of the woody parts (stem, bark, branches and twigs) of all living trees excluding stump and roots 2) per-pixel estimates of above-ground biomass uncertainty expressed as the standard deviation in Mg/ha (raster dataset) In addition, files describing the AGB change between two consecutive years (i.e., 2018-2017, 2019-2018 and 2020-2010) and over a decade (2020-2010) are provided (labelled as 2018_2017, 2019_2018, 2020_2019 and 2020_2010). Each AGB change product consists of two sets of maps: the standard deviation of the AGB change and a quality flag of the AGB change. Note that the change itself can be simply computed as the difference between two AGB maps, so is not provided directly. Data are provided in both netcdf and geotiff format.

本数据集包含2010、2017、2018、2019及2020年的森林地上生物量（Above Ground Biomass, AGB）估算结果。其基于对应年份的地球观测数据组合生成，涉及哥白尼哨兵-1（Copernicus Sentinel-1）任务、Envisat卫星的合成孔径雷达（ASAR）载荷以及日本宇宙航空研究开发机构（Japan Aerospace Exploration Agency, JAXA）的先进陆地观测卫星（ALOS-1和ALOS-2），同时辅以其他地球观测数据源的补充信息。

该数据由欧洲空间局（European Space Agency, ESA）气候变化倡议（Climate Change Initiative, CCI）计划下的生物量CCI工作组研制完成。本次发布的数据为第4版，相较于第3版，第4版更新了2010、2017、2018年的三幅AGB地图，并新增了2019和2020年的AGB地图；同时生成了连续年份（2018-2017、2019-2018、2020-2019）以及十年区间（2020-2010）的AGB变化地图。

本次遥感数据集涵盖了所有生物群区、所有年份的L波段多时序观测数据。AGB地图采用了修订后的异速生长模型，该模型基于GEDI任务与ICESat-2任务获取的更长时间序列星载激光雷达（LiDAR）数据构建。反演算法现已引入时序信息，以保留遥感数据所反映的生物量动态特征，并降低了2010年与近年数据之间的系统偏差。

本数据集包含两类全球栅格图层：
1. 地上生物量（AGB，单位：吨/公顷，即Mg/ha）估算栅格数据集。其定义为所有活立木（不含伐桩与根系）的木质部分（树干、树皮、枝条及细枝）的烘干质量；
2. 逐像素地上生物量不确定性估算栅格数据集，以Mg/ha为单位的标准差形式表示。

此外还提供了描述以下时段AGB变化的文件：连续年份（2018-2017、2019-2018、2020-2019）及十年时段（2020-2010），文件分别标记为2018_2017、2019_2018、2020_2019及2020_2010。每一类AGB变化产品包含两套地图：AGB变化的标准差以及AGB变化质量标志。需注意，AGB变化量可直接通过两幅AGB地图相减计算得到，因此未直接提供原始变化量数据。

本数据集以netCDF和GeoTIFF两种格式提供。

搜集汇总

背景与挑战

背景概述

该数据集提供了2010年至2020年全球森林地上生物量的估计值，结合了多种卫星观测数据，并包含生物量及其不确定性的全球图层。数据格式为netCDF和geotiff，适用于研究森林碳储量和气候变化影响。