ESA Biomass Climate Change Initiative (Biomass_cci): Global datasets of forest above-ground biomass for the years 2010, 2015, 2016, 2017, 2018, 2019, 2020 and 2021, v5.01

This dataset comprises estimates of forest above-ground biomass for the years 2010, 2015, 2016, 2017, 2018, 2019, 2020 and 2021. They are derived from a combination of Earth observation data, depending on the year, from the Copernicus Sentinel-1 mission, Envisat’s ASAR (Advanced Synthetic Aperture Radar) instrument and JAXA’s (Japan Aerospace Exploration Agency) 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 5. Compared to version 4, version 5 consists of an update of the three maps of AGB (aboveground biomass) for the years 2010, 2017, 2018, 2019, 2020 and new AGB maps for 2015, 2016 and 2021. New AGB change maps have been created for consecutive years (2015-2016, 2016-2017 and 2020-2021), alongside an update of change maps for years 2010-2020, 2017-2018, 2018-2019 and 2019-2020, 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)

Additionally provided in this version release are new aggregated data products. These aggregated products of the AGB and AGB change data layers are available at coarser resolutions (1, 10, 25 and 50km).

In addition, files describing the AGB change between two consecutive years (i.e., 2015-2016, 2016-2017, 2018-2017, 2019-2018, 2019-2020, 2020-2021) and over a decade (2020-2010) are provided (labelled as 2015_2016, 2016_2017, 2017_2018, 2018_2019, 2019_2020 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.

This version represents an update of v5.0 which was missing a number of tiles covering islands on the Pacific and Indian Ocean and one tile covering Scandinavia north of 70 deg latitude.

本数据集包含2010、2015、2016、2017、2018、2019、2020及2021年的森林地上生物量（above-ground biomass, AGB）估算值。这些估算值基于不同年份的多源地球观测数据，包括哥白尼计划（Copernicus）哨兵-1号（Sentinel-1）任务、环境卫星（Envisat）搭载的高级合成孔径雷达（Advanced Synthetic Aperture Radar, ASAR）仪器，以及日本宇宙航空研究开发机构（Japan Aerospace Exploration Agency, JAXA）的高级陆地观测卫星（Advanced Land Observing Satellite, ALOS-1和ALOS-2）获取的数据，同时辅以其他地球观测来源的补充信息。本数据集由欧洲空间局（European Space Agency, ESA）气候变化倡议（Climate Change Initiative, CCI）计划下的生物量CCI工作组制作完成。

本次发布的数据为第5版（v5）。相较于第4版，v5更新了2010、2017、2018、2019、2020年的3幅地上生物量（AGB）地图，并新增了2015、2016及2021年的AGB地图。同时新增了连续年份（2015-2016、2016-2017及2020-2021）的AGB变化地图，并更新了2010-2020、2017-2018、2018-2019、2019-2020年的变化地图，以及10年尺度（2020-2010）的变化地图。本次更新的遥感数据源池新增了覆盖所有生物群区、所有年份的L波段多时序观测数据。AGB地图基于修订后的异速生长模型，该模型依托来自GEDI和ICESat-2任务的更长时间序列星载激光雷达（LiDAR）数据构建。反演算法中现已加入时序信息，以保留遥感数据所反映的生物量动态变化，并减小了2010年与近年数据间的系统偏差。

本数据集产品包含2幅全球图层，分别为：
1. 地上生物量（AGB，单位：吨/公顷，即Mg/ha）栅格数据集。其定义为所有活立木的木质部分（茎、树皮、枝条及细枝）的烘干质量，不包含伐桩与根系。
2. 逐像素地上生物量不确定性估算值栅格数据集，以Mg/ha为单位的标准差形式表示。

本次版本发布还新增了聚合型数据产品。上述AGB及AGB变化数据图层的聚合产品可提供更粗的空间分辨率（1km、10km、25km及50km）。

此外，本次发布还包含描述连续年份（2015-2016、2016-2017、2018-2017、2019-2018、2019-2020、2020-2021）及10年尺度（2020-2010）间AGB变化的文件（命名格式为2015_2016、2016_2017、2017_2018、2018_2019、2019_2020及2020_2010）。每幅AGB变化产品包含两类地图：AGB变化的标准差，以及AGB变化的质量标记。需注意，AGB变化量可直接通过两幅AGB地图的差值计算得到，因此未直接提供该变化量数据。

数据以netCDF及GeoTIFF两种格式提供。

本版本是对v5.0的更新，原v5.0缺失了覆盖太平洋、印度洋岛屿的若干瓦片，以及覆盖斯堪的纳维亚半岛北纬70度以北区域的1片瓦片。

搜集汇总

背景与挑战

背景概述

该数据集由欧洲空间局气候变化倡议生物量团队生产，提供2010、2015-2021年全球森林地上生物量估计，数据源自哨兵-1、Envisat ASAR和ALOS卫星等多源遥感观测，并利用GEDI和ICESat-2激光雷达数据改进算法。数据集包括生物量及其不确定性的栅格图层、年度变化图以及多分辨率聚合产品，以netCDF和geotiff格式发布，支持全球森林碳循环和气候变化研究。