Gridded products of global river methane concentrations, flux rates and emissions

Information on the products on this repository These data is created using the R scripts with the random forest models and upscaling procedures found in: https://github.com/rocher-ros/RiverMethaneFlux. Raw files to reproduce this product can be found in https://doi.org/10.5281/zenodo.7733604 The results of this analysis are published in the article "Global Methane emissions form rivers and streams" (in Nature) (https://doi.org/10.1038/s41586-023-06344-6). Main author is Gerard Rocher-Ros, for which correspondence can be sent to [e-mail] Units of the variables in the product are: -River methane concentration: mmol CH4 m-3 -River methane diffusive flux rates: mmol CH4 m-2 d-1 (of river area) -River methane diffusive emissions: Mega grams of C-CH4 (for each pixel). The spatial resolution of the product is 0.25 degrees (which corresponds to around 27 km). The files are in WGS84. There are four main products in this folder, packed as geotiff files, and described below. + The file "river_methane_yearly.tiff" contains three layers: - Yearly average river CH4 concentrations (ch4_conc_avg) - Yearly average river CH4 diffusive flux rates (ch4_flux_avg) - Yearly total river CH4 diffusive emissions (ch4_emissions_year) + The file "river_methane_concs_monthly.tiff" contains twelve layers, with the modelled river methane concentrations for each month. + The file "river_methane_flux_monthly.tiff" contains twelve layers, with the modelled river methane flux rates for each month. + The file "river_methane_emissions_monthly.tiff" contains twelve layers, with the total river methane emissions for each month.

本仓库所载数据集相关说明如下：本数据集依托随机森林模型与升尺度处理流程，通过R脚本生成，相关代码可访问：https://github.com/rocher-ros/RiverMethaneFlux。用于复现该数据集的原始文件可通过https://doi.org/10.5281/zenodo.7733604获取。本分析结果已发表于《Nature》期刊论文《全球河流与溪流甲烷排放》（Global Methane emissions form rivers and streams，https://doi.org/10.1038/s41586-023-06344-6），通讯作者为Gerard Rocher-Ros，联系邮箱为[e-mail]。

本数据集各变量的单位如下：
- 河流甲烷浓度：mmol CH4 m⁻³
- 河流甲烷扩散通量率：mmol CH4 m⁻² d⁻¹（以河流面积为统计基准）
- 河流甲烷扩散排放量：兆克碳基甲烷（Mega grams of C-CH4）

本数据集空间分辨率为0.25度，对应约27千米的空间尺度，数据坐标系采用WGS84。

本文件夹中共包含4类核心数据集，均封装为地理标记图像文件（GeoTIFF）格式，具体说明如下：
1. `river_methane_yearly.tiff`：包含3个波段图层：
- 年平均河流甲烷浓度（ch4_conc_avg）
- 年平均河流甲烷扩散通量率（ch4_flux_avg）
- 年总河流甲烷扩散排放量（ch4_emissions_year）
2. `river_methane_concs_monthly.tiff`：包含12个波段图层，对应各月模拟得到的河流甲烷浓度数据。
3. `river_methane_flux_monthly.tiff`：包含12个波段图层，对应各月模拟得到的河流甲烷扩散通量率数据。
4. `river_methane_emissions_monthly.tiff`：包含12个波段图层，对应各月的河流甲烷总排放量数据。