Monthly pCO2, gas transfer velocity and CO2 efflux rate in global streams and rivers (the GRADES river networks)

TheGlobal Reach–level A priori Discharge Estimates for SWOT or GRADES river networks and associated river-reach slope and length estimates can be found at http://hydrology.princeton.edu/data/mpan/MERIT_Basins/. The GRADES daily discharge estimates can be found at http://hydrology.princeton.edu/data/mpan/GRADES/. Monthly river widths can be estimated utilizing the GRADES annual and monthly mean discharge, and downstream and at-a-station hydraulic geometry developed for each of the wetness conditions. Length, width and surface area are aggregaged to 78 cross-region basins based on hydrology and flow regime for stream order extrapolation (to an end width of 0.3 m). Total surface area of a basin is the sum of the surface area represented by the GRADES river networks and the extrapolated area. Both the GRADES and the extrapolated surface areas are corrected for loss due to temporal drying up and ice coverages. CO2 flux is the product of dissolved CO2 concentration (converted from pCO2 according to Henry's Law), gas transfer velocity (k) and stream/river surface area. CO2 flux can be calculated for each river reach of the GRADES river networks and each stream order for the extrapolated area. Total CO2 emission from streams and rivers in a basin is the sum of CO2 emission from the GRADES river reaches and extrapolated river surface area, taking into account both losses from both ephemeral streams and ice covered periods. Relevant codes are available at https:///github.com/lsdeel/globalRiverCO2emission.

针对SWOT或GRADES河网的河段级先验流量估算，以及配套的河段坡度与长度估算数据，可从http://hydrology.princeton.edu/data/mpan/MERIT_Basins/ 获取。GRADES日尺度流量估算数据可从http://hydrology.princeton.edu/data/mpan/GRADES/ 获取。可基于GRADES年、月平均流量，以及针对各湿度条件构建的下游与站址水力几何形态，估算月尺度河道宽度。基于水文与水流情势，将河道长度、宽度与表面积聚合至78个跨区域流域，用于河道级序（stream order）外推（外推至最终宽度0.3米）。流域总表面积为GRADES河网所代表的表面积与外推得到的表面积之和。GRADES河网与外推得到的表面积均已校正因暂时性断流与冰覆盖造成的面积损失。二氧化碳（CO₂）通量为溶解态CO₂浓度（依据亨利定律由二氧化碳分压（pCO₂）转换得到）、气体传输速率（k）与河道表面积三者的乘积。可针对GRADES河网的各河段，以及外推区域的各河道级序计算CO₂通量。流域内河道总CO₂排放量为GRADES河段与外推河道表面积对应的CO₂排放量之和，同时考虑了暂时性河道与冰覆盖期的排放量损失。相关代码可从https://github.com/lsdeel/globalRiverCO2emission 获取。

搜集汇总

背景与挑战

背景概述

该数据集提供了全球河流和溪流中月度溶解CO2分压（pCO2）、气体传输速度（k）和CO2排放率的估计数据，基于GRADES河流网络，空间分辨率约为1公里。数据集用于支持全球河流CO2排放估算和区域碳平衡研究，包含GeoTIFF和CSV格式文件，并整合了文献中的直接测量数据。