我想用卫星[Sentinel-5p NO2数据集][1]计算一年内的“NO2”总量。但问题是哨点卫星数据是以“mol/m^2”为单位存储的。但我必须将其与“磅”或“吨”或任何其他单位进行比较，以将“NO2”量与地面“NO2”测量值进行比较。**示例:**在我们的卫星数据集中，我们有“对流层NO2列数密度”，单位为“mol/m^2”。我们想计算出加州每年的NO2总量。所以我们汇总了加州全年>的数据。然后我们得到全年NO2 ' 4200 mol/m^2 '。我>想把这个转换成“克”或“吨”或“磅”。例如，加州每年的“NO2”总量为35000吨。同样，如果我把“mol/m^2”转换为“molec/cm^2”，那么它是否可能转换为总“克”或“吨”? **Research**: I have asked that question in [here][2]. After getting answers, I thought I have found the solutions. But after some more research, it turns out not easy. Because in satellite data what we get is tropospheric vertical column number density and convert them to total mass like total no2 in gram or ton is not straightforward. These forum posts ([#1][3], [#2][4], [#3][5]) also somewhat similar to mine, but I didn't get quite a solution to my problem. **EDIT**: I know that we can easily multiply by area in m^2 to cancel out m^2 in the unit and multiple by NO2 molar mass, but this is not a ground-based problem. We are talking about satellite imagery dataset especially **tropospheric vertical column density**. [#1][3], [#2][4], [#3][5] These posts shows why it is different for converting satellite imagery units to ground-based units. [1]: https://developers.google.com/earth-engine/datasets/catalog/COPERNICUS_S5P_OFFL_L3_NO2 [2]: https://gis.stackexchange.com/questions/353368/correlating-mol-m2-with-ton-and-lb [3]: //www.hoelymoley.com/questions/8860/convert-omi-no2-vertical-column-density-molecules-cm2-into-mixing-ratio-ppm [4]: //www.hoelymoley.com/questions/19391/convert-no2-concentration-in-sentinel-5p-data-from-mol-m2-to-%CE%BCg-m3-on-the-ground [5]: https://www.researchgate.net/post/How_can_I_convert_the_unit_from_molecules_cm2_to_ppm