The final step allows for converting the proto-flux into a mass flux, taking into the plume transport speed.
In most situations, plume transport speed can reasonably estimated from meteorological data. Here, hourly-resolved reanalysis ERA5 can be used to select wind speed at 37 pressure levels above the surface. To access to this functionality, click on the Speed from ERA5 button.
Then, you may adjust the prefered plume altitude using the Altitude guess slider. The black vector shows the direction of wind at the selected altitude. Checking the consistency of this predicted wind direction against the “true” plume direction in the TROPOMI image is advised. As in Step 3, a time slider is also available to scroll from one day to the next.
Finally, when you are satisfied with the result, you may download the SO2 flux time-series in .csv format by clicking on Download flux estimates.
