Earth System Science Hub Challenge February 2024 - Extreme Air Pollution in Northern India an Pakistan

[selviga19]

Hi,

We would like first to thank you for this opportunity to get our work published on EO Dashboard and for the version of the story you sent us.
However, this first version lacks clarity on some points, making the story map difficult to read for someone outside our field or from the general audience. This is how we would present our work : Air_pollution_India_EOdashboard_v2.docx. Here are the general changes/comments for each sections, that you can find on this document.

Introduction and Air Pollution and Health sections

• Nothing to say, we just reworded some sentences because they were repetitive. We really like the population density map !

Earth Observations

• We would change the title of this section to Earth Observation for air quality monitoring
• The part about measuring PM with satellite instruments is a bit confusing. Indeed, PM cannot be measured directly with satellite instruments. We can measure the optical properties of aerosols (including PM) but we don't have concentration values as we do for CO for example. We therefore propose a modified version in the document, which separates gases (whose concentration can be measured by satellite instruments) and aerosols (PM) to avoid any confusion. We have also added more information for each gaseous pollutant (references have been added at the bottom of the document).

Method and Datasets

• We thought it was more appropriate to talk about TROPOMI in the beginning of this section as a way of getting back to our work/challenge, after the Earth Observation for air quality monitoring section, which is more general.
• We've also mixed up the method and dataset subsections, as it seemed more natural for us to explain the method right after talking about TROPOMI and CO.
• To illustrate the air pollution episode, we would add the animation of CO that we did during the Challenge week.
• For the other datasets (VIIRS and ERA5), we rewrote some sentences and add more informations, so the readers can understand the Results section.
• After talking about the VIIRS data, you provide a link to explore the MODIS data. However, no MODIS data is displayed on the interactive map. Also, isn't it possible to display the VIIRS data, since we're using it in this work? Indeed, the 2 instruments are different, even though they have the same purpose (monitoring fires from space).
• To illustrate the fact that we used horizontal winds from the ERA5 reanalyses, you've added an interactive wind map, which can be difficult to read for those unfamiliar with this type of data. Usually, when we work with wind data, we draw a wind speed map. Wind speed is calculated using the following formula: WS = sqrt(u² + v²), where u is the eastward wind speed and v, the northward wind speed. Wind directions can be represented by arrows on the wind speed map, but it is not mandatory. Futhermore, the date is not indicated on the map that is currently displayed on the story map (is it hourly/daily/monthly data ?) . So, if you really want to display an interactive wind map, we will suggest you to plot an average wind speed map (using the formula above) for month of November for example. Otherwise, we think that the wind animation that we made during the challenge week is enough. Moreover, displaying the wind animation here helps to analyze the results.

Daily CO variation in 2023

• We would change the title of this section to Evolution of daily CO concentrations in 2023 in the IGP region
• We rephrased the comments/analysis for each city.
• We changed the title of the charts and plots for more clearness. Note that in the table, we first put "Total number of days in 2023" : we think "number of measurement days" is better.

Conclusion

• We just have shortened and rewritten this section

References

• We changed some references and we've tried to arrange them in the order in which they appear in the story map.
• Some references were not quoted directly in the story map but they helped us to analyze the November 2023 pollution episode, so we put them apart.

It may seem like a lot of changes all at once, but we're open to any modifications, depending on what you can and can't do. We can also redo any figures (like the animations) if you want to.

Thank you,

Selviga, Natacha and Ellie.