Earthdata Forum

This is Xiaohua from NASA GES DISC.

I'd like to know who I should contact regarding the AQ data at SEDAC.

1. I found some similar collections, as below. I wonder if some collections are similar but in different versions, e.g., V1.10 and v1. Which one is the current version?

https://www.earthdata.nasa.gov/search?keys=Daily+and+Annual+PM2.5+Concentrations+for+the+Contiguous+United+States%2C+1-km+Grids%2C+v1+%282000-2016%29

- Daily and Annual NO2 Concentrations for the Contiguous United States, 1-km Grids, Version 1.10 (2000-2016)
- Daily and Annual NO2 Concentrations for the Contiguous United States, 1-km Grids, v1 (2000 - 2016)

In addition, GES DISC curates a webpage for the HAQAST project: https://disc.gsfc.nasa.gov/information/mission-project?title=HAQAST. I want some experts from SEDAC to confirm the SEDAC collections.

Hello,

Thank you for your interest in the "Daily and Annual NO2 Concentrations for the Contiguous United States, 1-km Grids" data sets. The Version 1.10 is the more current version.

In version 1.10, the completeness of daily NO2 predictions have been enhanced by employing linear interpolation to impute missing values. Specifically, for days with small spatial patches of missing data with less than 100 grid cells, inverse distance weighting interpolation was used to fill the missing grid cells. Other missing daily NO2 predictions were interpolated from the nearest days with available data. Annual predictions were updated by averaging the imputed daily predictions for each year in each grid cell.

For the second question, could you clarify your question please?

I hope this helps.

Regards,
Lisa Lukang
SEDAC User Services

Hi Lisa,
I am glad to hear from you!
Thank you so much for your reply to my first question.
I will email you regarding the second question. It is complicated to explain through the forum.
Xiaohua

Hi. We will look out of your email. Thank you.