Accounting for Non-Detects in Satellite Ammonia Observations
Author Information
Author(s): White Evan, Shephard Mark W., Cady-Pereira Karen E., Kharol Shailesh K., Ford Sean, Dammers Enrico, Chow Evan, Thiessen Nikolai, Tobin David, Quinn Greg, O’Brien Jason, Bash Jesse
Primary Institution: Environment and Climate Change Canada
Hypothesis
How can we accurately account for non-detects in satellite measurements of ammonia?
Conclusion
Accounting for non-detects significantly improves the accuracy of satellite-derived ammonia measurements, especially in low concentration regions.
Supporting Evidence
- In regions with low ammonia concentrations, non-detects can exceed 70%, significantly affecting average values.
- Accounting for non-detects can reduce average ammonia values by over 50% in non-source conditions.
- The methodology developed allows for better representation of ammonia concentrations in satellite data.
- Non-detects were shown to have a minimal impact in regions with high ammonia emissions.
Takeaway
This study shows that when satellites can't detect low levels of ammonia, we can use other data to fill in the gaps, making our measurements more accurate.
Methodology
The study developed a methodology to identify and account for non-detects in satellite ammonia observations using a new cloud detection algorithm.
Potential Biases
Potential biases may arise from the limited number of surface stations used for representative values.
Limitations
The study relies on in-situ measurements from limited background sites, which may not fully represent all conditions.
Digital Object Identifier (DOI)
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