A comparative analysis of Tempo NO2 remote sensing with surface‐level monitoring through diurnal and seasonal trends, meteorology, and monitor characteristics

Nawaz, M. Omar, Huber, Daniel E., Kerr, Gaige H., Judd, Laura M., Acker, Summer J. and Goldberg, Daniel L. 2025. A comparative analysis of Tempo NO2 remote sensing with surface‐level monitoring through diurnal and seasonal trends, meteorology, and monitor characteristics. Journal of Geophysical Research: Atmospheres 130 (20) , e2025JD043923. 10.1029/2025jd043923

PDF - Published Version Available under License Creative Commons Attribution. Download (5MB)

Abstract

The NASA Tropospheric Emissions: Monitoring of Pollution (TEMPO) instrument—launched in August 2023—measures diurnal patterns of column NO2 at unprecedented spatial resolution. Given its nascent status, it is unknown how TEMPO V03 column NO2 compares to surface-level monitoring across long-term timescales. In this study, we explore how temporally averaged hourly TEMPO column NO2 observations compare to surface-level concentrations from monitors in the US EPA Air Quality System (AQS). Monthly averaged hourly TEMPO vertical column densities (VCDs) correlate to surface-level NO2 moderately (R2 = 0.42); however, there is notably stronger correlation for monitors that are not defined as “near road” across hourly annual-average equivalent timescales (R2 = 0.61). During the TROPOMI overpass (approximately 13:30 LT), annual-average TEMPO slant column densities (SCDs) at “not near road” sites are better correlated with surface-level NO2 (R2 = 0.72) than tropospheric VCDs from TROPOMI (R2 = 0.65) and TEMPO (R2 = 0.66) due to added uncertainty with a priori inputs in the AMF. In the future, a more accurate AMF could improve TEMPO VCDs correlation to the level of the TEMPO SCDs. TEMPO column NO2 are most poorly correlated in the early morning at 6:00 (R2 = 0.23) and 7:00 (R2 = 0.35) LT when TEMPO is less sensitive to near-surface pollution due to a longer sunlight path through the atmosphere and the subsequent increased sensitivity to retrieval assumptions. Ultimately, this analysis identifies conditions and characteristics that affect the correlation between TEMPO and ground-level monitoring that has implications for applying TEMPO remote sensing data to derive or interpret surface-level NO2.

Item Type:	Article
Date Type:	Published Online
Status:	Published
Schools:	Schools > Earth and Environmental Sciences
Additional Information:	License information from Publisher: LICENSE 1: URL: http://creativecommons.org/licenses/by/4.0/
Publisher:	American Geophysical Union
ISSN:	2169-897X
Date of First Compliant Deposit:	21 October 2025
Date of Acceptance:	9 October 2025
Last Modified:	21 Oct 2025 14:45
URI:	https://orca.cardiff.ac.uk/id/eprint/181819

Actions (repository staff only)

Edit Item