Open AccessEvaluating current satellite capability to observe diurnal change in nitrogen oxides in preparation for geostationary satellite missions
Author(s) -
Elise Penn,
Tracey Holloway
Publication year - 2020
Publication title -
environmental research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.37
H-Index - 124
ISSN - 1748-9326
DOI - 10.1088/1748-9326/ab6b36
Subject(s) - geostationary orbit , environmental science , satellite , diurnal cycle , meteorology , morning , daytime , remote sensing , geostationary operational environmental satellite , climatology , geography , atmospheric sciences , geology , physics , astronomy
This study characterizes the degree to which current polar-orbiting satellites can evaluate the daytime change in NO 2 vertical column density (VCD) in urban, suburban, and rural areas. We examine these issues by considering the diurnal cycle of NO 2 over the United States, using the large NO 2 monitoring network supported by states, tribes, and the US Environmental Protection Agency (EPA). Through this analysis, we identify the potential opportunities and limitations of current space-based NO 2 data in capturing diurnal change. Ground-based monitoring data from the US EPA are compared with satellite retrievals of NO 2 from the KNMI Tropospheric Emissions Monitoring Internet Service (TEMIS) for two instruments: GOME-2 with a mid-morning overpass, and OMI with an early afternoon overpass. Satellite data show evidence of higher morning NO 2 in the vicinity of large urban areas. Both satellites and ground monitors show ∼1.5–2x greater NO 2 abundance between morning and afternoon in urban areas. Despite differences in horizontal resolution and overpass time, the two satellite retrievals show similar agreement with ground-based NO 2 measurements. When analyzed on a pixel-by-pixel basis, we find evidence for spatial structure in the diurnal change in NO 2 between city center and surrounding areas in Southern California. Wider analysis of urban-suburban structure in diurnal NO 2 change is hindered by resolution differences in the two satellite instruments, which have the potential to create data artefacts. This study highlights the value of future geostationary instruments to provide comparable satellite retrievals for NO 2 over the course of a day, and research needs related to the effective utilization of NO 2 satellite data for air quality applications.