|
Titel |
Recent satellite-based trends of tropospheric nitrogen dioxide over large urban agglomerations worldwide |
VerfasserIn |
P. Schneider, W. A. Lahoz, R. van der A |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
1680-7316
|
Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 3 ; Nr. 15, no. 3 (2015-02-03), S.1205-1220 |
Datensatznummer |
250119386
|
Publikation (Nr.) |
copernicus.org/acp-15-1205-2015.pdf |
|
|
|
Zusammenfassung |
Trends in tropospheric nitrogen dioxide (NO2) columns over 66 large
urban agglomerations worldwide have been computed using data from the
SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY
(SCIAMACHY) instrument onboard the Envisat platform for the period August
2002 to March 2012. A seasonal model including a linear trend was fitted to
the satellite-based time series over each site. The results indicate distinct
spatial patterns in trends. While agglomerations in Europe, North America,
and some locations in East Asia/Oceania show decreasing tropospheric
NO2 levels on the order of −5% yr−1, rapidly
increasing levels of tropospheric NO2 are found for agglomerations in
large parts of Asia, Africa, and South America. The site with the most
rapidly increasing absolute levels of tropospheric NO2 was found to
be Tianjin in China with a trend of 3.04 (±0.47) × 1015 molecules cm−2yr−1, whereas the site with the most
rapidly increasing relative trend was Kabul in Afghanistan with 14.3 (±2.2) % yr−1. In total, 34 sites exhibited increasing trends of tropospheric NO2 throughout the study period, 24 of which were
found to be statistically significant. A total of 32 sites showed decreasing
levels of tropospheric NO2 during the study period, of which 20 sites
did so at statistically significant magnitudes. Overall, going beyond the
relatively small set of megacities investigated previously, this study
provides the first consistent analysis of recent changes in tropospheric
NO2 levels over most large urban agglomerations worldwide, and
indicates that changes in urban NO2 levels are subject to substantial
regional differences as well as influenced by economic and demographic
factors. |
|
|
Teil von |
|
|
|
|
|
|