English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

. In this study, we describe the recent changes inthe tropospheric ozone (O 3 ) columns measured by the Infrared AtmosphericSounding Interferometer (IASI), onboard the Metop satellite, during the first 9years of operation (January 2008 to May 2017). Using appropriatemultivariate regression methods, we differentiate significant linear trendsfrom other sources of O 3 variations captured by IASI. The geographicalpatterns of the adjusted O 3 trends are provided and discussed on theglobal scale. Given the large contribution of the natural variability incomparison with that of the trend (25–85 % vs. 15–50 %,respectively) to the total O 3 variations, we estimate that additionalyears of IASI measurements are generally required to detect the estimatedO 3 trends with high precision. Globally, additional 6 months to6 years of measurements, depending on the regions and the seasons, are neededto detect a trend of | 5 |  DU decade −1 . An exception is interestinglyfound during summer at mid- and high latitudes of the Northern Hemisphere (NH; ∼  40 to ∼  75 ∘  N), where the large absolute fitted trend values( ∼ | 0.5 |  DU yr −1 on average) combined with the small modelresiduals ( ∼  10 %) allow for detection of a band-like pattern ofsignificant negative trends. Despite no consensus in terms oftropospheric O 3 trends having been reached from the availableindependent datasets (UV or IR satellites, O 3 sondes, aircrafts,ground-based measurements, etc.) for the reasons that are discussed in thetext, this finding is consistent with the reported decrease in O 3 precursor emissions in recent years, especially in Europe and USA. Theinfluence of continental pollution on that latitudinal band is furtherinvestigated and supported by the analysis of the O 3 –CO relationship(in terms of correlation coefficient, regression slope and covariance) thatwe found to be the strongest at northern midlatitudes in summer.

Decrease in tropospheric O&lt;sub&gt;3&lt;/sub&gt; levels in the Northern Hemisphere observed by IASI

Decrease in tropospheric O<sub>3</sub> levels in the Northern Hemisphere observed by IASI