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 Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

A statistical method was developed to extract baseline levels of ground level ozonein Canada and the US, and to quantify the temporal changes of baseline ozone levelson annual, seasonal, diurnal and decadal scales for the period 1997 to 2006based on ground-level observations from 97 non-urban monitoring sites.Baseline ozone is defined here as ozone measured at a given site in the absence ofstrong local influences. The quantification of baseline levels involved using aPrincipal Component Analyses (PCA) to derive groups of commonly-varyingsites in contiguous regions by season, followed by using backward air parceltrajectories to systematically select ozone mixing ratios associated withthe baseline condition in each of the PCA-derived regions. Decadal trends wereestimated by season for each of the regions using a generalized linear mixedmodel (GLMM). Baseline ozone mixing ratios determined by this method were found to varygeographically and seasonally. For the 1997–2006 period, baseline mixing ratioswere calculated for annual and seasonal periods in seven regions of NorthAmerica based on multi-site multi-year averages of the baseline data sets. Theannual average (±1 standard deviation) baseline mixing ratios for the regionsare as follows: Continental Eastern Canada=30±9 ppb, ContinentalEastern US=30±10 ppb, Coastal Eastern Canada=27±9 ppb, CoastalWestern Canada=19±10 ppb; Coastal Western US=39±10 ppb,Continental Western Canada=28±10 ppb and Continental WesternUS=46±7 ppb. Trends in the baseline mixing ratios were also found to vary byseason and by geographical region. On a decadal scale, increasing baseline ozonetrends (temperature-adjusted) were observed in all seasons along the Pacificcoasts of Canada and the US, although the trends in California were notstatistically significant. In the coastal zone of Pacific Canada, positivetrends were found with a rate of increase of 0.28±0.26, 0.72±0.55,and 0.93±0.41 ppb/a in spring (MAM), summer (JJA) and winter (DJF), respectively. In the Atlanticcoastal region, the trends were also positive in 3 of the 4 seasons (butonly significantly so in MAM). In the high ozone precursor emission areas ofthe Eastern United States, decadal trends in baseline ozone are, in general,negative in the spring, summer and fall and appear to be controlled by thestrong within-region changes induced by decreasing ozone precursoremissions

Baseline levels and trends of ground level ozone in Canada and the United States