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

. Nine Pandoraspectrometer instruments (PSI) were installed at eight sites inSouth Korea as part of the KORUS-AQ (Korea U.S.-Air Quality) field studyintegrating information from ground, aircraft, and satellite measurementsfor validation of remote sensing air-quality studies. The PSI madedirect-sun measurements of total vertical column NO2 , C(NO2) , withhigh precision (0.05 DU, where 1 DU  = 2.69 × 10 16  molecules cm −2 )and accuracy (0.1 DU) that were retrieved using spectral fitting techniques.Retrieval of formaldehyde C(HCHO) total column amounts were also obtained atfive sites using the recently improved PSI optics. The C(HCHO) retrievals havehigh precision, but possibly lower accuracy than for NO2 because ofuncertainty about the optimum spectral window for all ground-based andsatellite instruments. PSI direct-sun retrieved values for C(NO2) andC(HCHO) are always significantly larger than OMI (AURA satellite OzoneMonitoring Instrument) retrieved C(NO2) and C(HCHO) for the OMIoverpass local times ( KST = 13.5 ± 0.5  h). In urban areas, PSI C(NO2) 30-day running averages are at least a factor of two larger thanOMI averages. Similar differences are seen for C(HCHO) in Seoul and nearbysurrounding areas. Late afternoon values of C(HCHO) measured by PSI are evenlarger, implying that OMI early afternoon measurements underestimate theeffect of poor air quality on human health. The primary cause of OMIunderestimates is the large OMI field of view (FOV) that includes regionscontaining low values of pollutants. In relatively clean areas, PSI and OMIare more closely in agreement. C(HCHO) amounts were obtained for five sites,Yonsei University in Seoul, Olympic Park, Taehwa Mountain, Amnyeondo, and Yeoju.Of these, the largest amounts of C(HCHO) were observed at Olympic Park andTaehwa Mountain, surrounded by significant amounts of vegetation.Comparisons of PSI C(HCHO) results were made with the Compact AtmosphericMultispecies Spectrometer CAMS during overflights on the DC-8 aircraft forTaehwa Mountain and Olympic Park. In all cases, PSI measured substantially moreC(HCHO) than obtained from integrating the CAMS altitude profiles. PSIC(HCHO) at Yonsei University in Seoul frequently reached 0.6 DU andoccasionally exceeded 1.5 DU. The semi-rural site, Taehwa Mountain, frequentlyreached 0.9 DU and occasionally exceeded 1.5 DU. Even at the cleanest site,Amnyeondo, C(HCHO) occasionally exceeded 1 DU.

atmospheric measurement techniques

NO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt; and HCHO measurements in Korea from 2012 to 2016 from Pandora spectrometer instruments compared with OMI retrievals and with aircraft measurements during the KORUS-AQ campaign