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

We present the first intercalibration of dry-air column-averaged molefractions of methane (XCH4) retrieved from solar Fourier transforminfrared (FTIR) measurements of the Network for the Detection of AtmosphericComposition Change (NDACC) in the mid-infrared (MIR) versus near-infrared(NIR) soundings from the Total Carbon Column Observing Network (TCCON). Thestudy uses multi-annual quasi-coincident MIR and NIR measurements from thestations Garmisch, Germany (47.48° N, 11.06° E,743 m a.s.l.), and Wollongong, Australia (34.41° S, 150.88° E,30 m a.s.l.). Direct comparison of the retrieved MIR and NIR XCH4 time series forGarmisch shows a quasi-periodic seasonal bias leading to a standarddeviation (stdv) of the difference time series (NIR–MIR) of 7.2 ppb. Afterreducing time-dependent a priori impact by using realistic site- andtime-dependent ACTM-simulated profiles as a common prior, the seasonal biasis reduced (stdv = 5.2 ppb). A linear fit to the MIR/NIR scatter plot ofmonthly means based on same-day coincidences does not show a y-intercept thatis statistically different from zero, and the MIR/NIR intercalibrationfactor is found to be close to ideal within 2-σ uncertainty, i.e.0.9996(8). The difference time series (NIR–MIR) do not show a significanttrend. The same basic findings hold for Wollongong. In particular an overallMIR/NIR intercalibration factor close to the ideal 1 is found within 2-σ uncertainty. At Wollongong the seasonal cycle of methane is less pronouncedand corresponding smoothing errors are not as significant, enabling standardMIR and NIR retrievals to be used directly, without correction to a common apriori. Our results suggest that it is possible to set up a harmonized NDACC andTCCON XCH4 data set which can be exploited for joint trend studies,satellite validation, or the inverse modeling of sources and sinks

atmospheric measurement techniques

First intercalibration of column-averaged methane from the Total Carbon Column Observing Network and the Network for the Detection of Atmospheric Composition Change