Near-real-time estimation of fossil fuel CO emissions from China based on atmospheric observations on Hateruma and Yonaguni Islands, Japan.

Unlabelled: We developed a near-real-time estimation method for temporal changes in fossil fuel CO (FFCO) emissions from China for 3 months [January, February, March (JFM)] based on atmospheric CO and CH observations on Hateruma Island (HAT, 24.06° N, 123.81° E) and Yonaguni Island (YON, 24.

Detection of fossil-fuel CO plummet in China due to COVID-19 by observation at Hateruma.

The COVID-19 pandemic caused drastic reductions in carbon dioxide (CO) emissions, but due to its large atmospheric reservoir and long lifetime, no detectable signal has been observed in the atmospheric CO growth rate. Using the variabilities in CO (ΔCO) and methane (ΔCH) observed at Hateruma Island, Japan during 1997-2020, we show a traceable CO emission reduction in China during February-March 2020. The monitoring station at Hateruma Island observes the outflow of Chinese emissions during winter and spring.

Emissions of methane from offshore oil and gas platforms in Southeast Asia.

Methane is a substantial contributor to climate change. It also contributes to maintaining the background levels of tropospheric ozone. Among a variety of CH4 sources, current estimates suggest that CH4 emissions from oil and gas processes account for approximately 20% of worldwide anthropogenic emissions.

Large emissions of perfluorocarbons in East Asia deduced from continuous atmospheric measurements.

The atmospheric mixing ratios of perfluorocarbons (PFCs), extremely potent greenhouse gases, have been continuously measured at two Japanese stations (Cape Ochiishi and Hateruma Island) since 2006, to infer their global and regional emissions. The baseline mixing ratios of the measured C(2)-C(4) PFCs [PFC-116 (C(2)F(6)), PFC-218 (C(3)F(8)), and PFC-318 (c-C(4)F(8))] showed slight annual increases of 1%-3%. Enhanced mixing ratios above baseline were occasionally observed at both sites in air masses that had passed over metropolitan regions in East Asia, suggesting high PFC emissions from those regions.

How well do we know VPDB? Variability of delta13C and delta18O in CO2 generated from NBS19-calcite.

In order to generate a local daughter scale from the material defining the international delta13C and delta18O stable isotope ratio scales (NBS19-calcite),1,2 the carbon and oxygen must be liberated to the gas phase, usually as CO2, using acid digestion of the calcite with H3PO4. It is during this conversion step that systematic errors can occur, giving rise to commonly observed discrepancies in isotopic measurements between different stable isotope laboratories. Scale consistency is of particular importance for air-CO2 isotope records where very small differences in isotopic composition have to be reliably compared between different laboratories and quantified over long time periods.

Field survey of trans-boundary air pollution with high time resolution at coastal sites on the Sea of Japan during winter in Japan.

An intensive field survey, with 6-h measurement intervals, of concentrations of chemical species in particulate matter and gaseous compounds was carried out at coastal sites on the Sea of Japan during winter. The concentration variation of SO(2)(g) and HNO(3)(g) were well correlated, whereas the NH(3)(g) concentration variation had no correlation with those of SO(2)(g) and HNO(3)(g). The NH(4) (+) (p)/non-sea-salt- (nss-)SO(4) (2 -)(p) ratio in particulate matter was mainly affected by the location of the sampling site.