Ozone concentrations, flux and potential effect on yield during wheat growth in the Northwest-Shandong Plain of China.

Ozone (O3) concentration and flux (Fo) were measured using the eddy covariance technique over a wheat field in the Northwest-Shandong Plain of China. The O3-induced wheat yield loss was estimated by utilizing O3 exposure-response models. The results showed that: (1) During the growing season (7 March to 7 June, 2012), the minimum (16.

Soil nitrite as a source of atmospheric HONO and OH radicals.

Hydroxyl radicals (OH) are a key species in atmospheric photochemistry. In the lower atmosphere, up to ~30% of the primary OH radical production is attributed to the photolysis of nitrous acid (HONO), and field observations suggest a large missing source of HONO. We show that soil nitrite can release HONO and explain the reported strength and diurnal variation of the missing source.

Air pollution and meteorological processes in the growing dryland city of Urumqi (Xinjiang, China).

Seven years (2000-2006) of monthly PM₁₀ (particulate matter, d ≤ 10 μm), SO₂, and NO₂ concentrations are reported for Urumqi, the capital of Xinjiang in NW China. Considerably high mean annual concentrations have been observed, which ranged between 150 and 240 μg m⁻³ (PM₁₀, 31 and 50 μg m⁻³ (NO₂), and 49 and 160 μg m⁻³ (SO₂). The shapes of seasonal variation of all pollutants were remarkably similar; however, winter/summer ratios of concentrations were quite different for PM₁₀ (2-3) and NO₂ (≈4) compared to SO₂ (up to 30).

Biogenic nitric oxide emission of mountain soils sampled from different vertical landscape zones in the Changbai Mountains, northeastern China.

Nitric oxide (NO) is an important component in nitrogen biogeochemical cycling produced through biological processes of nitrification and denitrification in soils, but the production and the consumption processes of NO in temperate mountain soil are less understood. Through laboratory experiments focusing on NO biogenic emissions from six kinds of mountain soils sampled from different vertical landscape zones, that is, coniferous and broadleaf mixed forest (CBF), fir forest (FF), spruce forest (SF), Erman's birch forest (EBF), alpine tundra (AT), and volcanic ash (VA), in the Changbai Mountains, northeastern China, we found that the optimum water-filled pore space (WFPS) for NO production varies between 22.5% and 35% for a range of mountain soils.

An automated analyzer to measure surface-atmosphere exchange fluxes of water soluble inorganic aerosol compounds and reactive trace gases.

Here, we present a new automated instrument for semicontinuous gradient measurements of water-soluble reactive trace gas species (NH3, HNO3, HONO, HCl, and SO2) and their related aerosol compounds (NH4+, NO3-, Cl-, SO4(2-)). Gas and aerosol samples are collected simultaneously at two heights using rotating wet-annular denuders and steam-jet aerosol collectors, respectively. Online (real-time) analysis using ion chromatography (IC) for anions and flow injection analysis (FIA) for NH4+ and NH3 provide a half-hourly averaged gas and aerosol gradients within each hour.

Nitrous oxide emission from Deyeuxia angustifolia freshwater marsh in northeast china.

Here we report N(2)O emission results for freshwater marshes isolated from human activities at the Sanjiang Experimental Station of Marsh Wetland Ecology in northeastern China. These results are important for us to understand N(2)O emission in natural processes in undisturbed freshwater marsh. Two adjacent plots of Deyeuxia angustifolia freshwater marsh with different water regimes, i.