scholarly journals Regional trend analysis of surface ozone observations from monitoring networks in eastern North America, Europe and East Asia

Elem Sci Anth ◽  
2017 ◽  
Vol 5 (0) ◽  
pp. 50 ◽  
Author(s):  
Kai-Lan Chang ◽  
Irina Petropavlovskikh ◽  
Owen R. Copper ◽  
Martin G. Schultz ◽  
Tao Wang
Keyword(s):  
North America ◽  
East Asia ◽  
Trend Analysis ◽  
Surface Ozone ◽  
Eastern North America ◽  
Monitoring Networks ◽  
Regional Trend

scholarly journals Evaluation of global EMEP MSC-W (rv4.34) WRF (v3.9.1.1) model surface concentrations and wet deposition of reactive N and S with measurements

2021 ◽  
Vol 14 (11) ◽  
pp. 7021-7046
Author(s):  
Yao Ge ◽  
Mathew R. Heal ◽  
David S. Stevenson ◽  
Peter Wind ◽  
Massimo Vieno
Keyword(s):  
North America ◽  
Southeast Asia ◽  
East Asia ◽  
Atmospheric Chemistry ◽  
Wet Deposition ◽  
Global Analysis ◽  
Monitoring Networks ◽  
Model Framework ◽  
Annual Total ◽  
Model Measurement

Abstract. Atmospheric pollution has many profound effects on human health, ecosystems, and the climate. Of concern are high concentrations and deposition of reactive nitrogen (Nr) species, especially of reduced N (gaseous NH3, particulate NH4+). Atmospheric chemistry and transport models (ACTMs) are crucial to understanding sources and impacts of Nr chemistry and its potential mitigation. Here we undertake the first evaluation of the global version of the EMEP MSC-W ACTM driven by WRF meteorology (1∘×1∘ resolution), with a focus on surface concentrations and wet deposition of N and S species relevant to investigation of atmospheric Nr and secondary inorganic aerosol (SIA). The model–measurement comparison is conducted both spatially and temporally, covering 10 monitoring networks worldwide. Model simulations for 2010 compared use of both HTAP and ECLIPSEE (ECLIPSE annual total with EDGAR monthly profile) emissions inventories; those for 2015 used ECLIPSEE only. Simulations of primary pollutants are somewhat sensitive to the choice of inventory in places where regional differences in primary emissions between the two inventories are apparent (e.g. China) but are much less sensitive for secondary components. For example, the difference in modelled global annual mean surface NH3 concentration using the two 2010 inventories is 18 % (HTAP: 0.26 µg m−3; ECLIPSEE: 0.31 µg m−3) but is only 3.5 % for NH4+ (HTAP: 0.316 µg m−3; ECLIPSEE: 0.305 µg m−3). Comparisons of 2010 and 2015 surface concentrations between the model and measurements demonstrate that the model captures the overall spatial and seasonal variations well for the major inorganic pollutants NH3, NO2, SO2, HNO3, NH4+, NO3-, and SO42- and their wet deposition in East Asia, Southeast Asia, Europe, and North America. The model shows better correlations with annual average measurements for networks in Southeast Asia (mean R for seven species: R7‾=0.73), Europe (R7‾=0.67), and North America (R7‾=0.63) than in East Asia (R5‾=0.35) (data for 2015), which suggests potential issues with the measurements in the latter network. Temporally, both model and measurements agree on higher NH3 concentrations in spring and summer and lower concentrations in winter. The model slightly underestimates annual total precipitation measurements (by 13 %–45 %) but agrees well with the spatial variations in precipitation in all four world regions (0.65–0.94 R range). High correlations between measured and modelled NH4+ precipitation concentrations are also observed in all regions except East Asia. For annual total wet deposition of reduced N, the greatest consistency is in North America (0.75–0.82 R range), followed by Southeast Asia (R=0.68) and Europe (R=0.61). Model–measurement bias varies between species in different networks; for example, bias for NH4+ and NO3- is largest in Europe and North America and smallest in East Asia and Southeast Asia. The greater uniformity in spatial correlations than in biases suggests that the major driver of model–measurement discrepancies (aside from differing spatial representativeness and uncertainties and biases in measurements) are shortcomings in absolute emissions rather than in modelling the atmospheric processes. The comprehensive evaluations presented in this study support the application of this model framework for global analysis of current and potential future budgets and deposition of Nr and SIA.

scholarly journals Evaluation of global EMEP MSC-W (rv4.34)-WRF (v3.9.1.1) model surface concentrations and wet deposition of reactive N and S with measurements

2021 ◽  
Author(s):  
Yao Ge ◽  
Mathew R. Heal ◽  
David S. Stevenson ◽  
Peter Wind ◽  
Massimo Vieno
Keyword(s):  
North America ◽  
Southeast Asia ◽  
East Asia ◽  
Atmospheric Chemistry ◽  
Wet Deposition ◽  
Global Analysis ◽  
Monitoring Networks ◽  
Model Framework ◽  
Annual Total ◽  
Model Measurement

Abstract. Atmospheric pollution has many profound effects on human health, ecosystems, and the climate. Of concern are high concentrations and deposition of reactive nitrogen (Nr) species, especially of reduced N (gaseous NH3, particulate NH4+). Atmospheric chemistry and transport models (ACTMs) are crucial to understanding sources and impacts of Nr chemistry and its potential mitigation. Here we undertake the first evaluation of the global version of the EMEP MSC-W ACTM driven by WRF meteorology (1° × 1° resolution), with a focus on surface concentrations and wet deposition of N and S species relevant to investigation of atmospheric Nr and secondary inorganic aerosol (SIA). The model-measurement comparison is conducted both spatially and temporally, covering 9 monitoring networks worldwide. Model simulations for 2010 compared use of both HTAP and ECLIPSEE (ECLIPSE annual total with EDGAR monthly profile) emissions inventories; those for 2015 used ECLIPSEE only. Simulations of primary pollutants are somewhat sensitive to the choice of inventory in places where regional differences in primary emissions between the two inventories are apparent (e.g. China), but much less so for secondary components. For example, the difference in modelled global annual mean surface NH3 concentration using the two 2010 inventories is 18 % (HTAP: 0.26 μg m−3; ECLIPSEE: 0.31 μg m−3) but only 3.5 % for NH4+ (HTAP: 0.316 μg m−3; ECLIPSEE: 0.305 μg m−3). Comparisons of 2010 and 2015 surface concentrations between model and measurement demonstrate that the model captures well the overall spatial and seasonal variations of the major inorganic pollutants NH3, NO2, SO2, HNO3, NH4+, NO3−, SO42−, and their wet deposition in East Asia, Southeast Asia, Europe and North America. The model shows better correlations with annual average measurements for networks in Southeast Asia (Mean R for 7 species:  = 0.73), Europe ( = 0.67) and North America ( = 0.63) than in East Asia ( = 0.35) (data for 2015), which suggests potential issues with the measurements in the latter network. Temporally, both model and measurement agree on higher NH3 concentrations in spring and summer, and lower concentrations in winter. The model slightly underestimates annual total precipitation measurements (by 13–34 %) but agrees well with the spatial variations in precipitation in all four world regions (0.65–0.78 R range). High correlations between measured and modelled NH4+ precipitation concentrations are also observed in all regions except East Asia. For annual total wet deposition of reduced N, the greatest consistency is in North America (R = 0.75), followed by Southeast Asia (R = 0.68) and Europe (R = 0.61). Model-measurement bias varies between species in different networks; for example, bias for NH4+ and NO3− is most in Europe and North America and least in East and Southeast Asia. The greater uniformity in spatial correlations than in biases suggests that the major driver of model-measurement discrepancies (aside from differing spatial representativeness and uncertainties and biases in measurements) are shortcomings in absolute emissions rather than in modelling the atmospheric processes. The comprehensive evaluations presented in this study support the application of this model framework for global analysis of current and potential future budgets and deposition of Nr and SIA.

scholarly journals Foreign influences on tropospheric ozone over East Asia through global atmospheric transport

2019 ◽  
Vol 19 (19) ◽  
pp. 12495-12514 ◽  
Author(s):  
Han Han ◽  
Jane Liu ◽  
Huiling Yuan ◽  
Tijian Wang ◽  
Bingliang Zhuang ◽  
...  
Keyword(s):  
North America ◽  
East Asia ◽  
Tropospheric Ozone ◽  
Large Scale ◽  
Transport Model ◽  
Surface Ozone ◽  
East Asian ◽  
South Asian High ◽  
Upper Troposphere ◽  
Ozone Concentrations

Abstract. Tropospheric ozone in East Asia is influenced by the transport of ozone from foreign regions around the world. However, the magnitudes and variations in such influences remain unclear. This study was performed to investigate the influences using a global chemical transport model, GEOS-Chem, through the tagged ozone and emission perturbation simulations. The results show that foreign ozone is transported to East Asia (20–60∘ N, 95–150∘ E) mainly through the middle and upper troposphere. In East Asia, the influence of foreign ozone increases rapidly with altitude. In the middle and upper troposphere, the regional mean concentrations of foreign ozone range from 32 to 65 ppbv, being 0.8–4.8 times higher than its native counterpart (11–18 ppbv). Annually, ∼60 % of foreign ozone in the East Asian middle and upper troposphere comes from North America (5–13 ppbv) and Europe (5–7 ppbv), as well as from foreign oceanic regions (9–21 ppbv). Over the East Asian tropospheric columns, foreign ozone appears most in spring when ozone concentrations in the foreign regions are high and the westerlies are strong and least in summer when the South Asian High blocks eastward foreign ozone from reaching East Asia south of 35∘ N. At the East Asian surface, the annual mean of foreign ozone concentrations is ∼22.2 ppbv, which is comparable to its native counterpart of ∼20.4 ppbv. In the meantime, the annual mean of anthropogenic ozone concentrations from foreign regions is ∼4.7 ppbv, half of which comes from North America (1.3 ppbv) and Europe (1.0 ppbv). Seasonally, foreign ozone concentrations at the East Asian surface are highest in winter (27.1 ppbv) and lowest in summer (16.5 ppbv). This strong seasonality is largely modulated by the East Asian monsoon (EAM) via its influence on vertical motion. The large-scale subsidence prevailing during the East Asian winter monsoon (EAWM) favours the downdraft of foreign ozone to the surface, while widespread convection in the East Asian summer monsoon (EASM) blocks such transport. Interannually, the variation in foreign ozone at the East Asian surface is found to be closely related to the intensity of the EAM. Specifically, the stronger the EAWM is in a winter, the more ozone from North America and Europe reaches the East Asian surface because of the stronger subsidence behind the East Asian trough. In summer, ozone from South and South-east Asia is reduced in strong EASM years due to weakened south-westerly monsoon winds. This study suggests substantial foreign influences on ozone at the East Asian surface and in its tropospheric columns. It also underscores the importance of the EAM in the seasonal and interannual variations in foreign influences on surface ozone in East Asia.

scholarly journals Effect of climate change on surface ozone over North America, Europe, and East Asia

2016 ◽  
Vol 43 (7) ◽  
pp. 3509-3518 ◽  
Author(s):  
Jordan L. Schnell ◽  
Michael J. Prather ◽  
Beatrice Josse ◽  
Vaishali Naik ◽  
Larry W. Horowitz ◽  
...  
Keyword(s):  
Climate Change ◽  
North America ◽  
East Asia ◽  
Surface Ozone

Resolving two enigmatic distributions in the genus Orthotrichum (Orthotrichaceae): A re-evaluation of Orthotrichum fenestratum and O. sordidum

2017 ◽  
Vol 39 (1) ◽  
pp. 115 ◽  
Author(s):  
DALE H. VITT
Keyword(s):  
North America ◽  
East Asia ◽  
Bering Sea ◽  
Eastern North America ◽  
Small Islands ◽  
Northern Regions ◽  
Northwestern North America ◽  
The Bering Sea

Orthotrichum fenestratum Card. & Thér, described from St. Paul Island and reported only from a few small islands in the Bering Sea and Aleutian Chain, was considered unique because of perforations in the exostome. Comparisons with the uncommon, but widespread, arctic-montane species, O. pylaisii Brid., indicates that like O. fenestratum, O. pylaisii also has exostomial perforations and these species are conspecific. The distribution of O. pylaisii is mapped for northwestern North America. Orthotrichum sordidum Sull. & Lesq. was described from eastern North America and then reported from East Asia and from scattered locations in Alaska and Greenland. All of the Alaskan specimens are O. pylaisii and also all of the Greenland specimens examined belong to this latter species; consequently O. sordidum should be removed from the floras of these northern regions. Similar to O. pylaisii, O. sordidum also has perforate (and fenestrate) exostome teeth, but differs in a number of features, including 8 vs.16 exostome teeth; deeply ribbed, emergent capsules vs. lightly ribbed, exserted capsules; and 8, well-developed endostome segments vs. rudimentary segments of O. pylaisii. Orthotrichum sordidum occurs almost exclusively on tree trunks, while O. pylaisii occurs on rock.

The Identification and Study of Indian Shell Middens in Eastern North America: 1643–1861

1986 ◽  
Vol 6 (3) ◽  
pp. 227-243 ◽  
Author(s):  
Andrew L. Christenson
Keyword(s):  
Nineteenth Century ◽  
Civil War ◽  
North America ◽  
East Coast ◽  
Eastern North America ◽  
Shell Midden ◽  
Shell Middens ◽  
Work Done

Although the interest in shell middens in North America is often traced to reports of the discoveries in Danish kjoekkenmoeddings in the mid-nineteenth century, extensive shell midden studies were already occurring on the East Coast by that time. This article reviews selected examples of this early work done by geologists and naturalists, which served as a foundation for shell midden studies by archaeologists after the Civil War.

Sign in / Sign up

Export Citation Format

Share Document