scholarly journals Interannual variation, decadal trend, and future change in ozone outflow from East Asia

2017 ◽  
Vol 17 (5) ◽  
pp. 3729-3747 ◽  
Author(s):  
Jia Zhu ◽  
Hong Liao ◽  
Yuhao Mao ◽  
Yang Yang ◽  
Hui Jiang
Keyword(s):  
Climate Change ◽  
East Asia ◽  
Meteorological Parameters ◽  
Anthropogenic Emissions ◽  
Interannual Variations ◽  
Zonal Winds ◽  
The Past ◽  
Decadal Trend ◽  
Tropospheric O3 ◽  
Ipcc Sres

Abstract. We examine the past and future changes in the O3 outflow from East Asia using a global 3-D chemical transport model, GEOS-Chem. The simulations of Asian O3 outflow for 1986–2006 are driven by the assimilated GEOS-4 meteorological fields, and those for 2000–2050 are driven by the meteorological fields archived by the NASA Goddard Institute for Space Studies (GISS) general circulation model (GCM) 3 under the IPCC SRES A1B scenario. The evaluation of the model results against measurements shows that the GEOS-Chem model captures the seasonal cycles and interannual variations of tropospheric O3 concentrations fairly well with high correlation coefficients of 0.82–0.93 at four ground-based sites and 0.55–0.88 at two ozonesonde sites where observations are available. The increasing trends in surface-layer O3 concentrations in East Asia over the past 2 decades are captured by the model, although the modeled O3 trends have low biases. Sensitivity studies are conducted to examine the respective impacts of meteorological parameters and emissions on the variations in the outflow flux of O3. When both meteorological parameters and anthropogenic emissions varied from 1986–2006, the simulated Asian O3 outflow fluxes exhibited a statistically insignificant decadal trend; however, they showed large interannual variations (IAVs) with seasonal values of 4–9 % for the absolute percent departure from the mean (APDM) and an annual APDM value of 3.3 %. The sensitivity simulations indicated that the large IAVs in O3 outflow fluxes were mainly caused by variations in the meteorological conditions. The variations in meteorological parameters drove the IAVs in O3 outflow fluxes by altering the O3 concentrations over East Asia and by altering the zonal winds; the latter was identified to be the key factor, since the O3 outflow was highly correlated with zonal winds from 1986–2006. The simulations of the 2000–2050 changes show that the annual outflow flux of O3 will increase by 2.0, 7.9, and 12.2 % owing to climate change alone, emissions change alone, and changes in both climate and emissions, respectively. Therefore, climate change will aggravate the effects of the increases in anthropogenic emissions on future changes in the Asian O3 outflow. Future climate change is predicted to greatly increase the Asian O3 outflow in the spring and summer seasons as a result of the projected increases in zonal winds. The findings from the present study help us to understand the variations in tropospheric O3 in the downwind regions of East Asia on different timescales and have important implications for long-term air quality planning in the regions downwind of China, such as Japan and the US.

scholarly journals Interannual variation, decadal trend, and future change in ozone outflow from East Asia

2016 ◽  
Author(s):  
Jia Zhu ◽  
Hong Liao ◽  
Yuhao Mao ◽  
Yang Yang ◽  
Hui Jiang
Keyword(s):  
Climate Change ◽  
East Asia ◽  
General Circulation ◽  
Meteorological Parameters ◽  
Transport Model ◽  
Circulation Model ◽  
Future Climate Change ◽  
Anthropogenic Emissions ◽  
Decadal Trend ◽  
Ipcc Sres

Abstract. We examine the past and future changes in O3 outflow from East Asia using a global three-dimensional chemical transport model GEOS-Chem. The simulations of Asian O3 outflow for 1986–2006 are driven by the assimilated GEOS-4 meteorological fields, and those for 2000–2050 are driven by the meteorological fields archived from the Goddard Institute for Space Studies (GISS) General Circulation Model (GCM) 3 under the IPCC SRES A1B scenario. Sensitivity studies are conducted to examine the respective impacts of meteorological parameters and emissions on the variations in the outflow flux of O3. When both meteorological parameters and anthropogenic emissions varied during 1986–2006, the simulated Asian O3 outflow fluxes exhibited a small and statistically insignificant decadal trend of −2.2 % decade−1, but large interannual variations (IAVs) with seasonal absolute percent departure from the mean (APDM) values of 4–9 % and annual APDM value of 3.3 %. Sensitivity simulations indicated that the large IAVs of O3 outflow fluxes were mainly caused by the variations in meteorological conditions. The simulations of the 2000–2050 changes show that the annual outflow flux of O3 will increase by 2.0 %, 7.9 %, and 12.2 %, respectively, owing to climate change alone, emissions change alone, and changes in both climate and emissions. Therefore, climate change will aggravate the effects of the increases in anthropogenic emissions on future changes in the Asian O3 outflow. Future climate change is predicted to greatly increase Asian O3 outflow in the spring and summer seasons as a result of the projected increases in zonal winds. Findings from the present study help to understand the variations in tropospheric O3 in the downwind regions of East Asia on different timescales, and have important implications for long-term air quality planning.

scholarly journals Impacts of historical climate and land cover changes on fine particulate matter (PM<sub>2.5</sub>) air quality in East Asia over 1980–2010

2016 ◽  
Author(s):  
Yu Fu ◽  
Amos P. K. Tai ◽  
Hong Liao
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Particulate Matter ◽  
Air Quality ◽  
Land Cover ◽  
East Asia ◽  
Fine Particulate Matter ◽  
Anthropogenic Emissions ◽  
Voc Emissions ◽  
Fine Particulate

Abstract. To examine the effects of changes in climate, land cover and land use (LCLU), and anthropogenic emissions on fine particulate matter (PM2.5) between the 5-year periods 1981–1985 and 2007–2011 in East Asia, we perform a series of simulations using a global chemical transport model (GEOS-Chem) driven by assimilated meteorological data and a suite of land cover and land use data. Our results indicate that climate change alone could lead to a decrease in wintertime PM2.5 concentration by 4.0–12.0 μg m−3 in northern China, but an increase in summertime PM2.5 by 6.0–8.0 μg m−3 in those regions. These changes are attributable to the changing chemistry and transport of all PM2.5 components driven by long-term trends in temperature, wind speed and mixing depth. The concentration of secondary organic aerosol (SOA) is simulated to increase by 0.2–0.8 μg m−3 in both summer and winter in most regions of East Asia due to climate change alone, mostly reflecting higher biogenic volatile organic compound (VOC) emissions under warming. The impacts of LCLU change alone on PM2.5 (−2.1 to +1.3 μg m−3) are smaller than that of climate change, but among the various components the sensitivity of SOA and thus organic carbon to LCLU change (−0.4 to +1.2 μg m−3) is quite significant especially in summer, which is driven mostly by changes in biogenic VOC emissions following cropland expansion and changing vegetation density. The combined impacts show that while the effect of climate change on PM2.5 air quality is more pronounced, LCLU change could offset part of the climate effect in some regions but exacerbate it in others. As a result of both climate and LCLU changes combined, PM2.5 levels are estimated to change by −12.0 to +12.0 μg m−3 across East Asia between the two periods. Changes in anthropogenic emissions remain the largest contributor to deteriorating PM2.5 air quality in East Asia during the study period, but climate and LCLU changes could lead to a substantial modification of PM2.5 levels.

scholarly journals Impacts of historical climate and land cover changes on fine particulate matter (PM<sub>2.5</sub>) air quality in East Asia between 1980 and 2010

2016 ◽  
Vol 16 (16) ◽  
pp. 10369-10383 ◽  
Author(s):  
Yu Fu ◽  
Amos P. K. Tai ◽  
Hong Liao
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Particulate Matter ◽  
Air Quality ◽  
Land Cover ◽  
East Asia ◽  
Fine Particulate Matter ◽  
Anthropogenic Emissions ◽  
Voc Emissions ◽  
Fine Particulate

Abstract. To examine the effects of changes in climate, land cover and land use (LCLU), and anthropogenic emissions on fine particulate matter (PM2.5) between the 5-year periods 1981–1985 and 2007–2011 in East Asia, we perform a series of simulations using a global chemical transport model (GEOS-Chem) driven by assimilated meteorological data and a suite of land cover and land use data. Our results indicate that climate change alone could lead to a decrease in wintertime PM2.5 concentration by 4.0–12.0 µg m−3 in northern China, but to an increase in summertime PM2.5 by 6.0–8.0 µg m−3 in those regions. These changes are attributable to the changing chemistry and transport of all PM2.5 components driven by long-term trends in temperature, wind speed and mixing depth. The concentration of secondary organic aerosol (SOA) is simulated to increase by 0.2–0.8 µg m−3 in both summer and winter in most regions of East Asia due to climate change alone, mostly reflecting higher biogenic volatile organic compound (VOC) emissions under warming. The impacts of LCLU change alone on PM2.5 (−2.1 to +1.3 µg m−3) are smaller than that of climate change, but among the various components the sensitivity of SOA and thus organic carbon to LCLU change (−0.4 to +1.2 µg m−3) is quite significant especially in summer, which is driven mostly by changes in biogenic VOC emissions following cropland expansion and changing vegetation density. The combined impacts show that while the effect of climate change on PM2.5 air quality is more pronounced, LCLU change could offset part of the climate effect in some regions but exacerbate it in others. As a result of both climate and LCLU changes combined, PM2.5 levels are estimated to change by −12.0 to +12.0 µg m−3 across East Asia between the two periods. Changes in anthropogenic emissions remain the largest contributor to deteriorating PM2.5 air quality in East Asia during the study period, but climate and LCLU changes could lead to a substantial modification of PM2.5 levels.

scholarly journals Non-Pessimistic Predictions of the Distributions and Suitability of Metasequoia glyptostroboides under Climate Change Using a Random Forest Model

Forests ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 62
Author(s):  
Xiaoyan Zhang ◽  
Haiyan Wei ◽  
Xuhui Zhang ◽  
Jing Liu ◽  
Quanzhong Zhang ◽  
...  
Keyword(s):  
Climate Change ◽  
Random Forest ◽  
East Asia ◽  
Potential Distribution ◽  
Western Europe ◽  
Metasequoia Glyptostroboides ◽  
The Past ◽  
Bioclimatic Variables ◽  
The Future ◽  
Suitable Habitats

Metasequoia glyptostroboides Hu & W. C. Cheng, which is a remarkable rare relict plant, has gradually been reduced to its current narrow range due to climate change. Understanding the comprehensive distribution of M. glyptostroboides under climate change on a large spatio-temporal scale is of great significance for determining its forest adaptation. In this study, based on 394 occurrence data and 10 bioclimatic variables, the global potential distribution of M. glyptostroboides under eight different climate scenarios (i.e., the past three, the current one, and the next four) from the Quaternary glacial to the future was simulated by a random forest model built with the biomod2 package. The key bioclimatic variables affecting the distribution of M. glyptostroboides are BIO2 (mean diurnal range), BIO1 (annual mean temperature), BIO9 (mean temperature of driest quarter), BIO6 (min temperature of coldest month), and BIO18 (precipitation of warmest quarter). The result indicates that the temperature affects the potential distribution of M. glyptostroboides more than the precipitation. A visualization of the results revealed that the current relatively suitable habitats of M. glyptostroboides are mainly distributed in East Asia and Western Europe, with a total area of approximately 6.857 × 106 km2. With the intensification of global warming in the future, the potential distribution and the suitability of M. glyptostroboides have a relatively non-pessimistic trend. Whether under the mild (RCP4.5) and higher (RCP8.5) emission scenarios, the total area of suitable habitats will be wider than it is now by the 2070s, and the habitat suitability will increase to varying degrees within a wide spatial range. After speculating on the potential distribution of M. glyptostroboides in the past, the glacial refugia of M. glyptostroboides were inferred, and projections regarding the future conditions of these places are expected to be optimistic. In order to better protect the species, the locations of its priority protected areas and key protected areas, mainly in Western Europe and East Asia, were further identified. Our results will provide theoretical reference for the long-term management of M. glyptostroboides, and can be used as background information for the restoration of other endangered species in the future.

Spatial Redistribution of U.S. Tornado Activity between 1954 and 2013

2016 ◽  
Vol 55 (8) ◽  
pp. 1681-1697 ◽  
Author(s):  
Ernest Agee ◽  
Jennifer Larson ◽  
Samuel Childs ◽  
Alexandra Marmo
Keyword(s):  
Climate Change ◽  
Meteorological Parameters ◽  
Temporal Change ◽  
Preliminary Investigation ◽  
Warming Trend ◽  
Central Plains ◽  
Climate Change Effects ◽  
The Past ◽  
Spatial Redistribution ◽  
Seasonal Analysis

AbstractClimate change over the past several decades prompted this preliminary investigation into the possible effects of global warming on the climatological behavior of U.S. tornadoes for the domain bounded by 30°–50°N and 80°–105°W. On the basis of a warming trend over the past 30 years, the modern tornado record can be divided into a cold “Period I” from 1954 to 1983 and a subsequent 30-year warm “Period II” from 1984 to 2013. Tornado counts and days for (E)F1–(E)F5, significant, and the most violent tornadoes across a 2.5° × 2.5° gridded domain indicate a general decrease in tornado activity from Period I to Period II concentrated in Texas/Oklahoma and increases concentrated in Tennessee/Alabama. These changes show a new geographical distribution of tornado activity for Period II when compared with Period I. Statistical analysis that is based on field significance testing and the bootstrapping method provides proof for the observed decrease in annual tornado activity in the traditional “Tornado Alley” and the emergence of a new maximum center of tornado activity. Seasonal analyses of both counts and days for tornadoes and significant tornadoes show similar results in the spring, summer, and winter seasons, with a substantial decrease in the central plains during summer. The autumn season displays substantial increases in both tornado counts and significant-tornado counts in the region stretching from Mississippi into Indiana. Similar results are found from the seasonal analysis of both tornado days and significant-tornado days. This temporal change of spatial patterns in tornado activity for successive cold and warm periods may be suggestive of climate change effects yet warrants the climatological study of meteorological parameters responsible for tornado formation.

scholarly journals Eco-Development Response to Climate Change and the Isostatic Uplift of Southwestern Finland

2019 ◽  
Vol 11 (21) ◽  
pp. 6098
Author(s):  
Verstraeten ◽  
Verstraeten
Keyword(s):  
Climate Change ◽  
Anthropogenic Emissions ◽  
Remotely Sensed Data ◽  
Surface Wetness ◽  
Greenhouse Gasses ◽  
The Past ◽  
Isostatic Uplift ◽  
Earth’S Climate ◽  
Development Paradigm ◽  
Northwestern Russia

To date, care for our planet is mainly focused on the remediation of climate change induced by the huge amount of anthropogenic emissions of greenhouse gasses and its precursors. Transforming fossil combustion to more sustainable energy worldwide is a wellknown example. In contrast, what is little known is that the environment shaped by humans is also challenged by relatively fast geological dynamical phenomena such as the isostatic uplift of Fennoscandia, parts of Canada and northwestern Russia. Due to this uplift, the archipelago along the coast of southwestern Finland and Sweden changes rapidly to mainland. This phenomenon deeply affects both nature as well as the environment, resulting in the relocation of human activities. Here, we interpret the on-ground observed regression of the Gulf of Bothnia on the coasts of southwestern Finland and its implications on countryside activities in the framework of the eco-development paradigm. Furthermore, remotely sensed data on surface wetness confirms this sea regression and the silting-up of the nearby lakes that drain precipitation to the Gulf. We show that this eco-development paradigm may rebalance nature, environment, humans and culture and that it is a valid alternative against the past and present-day socioeconomical approach that has accelerated the change in the Earth’s climate.

scholarly journals Impacts of historical climate and land cover changes on tropospheric ozone air quality and public health in East Asia over 1980–2010

2015 ◽  
Vol 15 (10) ◽  
pp. 14111-14139 ◽  
Author(s):  
Y. Fu ◽  
A. P. K. Tai
Keyword(s):  
Public Health ◽  
Climate Change ◽  
Air Quality ◽  
Land Cover ◽  
East Asia ◽  
Land Cover Change ◽  
Surface Ozone ◽  
Land Cover Changes ◽  
The Past ◽  
Premature Deaths

Abstract. Understanding how historical climate and land cover changes have affected tropospheric ozone in East Asia would help constrain the large uncertainties associated with future East Asian air quality projections. We perform a series of simulations using a global chemical transport model driven by assimilated meteorological data and a suite of land cover and land use data to examine the public health effects associated with changes in climate, land cover, land use, and anthropogenic emissions over the past 30 years (1980–2010) in East Asia. We find that over 1980–2010 land cover change alone could lead to a decrease in summertime surface ozone by up to 4 ppbv in East Asia and ~2000 fewer ozone-related premature deaths per year, driven mostly by enhanced dry deposition resulting from climate- and CO2-induced increase in vegetation density, which more than offsets the effect of reduced isoprene emission arising from cropland expansion. Over the same period, climate change alone could lead to an increase in summertime ozone by 2–10 ppbv in most regions of East Asia and ~6000 more premature deaths annually, mostly attributable to warming. The combined impacts (−2 to +12 ppbv) show that while the effect of climate change is more pronounced, land cover change could offset part of the climate effect and lead to a previously unknown public health benefit. While the changes in anthropogenic emissions remain the largest contributor to deteriorating ozone air quality in East Asia over the past 30 years, we show that climate change and land cover changes could lead to a substantial modification of ozone levels, and thus should come into consideration when formulating future air quality management strategies. We also show that the sensitivity of surface ozone to land cover change is more dependent on dry deposition than isoprene emission in most of East Asia, leading to ozone responses that are quite distinct from that in North America, where most ozone-vegetation sensitivity studies to date have been conducted.

scholarly journals Simulation of the interannual variations of aerosols in China: role of variations in meteorological parameters

2014 ◽  
Vol 14 (8) ◽  
pp. 11177-11219 ◽  
Author(s):  
Q. Mu ◽  
H. Liao
Keyword(s):  
Organic Carbon ◽  
Meteorological Parameters ◽  
Transport Model ◽  
Three Dimensional ◽  
Specific Humidity ◽  
Anthropogenic Emissions ◽  
Interannual Variations ◽  
Chemical Transport Model ◽  
June July

Abstract. We used the nested grid version of the global three-dimensional Goddard Earth Observing System chemical transport model (GEOS-Chem) to examine the interannual variations (IAVs) of aerosols over heavily polluted regions in China for years 2004–2012. The role of variations in meteorological parameters was quantified by a simulation with fixed anthropogenic emissions at year 2006 levels and changes in meteorological parameters over 2004–2012. Simulated PM2.5 (particles with a diameter of 2.5 μm or less) aerosol concentrations exhibited large IAVs in North China (NC, 32–42° N, 110–120° E), with regionally averaged absolute percent departure from the mean (APDM) values of 17, 14, 14, and 11% in December-January-February (DJF), March-April-May (MAM), June-July-August (JJA), and September-October-November (SON), respectively. Over South China (SC, 22–32° N, 110–120° E), the IAVs in PM2.5 were found to be the largest in JJA, with the regional mean APDM values of 14% in JJA and of about 9% in other seasons. Concentrations of PM2.5 over the Sichuan Basin (SCB, 27–33° N, 102–110° E) were simulated to have the smallest IAVs among the polluted regions examined in this work, with the APDM values of 8–9% in all seasons. All aerosol species (sulfate, nitrate, ammonium, black carbon, and organic carbon) were simulated to have the largest IAVs over NC in DJF, corresponding to the large variations in meteorological parameters over NC in this season. Process analyses were performed to identify the key meteorological parameters that determined the IAVs of different aerosol species in different regions. While the variations in temperature and specific humidity, which influenced the gas-phase formation of sulfate, jointly determined the IAVs of sulfate over NC in both DJF and JJA, wind (or convergence of wind) in DJF and precipitation in JJA were the dominant meteorological factors to influence IAVs of sulfate over SC and the SCB. The IAVs in temperature and specific humidity influenced gas-to-aerosol partitioning, which were the major factors that led to the IAVs of nitrate aerosol in China. The IAVs in wind and precipitation were found to drive the IAVs of organic carbon aerosol. We also compared the IAVs of aerosols simulated with variations in meteorological parameters alone with those simulated with variations in both meteorological parameters and anthropogenic emissions; the variations in meteorological fields were found to dominate the IAVs of aerosols in China.

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