Suchergebnisse

In north India, agricultural burning adversely affects local and regional air quality during the post-monsoon season (October to November), when the prevailing meteorology is favorable for smog and haze formation. Quantifying the contribution of smoke to air pollution in this region, however, is challenging. While the Moderate Resolution Imaging Spectroradiometer (MODIS), aboard NASA's Terra and Aqua satellites, provides a nearly 20-year record of global fire activity, the sensor cannot adequately capture small, short-lasting agricultural fires due to its moderate spatial resolution (500 m–1 km) and limited overpasses (twice daily for each satellite), as well as the hazy conditions that typically obscure the north India land surface at this time of year. Moreover, current global fire emissions inventories based on MODIS observations can differ by up to an order of magnitude in this region. Here we incorporate household survey data to bridge gaps in MODIS observations and improve estimates of fire emissions over the states of Punjab, Haryana, Uttar Pradesh, and Bihar during the 2003–2018 post-monsoon burning seasons. We develop a novel method that adjusts MODIS Fire Radiative Power (FRP) for: (1) small fires detected by the Visible Infrared Imaging Radiometer Suite (VIIRS) at 375-m spatial resolution, (2) cloud/haze gaps in satellite observations, (3) partial-field burning practices, and (4) the diurnal cycle of fire activity. Adjusting FRP for the fire diurnal cycle yields the largest boost to emissions due to the short lifetime of the fires (~1/2 h) and the brief windows of satellite detection. Using adjusted FRP, we estimate on average 10.4 ± 3 Tg dry matter (DM) burned each year, yielding emissions of 65 ± 18 Gg organic carbon (OC), 5.6 ± 1.6 Gg black carbon (BC), 791 ± 225 Gg CO, and 14.9 ± 4.2 Tg CO2. On average, our OC + BC emissions are 3.4 times (min: 0.6, max: 6.6) the estimates from five widely used global fire emissions inventories. Our estimate for Punjab, which contributes more than two-thirds of emissions in the region, is consistent with our bottom-up validation, which uses burn rates from the household survey and government crop production statistics in 2016 and 2017. We spatially disaggregate the state-level emissions to construct a gridded inventory at daily, 0.25 ° × 0.25 ° resolution over north India from 2003 to 2018. The inventory, SAGE-IGP (Survey Constraints on FRP-based Agricultural Fire Emissions in the Indo-Gangetic Plain), improves modeling assessments of air quality impacts from agricultural burning, thus supporting effective policy development.

The strictest ever clean air action (CAA) plan has been implemented by the Chinese government since 2013 to alleviate the severe haze pollution. The PM 2.5 mass concentration was found to largely be reduced in response to emission mitigation policies, but the response of particle number concentrations (PNCs) to CAA was less evaluated in the previous studies, which may be significantly different from PM 2.5 mass due to newly formed particle impacts. In this work, the first in situ observation of particle number size distributions (PNSDs) during 2012–2019 in urban Lanzhou was used to analyze long-term PNC variations and CAA impacts. The average number of particles in nucleation ( N 13−25 , particle number in the size range of 13–25 nm), Aitken ( N 25−100 , particle number in the size range of 25–100 nm) and accumulation ( N 100−800 , particle number in the size range of 100–800 nm) modes were respectively 2514.0, 10 768.7 and 3258.4 cm −3 , and N 25−100 accounted for about 65.1 % of total PNCs during the campaign. The k -means clustering technique was used to classify the hourly mean PNSDs into six clusters, and each cluster corresponded to a specific source and influencing factor. The polluted clusters governed the winter PNCs before 2016, and their occurrence was less and less frequent after 2016, which was largely dominated by reduction in primary emissions. However, the contribution of new particle formation (NPF) events to summer N 13−25 decreased from 50 % to about 10 % during 2013 to 2015 and then increased to reach around 60 % in 2019. The trends of size-resolved PNCs for each cluster were quantified by Theil–Sen regression. The size-segregated PNCs exhibited downward trends for all clusters during 2012–2015, especially in spring. The annual relative slopes of spring PNCs varied from − 54.7 % to − 17.2 %, − 42.6 % to − 14.1 %, and − 40.7 % to − 17.5 % per year for 13–25, 25–100, and 100–800 nm size ranges, and the reduction in the polluted clusters was much larger than NPF clusters. The ultrafine particle number was increased, and the amplitude was much greater during 2016–2019. The annual relative slopes of N 13−25 varied between 8.0 % in fall and 135.5 % in spring for the NPF cluster. In response to CAA, the increased daytime net radiation, higher ambient temperature and lower relative humidity at noon for NPF events also could partly explain the higher N 13−25 induced by the more frequent nucleation events after 2016, especially in spring. The air masses were mainly from the adjacent regions of urban Lanzhou and less affected by long-range transport for NPF events, and thus the particles were not easily grown by coagulation during transport processes, which was helpful for the occurrence of NPF events. Therefore, some effective measures to cooperatively control particle number concentration and mass should be taken for the Chinese megacities.

The strictest ever Clean Air Action (CAA) has been implemented by Chinese government since 2013 to alleviate the severe haze pollution. The PM 2.5 mass concentration was found to be largely reduced in response to emission mitigation policies, but response of particle number concentrations (PNCs) to CAA was less evaluated in the previous studies, which may be largely different from PM 2.5 mass due to newly formed particle impacts. In this work, the first in-situ observation of particle number size distributions (PNSDs) during 2012–2019 in urban Lanzhou was used to analyze long-term PNCs variations and CAA impacts. The average number of particles in nucleation ( N 13–25 , particle number in the size range of 13–25 nm), Aitken ( N 25–100 , particle number in the size range of 25–100 nm) and accumulation ( N 100–800 , particle number in the size range of 100–800 nm) modes were respectively 2514.0 cm −3 , 10768.7 cm −3 , and 3258.4 cm −3 , and N 25–100 accounted for about 65.1 % of total PNCs during the campaign. K-means clustering technique was used to classify the hourly mean PNSDs into six clusters, and each cluster corresponded to a specific source and influencing factor. The polluted clusters governed the winter PNCs before 2016, and their occurrence was less and less frequent after 2016, which was largely dominated by reduction in primary emissions. However, the contribution of new particle formation (NPF) events to summer N 13–25 decreased from 50 % to about 10 % during 2013 to 2015, and then increased to reach around 60 % in 2019. The trends of size-resolved PNCs for each cluster were quantified by Theil-Sen regression. The size-segregated PNCs exhibited downward trends for all clusters during 2012–2015, especially in spring. The annual relative slopes of spring PNCs varied from −54.7 % to −17.2 %, −42.6 % to −14.1 %, and −40.7 % to −17.5 % per year for 13–25, 25–100, and 100–800 nm size ranges, and the reduction in the polluted clusters was much larger than NPF clusters. The ultrafine particle number was increased and the amplitude was much greater during 2016–2019. The annual relative slopes of N 13–25 varied between 8.0 % in fall and 135.5 % in spring for NPF cluster. In response to CAA, the increased daytime net radiation, higher ambient temperature and lower relative humidity at noon for NPF events also could partly explain the higher N 13–25 induced by the more frequent nucleation events after 2016, especially in spring. The air mass were mainly from the adjacent regions of urban Lanzhou and less affected by long-range transport for NPF events, and the thus particles were not easily grown by coagulation during transport processes, which was helpful for occurrence of NPF events. Therefore, some effective control measures cooperatively controlled particle number and mass should be took for the Chinese megacities.

The strictest ever clean air action (CAA) plan has been implemented by the Chinese government since 2013 to alleviate the severe haze pollution. The PM2.5 mass concentration was found to largely be reduced in response to emission mitigation policies, but the response of particle number concentrations (PNCs) to CAA was less evaluated in the previous studies, which may be significantly different from PM2.5 mass due to newly formed particle impacts. In this work, the first in situ observation of particle number size distributions (PNSDs) during 2012–2019 in urban Lanzhou was used to analyze long-term PNC variations and CAA impacts. The average number of particles in nucleation (N13−25, particle number in the size range of 13–25 nm), Aitken (N25−100, particle number in the size range of 25–100 nm) and accumulation (N100−800, particle number in the size range of 100–800 nm) modes were respectively 2514.0, 10 768.7 and 3258.4 cm−3, and N25−100 accounted for about 65.1 % of total PNCs during the campaign. The k-means clustering technique was used to classify the hourly mean PNSDs into six clusters, and each cluster corresponded to a specific source and influencing factor. The polluted clusters governed the winter PNCs before 2016, and their occurrence was less and less frequent after 2016, which was largely dominated by reduction in primary emissions. However, the contribution of new particle formation (NPF) events to summer N13−25 decreased from 50 % to about 10 % during 2013 to 2015 and then increased to reach around 60 % in 2019. The trends of size-resolved PNCs for each cluster were quantified by Theil–Sen regression. The size-segregated PNCs exhibited downward trends for all clusters during 2012–2015, especially in spring. The annual relative slopes of spring PNCs varied from −54.7 % to −17.2 %, −42.6 % to −14.1 %, and −40.7 % to −17.5 % per year for 13–25, 25–100, and 100–800 nm size ranges, and the reduction in the polluted clusters was much larger than NPF clusters. The ultrafine particle number was increased, and the amplitude was much greater during 2016–2019. The annual relative slopes of N13−25 varied between 8.0 % in fall and 135.5 % in spring for the NPF cluster. In response to CAA, the increased daytime net radiation, higher ambient temperature and lower relative humidity at noon for NPF events also could partly explain the higher N13−25 induced by the more frequent nucleation events after 2016, especially in spring. The air masses were mainly from the adjacent regions of urban Lanzhou and less affected by long-range transport for NPF events, and thus the particles were not easily grown by coagulation during transport processes, which was helpful for the occurrence of NPF events. Therefore, some effective measures to cooperatively control particle number concentration and mass should be taken for the Chinese megacities.

The Indonesian "haze" that engulfs Southeast Asia is a result of the burning of forests and has a detrimental effect on the health of millions of people. Indonesia is currently the third largest emitter of carbon dioxide in the world. In response to the dangers posed by forest fires to national and global environmental security, the then Indonesian president publicly declared a "war on haze" in 2006 and called for the use of all necessary measures to stop the deliberate setting of fires. Although his strong "securitising" rhetoric received much public support, it is yet to produce results. The Indonesian authorities have had little success in preventing fires or prosecuting the culprits. Indonesia thus appears to be a null case - that is, a case of an unsuccessful securitisation. We argue that this unsuccessful securitisation needs to be understood against the backdrop of Indonesia's vast decentralisation process, which resulted in certain powers being devolved from Jakarta to the provinces. We find that it is the ability of local and regional elites (often entrenched in patronage networks with plantation owners) to curtail environmental policies which explains the continuation of forest fires. With regard to securitisation theory, our findings suggest that securitising moves and audience acceptance do not necessarily lead to the successful implementation of emergency measures. It appears that there are intermediate factors - in our case mainly linked to the nature of and the distribution of power within the political regime - that impact on the success of securitisation processes. (JCSA/GIGA)

Large-scale, recurrent fires in Indonesia in recent decades have caused widespread deforestation and transformation of peatlands, and have contributed to substantial smoke haze and greenhouse-gas pollution. In some areas, local community use of fire for livelihood needs could be a major factor behind the widespread fires. The authors assessed fire patterns and their causes from the 1980s to the present in the Middle Mahakam peatlands of East Kalimantan. This was achieved through satellite image and GIS analysis, biological and social field surveys, and rapid rural appraisals in the villages. People living in or using the swamps employ fire annually along the waterways and adjacent open floodplains and forests, in conjunction with fishing, agriculture, and other livelihood activities. Local communities perceive that uncontrolled burning does not affect the fish, which is their economic mainstay. Dry and windy conditions, failure of regular livelihoods, new markets for turtles and tree bark, and easing of government quotas for these resources led to more widespread fires in the El Niño periods of 1982–1983 and 1997–1998. Repeated burning ultimately transforms larger and larger areas of peat forest into open floodplains and shallow lakes. Local communities promote the transformation, believing it enhances fishing conditions. Even if the interior forests were kept fire free for a lengthy period, they would likely not fully recover, but these areas were rendered highly fire prone during the last El Niño event in 1997–1998. Another long drought in the near future, coupled with widespread community burning, could cause more severe, long-lasting damage to the peat forests and contribute substantially to regional smoke haze and greenhouse-gas pollution. This paper discusses the scope for resolving the trade-offs between the communities' perceived benefits of fire use, and national and global environmental concerns arising from peatland burning.

Cover -- Half Title -- Title Page -- Copyright Page -- Dedication -- Table of Contents -- Preface -- Acknowledgments -- Authors -- Chapter 1 Atmosphere -- 1.1 Chemical Composition -- 1.1.1 General Composition -- 1.1.2 Water -- 1.2 Physical Phenomena -- 1.2.1 Solar Radiation -- 1.2.2 Terrestrial Thermal Radiation -- 1.2.3 Energy Balance -- 1.2.4 Surface Temperatures -- 1.2.5 Vertical Temperature Gradients -- 1.2.6 Gravity -- 1.2.7 Atmospheric Density -- 1.2.8 Atmospheric Pressure -- 1.3 Atmospheric Motion -- 1.3.1 Winds -- 1.3.2 Pressure Gradient Force -- 1.3.3 Coriolis Effect -- 1.3.4 Friction -- 1.3.5 Cyclones and Anticyclones -- 1.3.6 General Circulation of the Atmosphere -- 1.4 Evolution of the Atmosphere -- Readings -- Questions -- Chapter 2 Atmospheric Pollution and Pollutants -- 2.1 Natural Air Pollution -- 2.2 Anthropogenic Air Pollution -- 2.2.1 Smog -- 2.2.2 Haze -- 2.2.3 Nontraditional Air Pollutants -- 2.2.4 Gases and Particles -- 2.2.4.1 Sources -- 2.2.4.2 National Emission Estimates -- 2.2.4.3 National Emissions Picture -- 2.3 Gas-Phase Pollutants -- 2.3.1 Carbon Oxides -- 2.3.1.1 Carbon Dioxide -- 2.3.1.2 Carbon Monoxide -- 2.3.2 Sulfur Compounds -- 2.3.2.1 Sulfur Oxides -- 2.3.2.2 Reduced Sulfur Compounds -- 2.3.3 Nitrogen Compounds -- 2.3.3.1 Nitrous Oxide -- 2.3.3.2 Nitric Oxide -- 2.3.3.3 Nitrogen Dioxide -- 2.3.3.4 Nitrogen Oxides -- 2.3.3.5 Ammonia -- 2.3.3.6 Hydrogen Cyanide -- 2.3.3.7 Organic Nitrate Compounds -- 2.3.4 Hydrocarbon Compounds -- 2.3.4.1 Hydrocarbon Chemistry -- 2.3.4.2 Oxyhydrocarbons -- 2.3.4.3 Nonmethane Hydrocarbons -- 2.3.4.4 Methane -- 2.3.4.5 Halogenated Hydrocarbons -- 2.3.5 Photochemical Oxidants -- 2.3.5.1 Tropospheric Ozone Concentrations -- 2.3.5.2 Ozone Sinks -- 2.4 Atmospheric Particles -- 2.4.1 Classes and Sources -- 2.4.2 Size -- 2.4.3 Particle Shape -- 2.4.4 Chemical Composition.

In the middle of 2019, Thailand introduced an urgent measure to solve the haze and fine particles problem caused by preharvest sugarcane. The measure is to eradicate the burning of sugarcane before harvesting within the next four years. This study focuses on estimation of future reduced air emissions from the implementation of this measure. The study results showed that without the implementation of the measure in the production season 2022/23, the amount of burned sugarcane will be as high as 102.4 ± ; 1.0 Mt/yr, resulting in the release of small particulate matter of 2.5 microns or less in diameter (PM2.5) emissions into the atmosphere at 30.6 ± ; 8.6 kt/yr, which is about a 21% increase in emissions from the 2018/19 season. However, with the government&rsquo ; s enforcement of the measure to reduce burned sugarcane, the amount of air emissions will immediately be reduced in the first year. In order to effectively implement the sugarcane burning reduction measure, in which the harvesting methods will change from cutting burned sugarcane to cutting fresh sugarcane with human labor and with machinery, the government must provide financial support, to farmers, of approximately 3.3 USD per ton of fresh sugarcane for the use of human labor and 2.9 USD per ton of fresh sugarcane for the use of machinery. The costs of investment to reduce PM2.5 emissions can be calculated in the range of 9.7&minus ; 11.0 million USD per kiloton of PM2.5.

1.1. Voyage of the SS Manhattan -- 1.2. Voyage of the USCGC Polar Sea -- 1.3. European Union and China -- 1.4.1988 Arctic Cooperation Agreement -- 1.5. Concerns about a precedent -- 2. Northern Sea Route -- 2.1. Vil'Kitskii incidents -- 2.2. Opening of the Northern Sea Route -- 3. Assessment of Canada's and Russia's legal positions -- 4. Canada-Russia cooperation -- 5. Canada-United States cooperation -- 6. Bering Strait -- 7. Unimak Pass -- 8. Nares Strait -- 9. Multilateral mechanisms available to "strait states" -- 10. Submarine voyages -- 11. Summary -- 6. Environmental protection -- 1. Species protection -- 1.1. Northern fur seals -- 1.2. Polar bears -- 1.3. Whales -- 2. Fisheries -- 2.1. Bering Sea "donut hole" -- 2.2. Arctic Ocean Fisheries Organization -- 3. Shipping -- 3.1. Ship safety -- 3.2. Ballast water -- 4. Nuclear accidents -- 5. Deep-sea mining -- 6. Air-borne pollution -- 6.1. Persistent organic pollutants -- 6.2. Arctic haze -- 6.3. Black carbon -- 7. Oil spills.

AbstractIn the 1960s and 1970s, Iranian officials embraced natural gas as a new energy source for their rapidly industrializing society, seeing it as a readily available substitute for the lucrative oil products their country's citizens were consuming in increasing amounts. Reacting to the growing concentrations of smoke and haze in cities, and unable to alter the mountainous terrain and semiarid climate that intensified them, gas seemingly promised to be a technical savior upon which to build an Iran as environmentally sound as it was prosperous, technologically sophisticated, and energy hungry. Pahlavi-era developmental choices were shaped by officials' concern for deteriorating environmental conditions, the natural factors that compounded the issue, and the interests of private industry. Using archival and published materials collected in Iran, this article focuses on urban air pollution and the fitful efforts to mitigate it through the conversion of industrial facilities to gas.