ALBERT

Description: The two-phase fluid model is applied in this study to calculate the steady velocity of a debris flow along a channel bed. By using the momentum equations of the solid and liquid phases in the debris flow together with an empirical formula to describe the interaction between two phases, the steady velocities of the solid and liquid phases are obtained theoretically. The comparison of those velocities obtained by the proposed method with the observed velocities of two real-world debris flows shows that the proposed method can estimate accurately the velocity for a debris flow.

Description: The two-phase fluid model is applied in this study to calculate the steady velocity of a debris flow along a channel bed. By using the momentum equations of the solid and liquid phases in the debris flow together with an empirical formula to describe the interaction between two phases, the steady velocities of the solid and liquid phases are obtained theoretically. The comparison of those velocities obtained by the proposed method with the observed velocities of two real-world debris flows shows that the proposed method can estimate the velocity for a debris flow.

Description: The quantification of ammonia (NH3) emissions is essential to the more accurate quantification of atmospheric nitrogen deposition, improved air quality and the assessment of ammonia-related agricultural policy and climate mitigation strategies. The quantity, geographic distribution and historical trends of these emissions remain largely uncertain. In this paper, a new Chinese agricultural fertilizer NH3 (CAF_NH3) emissions inventory has been compiled that exhibits the following improvements: (1) a 1 km × 1 km gridded map on the county level was developed for 2008, (2) a combined bottom-up and top-down method was used for the local correction of emission factors (EFs) and parameters, (3) the spatial and temporal patterns of historical time trends for 1978–2008 were estimated and the uncertainties were quantified for the inventories, and (4) a sensitivity test was performed in which a province-level disaggregated map was compared with CAF_NH3 emissions for 2008. The total CAF_NH3 emissions for 2008 were 8.4 Tg NH3 yr−1 (a 6.6–9.8 Tg interquartile range). From 1978 to 2008, annual NH3 emissions fluctuated with three peaks (1987, 1996 and 2005), and total emissions increased from 3.2 to 8.4 Tg at an annual rate of 3.0 %. During the study period, the contribution of livestock manure spreading increased from 37.0 to 45.5 % because of changing fertilization practices and the rapid increase in egg, milk and meat consumption. The average contribution of synthetic fertilizer, which has a positive effect on crop yields, was approximately 38.3 % (minimum: 33.4 %; maximum: 42.7 %). With rapid urbanization causing a decline in the rural population, the contribution of the rural excrement sector varied widely between 20.3 and 8.5 %. The average contributions of cake fertilizer and straw returning were approximately 3.8 and 4.5 %, respectively, thus small and stable. Collectively, the CAF_NH3 emissions reflect the nation's agricultural policy to a certain extent. An effective approach to decreasing PM2.5 concentrations in China would be to simultaneously decrease NOx, SO2 and NH3 emissions.

Description: The new Ozone Mapping and Profiler Suite (OMPS) launched on the Suomi National Polar-orbiting Partnership satellite in October 2011 gives a more detailed view of the development of the Antarctic ozone hole than ever before. This instrumental suite extends the long series of satellite ozone measurements that go back to the early 1970s. The OMPS includes two modules – nadir and limb – to measure profile and total ozone concentrations. The new limb module is designed to measure the vertical profile of ozone between the lowermost stratosphere and the mesosphere. The OMPS observations over Antarctica show excellent agreement with the measurements obtained from independent satellite and ground-based instruments. This validation demonstrates that OMPS data can ably extend the ozone time series over Antarctica in the future. The OMPS observations are used to monitor and characterize the evolution of the 2012 Antarctic ozone hole. While large ozone losses were observed in September 2012, a strong ozone rebound occurred in October and November 2012. This ozone rebound is characterized by rapid increases of ozone at mid-stratospheric levels and a splitting of the ozone hole in early November. The 2012 Antarctic ozone hole was the second smallest on record since 1988.

Description: The quantification of ammonia (NH3) emissions is essential to the more accurate quantification of atmospheric nitrogen deposition, improved air quality and the assessment of ammonia-related agricultural policy and climate mitigation strategies. The quantity, geographic distribution and historical trends of these emissions remain largely uncertain. In this paper, a new Chinese agricultural fertilizer NH3 (CAF_NH3) emissions inventory has been compiled that exhibits the following improvements: (1) a 1  ×  1 km gridded map on the county level was developed for 2008; (2) a combined bottom-up and top-down method was used for the local correction of emission factors (EFs) and parameters; (3) the temporal patterns of historical time trends for 1978–2008 were estimated and the uncertainties were quantified for the inventories; and (4) a sensitivity test was performed in which a province-level disaggregated map was compared with CAF_NH3 emissions for 2008. The total CAF_NH3 emissions for 2008 were 8.4 TgNH3 yr−1 (a 6.6–9.8 Tg interquartile range). From 1978 to 2008, annual NH3 emissions fluctuated with three peaks (1987, 1996 and 2005), and total emissions increased from 3.2 to 8.4 Tg at an annual rate of 3.0 %. During the study period, the contribution of livestock manure spreading increased from 37.0 to 45.5 % because of changing fertilization practices and the rapid increase in egg, milk, and meat consumption. The average contribution of synthetic fertilizer, which has a positive effect on crop yields, was approximately 38.3 % (minimum: 33.4 %; maximum: 42.7 %). With rapid urbanization causing a decline in the rural population, the contribution of the rural excrement sector varied widely between 20.3 % and 8.5 %. The average contributions of cake fertilizer and straw returning were approximately 3.8 and 4.5 %, respectively, thus small and stable. Collectively, the CAF_NH3 emissions reflect the nation's agricultural policy to a certain extent. An effective approach to decreasing PM2.5 concentrations in China would be to simultaneously decrease NOx, SO2, and NH3 emissions.

Description: The new Ozone Mapping and Profiler Suite (OMPS), which launched on the Suomi National Polar-orbiting Partnership satellite in October 2011, gives a detailed view of the development of the Antarctic ozone hole and extends the long series of satellite ozone measurements that go back to the early 1970s. OMPS includes two modules – nadir and limb – to measure profile and total ozone concentrations. The new limb module is designed to measure the vertical profile of ozone between the lowermost stratosphere and the mesosphere. The OMPS observations over Antarctica show excellent agreement with the measurements obtained from independent satellite and ground-based instruments. This validation demonstrates that OMPS data can ably extend the ozone time series over Antarctica in the future. The OMPS observations are used to monitor and characterize the evolution of the 2012 Antarctic ozone hole. While large ozone losses were observed in September 2012, a strong ozone rebound occurred in October and November 2012. This ozone rebound is characterized by rapid increases of ozone at mid-stratospheric levels and a splitting of the ozone hole in early November. The 2012 Antarctic ozone hole was the second smallest on record since 1988.