ALBERT

Description: © The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Deep Sea Research Part I: Oceanographic Research Papers 104 (2015): 72-91, doi:10.1016/j.dsr.2015.06.012.

Description: Nitrogen fixation is an important yet still incompletely constrained component of the marine nitrogen cycle, particularly in the subsurface. A Video Plankton Recorder (VPR) survey in the subtropical North Atlantic found higher than expected Trichodesmium colony abundances at depth, leading to the hypothesis that deep nitrogen fixation in the North Atlantic may have been previously underestimated. Here, Trichodesmium colony abundances and modeled nitrogen fixation from VPR transects completed on two cruises in the tropical and subtropical North Atlantic in fall 2010 and spring 2011 were used to evaluate that hypothesis. A bio-optical model was developed based on carbon-normalized nitrogen fixation rates measured on those cruises. Estimates of colony abundance and nitrogen fixation were similar in magnitude and vertical and geographical distribution to conventional estimates in a recently compiled climatology. Thus, in the mean, VPR-based estimates of volume-specific nitrogen fixation rates at depth in the tropical North Atlantic were not inconsistent with estimates derived from conventional sampling methods. Based on this analysis, if Trichodesmium nitrogen fixation by colonies is underestimated, it is unlikely that it is due to underestimation of deep abundances by conventional sampling methods.

Description: We gratefully acknowledge support of this research by NSF and NASA. A NASA Earth and Space Science Fellowship supported E. Olson's graduate studies.

Description: © The Author(s), 2014. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Atmosphere 5 (2014): 973-1001, doi:10.3390/atmos5040973.

Description: An analysis of coastal meteorological mechanisms facilitating the transit pollution plumes emitted from sources in the Northeastern U.S. was based on observations from the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) 2004 field campaign. Particular attention was given to the relation of these plumes to coastal transport patterns in lower tropospheric layers throughout the Gulf of Maine (GOM), and their contribution to large-scale pollution outflow from the North American continent. Using measurements obtained during a series of flights of the National Oceanic & Atmospheric Administration (NOAA) WP-3D and the National Aeronautics and Space Administration (NASA) DC-8, a unique quasi-Lagrangian case study was conducted for a freshly emitted plume emanating from the New York City source region in late July 2004. The development of this plume stemmed from the accumulation of boundary layer pollutants within a coastal residual layer, where weak synoptic conditions allowed for its advection into the marine troposphere and transport by a mean southwesterly flow. Upon entering the GOM, analysis showed that the plume layer vertical structure evolved into an internal boundary layer form, with signatures of steep vertical gradients in temperature, moisture and wind speed often resulting in periodic turbulence. This structure remained well-defined during the plume study, allowing for the detachment of the plume layer from the surface and minimal plume-sea surface exchange. In contrast, shear driven turbulence within the plume layer facilitated lateral mixing with other low-level plumes during its transit. This turbulence was periodic and further contributed to the high spatial variability in trace gas mixing ratios. Further influences of the turbulent mixing were observed in the impact of the plume inland as observed by the Atmospheric Investigation, Regional Modeling, Analysis and Prediction (AIRMAP) air quality network. This impact was seen as extreme elevations of surface ozone and CO levels, equaling the highest observed that summer.

Description: Financial support for this work was from the NOAA Office of Oceanic and Atmospheric Research under grant #NA07OAR4600514. - See more at: http://www.mdpi.com/2073-4433/5/4/973/htm#sthash.E0atBClM.dpuf

Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zhang, Bo -- Davis, Wayne S -- England -- Nature. 2015 Nov 26;527(7579):446. doi: 10.1038/527446f.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Information Center, Ministry of Environmental Protection, Beijing, China. ; EPA, Washington DC, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26607534" target="_blank"〉PubMed〈/a〉

Description: Nearly three-quarters of the growth in global carbon emissions from the burning of fossil fuels and cement production between 2010 and 2012 occurred in China. Yet estimates of Chinese emissions remain subject to large uncertainty; inventories of China's total fossil fuel carbon emissions in 2008 differ by 0.3 gigatonnes of carbon, or 15 per cent. The primary sources of this uncertainty are conflicting estimates of energy consumption and emission factors, the latter being uncertain because of very few actual measurements representative of the mix of Chinese fuels. Here we re-evaluate China's carbon emissions using updated and harmonized energy consumption and clinker production data and two new and comprehensive sets of measured emission factors for Chinese coal. We find that total energy consumption in China was 10 per cent higher in 2000-2012 than the value reported by China's national statistics, that emission factors for Chinese coal are on average 40 per cent lower than the default values recommended by the Intergovernmental Panel on Climate Change, and that emissions from China's cement production are 45 per cent less than recent estimates. Altogether, our revised estimate of China's CO2 emissions from fossil fuel combustion and cement production is 2.49 gigatonnes of carbon (2 standard deviations = +/-7.3 per cent) in 2013, which is 14 per cent lower than the emissions reported by other prominent inventories. Over the full period 2000 to 2013, our revised estimates are 2.9 gigatonnes of carbon less than previous estimates of China's cumulative carbon emissions. Our findings suggest that overestimation of China's emissions in 2000-2013 may be larger than China's estimated total forest sink in 1990-2007 (2.66 gigatonnes of carbon) or China's land carbon sink in 2000-2009 (2.6 gigatonnes of carbon).〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Liu, Zhu -- Guan, Dabo -- Wei, Wei -- Davis, Steven J -- Ciais, Philippe -- Bai, Jin -- Peng, Shushi -- Zhang, Qiang -- Hubacek, Klaus -- Marland, Gregg -- Andres, Robert J -- Crawford-Brown, Douglas -- Lin, Jintai -- Zhao, Hongyan -- Hong, Chaopeng -- Boden, Thomas A -- Feng, Kuishuang -- Peters, Glen P -- Xi, Fengming -- Liu, Junguo -- Li, Yuan -- Zhao, Yu -- Zeng, Ning -- He, Kebin -- England -- Nature. 2015 Aug 20;524(7565):335-8. doi: 10.1038/nature14677.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉John F. Kennedy School of Government, Harvard University, Cambridge, Massachusetts 02138, USA. ; Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China. ; Resnick Sustainability Institute, California Institute of Technology, Pasadena, California 91125, USA. ; Ministry of Education Key Laboratory for Earth System Modeling, Center for Earth System Science, Tsinghua University, Beijing 100084, China. ; School of International Development, University of East Anglia, Norwich NR4 7TJ, UK. ; CAS Key Laboratory of Low-carbon Conversion Science and Engineering, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201203, China. ; Department of Earth System Science, University of California, Irvine, California 92697, USA. ; Laboratoire des Sciences du Climat et de l'Environnement, CEA-CNRS-UVSQ, CE Orme des Merisiers, 91191 Gif sur Yvette Cedex, France. ; State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Science, Taiyuan 030001, China. ; CNRS and UJF Grenoble 1, Laboratoire de Glaciologie et Geophysique de l'Environnement (LGGE, UMR5183), 38041 Grenoble, France. ; Department of Geographical Sciences, University of Maryland, College Park, Maryland 20742, USA. ; Research Institute for Environment, Energy, and Economics, Appalachian State University, Boone, North Carolina 28608, USA. ; Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA. ; Cambridge Centre for Climate Change Mitigation Research, Department of Land Economy, University of Cambridge, 19 Silver Street, Cambridge CB3 9EP, UK. ; Laboratory for Climate and Ocean-Atmosphere Studies, Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing 100871, China. ; State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China. ; Center for International Climate and Environmental Research-Oslo (CICERO), N-0318 Oslo, Norway. ; CAS Key Laboratory of Pollution Ecology and Environmental Engineering, Chinese Academy of Sciences, Shenyang 110016, China. ; School of Nature Conservation, Beijing Forestry University, Beijing 10083, China. ; Ecosystems Services &Management Program, International Institute for Applied Systems Analysis, Schlossplatz 1, A-2361 Laxenburg, Austria. ; School of Environmental Science and Engineering, South University of Science and Technology of China, Shenzhen 518055, China. ; State Key Laboratory of Pollution Control &Resource Reuse and School of the Environment, Nanjing University, Nanjing 210023, China. ; Department of Atmospheric and Oceanic Science and Earth System Science Interdisciplinary Center, University of Maryland, College Park, Maryland 20742-2425, USA. ; Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26289204" target="_blank"〉PubMed〈/a〉