Variability of Arctic and North Atlantic sea ice: A combined analysis of model results and observations from 1978 to 2001

Ice cover data simulated by a coupled sea ice-oceanmodel of the North Atlantic and the Arctic Ocean are compared withsatellite observations for the period 1978 to 2001. The capability ofthe model in reproducing the long-term mean state and the inter-seasonalvariability is demonstrated. The main modes of variability of thesatellite data and the simulation in the summer and winter half yearsare highly similar.Using NCEP/NCAR reanalysis data and the results from the sea ice-oceanmodel, we describe the relationship with atmospheric and oceanicvariables for the first two modes of sea-ice concentration variabilityin winter and in summer. The first winter mode shows a time delayedresponse to the Arctic Oscillation due to advection of heatanomalies in the ocean. The second winter mode is dominated by anevent in the late 1990s that is characterized by anomalously highpressure over the eastern Arctic. The first summer mode isstrongly influenced by the Arctic Oscillation of the previouswinter. The second summer mode is caused by anomalous air temperaturein the Arctic. This mode shows a distinctive trend and is related to anice extent reduction of about 4 10^5 km^2 over the 23 years ofanalysis

Mobile Source and Livestock Feed Contributions to Regional Ozone Formation in Central California

A three-dimensional air quality model with 8 km horizontal resolution was applied to estimate the summertime ozone (O₃) production from mobile sources and fermented livestock feed in California’s San Joaquin Valley (SJV) during years 2000, 2005, 2010, 2015, and 2020. Previous studies have estimated that animal feed emissions of volatile organic compounds (VOCs) have greater O₃ formation potential than mobile-source VOC emissions when averaging across the entire SJV. The higher spatial resolution in the current study shows that the proximity of oxides of nitrogen (NO_<i>x</i>) and VOC emissions from mobile sources enhances their O₃ formation potential. Livestock feed VOC emissions contributed 3–4 ppb of peak O₃ (8-h average) in Tulare County and 1–2 ppb throughout the remainder of the SJV during the CCOS 2000 July–August episode. In total, livestock feed contributed ∼3.5 tons of the ground level peak O₃ (8 h average) in the SJV region, and mobile VOC contributed ∼12 tons in this episode. O₃ production from mobile sources is declining over time in response to emissions control plans that call for cleaner fuels and engines with advanced emissions controls. Projecting forward to the year 2020, mobile-source VOC emissions are predicted to produce ∼3 tons of the ground level peak O₃ (8-h average) and livestock feed VOC emissions are predicted to contribute ∼2.5 tons making these sources nearly equivalent

Flexibles Fotolithographisches Prozesscenter (FFP). Teilprojekt: Qualifizierung Modul 6000 Ergebnisbericht

Available from TIB Hannover: FR 5128+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

"What We Breathe Impacts Our Health : Improving Understanding of the Link between Air Pollution and Health"

Air pollution contributes to the premature deaths of millions of people each year around the world, and air quality problems are growing in many developing nations. While past policy efforts have succeeded in reducing particulate matter and trace gases in North America and Europe, adverse health effects are found at even these lower levels of air pollution. Future policy actions will benefit from improved understanding of the interactions and health effects of different chemical species and source categories. Achieving this new understanding requires air pollution scientists and engineers to work increasingly closely with health scientists. In particular, research is needed to better understand the chemical and physical properties of complex air pollutant mixtures, and to use new observations provided by satellites, advanced in situ measurement techniques, and distributed micro monitoring networks, coupled with models, to better characterize air pollution exposure for epidemiological and toxicological research, and to better quantify the effects of specific source sectors and mitigation strategies