The geochemical cycling of reactive chlorine through the marine troposphere

Heterogeneous reactions involving sea‐salt aerosol in the marine troposphere are the major global source for volatile inorganic chlorine. We measured reactant and product species hypothesized to be associated with these chemical transformations as a function of phase, particle size, and altitude over the North Atlantic Ocean during the summer of 1988. Concentrations of HCl were typically less than 1.0 ppbv near the sea surface and decreased with altitude and with distance from the U.S. east coast. Concentrations of Cl volatilized from aerosols were generally equivalent to the corresponding concentrations of HCl and ranged from less than detection limits to 125 nmol m−3 STP. Highest absolute and percentage losses of particulate Cl were typically associated with elevated concentrations of anthropogenic combustion products. Concentrations of product nss SO42− and N03− in coarse aerosol fractions indicate that on average only 38% of measured Cl− deficits could be accounted for by the combined effects of acid‐base desorption and reactions involving nonacidic N gases. We hypothesize a mechanism for the Cl loss initiated by reaction of O3 at sea‐salt aerosol surfaces, generating Cl2 followed by rapid photochemical conversion of Cl2 to HCl via Cl atoms (Cl˙) and eventual recapture of HCl by the aerosol. Simulations with a zero‐dimension (0‐D) photochemical model suggest that oxidation by Cl˙ may be an important tropospheric sink for dimethyl sulfide and hydrocarbons. Under low‐NOx conditions, the rapid cycling of reactive Cl would provide a catalytic loss mechanism for O3, which would possibly explain the low O3 concentrations often observed above the world\u27s oceans

A pervasive role for biomass burning in tropical high ozone/low water structures.

Air parcels with mixing ratios of high O3 and low H2O (HOLW) are common features in the tropical western Pacific (TWP) mid-troposphere (300-700 hPa). Here, using data collected during aircraft sampling of the TWP in winter 2014, we find strong, positive correlations of O3 with multiple biomass burning tracers in these HOLW structures. Ozone levels in these structures are about a factor of three larger than background. Models, satellite data and aircraft observations are used to show fires in tropical Africa and Southeast Asia are the dominant source of high O3 and that low H2O results from large-scale descent within the tropical troposphere. Previous explanations that attribute HOLW structures to transport from the stratosphere or mid-latitude troposphere are inconsistent with our observations. This study suggest a larger role for biomass burning in the radiative forcing of climate in the remote TWP than is commonly appreciated.We thank L. Pan for coordinating the CONTRAST flights and her constructive criticism of an early version of the manuscript; S. Schauffler, V. Donets and R. Lueb for collecting and analysing AWAS samples; T. Robinson and O. Shieh for providing meteorology forecasts in the field; and the pilots and crews of the CAST BAe-146 and CONTRAST Gulfstream V aircrafts for their dedication and professionalism. CAST was funded by the Natural Environment Research Council; CONTRAST was funded by the National Science Foundation. Research at the Jet Propulsion Laboratory, California Institute of Technology, is performed under contract with the National Aeronautics and Space Administration (NASA). A number of the US-based investigators also benefitted from the support of NASA as well as the National Oceanic and Atmospheric Administration. The views, opinions, and findings contained in this report are those of the author(s) and should not be construed as an official National Oceanic and Atmospheric Administration or US Government position, policy or decision. We would like to acknowledge high-performance computing support from Yellowstone (ark:/85065/d7wd3xhc) provided by NCAR's Computational and Information Systems Laboratory. NCAR is sponsored by the National Science Foundation.This is the final version of the article. It first appeared from Nature Publishing Group via http://dx.doi.org/10.1038/ncomms1026

Marktanalyse und Strategien zum Aufbau des Objektgeschäfts in Spanien am Beispiel der Häfele GmbH & Co KG

This paper was written for the Häfele GmbH & Co KG during the period from October 2015 to February 2016. In 2016 the Häfele group wants to start business activities in the Spanish project business. The market entry should be carried out by the Spanish subsidiary Häfele Herrajes S.L. For that reason, the purpose of this bachelor thesis is to realize a market analysis and to develop suitable strategies for the Spanish market. Through the application of analytical tools of strategic management the business environment and the company have been analyzed. After an introduction a PEST-Analysis has been carried out to assess the macroenvironment of the company. Additionally, an industry structure analysis should give an overview of the characteristics of the project business and the actual situation of the Spanish construction sector. A more detailed analysis including a potential sales volume calculation has been carried out of the hotel construction segment due to the reason that the Häfele group has already established business relations in this segment through operations in other markets. Furthermore, a competition analysis has been realized which focuses on the three most important competitors of the market. In this context the largest competitor is compared with the Häfele Herrajes S.L. The comparison is based on the key success factors of the industry which have been determined beforehand with experts of the Häfele group. A SWOT-Analysis is used to elaborate strategic actions by summarizing the results of the previous insights. The main conclusions of the thesis for the Häfele Herrajes S.L. are that the subsidiary should focus on the hotel construction market in the regions of Madrid, Barcelona and the Balearic Islands. Moreover, the subsidiary should concentrate on the construction of hotels in four and five star segment. Besides that, the company wide corporation and the use of established business relations will be necessary to establish the Häfele Herrajes S.L. in the long term on the Spanish project market