Impact of Portugal fires on 2003 European pollution

In 2003, an exceptional heatwave affected Western Europe leading to maximum record temperature breaks in some countries. Stagnant anticyclonic conditions and long sunny periods allowed pollution to reach very high levels. Furthermore devastating forest fires occurred because of hot temperature and drought. For example, in Portugal more than 390000 ha burned which represents 5.6% of the forest surface. The objective of this study is to analyse the impact of long range transport atmospheric pollution during the hot summer 2003 period. We use MOZAIC data from aircraft taking off or landing at Frankfurt, Paris and Vienna. This data set shows pollution which striked Europe in the first half of August 2003. For Frankfurt, between 0 and 2 km heigh, ozone concentration reach 90 ppbv all the 13 days long and the difference with climatology is near + 40 ppbv. This difference rise to an altitude of 6 km the 10 and 11 August. We also see high concentration for carbon monoxide (mean 250 ppbv). Maximas occured the 8, 9 and 10 August in the first kilometre of atmosphere and peaks are visible at high altitude the 4, 5 and 6 August. In order to analyse ozone and precursors evolution we work with the Lagrangian particle dispersion model Flexpart which calculate, forward or backward in time, air particle dispersion by winds. Flexpart allows us to determine air mass origin by identifying ozone precursors emitting region at surface and by analysing particle resident time of retro-plume. The analysis of the 4 August CO peak indicate that the air mass came from Portugal in 4 days and passed some time near the ground. For boundary layer high concentrations, we concentrate our study on air mass contribution from Portugal. About 15% of air crossed by aircraft over Frankfurt under 2 km came from Portugal in 6 to 10 days. It seems that Portugal fires played an important role in the second week of the heat wave when pollution was maximum. This is true for Paris and Vienna even if Paris is nearest the anticylone center. The heatwave has contributed to create high levels in pollutants by its meteorological properties but its consequences like fires played an important role for rising pollutants concentration moreover. [no pdf

Organic potassium salts or fibers effects on mineral balance and digestive fermentations in rats adapted to an acidogenic diet

Background Fibers and potassium (K) organic salts in plant foods are liable to affect Ca and Mg balance at digestive and renal levels, respectively. K organic salts could counteract the acidifying effects of western diets and consequences of excess NaCl. Aim of the study To study this question, male rats were adapted to a basal acidifying low-K (LK) diet, or to diets supplemented with a fiber mix (LK/F), or K citrate (HK) or both (HK/F). Results HK and HK/F diets displayed a marked alkalinizing effect in urine and promoted citraturia, but this effect was not modulated by fibers. The effect of fibers on Ca digestive absorption was more potent than K citrate effect on Ca renal excretion. In contrast, K citrate effect on kidney Mg excretion was more effective than that of fibers on Mg digestive absorption, a maximal effect on Mg balance was observed in rats fed the HK/F diet. Digestive fermentations in rats fed the LK/F diet were characterized by high-propionic acid fermentations and succinate accumulation. In rats adapted to the HK/F diet, K citrate supplementation depressed succinate and increased butyrate concentrations. Conclusion Organic anions arising from digestive fermentations seem to be not directly involved in the alkalinizing effects of plant foods. Fibers and organic K salts exert distinct effects on Ca and Mg metabolism, but with interesting interactions as to Mg balance, digestive fermentations and urine pH

Expanding Tara Oceans Protocols for Underway, Ecosystemic Sampling of the Ocean-Atmosphere Interface During Tara Pacific Expedition (2016-2018)

Interactions between the ocean and the atmosphere occur at the air-sea interface through the transfer of momentum, heat, gases and particulate matter, and through the impact of the upper-ocean biology on the composition and radiative properties of this boundary layer. The Tara Pacific expedition, launched in May 2016 aboard the schooner Tara, was a 29-month exploration with the dual goals to study the ecology of reef ecosystems along ecological gradients in the Pacific Ocean and to assess inter-island and open ocean surface plankton and neuston community structures. In addition, key atmospheric properties were measured to study links between the two boundary layer properties. A major challenge for the open ocean sampling was the lack of ship-time available for work at "stations". The time constraint led us to develop new underway sampling approaches to optimize physical, chemical, optical, and genomic methods to capture the entire community structure of the surface layers, from viruses to metazoans in their oceanographic and atmospheric physicochemical context. An international scientific consortium was put together to analyze the samples, generate data, and develop datasets in coherence with the existing Tara Oceans database. Beyond adapting the extensive Tara Oceans sampling protocols for high-resolution underway sampling, the key novelties compared to Tara Oceans' global assessment of plankton include the measurement of (i) surface plankton and neuston biogeography and functional diversity; (ii) bioactive trace metals distribution at the ocean surface and metal-dependent ecosystem structures; (iii) marine aerosols, including biological entities; (iv) geography, nature and colonization of microplastic; and (v) high-resolution underway assessment of net community production via equilibrator inlet mass spectrometry. We are committed to share the data collected during this expedition, making it an important resource important resource to address a variety of scientific questions