Anthropogenic aerosols, greenhouse gases, and the uptake, transport, and storage of excess heat in the climate system

Author Posting. © American Geophysical Union, 2019. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters, 46(9), (2019):4894-4903, doi:10.1029/2019GL082015.The largest contributor to the planetary energy imbalance is well‐mixed greenhouse gases (GHGs), which are partially offset by poorly mixed (and thus northern midlatitude dominated) anthropogenic aerosols (AAs). To isolate the effects of GHGs and AAs, we analyze data from the CMIP5 historical (i.e., all natural and anthropogenic forcing) and single forcing (GHG‐only and AA‐only) experiments. Over the duration of the historical experiment (1861–2005) excess heat uptake at the top of the atmosphere and ocean surface occurs almost exclusively in the Southern Hemisphere, with AAs canceling the influence of GHGs in the Northern Hemisphere. This interhemispheric asymmetry in surface heat uptake is eliminated by a northward oceanic transport of excess heat, as there is little hemispheric difference in historical ocean heat storage after accounting for ocean volume. Data from the 1pctCO2 and RCP 8.5 experiments suggests that the future storage of excess heat will be skewed toward the Northern Hemisphere oceans.We acknowledge the World Climate Research Programme's Working Group on Coupled Modelling, which is responsible for CMIP, and we thank the climate modeling groups for producing and making available their model output. CMIP data can be accessed at the ESGF website (https://esgfnode.llnl.gov/projects/esgfllnl/). For CMIP the U.S. Department of Energy's Program for Climate Model Diagnosis and Intercomparison provides coordinating support and led development of software infrastructure in partnership with the Global Organization for Earth System Science Portals. We also thank Paola Petrelli from the ARC Centre of Excellence for Climate Extremes, for her assistance with downloading/managing the CMIP5 data archive at the National Computational Infrastructure

Marine Biotechnology: A New Vision and Strategy for Europe

Marine Board-ESF The Marine Board provides a pan-European platform for its member organisations to develop common priorities, to advance marine research, and to bridge the gap between science and policy in order to meet future marine science challenges and opportunities. The Marine Board was established in 1995 to facilitate enhanced cooperation between European marine science organisations (both research institutes and research funding agencies) towards the development of a common vision on the research priorities and strategies for marine science in Europe. In 2010, the Marine Board represents 30 Member Organisations from 19 countries. The Marine Board provides the essential components for transferring knowledge for leadership in marine research in Europe. Adopting a strategic role, the Marine Board serves its Member Organisations by providing a forum within which marine research policy advice to national agencies and to the European Commission is developed, with the objective of promoting the establishment of the European Marine Research Area

The contrast between Atlantic and Pacific surface water fluxes

The Atlantic Ocean is known to have higher sea surface salinity than the Pacific Ocean at all latitudes. This is thought to be associated with the Atlantic Meridional Overturning Circulation and deep water formation in the high latitude North Atlantic - a phenomenon not present anywhere in the Pacific. This asymmetry may be a result of salt transport in the ocean or an asymmetry in the surface water flux (evaporation minus precipitation; E − P ) with greater E − P over the Atlantic than the Pacific. In this paper we focus on the surface water flux. Seven estimates of the net freshwater flux (E − P − R including runoff, R), calculated with different methods and a range of data sources (atmospheric and oceanic reanalyses, surface flux datasets, hydrographic sections), are compared. It is shown that E − P − R over the Atlantic is consistently greater than E − P − R over the Pacific by about 0.4 Sv (1 Sv ≡ 106 m3 s−1). The Atlantic/Pacific E − P − R asymmetry is found at all latitudes between 30◦S and 60◦N. Further analysis with ERA-Interim combined with a runoff dataset demonstrates that the basin E − P − R asymmetry is dominated by an evaporation asymmetry in the northern high-latitudes, but by a precipitation asymmetry everywhere south of 30◦N. At the basin scale, the excess of precipitation over the Pacific compared to the Atlantic (∼ 30◦S - 60◦N) dominates the asymmetry. Also it is shown that the asymmetry is present throughout the year and quite steady from year to year. Investigation of the interannual variability and trends suggest that the precipitation trends are not robust between datasets and are indistinguishable from variability. However, a positive trend in evaporation (comparable to other published estimates) is seen in ERA-Interim, consistent with sea surface temperature increases

Voltage analysis after multi-electrode ablation with duty-cycled bipolar and unipolar radiofrequency energy: a case report

Pulmonary vein ablation with a single-tip catheter remains long and complex. We describe a typical case of a novel efficient technique with a decapolar ring catheter utilizing alternating unipolar/bipolar radiofrequency energy. Voltage analysis and electrical mapping demonstrate the potential for antrum ablation and pulmonary vein isolation

Effects of shear stress on the microalgae Chaetoceros muelleri

The effect of shear stress on the viability of Chaetoceros muelleri was studied using a combination of a rheometer and dedicated shearing devices. Different levels of shear stress were applied by varying the shear rates and the medium viscosities. It was possible to quantify the effect of shear stress over a wide range, whilst preserving laminar flow conditions through the use of a thickening agent. The threshold value at which the viability of algae was negatively influenced was between 1 and 1.3 Pa. Beyond the threshold value the viability decreased suddenly to values between 52 and 66%. The effect of shear stress was almost time independent compared to normal microalgae cultivation times. The main shear stress effect was obtained within 1 min, with a secondary effect of up to 8 min

Cyanobacterial growth and cyanophycin production with urea and ammonium as nitrogen source

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Metabolic engineering of Pseudomonas putida KT2440 for medium-chain-length fatty alcohol and ester production from fatty acids

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