A monitoring system for spatiotemporal electrical self-potential measurements in cryospheric environments Geoscientific Instrumentation, Methods and Data Systems DOI 10.5194/gi-9-317-2020 20 August 2020 In times of global warming, permafrost is starting to degrade at alarming rates, requiring new and improved characterization approaches. We describe the design and test installation, as well as detailed data quality assessment, of a monitoring system used to capture natural electrical potentials in the subsurface. These self-potential signals are of great interest for the noninvasive investigation of water flow in the non-frozen or partially frozen subsurface. Read more
Revisiting the global hydrological cycle: is it intensifying? Hydrology and Earth System Sciences DOI 10.5194/hess-24-3899-2020 20 August 2020 We overview and retrieve a great amount of global hydroclimatic data sets. We improve the quantification of the global hydrological cycle, its variability and its uncertainties through the surge of newly available data sets. We test (but do not confirm) established climatological hypotheses, according to which the hydrological cycle should be intensifying due to global warming. We outline a stochastic view of hydroclimate, which provides a reliable means of dealing with its variability. Read more
Molecular understanding of new-particle formation from α-pinene between-50 and +25 ∘C Atmospheric Chemistry and Physics DOI 10.5194/acp-20-9183-2020 18 August 2020 Highly oxygenated organic compounds (HOMs) have been identified as key vapors involved in atmospheric new-particle formation (NPF). The molecular distribution, HOM yield, and NPF from α-pinene oxidation experiments were measured at the CLOUD chamber over a wide tropospheric-temperature range. This study shows on a molecular scale that despite the sharp reduction in HOM yield at lower temperatures, the reduced volatility counteracts this effect and leads to an overall increase in the NPF rate. Read more
Relating climate sensitivity indices to projection uncertainty Earth System Dynamics DOI 10.5194/esd-11-721-2020 18 August 2020 Here, we assess the degree to which the idealized responses to transient forcing increase and step change forcing increase relate to warming under future scenarios. We find a possible explanation for the poor performance of transient metrics (relative to equilibrium response) as a metric of high-emission future warming in terms of their sensitivity to non-equilibrated initial conditions, and propose alternative metrics which better describe warming under high mitigation scenarios. Read more
Incremental improvements of 2030 targets insufficient to achieve the Paris Agreement goals Earth System Dynamics DOI 10.5194/esd-11-697-2020 13 August 2020 Current global mitigation ambition in the National Determined Contributions (NDCs) up to 2030 is insufficient to achieve the 1.5 °C long-term temperature limit. As governments are preparing new and updated NDCs for 2020, we address the question of what level of collective ambition is pivotal regarding the Paris Agreement goals. We provide estimates for global mean temperature increase by 2100 for different incremental NDC update scenarios and illustrate climate impacts under those scenarios. Read more
Remote sensing of methane leakage from natural gas and petroleum systems revisited Atmospheric Chemistry and Physics DOI 10.5194/acp-20-9169-2020 13 August 2020 The switch from the use of coal to natural gas or oil for energy generation potentially reduces the impact on global warming due to lower CO 2 emissions with the same energy content. However, this climate benefit is offset by fugitive methane emissions during the production and distribution process. We quantify emission and leakage rates relative to production for several large production regions based on satellite observations to evaluate the climate footprint of the gas and oil industry. Read more
Survival of the Qaidam mega-lake system under mid-Pliocene climates and itsrestoration under future climates Hydrology and Earth System Sciences DOI 10.5194/hess-24-3835-2020 11 August 2020 During the Pliocene, the Qaidam Basin on the Tibetan Plateau contained a mega-lake system. During the Pleistocene, it disappeared almost completely. Today, hyperarid climates prevail in the low-altitude parts of the basin. This study reveals that today’s mean water balance of the Qaidam Basin is nearly zero and is positive during warmer, less dry years. The results explain how the mega-lake system could survive for a long time in the past and could eventually be restored in the future. Read more
The recent state and variability of the carbonate system of the CanadianArctic Archipelago and adjacent basins in the context of ocean acidification Biogeosciences DOI 10.5194/bg-17-3923-2020 11 August 2020 Ocean acidification is the process by which the oceans are changing due to carbon dioxide emissions from human activities. Studying this process in the Arctic Ocean is essential as this ocean and its ecosystems are more vulnerable to the effects of acidification. Water chemistry measurements made in recent years show that waters in and around the Canadian Arctic Archipelago are considerably affected by this process and show dynamic conditions that might have an impact on local marine organisms. Read more
Impact of environmental changes and land management practices on wheatproduction in India Earth System Dynamics DOI 10.5194/esd-11-641-2020 6 August 2020 Spring wheat, a staple for millions of people in India and the world, is vulnerable to changing environmental and management factors. Using a new spring wheat model, we find that over the 1980–2016 period elevated CO 2 levels, irrigation, and nitrogen fertilizers led to an increase of 30 %, 12 %, and 15 % in countrywide production, respectively. In contrast, rising temperatures have reduced production by 18 %. These effects vary across the country, thereby affecting production at regional scales. Read more
Multidecadal trend analysis of in situ aerosol radiative properties around the world Atmospheric Chemistry and Physics DOI 10.5194/acp-20-8867-2020 6 August 2020 Long-term trends of aerosol radiative properties (52 stations) prove that aerosol load has significantly decreased over the last 20 years. Scattering trends are negative in Europe (EU) and North America (NA), not ss in Asia, and show a mix of positive and negative trends at polar stations. Absorption has mainly negative trends. The single scattering albedo has positive trends in Asia and eastern EU and negative in western EU and NA, leading to a global positive median trend of 0.02 % per year. Read more