NOx emission trends over Chinese cities estimated from OMI observations during 2005 to 2015 Atmospheric Chemistry and Physics DOI 10.5194/acp-17-9261-2017 1 August 2017 We assess NOx emission trends over Chinese cities based on satellite NO2 observations using a method independent of chemical transport models. NOx emissions over 48 Chinese cities have decreased significantly since 2011. Cities with different dominant emission sources (i.e. power, industrial, and transportation sectors) showed variable emission decline timelines that corresponded to the schedules for emission control in different sectors. Read more
An intercomparison of approaches for improving operational seasonal streamflow forecasts Hydrology and Earth System Sciences DOI 10.5194/hess-21-3915-2017 31 July 2017 Water supply forecasts are critical to support water resources operations and planning. The skill of such forecasts depends on our knowledge of (i) future meteorological conditions and (ii) the amount of water stored in a basin. We address this problem by testing several approaches that make use of these sources of predictability, either separately or in a combined fashion. The main goal is to understand the marginal benefits of both information and methodological complexity in forecast skill. Read more
Every apple has a voice: using stable isotopes to teach about food sourcing and the water cycle Hydrology and Earth System Sciences DOI 10.5194/hess-21-3799-2017 25 July 2017 Fruits take up soil water as they grow, and thus the fruit water is related to the rain or irrigation the crop receives. We used a novel sampling system to measure the stable isotopes of H and O in the fruit water to determine its geographic origin by comparing it to maps of isotopes in rain. We used this approach to teach an audience of science students and teachers about water cycle concepts and how humans may modify the water cycle through agriculture and irrigation water diversions. Read more
The double high tide at Port Ellen: Doodson’s criterion revisited Ocean Science DOI 10.5194/os-13-599-2017 20 July 2017 Some places experience double high tides, where the tide starts to ebb for a short while, only to briefly flood again before finally receding. The result is a very long high tide with weak currents, and is important for navigational purposes. The existing theory for when and where double high tides occur does not always capture them, and it can only be applied to double highs occurring on a twice-daily tide. Here, the criterion has been generalized to capture all double high or low tides. Read more
Reviews and syntheses: Systematic Earth observations for use in terrestrial carbon cycle data assimilation systems Biogeosciences DOI 10.5194/bg-14-3401-2017 19 July 2017 This paper briefly reviews data assimilation techniques in carbon cycle data assimilation and the requirements of data assimilation systems on observations. We provide a non-exhaustive overview of current observations and their uncertainties for use in terrestrial carbon cycle data assimilation, focussing on relevant space-based observations. Read more
The CarbonTracker Data Assimilation Shell (CTDAS) v1.0: implementation and global carbon balance 2001–2015 Geoscientific Model Development DOI 10.5194/gmd-10-2785-2017 18 July 2017 The CarbonTracker Data Assimilation Shell (CTDAS) is the new modular implementation of the CarbonTracker Europe (CTE) data assimilation system. We present and document CTDAS and demonstrate its ability to estimate global carbon sources and sinks. We present the latest CTE results including the distribution of the carbon sinks over the hemispheres and between the land biosphere and the oceans. We show the versatility of CTDAS with an overview of the wide range of other applications. Read more
Periodic input of dust over the Eastern Carpathians during the Holocene linked with Saharan desertification and human impact Climate of the Past DOI 10.5194/cp-13-897-2017 18 July 2017 We present the first record of dust input into an eastern European bog over the past 10 800 years. We find significant changes in past dust deposition, with large inputs related to both natural and human influences. We show evidence that Saharan desertification has had a significant impact on dust deposition in eastern Europe for the past 6100 years. Read more
Young people’s burden: requirement of negative CO2 emissions Earth System Dynamics DOI 10.5194/esd-8-577-2017 18 July 2017 Global temperature now exceeds +1.25 °C relative to 1880–1920, similar to warmth of the Eemian period. Keeping warming less than 1.5 °C or CO2 below 350 ppm now requires extraction of CO2 from the air. If rapid phaseout of fossil fuel emissions begins soon, most extraction can be via improved agricultural and forestry practices. In contrast, continued high emissions places a burden on young people of massive technological CO2 extraction with large risks, high costs and uncertain feasibility. Read more
Analysis of single-Alter-shielded and unshielded measurements of mixed and solid precipitation from WMO-SPICE Hydrology and Earth System Sciences DOI 10.5194/hess-21-3525-2017 14 July 2017 Precipitation measurements were combined from eight separate precipitation testbeds to create multi-site transfer functions for the correction of unshielded and single-Alter-shielded precipitation gauge measurements. Site-specific errors and more universally applicable corrections were created from these WMO-SPICE measurements. The importance and magnitude of such wind speed corrections were demonstrated. Read more
Update of the Polar SWIFT model for polar stratospheric ozone loss (Polar SWIFT version 2) Geoscientific Model Development DOI 10.5194/gmd-10-2671-2017 13 July 2017 The Polar SWIFT model is a fast scheme for calculating the chemistry of stratospheric ozone depletion in polar winter. It is intended for use in global climate models (GCMs) and Earth system models (ESMs) to enable the simulation of mutual interactions between the ozone layer and climate. Read more
