Changes in frost, snow and Baltic sea ice by the end of the twenty-first century based on climate model projections for Europe

Changes in indices related to frost and snow in Europe by the end of the twenty-first century were analyzed based on experiments performed with seven regional climate models (RCMs). All the RCMs regionalized information from the same general circulation model (GCM), applying the IPCC-SRES A2 radiative forcing scenario. In addition, some simulations used SRES B2 radiative forcing and/or boundary conditions provided by an alternative GCM. Ice cover over the Baltic Sea was examined using a statistical model that related the annual maximum extent of ice to wintertime coastal temperatures. Fewer days with frost and snow, shorter frost seasons, a smaller liquid water equivalent of snow, and milder sea ice conditions were produced by all model simulations, irrespective of the forcing scenario and the driving GCM. The projected changes have implications across a diverse range of human activities. Details of the projections were subject to differences in RCM design, deviations between the boundary conditions of the driving GCMs, uncertainties in future emissions and random effects due to internal climate variability. A larger number of GCMs as drivers of the RCMs would most likely have resulted in somewhat wider ranges in the frost, snow and sea ice estimates than those presented in this paper.     

Assessment of ZTD derived from ECMWF/NCEP data with GPS ZTD over China

The accuracy and feasibility of computing the zenith tropospheric delays (ZTDs) from data of the European Center for Medium-Range Weather Forecasts (ECMWF) and the United States National Centers for Environmental Prediction (NCEP) are studied. The ZTDs are calculated from ECMWF/NCEP pressure-level data by integration and from the surface data with the Saastamoinen model method and then compared with the solutions measured from 28 global positioning system (GPS) stations of the Crustal Movement Observation Network of China (CMONOC) for 1 year. The results are as follows: (1) the error of the integration method is 1–3 cm less than that of the Saastamoinen model method. The agreement between the ECMWF ZTD and GPS ZTD is better than that between NCEP ZTD and GPS ZTD; (2) the bias and root mean square difference (RMSD), especially the latter, have a seasonal variation, and the RMSD decreases with increasing altitude while the variation with latitude is not obvious; and (3) when using the full horizontal resolution of 0.5° × 0.5° of the ECMWF meteorological data in place of a reduced 2.5° × 2.5° grid, the mean RMSD between GPS and ECMWF ZTD decreases by 4.5 mm. These results illuminated the accuracy and feasibility of computing the tropospheric delays and establishing the ZTD prediction model over China for navigation and positioning with ECMWF and NCEP data.     

Enhancing the OGC WPS interface with GeoPipes support for real-time geoprocessing

ABSTRACT

Real-time geospatial information is used in various applications such as risk management or alerting services. Especially, the rise of new sensing technologies also increases the demand for processing the data in real time. Today’s spatial data infrastructures, however, do not meet the requirements for real-time geoprocessing. The OpenGIS^® Web Processing Service (WPS) is not designed to process real-time workflows. It has some major drawbacks in asynchronous processing and cannot handle (geo) data streams out of the box. In previous papers, we introduced the GeoPipes approach to share spatiotemporal data in real time. We implemented the concept extending the Message Queue and Telemetry Transport (MQTT) protocol by a spatial and temporal dimension, which we call GeoMQTT. In this paper, we demonstrate the integration of the GeoPipes idea in the WPS interface to expose standardized real-time geoprocessing services. The proof of the concept is illustrated in some exemplary real-time geo processes.     

Simulated changes in vegetation distribution, land carbon storage, and atmospheric CO2 in response to a collapse of the North Atlantic thermohaline circulation

It is investigated how abrupt changes in the North Atlantic (NA) thermohaline circulation (THC) affect the terrestrial carbon cycle. The Lund–Potsdam–Jena Dynamic Global Vegetation Model is forced with climate perturbations from glacial freshwater experiments with the ECBILT-CLIO ocean–atmosphere–sea ice model. A reorganisation of the marine carbon cycle is not addressed. Modelled NA THC collapses and recovers after about a millennium in response to prescribed freshwater forcing. The initial cooling of several Kelvin over Eurasia causes a reduction of extant boreal and temperate forests and a decrease in carbon storage in high northern latitudes, whereas improved growing conditions and slower soil decomposition rates lead to enhanced storage in mid-latitudes. The magnitude and evolution of global terrestrial carbon storage in response to abrupt THC changes depends sensitively on the initial climate conditions. These were varied using results from time slice simulations with the Hadley Centre model HadSM3 for different periods over the past 21 kyr. Changes in terrestrial storage vary between −67 and +50 PgC for the range of experiments with different initial conditions. Simulated peak-to-peak differences in atmospheric CO₂ are 6 and 13 ppmv for glacial and late Holocene conditions. Simulated changes in δ¹³C are between 0.15 and 0.25‰. These simulated carbon storage anomalies during a NA THC collapse depend on their magnitude on the CO₂ fertilisation feedback mechanism. The CO₂ changes simulated for glacial conditions are compatible with available evidence from marine studies and the ice core CO₂ record. The latter shows multi-millennial CO₂ variations of up to 20 ppmv broadly in parallel with the Antarctic warm events A1 to A4 in the South and cooling in the North.     

A reconstructed dynamic Indian monsoon index extended back to 1880

The authors present a reconstruction of summer (June–July–August) mean dynamic Indian monsoon index (DIMI) back to 1880 based on a large number of historical surface observation data as well as information from the upper air data. The reconstruction shows a satisfying skill in terms of both the value of reduction of error and an evaluation against other independent monsoon indices. The skill of reconstruction increases over time with more predictor data (in particular upper-level data) becoming available. A comparison with the observed all Indian summer monsoon rainfall index (AIRI) shows a high consistence in both inter-decadal and inter-annual variability. The reconstruction shows stronger than normal monsoon during the 1880s, 1915–1925 (around 1920) and 1930–1945 (around 1940) as the AIRI. The El Nino/Southern Oscillation (ENSO)—monsoon relationship is reasonably captured in the reconstruction. Powers concentrating within quasi-biennial band stand out in the reconstruction as well as in the AIRI. A comparison of the reconstruction against an atmospheric general circulation model simulation with specified SST and external forcing agents spanning 1901–1999 indicates a slightly higher reproducibility of monsoon circulation than monsoon rainfall in terms of interannual variability. The relationship between the Asian continent warming and the ENSO–monsoon connection is also discussed by using the new dynamic index.     

Electricity regulation in the Chinese national emissions trading scheme (ETS): lessons for carbon leakage and linkage with the EU ETS

Carbon leakage is central to the discussion on how to mitigate climate change. The current carbon leakage literature focuses largely on industrial production, and less attention has been given to carbon leakage from the electricity sector (the largest source of carbon emissions in China). Moreover, very few studies have examined in detail electricity regulation in the Chinese national emissions trading system (which leads, for example, to double counting) or addressed its implications for potential linkage between the EU and Chinese emissions trading systems (ETSs). This article seeks to fill this gap by analysing the problem of ‘carbon leakage’ from the electricity sector under the China ETS. Specifically, a Law & Economics approach is applied to scrutinize legal documents on electricity/carbon regulation and examine the economic incentive structures of stakeholders in the inter-/intra-regional electricity markets. Two forms of ‘electricity carbon leakage’ are identified and further supported by legal evidence and practical cases. Moreover, the article assesses the environmental and economic implications for the EU of potential linkage between the world’s two largest ETSs. In response, policy suggestions are proposed to address electricity carbon leakage, differentiating leakage according to its sources.

Key policy insights

• Electricity carbon leakage in China remains a serious issue that has yet to receive sufficient attention.

• Such leakage arises from the current electricity/carbon regulatory framework in China and jeopardizes mitigation efforts.

• With the US retreat on climate efforts, evidence suggests that EU officials are looking to China and expect an expanded carbon market to reinforce EU global climate leadership.

• Given that the Chinese ETS will be twice the size of the EU ETS, a small amount of carbon leakage in China could have significant repercussions. Electricity carbon leakage should thus be considered in any future EU–China linking negotiations.

     

Technical paper: FluMo—a mobile fluid–chemical monitoring unit for geothermal plants

A versatile fluid–chemical monitoring unit has been developed in the framework of the geothermal research platform Groß Schönebeck, Germany. It enables selective online and in situ measurements of various physico-chemical parameters at different surface locations of a geothermal fluid loop. Sensors are provided for pressure, temperature, volumetric flow rate, density, pH-value, redox potential, oxygen content, and electrical conductivity. In addition, the apparatus features two fluid samplers to manually collect fluid under in situ conditions and ultimately analyze the solution composition. All devices are mounted on a rack allowing easy transfer of the apparatus to other geothermal plants. The maximum operating pressure and temperature of the unit are 15 bar and 150 °C, respectively. The scientific and technical purpose of the system is to monitor a compositional variability of the produced fluid and chemical processes potentially occurring within the plant. These may result from reactions between the fluid and the surrounding materials, e.g., corrosion. Also, mineral precipitation as a consequence of temperature and/or pressure decrease or oxygen contamination may occur. This information is of paramount importance as so induced reactions might lead to failure of plant components or may damage the geothermal reservoir upon fluid reinjection and thus decrease injectivity.     

Fabric development in a fragment of tethyan oceanic lithosphere from the piemonte ophiolite nappe of the western Alps, Valtournanche, Italy

South of the Matterhorn the Valtournanche cuts through Alpine serpentinites, metagabbros, meta-pillowbasalts and metasediments—dismembered remnants of the Jurassic Tethyan oceanic crust, reassembled in the Piemonte ophiolite nappe. This study deals with a serpentinized ultramafic to mafic layered complex stemming from a spreading ridge environment. Cumulus fabrics of various kinds can be read through antigorite pseudomorphs, still allowing the detailed reconstruction of deep oceanic crust. Relics of igneous and metamorphic olivine prove crustal conditions during deformation. Fracturing of cumulus olivine was succeeded by plastic flow that activated low-temperature slip systems. Concomitant recrystallization produced metaperidotite only along shear zones, which are ascribed to subduction of the oceanic crust. At the turning point from subduction to obduction a static metamorphic event resulted in recovery and grain growth of recrystallized olivine. Afterwards serpentinization of the complex took place still under static conditions. Deformation of the serpentinite led to a sequence of four phases, involving non-penetrative cleavage formation, stretching and folding. This deformation is structurally related to obduction of the complex although partly accompanied by subduction zone metamorphism. Final movements of the ophiolites were due to cataclastic thrusting forming subnappe boundaries.