bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lagrangian process attribution of isotopic variations in near-surface water vapour in a 30-year regional climate simulation over Europe
Authors: Dütsch Marina , Pfahl Stephan , Meyer Miro , Wernli Heini 
Published: February 2018

Abstract. Stable water isotopes are naturally available tracers of moisture in the
atmosphere. Due to isotopic fractionation, they record information about
condensation and evaporation processes during the transport of air parcels,
and therefore present a valuable means for studying the global water cycle.
However, the meteorological processes driving isotopic variations are complex
and not very well understood so far, in particular on short (hourly to daily)
timescales. This
study presents a Lagrangian method for attributing the isotopic composition
of air parcels to meteorological processes, which provides new insight into
the isotopic history of air parcels. It is based on the temporal evolution of
the isotope ratios, the humidity, the temperature, and the location of the
air parcels. Here these values are extracted along 7-day backward
trajectories started every 6 hours
from near the surface in a 30-year regional climate simulation over
Europe with the isotope-enabled version of the model of the Consortium for
Small-Scale Modelling (COSMOiso). The COSMOiso simulation has a horizontal
resolution of 0.25∘ and is driven at the lateral boundaries by a T106
global climate simulation with the isotope-enabled version of the European
Centre Hamburg model (ECHAMwiso).
Both simulations are validated against
measurements from the Global Network of Isotopes in Precipitation (GNIP),
which shows that nesting COSMOiso within ECHAMwiso improves the
representation of δ2H and deuterium excess in monthly accumulated
precipitation. The method considers all isotopic changes that occur inside
the COSMOiso model domain, which, on average, correspond to more than half of
the mean and variability in both δ2H and deuterium excess at the air
parcels' arrival points. Along every trajectory, the variations in the
isotope values are quantitatively decomposed into eight process categories
(evaporation from the ocean, evapotranspiration from land, mixing with
moister air, mixing with drier air, liquid cloud formation, mixed phase cloud
formation, ice cloud formation, and no process). The results show that for
air parcels arriving over the ocean, evaporation from the ocean is the
primary factor controlling δ2H and deuterium excess. Over land,
evapotranspiration from land and mixing with moister air are similarly
important. Liquid and mixed phase cloud formation contribute to the
variability of δ2H and deuterium excess, especially over continental
Europe. In summary, the presented method helps to better understand the
linkage between the meteorological history of air parcels and their isotopic
composition, and may support the interpretation of stable water isotope
measurements in future.
Climate pattern-scaling set for an ensemble of 22 GCMs – adding uncertainty to the IMOGEN version 2.0 impact system
Authors: Zelazowski Przemyslaw , Huntingford Chris , Mercado Lina M. , Schaller Nathalie 
Published: February 2018

Abstract. Global circulation models (GCMs) are the best tool to understand
climate change, as they attempt to represent all the important Earth
system processes, including anthropogenic perturbation through
fossil fuel burning. However, GCMs are computationally very
expensive, which limits the number of simulations that can be
made. Pattern scaling is an emulation technique that takes advantage
of the fact that local and seasonal changes in surface climate are
often approximately linear in the rate of warming over land and
across the globe. This allows interpolation away from a limited number of
available GCM simulations, to assess alternative future emissions
scenarios. In this paper, we present a climate pattern-scaling set
consisting of spatial climate change patterns along with parameters
for an energy-balance model that calculates the amount of global
warming. The set, available for download, is derived from 22 GCMs of
the WCRP CMIP3 database, setting the basis for similar eventual
pattern development for the CMIP5 and forthcoming CMIP6
ensemble. Critically, it extends the use of the IMOGEN (Integrated
Model Of Global Effects of climatic aNomalies) framework to enable
scanning across full uncertainty in GCMs for impact studies. Across
models, the presented climate patterns represent consistent global
mean trends, with a maximum of 4 (out of 22) GCMs exhibiting
the opposite sign to the global trend per variable (relative
humidity). The described new climate regimes are generally warmer,
wetter (but with less snowfall), cloudier and windier, and have
decreased relative humidity. Overall, when averaging individual
performance across all variables, and without considering
co-variance, the patterns explain one-third of regional change in
decadal averages (mean percentage variance explained, PVE, 34.25±5.21), but the signal in some models exhibits much more
linearity (e.g. MIROC3.2(hires): 41.53) than in others (GISS_ER:
22.67). The two most often considered variables, near-surface
temperature and precipitation, have a PVE of 85.44±4.37 and
14.98±4.61, respectively. We also provide an example
assessment of a terrestrial impact (changes in mean runoff) and
compare projections by the IMOGEN system, which has one land surface
model, against direct GCM outputs, which all have alternative
representations of land functioning. The latter is noted as an
additional source of uncertainty. Finally, current and potential
future applications of the IMOGEN version 2.0 modelling system in the
areas of ecosystem modelling and climate change impact assessment
are presented and discussed.
Effectiveness of Operationalized Gestalt Therapy Role-Playing in the Treatment of Phobic Behaviors
Authors: Martinez Mario E. 
Published: February 2018

Abstract
The Gestalt therapy role-playing technique applied to dreams is based on the assumption that unwarranted avoidance behaviors in a dream are maintained by failing to recognize that the aversive properties attributed or projected to avoided stimuli are self-created. This study extrapolates that the recognition of these projections through the Gestalt role-playing technique can also reduce avoidance in phobic behavior. Twenty-four participants with phobias of long duration were randomly assigned to three groups with operationalized components of the role-playing technique that varied as follows: full treatment (FT) role-playing both the phobic responses and the aversive properties attributed to the phobic stimulus; stimulus role-playing (SRP) role-playing only the aversive properties attributed to the phobic stimulus; and response role-playing (RRP) role-playing only the phobic responses. Across several measures, the two groups that role-played the aversive properties attributed to the phobic stimulus (FT and SRP) were significantly more effective in reducing their phobias than the RRP group, which only role-played the phobic responses. Results are interpreted as support for the Gestalt therapy projections construct. Furthermore, the cognitive restructuring related to the reduction of a phobic response may be achieved more effectively through an abbreviated role-playing technique that focuses on reenacting the aversive properties attributed to the phobic stimulus rather than on the phobic response.
Trends in prevalence of obesity and hypertension in an urban Congolese community
Authors: MP Bayauli , JR M'Buyamba-Kayamba , NG Ngoyi , BF Lepira , KP Kayembe , D Lemogoum , MN Buila , L Thijs , MS Ditu , R Fagard , JP Degaute , P Van Den Borne , JA Staessen , JR M'Buyamba-Kabangu 
Published: February 2018

Objective: To assess trends over time in the prevalence of overweight/obesity and hypertension among adult Congolese people.Methods: Data from 1292 inhabitants of an urban Congolese community collected in 2007-8 were confronted to observations from a 1983-4 survey of 424 participants from the same location. Prevalence of overweight/obesity and hypertension was directly standardized for gender and age. We modeled the risk of hypertension in a multivariable logistic regression analysis including the participants from the two periods and a dummy variable (coded 0 for 1983-4, 1 for 2007-8).Results: Gender distribution was similar in 2007-8 and 1983-4 with women representing 56.6% and 55.2% of the participants, respectively. Age averaged 37±15 years in 2007-8 vs. 33±12 years in 1983-4 (P˂.0001). Crude prevalence of overweight/obesity (26.7 vs 42.3%; P<.0001) and hypertension (21.5% vs. 30.9%; P=.0002) was higher in 2007-8. The 2007-8 prevalence of overweight/obesity was 15.6%, 14.2% and 16.8% higher respectively for all subjects, women and men. The respective differences were 9.4%, 16.7% and 0.3% for hypertension. Overweight/obesity predominated among women at both periods, hypertension among men in 1983-4 with a trend in women at the latter period. The gender-age directly standardized prevalence was higher in 2007-8 for overweight/obesity [28.4(24.1–32.7)% vs. 41.3(38.8–43.7)%] and borderline for hypertension [24.9(20–28.9)% vs. 29.7(27.4–31.9)%]. The 1983-4/2007-8 risk ratio was 0.69 for overweight/obesity (P<.0001), 0.84 for hypertension (P=.054). Awareness, treatment and control of hypertension were higher in 2007-8 for all subjects and women, not for men. They were similar in both genders in 1983-4 but higher among women in 2007-8. In the logistic model including participants from both periods, the risk of hypertension increased with gender (OR for men vs women: 1.47 [95% CI:1.14–1.88]; P=.0029), age (for age ≥ 45 years: 5.62 [4.37–7.23]; P<.0001), overweight/obesity (present vs absent; 2.27 [1.77–2.91]; P<.0001) and pulse rate (for each 10 beats/min: 1.20 [1.08–1.32]; P=.0005); the risk was 35% higher in 2007-8 compared to 1983-4 (OR:1.35;95% CI:1.01–1.80; P=.0416).Conclusion: The data highlight the increment overtime in the prevalence of hypertension and overweight/obesity among adult urban Congolese dwellers whose global cardiovascular risk is rather high. Control of these features should be considered mandatory for prevention of cardiovascular diseases.
Oxygen Isotope Composition of Arctica islandica Aragonite in the Context of Shell Architectural Organization: Implications for Paleoclimate Reconstructions
Authors: Trofimova Tamara , Milano Stefania , Andersson Carin , Bonitz Fabian G. W. , Schöne Bernd R. 
Published: February 2018

AbstractThe analysis of the stable isotopic composition of bivalve shells provides the data needed to construct climate records at high temporal resolution. Yet, the reproducibility of the results and the effect of microstructural organization on the isotopic signature and measurements have not been extensively studied. Here, we examine the architectural changes within Arctica islandica shells, specifically if samples from microstructurally different shell layers differ in respect to stable oxygen isotope values. The oxygen isotope profiles of two microstructurally different shell layers, each sampled at different temporal resolution, were compared to each other. Our results show that aragonite, collected from the layer that is dominated by cross‐acicular/lamellar structures, tends to be enriched in heavier oxygen isotopes compared to samples from portions of the outer shell layer dominated by homogeneous microstructure. In some cases, this difference exceeded 0.3 ‰, which can significantly affect the interpretation of a recorded environmental signal. Observed differences in stable oxygen isotope data may be associated with the physiology of the mollusk and the physical and chemical composition of studied shell layers.
Satellite Observations of Stratospheric Gravity Waves Associated With the Intensification of Tropical Cyclones
Authors: Hoffmann Lars , Wu Xue , Alexander M. Joan 
Published: February 2018

AbstractForecasting the intensity of tropical cyclones is a challenging problem. Rapid intensification is often preceded by the formation of “hot towers” near the eyewall. Driven by strong release of latent heat, hot towers are high‐reaching tropical cumulonimbus clouds that penetrate the tropopause. Hot towers are a potentially important source of stratospheric gravity waves. Using 13.5 years (2002–2016) of Atmospheric Infrared Sounder observations of stratospheric gravity waves and tropical cyclone data from the International Best Track Archive for Climate Stewardship, we found empirical evidence that stratospheric gravity wave activity is associated with the intensification of tropical cyclones. The Atmospheric Infrared Sounder and International Best Track Archive for Climate Stewardship data showed that strong gravity wave events occurred about twice as often for tropical cyclone intensification compared to storm weakening. Observations of stratospheric gravity waves, which are not affected by obscuring tropospheric clouds, may become an important future indicator of storm intensification.
Fat Plumes May Reflect the Complex Rheology of the Lower Mantle
Authors: Davaille A. , Carrez Ph. , Cordier P. 
Published: February 2018

AbstractRecent tomographic imaging of the mantle below major hot spots shows slow seismic velocities extending down to the core‐mantle boundary, confirming the existence of mantle plumes. However, these plumes are much thicker than previously thought. Using new laboratory experiments and scaling laws, we show that thermal plumes developing in a visco‐plastic fluid present much larger diameters than plumes developing in a Newtonian fluid. Such a rheology requiring a yield stress is consistent with a lower mantle predominantly deforming by pure dislocation climb. Yield stress values between 1 and 10 MPa, implying dislocation densities between 108 and 1010 m−2, would be sufficient to reproduce the plumes morphology observed in tomographic images.
Ionospheric Variability Due to Tides and Quasi‐Two Day Wave Interactions
Authors: Gu Sheng‐Yang , Liu Han‐Li , Dou Xiankang , Jia Mingjiao 
Published: February 2018

AbstractThe ionospheric variabilities due to planetary waves (PWs) are complicated due to their nonlinear interaction with tides (migrating diurnal and semidiurnal tides [DW1 and SW2]) in the mesosphere and lower thermosphere region. The quasi‐two day wave (QTDW) is the most dominant oscillation during austral summer period except tides. This paper quantitatively studies the contribution of W3 QTDW, secondary PWs generated by the QTDW‐tide interaction, and the change of tides to the ionospheric vertical drift variabilities. It is found that the secondary PWs generated by the QTDW‐DW1 interaction (16 hr W4 and 48 hr E2) contribute more to the ionospheric variability than those generated by the QTDW‐SW2 interaction (9.6 hr W5 and 16 hr E1). The latitudinal distribution of the vertical drift induced by tides and PWs varies due to their different wind structures. The vertical drift induced by DW1 is weakened at all latitudes due to the existence of W3 QTDW, whereas the SW2‐induced vertical drift is enhanced at low latitudes and decreased at middle latitudes. The W3 QTDW induces weaker vertical drift in the equatorial region than that induced by 16 hr W4, 48 hr E2, and the change of tides. At middle latitudes, the vertical drift induced by W3 QTDW is slightly stronger than that induced by 48 hr E2 and the change of DW1 but is comparable to that induced by 16 hr W4 and the change of SW2. Our simulations show that the changes of tidal amplitudes and secondary PWs are as important as the QTDW itself to the day‐to‐day ionospheric variabilities.
Three‐Dimensional Dynamics of Baroclinic Tides Over a Seamount
Authors: Vlasenko Vasiliy , Stashchuk Nataliya , Nimmo‐Smith W. Alex M. 
Published: February 2018

AbstractThe Massachusetts Institute of Technology general circulation model is used for the analysis of baroclinic tides over Anton Dohrn Seamount (ADS), in the North Atlantic. The model output is validated against in situ data collected during the 136th cruise of the RRS “James Cook” in May–June 2016. The observational data set includes velocity time series recorded at two moorings as well as temperature, salinity, and velocity profiles collected at 22 hydrological stations. Synthesis of observational and model data enabled the reconstruction of the details of baroclinic tidal dynamics over ADS. It was found that the baroclinic tidal waves are generated in the form of tidal beams radiating from the ADS periphery to its center, focusing tidal energy in a surface layer over the seamount's summit. This energy focusing enhances subsurface water mixing and the local generation of internal waves. The tidal beams interacting with the seasonal pycnocline generate short‐scale internal waves radiating from the ADS center. An important ecological outcome from this study concerns the pattern of residual currents generated by tides. The rectified flows over ADS have the form of a pair of dipoles, cyclonic and anticyclonic eddies located at the seamount's periphery. These eddies are potentially an important factor in local larvae dispersion and their escape from ADS.
Extreme Marine Warming Across Tropical Australia During Austral Summer 2015–2016
Authors: Benthuysen Jessica A. , Oliver Eric C. J. , Feng Ming , Marshall Andrew G. 
Published: February 2018

AbstractDuring austral summer 2015–2016, prolonged extreme ocean warming events, known as marine heatwaves (MHWs), occurred in the waters around tropical Australia. MHWs arose first in the southeast tropical Indian Ocean in November 2015, emerging progressively east until March 2016, when all waters from the North West Shelf to the Coral Sea were affected. The MHW maximum intensity tended to occur in March, coinciding with the timing of the maximum sea surface temperature (SST). Large areas were in a MHW state for 3–4 months continuously with maximum intensities over 2°C. In 2016, the Indonesian‐Australian Basin and areas including the Timor Sea and Kimberley shelf experienced the longest and most intense MHW from remotely sensed SST dating back to 1982. In situ temperature data from temperature loggers at coastal sites revealed a consistent picture, with MHWs appearing from west to east and peaking in March 2016. Temperature data from moorings, an Argo float, and Slocum gliders showed the extent of warming with depth. The events occurred during a strong El Niño and weakened monsoon activity, enhanced by the extended suppressed phase of the Madden‐Julian Oscillation. Reduced cloud cover in January and February 2016 led to positive air‐sea heat flux anomalies into the ocean, predominantly due to the shortwave radiation contribution with a smaller additional contribution from the latent heat flux anomalies. A data‐assimilating ocean model showed regional changes in the upper ocean circulation and a change in summer surface mixed layer depths and barrier layer thicknesses consistent with past El Niño events.
New Parametrization for Heat Transport Through Diffusive Convection Interface
Authors: Guo Shuang‐Xi , Cen Xian‐Rong , Zhou Sheng‐Qi 
Published: February 2018

AbstractA laboratory experiment of two‐layer diffusive convection (DC) within a rectangular cell is reported. The run‐down evolution of two mixed layers and their interface is exhibited by the temperature and salinity structures, where the interface thicknesses of temperature and salinity increase with time as
and
. Heat flux across the interface is respectively evaluated in terms of the heat energy conservation and the assumption of conductive interface. Both of them give the consistent heat flux values. When the 4/3 scaling between heat flux
and temperature difference across the interface
holds (
, where
is function of density ratio
), previous heat flux parameterizations are found to have low coefficient of determination (
) with our heat flux data within
. Heat flux is proposed to be a power law function of
, and the best fitting is
, resulting in r2 as high as 0.74. By using all available heat flux data over a wide
range (1.2–27.6), including those collected in previous literatures,
is revised as
accompanied by
and a reduced chi‐square
. Alternatively,
can be derived from previous DC layer thickness parameterization, which is expressed as
. This formula is also superior to previous parameterizations in the evaluation of heat flux, indicated by high r2 and low
.
Mechanisms of the 40–70 Day Variability in the Yucatan Channel Volume Transport
Authors: van Westen René M. , Dijkstra Henk A. , Klees Roland , Riva Riccardo E. M. , Slobbe D. Cornelis , van der Boog Carine G. , Katsman Caroline A. , Candy Adam S. , Pietrzak Julie D. , Zijlema Marcel , James Rebecca K. , Bouma Tjeerd J. 
Published: February 2018

AbstractThe Yucatan Channel connects the Caribbean Sea with the Gulf of Mexico and is the main outflow region of the Caribbean Sea. Moorings in the Yucatan Channel show high‐frequent variability in kinetic energy (50–100 days) and transport (20–40 days), but the physical mechanisms controlling this variability are poorly understood. In this study, we show that the short‐term variability in the Yucatan Channel transport has an upstream origin and arises from processes in the North Brazil Current. To establish this connection, we use data from altimetry and model output from several high resolution global models. A significant 40–70 day variability is found in the sea surface height in the North Brazil Current retroflection region with a propagation toward the Lesser Antilles. The frequency of variability is generated by intrinsic processes associated with the shedding of eddies, rather than by atmospheric forcing. This sea surface height variability is able to pass the Lesser Antilles, it propagates westward with the background ocean flow in the Caribbean Sea and finally affects the variability in the Yucatan Channel volume transport.
June 2017: The Earliest European Summer Mega‐heatwave of Reanalysis Period
Authors: Sánchez‐Benítez A. , García‐Herrera R. , Barriopedro D. , Sousa P. M. , Trigo R. M. 
Published: February 2018

AbstractThis paper examines the characteristics of the heatwave that affected western and central Europe in June 2017. Using a novel algorithm, we show that its extension, intensity, and persistence were comparable to those of other European mega‐heatwaves, but it occurred earlier in the summer. The most affected area was Iberia, which experienced devastating forest fires with human casualties and the warmest temperatures of the reanalysis period from daily to seasonal scales. The peak of the mega‐heatwave displayed an unprecedented warm air intrusion due to a record‐breaking subtropical ridge with signatures closer to those of July and August. The atmospheric circulation was the main triggering factor of the event. However, thermodynamical changes of the last decades made a substantial contribution to the event, by increasing the likelihood of surpassing high‐temperature thresholds. This episode could be a good example of a coming future, with high‐summer mega‐heatwaves occurring earlier.