bluuebunny/crossref_metadata_2025_split huggingface dataset:
Compensation between Model Feedbacks and Curtailment of Climate Sensitivity
Authors: Huybers Peter 
Published: February 2010

AbstractThe spread in climate sensitivity obtained from 12 general circulation model runs used in the Fourth Assessment of the Intergovernmental Panel on Climate Change indicates a 95% confidence interval of 2.1°–5.5°C, but this reflects compensation between model feedbacks. In particular, cloud feedback strength negatively covaries with the albedo feedback as well as with the combined water vapor plus lapse rate feedback. If the compensation between feedbacks is removed, the 95% confidence interval for climate sensitivity expands to 1.9°–8.0°C. Neither of the quoted 95% intervals adequately reflects the understanding of climate sensitivity, but their differences illustrate that model interdependencies must be understood before model spread can be correctly interpreted.The degree of negative covariance between feedbacks is unlikely to result from chance alone. It may, however, result from the method by which the feedbacks were estimated, physical relationships represented in the models, or from conditioning the models upon some combination of observations and expectations. This compensation between model feedbacks—when taken together with indications that variations in radiative forcing and the rate of ocean heat uptake play a similar compensatory role in models—suggests that conditioning of the models acts to curtail the intermodel spread in climate sensitivity. Observations used to condition the models ought to be explicitly stated, or there is the risk of doubly calling on data for purposes of both calibration and evaluation. Conditioning the models upon individual expectation (e.g., anchoring to the Charney range of 3° ± 1.5°C), to the extent that it exists, greatly complicates statistical interpretation of the intermodel spread.
Changes in Characteristics of Late-Summer Precipitation over Eastern China in the Past 40 Years Revealed by Hourly Precipitation Data
Authors: Yu Rucong , Li Jian , Yuan Weihua , Chen Haoming 
Published: February 2010

Abstract
Using hourly station rain gauge data during 1966–2005, the authors studied changes in the characteristics of the late-summer (July–August) rainfall, which has exhibited a so-called southern flooding and northern drought (SFND) pattern over eastern China in recent decades. Although the rainfall amount and frequency have significantly increased (decreased) in the mid–lower reaches of the Yangtze River valley (North China) during this period, the rainfall intensity has decreased (increased). This finding differs from previous results based on daily data, which showed that the rainfall intensity has increased in the mid–lower reaches of the Yangtze River valley. In this region, the mean rainfall hours on rainy days have increased because of the prolonged rainfall duration, which has led to an increased daily rainfall amount and to a decreased hourly rainfall intensity. Results also show that the SFND pattern is mostly attributed to changes in precipitation with moderate and low intensity (≤10 mm h−1), which contributes 65% (96%) of rainfall amount to the “flooding” (“drought”) in the mid–lower reaches of the Yangtze River valley. Neither frequency nor amount of strong intensity (&gt;20 mm h−1) rainfall exhibits the SFND pattern.
Multisensor Precipitation Reanalysis
Authors: Nelson Brian R. , Seo D-J. , Kim Dongsoo 
Published: February 2010

Abstract
Temporally consistent high-quality, high-resolution multisensor precipitation reanalysis (MPR) products are needed for a wide range of quantitative climatological and hydroclimatological applications. Therefore, the authors have reengineered the multisensor precipitation estimator (MPE) algorithms of the NWS into the MPR package. Owing to the retrospective nature of the analysis, MPR allows for the utilization of additional rain gauge data, more rigorous automatic quality control, and post factum correction of radar quantitative precipitation estimation (QPE) and optimization of key parameters in multisensor estimation. To evaluate and demonstrate the value of MPR, the authors designed and carried out a set of cross-validation experiments in the pilot domain of North Carolina and South Carolina. The rain gauge data are from the reprocessed Hydrometeorological Automated Data System (HADS) and the daily Cooperative Observer Program (COOP). The radar QPE data are the operationally produced Weather Surveillance Radar-1988 Doppler digital precipitation array (DPA) products. To screen out bad rain gauge data, quality control steps were taken that use rain gauge and radar data. The resulting MPR products are compared with the stage IV product on a daily scale at the withheld COOP gauge locations. This paper describes the data, the MPR procedure, and the validation experiments, and it summarizes the findings.
Performance Metrics for Soil Moisture Retrievals and Application Requirements
Authors: Entekhabi Dara , Reichle Rolf H. , Koster Randal D. , Crow Wade T. 
Published: February 2010

Abstract
Quadratic performance metrics such as root-mean-square error (RMSE) and time series correlation are often used to assess the accuracy of geophysical retrievals (satellite measurements) with respect to true fields. These metrics are related; nevertheless, each has advantages and disadvantages. In this study the authors explore the relation between the RMSE and correlation metrics in the presence of biases in the mean as well as in the amplitude of fluctuations (standard deviation) between estimated and true fields. Such biases are common, for example, in satellite retrievals of soil moisture and impose constraints on achievable and meaningful RMSE targets. Last, an approach is introduced for converting a requirement in an application’s product into a corresponding requirement for soil moisture accuracy. The approach can help with the formulation of soil moisture measurement requirements. It can also help determine the utility of a given retrieval product for applications.
The Three-Dimensional Steady Circulation in a Homogenous Ocean Induced by a Stationary Hurricane
Authors: Lu Zhu Min , Huang Rui Xin 
Published: February 2010

Abstract
Based on the classical Ekman layer theory, a simple analytical solution of the steady flow induced by a stationary hurricane in a homogenous ocean is discussed. The model consists of flow converging in an inward spiral in the deeper layer and diverging in the upper layer. The simple analytical model indicates that both the upwelling flux and the horizontal transport increase linearly with increasing radius of maximum winds. Furthermore, they both have a parabolic relationship with the maximum wind speed. The Coriolis parameter also affects the upwelling flux: the response to a hurricane is stronger at low latitudes than that at middle latitudes. Numerical solutions based on a regional version of an ocean general circulation model are similar to the primary results obtained through the analytical solution. Thus, the simplifications made in formulating the analytical solution are reasonable. Although the analytical solution in this paper is sought for a rather idealized ocean, it can help to make results from the more complicated numerical model understandable. These conceptual models provide a theoretical limit structure of the oceanic response to a moving hurricane over a stratified ocean.
Flux Attenuation due to Sensor Displacement over Sea
Authors: Nilsson Erik O. , Rutgersson Anna , Sullivan Peter P. 
Published: February 2010

AbstractWhen using the eddy correlation method to measure turbulent scalar fluxes, there is often a spatial separation between the instruments measuring the scalar and the vertical velocity. The attenuation of the flux due to this separation is studied here for marine conditions. Measurements of a two-point covariance between vertical velocity and temperature are compared to covariance measurements from collocated sensors for both horizontal and vertical displacements, with the purpose of finding the approximate functions to describe the flux loss for typical separation distances. On the basis of this study’s measurements, there is only a slight directional dependence (i.e., streamwise or crosswind separation) of the flux loss for sensor separation distances less than 1 m but an increasing dependence with increasing displacement distance. For a vertical displacement, observations from this study confirm that flux loss is less with the scalar sensor positioned below the velocity sensor than at an equal distance above. Furthermore, the data show a clear dependence on atmospheric stability with increasing flux loss for increasing stable stratification, but it is not as large as that found in previous studies of flux attenuation over land. For example, the authors compare estimated flux loss for neutral and moderately stable (z/L = 0.3) stratification at a measuring height of z = 10 m and a sensor displacement r = 0.3 m, where L is the Obukhov length. For neutral (stable, z/L = 0.3) stratification the estimated loss of flux is 3% (5%) of the total flux for horizontal displacement. Whereas for an equal vertical separation the estimates are 2% (4%) when the scalar sensor is placed above the anemometer but less than 1% (2%) if it is placed below. Thus, the authors conclude that placing the scalar sensor below the anemometer minimizes the flux loss due to sensor separation, and that a simple correction function can be used to quantify the mean flux loss due to sensor separation over sea.
A Model-Based Observation-Thinning Scheme for the Assimilation of High-Resolution SST in the Shelf and Coastal Seas around China
Authors: Li Xichen , Zhu Jiang , Xiao Yiguo , Wang Ruiwen 
Published: February 2010

Abstract
The use of high-density remote sensing buoys and ship-based observations play an increasingly crucial role in the operational assimilation and forecast of oceans. With the recent release of several high-resolution observation datasets, such as the Global Ocean Data Assimilation Experiment (GODAE) high-resolution SST (GHRSST) datasets, the development of observation-thinning schemes becomes important in the process of data assimilation because the huge quantity and dense spatial–temporal distributions of these datasets might make it expensive to assimilate the full dataset into ocean models or even decay the assimilation result. In this paper, an objective model simulation ensemble-based observation-thinning scheme is proposed and applied to a Chinese shelf–coastal seas eddy-resolving model. A successful thinning scheme should select a subset of observations yielding a small analysis error variance (AEV) while keeping the number of observations to as few as possible. In this study, the background error covariance (BEC) is estimated using the historical ensemble and then the subset of observations to minimize the AEV is selected, which is estimated from the Kalman theory. The authors used this method in the GHRSST product to cover the shelf and coastal seas around China and then verified the result with an estimation function and assimilation–forecast systems.
Major Extratropical Cyclones of the Northwest United States: Historical Review, Climatology, and Synoptic Environment
Authors: Mass Clifford , Dotson Brigid 
Published: February 2010

Abstract
The northwest United States is visited frequently by strong midlatitude cyclones that can produce hurricane-force winds and extensive damage. This article reviews these storms, beginning with a survey of the major events of the past century. A climatology of strong windstorms is presented for the area from southern Oregon to northern Washington State and is used to create synoptic composites that show the large-scale evolution associated with such storms. A recent event, the Hanukkah Eve Storm of December 2006, is described in detail, with particular attention given to the impact of the bent-back front/trough and temporal changes in vertical stability and structure. The discussion section examines the general role of the bent-back trough, the interactions of such storms with terrain, and the applicability of the “sting jet” conceptual model. A conceptual model of the evolution of Northwest windstorm events is presented.
Role of Diurnal Warm Layers in the Diurnal Cycle of Convection over the Tropical Indian Ocean during MISMO
Authors: Bellenger H. , Takayabu Y. N. , Ushiyama T. , Yoneyama K. 
Published: February 2010

Abstract
The role of air–sea interaction in the diurnal variations of convective activity during the suppressed and developing stages of an intraseasonal convective event is analyzed using in situ observations from the Mirai Indian Ocean cruise for the Study of the Madden–Julian oscillation (MJO)-convection Onset (MISMO) experiment. For the whole period, convection shows a clear average diurnal cycle with a primary maximum in the early morning and a secondary one in the afternoon. Episodes of large diurnal sea surface temperature (SST) variations are observed because of diurnal warm layer (DWL) formation. When no DWL is observed, convection exhibits a diurnal cycle characterized by a maximum in the early morning, whereas when DWL forms, convection increases around noon and peaks in the afternoon. Boundary layer processes are found to control the diurnal evolution of convection. In particular, when DWL forms, the change in surface heat fluxes can explain the decrease of convective inhibition and the intensification of the convection during the early afternoon.
Repair versus Reconstruction of the Fibular Collateral Ligament and Posterolateral Corner in the Multiligament-Injured Knee
Authors: Levy Bruce A. , Dajani Khaled A. , Morgan Joseph A. , Shah Jay P. , Dahm Diane L. , Stuart Michael J. 
Published: February 2010

Background Treatment of the multiligament-injured knee remains controversial. Purpose To compare clinical and functional outcomes of a consecutive series of multiligament-injured knees that underwent repair of the fibular collateral ligament (FCL) and posterolateral corner (PLC), followed by delayed cruciate ligament reconstructions, with those that had single-stage multiligament reconstruction. Study Design Cohort study; Level of evidence, 3. Methods Patients with multiligament knee injury treated by a single surgeon were identified in our prospective database. Between February 2004 and May 2005, patients underwent repair of medial- and lateral-sided injuries, followed by delayed cruciate ligament reconstructions. Between May 2005 and February 2007, patients underwent single-stage multiligament knee reconstruction. All patients followed a standard rehabilitation protocol. Inclusion criteria were minimum 2-year follow-up and multiligament knee injury including the FCL/PLC. International Knee Documentation Committee subjective and Lysholm scores and objective clinical data were documented. Results We identified 45 knees (42 patients); 17 knees (14 patients) were excluded, leaving 28 knees (28 patients) in the study. The repair/staged group (10 knees in 10 patients) had a mean follow-up of 34 months (range, 24-49 months). The reconstruction group (18 knees in 18 patients) had a mean follow-up of 28 months (range, 24-41 months). Four of the 10 FCL/PLC repairs (40%) and 1 of the 18 FCL/PLC reconstructions (6%) failed (P = .04). After revision reconstructions, there were no statistically significant differences between mean International Knee Documentation Committee subjective scores (79 vs. 77, P = .92) and mean Lysholm scores (85 vs 88, P = .92). Regression analysis showed no effect on failure based on age, sex, injury mechanism, time to surgery, interval between stages, total number of ligaments injured, or location of tear. Conclusion Our series demonstrated a statistically significant higher rate of failure for repair compared with reconstruction of the FCL/PLC. Reconstruction of the FCL/PLC structures is a more reliable option than repair alone in the setting of a multiligament knee injury.
Assessment of Bone Quality within the Tuberosities of the Osteoporotic Humeral Head
Authors: Kirchhoff Chlodwig , Braunstein Volker , Milz Stefan , Sprecher Christoph M. , Fischer Florian , Tami Andrea , Ahrens Philipp , Imhoff Andreas B. , Hinterwimmer Stefan 
Published: February 2010

Background Tears of the rotator cuff are highly prevalent in patients older than 60 years, thereby presenting a population also suffering from osteopenia or osteoporosis. Suture fixation in the bone depends on the holding strength of the anchoring technique, whether a bone tunnel or suture anchor is selected. Because of osteopenic or osteoporotic bone changes, suture anchors in the older patient might pull out, resulting in failure of repair. Hypothesis The aim of our study was to analyze the bone quality within the tuberosities of the osteoporotic humeral head using high-resolution quantitative computed tomography (HR-pQCT). Study Design Descriptive laboratory study. Methods Thirty-six human cadaveric shoulders were analyzed using HR-pQCT. The mean bone volume to total volume (BV/TV) as well as trabecular bone mineral densities (trabBMDs) of the greater tuberosity (GT) and the lesser tuberosity (LT) were determined. Within the GT, 6 volumes of interest (VOIs) within the LT, and 2 VOIs and 1 control volume within the subchondral area beyond the articular surface were set. Results Comparing BV/TV of the medial and the lateral row, significantly higher values were found medially (P < .001). The highest BV/TV, 0.030% ± 0.027%, was found in the posteromedial portion of the GT (P < .05). Regarding the analysis of the LT, no difference was found comparing the superior (BV/TV: 0.024% ± 0.022%) and the inferior (BV/TV: 0.019% ± 0.016%) portion. Analyzing trabBMD, equal proportions were found. An inverse correlation with a correlation coefficient of —0.68 was found regarding BV/TV of the posterior portion of the GT and age (P < .05). Conclusion Significant regional differences of trabecular microarchitecture were found in our HR-pQCT study. The volume of highest bone quality resulted for the posteromedial aspect of the GT. Moreover, a significant correlation of bone quality within the GT and age was found, while the bone quality within the LT seems to be independent from it. Clinical Relevance The shape of the rotator cuff tear largely determines the bony site of tendon reattachment, although the surgeon has distinct options to modify anchor positioning. According to our results, placement of suture anchors in a medialized way at the border to the articular surface might guarantee a better structural bone stock.
Preliminary studies on human aldosterone synthase (CYP11B2) gene polymorphism, matrix metalloprotease-9, apoptosis, and carotid atherosclerosis plaque size by proton magnetic resonance imaging
Authors: Sharma Rakesh , Katz Jose 
Published: February 2010

Hypothesis. Aldosterone has direct or indirect effects on atherosclerosis, and polymorphisms occur in the gene encoding aldosterone synthase (CYP11B2), the enzyme catalysing aldosterone biosynthesis. Genetic variations in aldosterone synthesis may influence progression of carotid atherosclerosis. Materials and methods. Ten subjects were genotyped through the use of the polymerase chain reaction for two diallelic polymorphisms in CYP11B2: one in the transcriptional regulatory region (promotor) and the other in the second intron. In vivo plaque size was estimated by H-1 magnetic resonance imaging using gradient echo pulse sequence. Media-intima thickness and ex vivo plaque in endarterectomy samples were measured by histology. Matrix metalloprotease (MMP)-9 was stained in endarterectomy histology sections and apoptosis index was counted in these sections. Results. The CYP11B2 promoter genotype patterns were associated significantly with the plaque size in carotid artery (r2=0.9987; p=0.001), MMP-9 levels (r 2=0.9878; p=0.0001) and apoptotic indices (r2=0.9495; p=0.005) by multiple regression analysis. The media-intima thickness was not significantly correlated with genotype patterns. Conclusion. Genetic variations in aldosterone synthase (CYP11B2) gene are associated with the progression of atherosclerotic plaque size, MMP-9 and apoptosis in the carotid artery.
Climatic changes during the Pliocene as observed from climate-sensitive rocks and clay minerals of the Sedom formation, the Dead Sea Basin
Authors: Shoval S. , Zlatkin O. 
Published: February 2010

AbstractThe climatic history of the Dead Sea region during the Pliocene and its global connection are observed from climate-sensitive rocks and clay minerals of the Sedom formation. The Sedom formation consists of evaporative halitic rock salt units and calcareous shale units that were deposited in the Dead Sea Basin during the Pliocene. The precipitation of the rock salts took place in the hypersaline sabkha environment of the Sedom Lagoon. The extensive evaporative conditions are related to an extremely dry and warm arid climate at that time. In the arid climate, the influx of meteoric water by the drainage system of the Sedom Lagoon was limited and permitted a large concentration of lagoonal brine as well as a small rate of detritus transportation to the lagoon. Accessory sepiolite found in the rock salt appears to be neoformed from brine enriched with Mg and poor in Al under the extreme salinity condition. The small amounts of Al are in accordance with the small number of detrital minerals in the rock salts. The replacement in the deposition of the rock salt members with the calcareous shale members demonstrates a decrease in the salinity of the brine in the Sedom Basin and an increase in the deposition of detritus. The change in conditions was related to a period of deposition under a more humid climate where the erosion and the transport of detritus by the drainage system to the Sedom Basin was higher, causing the deposition of calcareous shales. Palygorskite found in the calcareous shales appears to be neoformed from brine enriched with Mg and containing Al in conditions of reduced salinity of the Sedom Basin. The larger amounts of Al are in accordance with the abundance of detrital minerals in the calcareous shales.The depositional cycles of the Sedom formation, the cyclic fluctuation of the climatic-hydrologic conditions from an arid to a more humid climate and their correlation with sea-level fluctuations and transgression-regression cycles of the Mediterranean Sea seem to be a response to corresponding global interglacial and glacial periods during the Pliocene.
Removal of heavy metal ions from wastewaters using natural clays
Authors: Bedelean H. , Măicăneanu A. , Burcă S. , Stanca M. 
Published: February 2010

AbstractA bentonite sample from the Petreş ti deposit, Cluj County (Romania), was used to remove heavy-metal ions (Cd2+, Pb2+, Cr3+) from wastewaters. A representative sample of bentonite (P) was characterized using the Brunauer-Emmett-Teller (BET) method, wet chemical analyses, X-ray diffraction (XRD) and Fourier-transform infrared (FTIR) spectroscopy. The bentonite deposit from Petreş ti is present at the contact between Upper Jurassic limestones and basaltic andesites with subordinate basalt bodies. These rocks are composed of clay minerals (mainly smectite), with opal, quartz, feldspar and mica/illite as minor phases. The bentonite sample was used in powdered form (d< 0.2 mm) without any chemical treatment. The influence of the working regime, static and dynamic, on the process efficiency was studied using monocomponent synthetic wastewaters containing Cd, Pb and Cr ions. The bentonite sample proved to be efficient for the removal of these heavy-metal ions; removal efficiencies up to 100% (lead removal) were achieved.