bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effects of SST-Induced Surface Wind Speed and Direction Gradients on Midlatitude Surface Vorticity and Divergence
Authors: O’Neill Larry W. , Chelton Dudley B. , Esbensen Steven K. 
Published: June 2009

Abstract
The effects of surface wind speed and direction gradients on midlatitude surface vorticity and divergence fields associated with mesoscale sea surface temperature (SST) variability having spatial scales of 100–1000 km are investigated using vector wind observations from the SeaWinds scatterometer on the Quick Scatterometer (QuikSCAT) satellite and SST from the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) Aqua satellite. The wind–SST coupling is analyzed over the period June 2002–August 2008, corresponding to the first 6+ years of the AMSR-E mission. Previous studies have shown that strong wind speed gradients develop in response to persistent mesoscale SST features associated with the Kuroshio Extension, Gulf Stream, South Atlantic, and Agulhas Return Current regions. Midlatitude SST fronts also significantly modify surface wind direction; the surface wind speed and direction responses to typical SST differences of about 2°–4°C are, on average, about 1–2 m s−1 and 4°–8°, respectively, over all four regions. Wind speed perturbations are positively correlated and very nearly collocated spatially with the SST perturbations. Wind direction perturbations, however, are displaced meridionally from the SST perturbations, with cyclonic flow poleward of warm SST and anticyclonic flow poleward of cool SST.
Previous observational analyses have shown that small-scale perturbations in the surface vorticity and divergence fields are related linearly to the crosswind and downwind components of the SST gradient, respectively. When the vorticity and divergence fields are analyzed in curvilinear natural coordinates, the wind speed contributions to the SST-induced vorticity and divergence depend equally on the crosswind and downwind SST gradients, respectively. SST-induced wind direction gradients also significantly modify the vorticity and divergence fields, weakening the vorticity response to crosswind SST gradients while enhancing the divergence response to downwind SST gradients.
The Influence of Solar Forcing on Tropical Circulation
Authors: Lee Jae N. , Shindell Drew T. , Hameed Sultan 
Published: June 2009

AbstractThe response of the seasonal tropical circulation to an 11-yr solar cycle forcing is studied with the Goddard Institute for Space Studies (GISS) ModelE, which includes fully interactive atmospheric chemistry. To identify characteristic solar signals in the tropical circulation, the model experiments are carried out with certain imposed conditions: a doubly amplified solar forcing and the present-day and preindustrial greenhouse gases and aerosol conditions, with the mixed layer or fully coupled dynamic ocean model. In both the model and the NCEP reanalysis, tropical humidity increases in response to enhanced solar irradiance are found to be statistically significant in both solstice seasons. Changes are also found in the vertical velocities for both the Hadley and Walker circulations in some areas of the Pacific region. With present-day greenhouse gas and aerosol conditions, the ascending branch of the Hadley cell is enhanced near the equator, and the intertropical convergence zone (ITCZ) is shifted northward in response to solar forcing during the boreal winter. Enhancement of the meridionally averaged vertical velocity over the western Pacific indicates strengthening of the Walker circulation in response to solar forcing in both solstice seasons. In present-day conditions, the tropical circulation response to an 11-yr solar forcing is generally consistent with that derived from previous observational works.
Historical SAM Variability. Part II: Twentieth-Century Variability and Trends from Reconstructions, Observations, and the IPCC AR4 Models*
Authors: Fogt Ryan L. , Perlwitz Judith , Monaghan Andrew J. , Bromwich David H. , Jones Julie M. , Marshall Gareth J. 
Published: June 2009

Abstract
This second paper examines the Southern Hemisphere annular mode (SAM) variability from reconstructions, observed indices, and simulations from 17 Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) models from 1865 to 2005. Comparisons reveal the models do not fully simulate the duration of strong natural variability within the reconstructions during the 1930s and 1960s.
Seasonal indices are examined to understand the relative roles of forced and natural fluctuations. The models capture the recent (1957–2005) positive SAM trends in austral summer, which reconstructions indicate is the strongest trend during the last 150 yr; ozone depletion is the dominant mechanism driving these trends. In autumn, negative trends after 1930 in the reconstructions are stronger than the recent positive trend. Furthermore, model trends in autumn during 1957–2005 are the most different from observations. Both of these conditions suggest the recent autumn trend is most likely natural climate variability, with external forcing playing a secondary role. Many models also produce significant spring trends during this period not seen in observations. Although insignificant, these differences arise because of vastly different spatial structures in the Southern Hemisphere pressure trends. As the trend differences between models and observations in austral spring have been increasing over the last 30 yr, care must be exercised when examining the future SAM projections and their impacts in this season.
Relationships between Lightning Location and Polarimetric Radar Signatures in a Small Mesoscale Convective System
Authors: Lund Nicole R. , MacGorman Donald R. , Schuur Terry J. , Biggerstaff Michael I. , Rust W. David 
Published: June 2009

Abstract
On 19 June 2004, the Thunderstorm Electrification and Lightning Experiment observed electrical, microphysical, and kinematic properties of a small mesoscale convective system (MCS). The primary observing systems were the Oklahoma Lightning Mapping Array, the KOUN S-band polarimetric radar, two mobile C-band Doppler radars, and balloonborne electric field meters. During its mature phase, this MCS had a normal tripolar charge structure (lightning involved a midlevel negative charge between an upper and a lower positive charge), and flash rates fluctuated between 80 and 100 flashes per minute. Most lightning was initiated within one of two altitude ranges (3–6 or 7–10 km MSL) and within the 35-dBZ contours of convective cells embedded within the convective line. The properties of two such cells were investigated in detail, with the first lasting approximately 40 min and producing only 12 flashes and the second lasting over an hour and producing 105 flashes. In both, lightning was initiated in or near regions containing graupel. The upper lightning initiation region (7–10 km MSL) was near 35–47.5-dBZ contours, with graupel inferred below and ice crystals inferred above. The lower lightning initiation region (3–6 km MSL) was in the upper part of melting or freezing layers, often near differential reflectivity columns extending above the 0°C isotherm, which is suggestive of graupel formation. Both lightning initiation regions are consistent with what is expected from the noninductive graupel–ice thunderstorm electrification mechanism, though inductive processes may also have contributed to initiations in the lower region.
Voronoi, Delaunay, and Block-Structured Mesh Refinement for Solution of the Shallow-Water Equations on the Sphere
Authors: Weller Hilary , Weller Henry G. , Fournier Aimé 
Published: June 2009

Abstract
Alternative meshes of the sphere and adaptive mesh refinement could be immensely beneficial for weather and climate forecasts, but it is not clear how mesh refinement should be achieved. A finite-volume model that solves the shallow-water equations on any mesh of the surface of the sphere is presented. The accuracy and cost effectiveness of four quasi-uniform meshes of the sphere are compared: a cubed sphere, reduced latitude–longitude, hexagonal–icosahedral, and triangular–icosahedral. On some standard shallow-water tests, the hexagonal–icosahedral mesh performs best and the reduced latitude–longitude mesh performs well only when the flow is aligned with the mesh. The inclusion of a refined mesh over a disc-shaped region is achieved using either gradual Delaunay, gradual Voronoi, or abrupt 2:1 block-structured refinement. These refined regions can actually degrade global accuracy, presumably because of changes in wave dispersion where the mesh is highly nonuniform. However, using gradual refinement to resolve a mountain in an otherwise coarse mesh can improve accuracy for the same cost. The model prognostic variables are height and momentum collocated at cell centers, and (to remove grid-scale oscillations of the A grid) the mass flux between cells is advanced from the old momentum using the momentum equation. Quadratic and upwind biased cubic differencing methods are used as explicit corrections to a fast implicit solution that uses linear differencing.
The Drying Out of Soil Moisture following Rainfall in a Numerical Weather Prediction Model and Implications for Malaria Prediction in West Africa
Authors: Cui Xuefeng , Parker Douglas J. , Morse Andrew P. 
Published: June 2009

Abstract
This paper investigates the response of the land surface and the lowest section of the atmospheric surface layer to rainfall events and through the subsequent drying out period. The impacts of these sequences of rainfall and drying events in controlling near-surface temperatures are put into the context of malaria transmission modeling using temperature controls on the survivability of mosquitoes that are developing the malaria parasite. Observations using measurements from a dwelling hut, constructed to a local design at Wankama near Niamey, Niger, show that as the atmosphere gets moister and colder following rainfall, there is a potentially higher risk of malaria transmission during the rainy days. As the atmosphere gets warmer and drier during the drying period, there is a potentially decreasing rate of malaria transmission as the increasing temperature reduces the survivability of the mosquitoes. A numerical weather prediction model comparison shows that the high-resolution limited-area model outperforms the global-scale model and shows good agreement with the observations. Statistical analysis from the model results confirms that the findings are not restricted to a single location or single time of the day. It was also found that air temperatures over forest areas do not change as much during the study period, since the longer memory of the soil moisture means there is relatively little influence from single rainfall events.
Synoptic Climatological Analyses of Extreme Snowfalls in the Sierra Nevada
Authors: O’Hara Brian F. , Kaplan Michael L. , Underwood S. Jeffrey 
Published: June 2009

Abstract
The Sierra Nevada of eastern California receives heavy snowfall each year. However, it is the snowstorms that deposit heavy snowfall in a relatively short period of time that can cause major inconveniences and even life-threatening situations for the residents and visitors to the region. Some of these snowstorms are so extreme as to become legendary, and with increased population in this region a synoptic climatology of these extreme snowstorms can be a useful tool for assessing snowfall potential by operational forecasters. Additionally, the hydrological and climatological implications of extreme Sierra Nevada snowfalls are important for state and local resource- and emergency-planning purposes.
A climatology of these snowstorms will be presented. The period of study will include the snowfall seasons (October–May) 1949/50 through 2004/05. A total of 542 snowstorms occurred during these 56 snowfall seasons. These snowstorms were analyzed to determine any common synoptic features. The most intense snowstorms in the highest decile of snowfall totals were analyzed in more detail in order to determine the parameters associated with these strongest snowstorms.
Upper-level synoptic and thermodynamic characteristics associated with each snowstorm were then diagnosed to determine what common synoptic hydrodynamic and thermodynamic parameters the snowstorms share. Synoptic patterns were studied using the National Centers for Environmental Prediction (NCEP) model reanalysis data. Wind speeds at 200 hPa, and height anomalies at 500 hPa, were analyzed for each snowstorm from 3 days prior to the start of snowfall and continuing through the end of the storm. Anomalies and the transport of precipitable water were studied in order to determine the relative amount of moisture that was available to each snowstorm.
A conceptual model for forecasting the strongest snowstorms was developed. Key findings include the following: 1) the importance of a fetch of moisture from the subtropics with relatively large positive moisture anomalies, 2) the importance of the atmospheric moisture stream being normal to the Sierra, 3) the low static stability accompanying these snowstorms, and 4) the importance of relatively strong upper-level dynamics, which helped to intensify the systems as they approached the Sierra.
A New Method for Estimating Tropical Cyclone Wind Speed Probabilities
Authors: DeMaria Mark , Knaff John A. , Knabb Richard , Lauer Chris , Sampson Charles R. , DeMaria Robert T. 
Published: June 2009

Abstract
The National Hurricane Center (NHC) Hurricane Probability Program (HPP) was implemented in 1983 to estimate the probability that the center of a tropical cyclone would pass within 60 n mi of a set of specified points out to 72 h. Other than periodic updates of the probability distributions, the HPP remained unchanged through 2005. Beginning in 2006, the HPP products were replaced by those from a new program that estimates probabilities of winds of at least 34, 50, and 64 kt, and incorporates uncertainties in the track, intensity, and wind structure forecasts. This paper describes the new probability model and a verification of the operational forecasts from the 2006–07 seasons.
The new probabilities extend to 120 h for all tropical cyclones in the Atlantic and eastern, central, and western North Pacific to 100°E. Because of the interdependence of the track, intensity, and structure forecasts, a Monte Carlo method is used to generate 1000 realizations by randomly sampling from the operational forecast center track and intensity forecast error distributions from the past 5 yr. The extents of the 34-, 50-, and 64-kt winds for the realizations are obtained from a simple wind radii model and its underlying error distributions.
Verification results show that the new probability model is relatively unbiased and skillful as measured by the Brier skill score, where the skill baseline is the deterministic forecast from the operational centers converted to a binary probabilistic forecast. The model probabilities are also well calibrated and have high confidence based on reliability diagrams.
The Effect of Grip Size on the Hitting Force During a Soft Tennis Forehand Stroke
Authors: Ohguni Mika , Aoki Mitsuhiro , Sato Hiroki , Imada Kohdai , Funane Sota 
Published: June 2009

Background: Grip size of a tennis racquet has been reported to influence performance, but clear evidence of a correlation has yet to be established. Hypothesis: Hitting force during a soft tennis forehand stroke correlates with grip size. Study Design: Controlled clinical study. Methods: A total of 40 healthy volunteers (20 men and 20 women) with a mean age of 21.9 years were enrolled. Of the 40 participants, 20 were experienced soft tennis players (10 men and 10 women) and 20 were nonexperienced soft tennis players (10 men and 10 women). Based on racquets with 5 different grip sizes, the hitting force during a soft tennis forehand stroke was measured with a handheld dynamometer. Correlations between 4 factors (sex, experience, grip and pinch strengths, and middle finger length) and hitting force were evaluated with each grip size. Measurements for each factor were repeated, and a 2-way analysis of variance was performed on the obtained data. Results: The hitting force was greater for male players than for female players and greater for experienced players than for nonexperienced players ( P < .01). Men with large grip and pinch strengths demonstrated an increased hitting force with an increase in grip size. Men who had a long middle finger also demonstrated increased hitting force when grip size increased ( P < .05). Conclusion: The hypothesis proved accurate for experienced men who had a large grip strength, a large pinch strength, and a long middle finger. Clinical Relevance: Large-grip-sized racquets may result in better forehand stroke performance when used by experienced male soft tennis players with a large grip strength, a large pinch strength, and a long middle finger.
Preclinical characterization of 1-7F9, a novel human anti–KIR receptor therapeutic antibody that augments natural killer–mediated killing of tumor cells
Authors: Romagné Francois , André Pascale , Spee Pieter , Zahn Stefan , Anfossi Nicolas , Gauthier Laurent , Capanni Marusca , Ruggeri Loredana , Benson Don M. , Blaser Bradley W. , Della Chiesa Mariella , Moretta Alessandro , Vivier Eric , Caligiuri Michael A. , Velardi Andrea , Wagtmann Nicolai 
Published: June 2009

Abstract
Inhibitory-cell killer immunoglobulin-like receptors (KIR) negatively regulate natural killer (NK) cell–mediated killing of HLA class I–expressing tumors. Lack of KIR-HLA class I interactions has been associated with potent NK-mediated antitumor efficacy and increased survival in acute myeloid leukemia (AML) patients upon haploidentical stem cell transplantation from KIR-mismatched donors. To exploit this pathway pharmacologically, we generated a fully human monoclonal antibody, 1-7F9, which cross-reacts with KIR2DL1, -2, and -3 receptors, and prevents their inhibitory signaling. The 1-7F9 monoclonal antibody augmented NK cell–mediated lysis of HLA-C–expressing tumor cells, including autologous AML blasts, but did not induce killing of normal peripheral blood mononuclear cells, suggesting a therapeutic window for preferential enhancement of NK-cell cytotoxicity against malignant target cells. Administration of 1-7F9 to KIR2DL3-transgenic mice resulted in dose-dependent rejection of HLA-Cw3–positive target cells. In an immunodeficient mouse model in which inoculation of human NK cells alone was unable to protect against lethal, autologous AML, preadministration of 1-7F9 resulted in long-term survival. These data show that 1-7F9 confers specific, stable blockade of KIR, boosting NK-mediated killing of HLA-matched AML blasts in vitro and in vivo, providing a preclinical basis for initiating phase 1 clinical trials with this candidate therapeutic antibody.
Improving survival in patients with chronic lymphocytic leukemia (1980-2008): the Hospital Clínic of Barcelona experience
Authors: Abrisqueta Pau , Pereira Arturo , Rozman Ciril , Aymerich Marta , Giné Eva , Moreno Carol , Muntañola Ana , Rozman María , Villamor Neus , Hodgson Kate , Campo Elías , Bosch Francesc , Montserrat Emili 
Published: June 2009

AbstractWhether advances in treatment are prolonging survival of patients with chronic lymphocytic leukemia (CLL) is unclear. We analyzed presentation patterns and survival over time in 929 patients followed from 1980 to 2008 at the Hospital Clinic of Barcelona. The 5- and 10-year relative survival (adjusted for the expected survival in the general population) was estimated in patients seen in 2 periods of time: 1980-1994 (n = 451) and 1995-2004 (n = 365). We found that CLL shortens life expectancy in all age groups independently of clinical features at diagnosis. Nevertheless, survival is improving, particularly in some groups of patients. Thus, relative survival was significantly higher in the 1995-2004 cohort than in the 1980-1994 group both at 5 years (incidence rate ratio [IRR] = 0.46; P = .004) and 10 years (IRR = 0.65; P = .007) from diagnosis. The improved survival was largely due to a decrease in CLL-attributable mortality in patients younger than 70 years in Binet stage B or C at diagnosis (IRR = 0.40; P = .001 at 5 years; IRR = 0.33; P < .001 at 10 years). These results suggest that newer treatments are changing the prognosis of CLL, particularly in younger patients with advanced disease, whereas no improvement is yet observed in older subjects or those with lower-risk disease.
Association of hereditary thrombocythemia and distal limb defects with a thrombopoietin gene mutation
Authors: Graziano Claudio , Carone Simona , Panza Emanuele , Marino Flora , Magini Pamela , Romeo Giovanni , Pession Andrea , Seri Marco 
Published: June 2009

Abstract
Hereditary thrombocythemia is a rare autosomal dominant disorder caused by mutations in either the thrombopoietin gene (TPO) or its receptor c-MPL. TPO mutations described so far lead to thrombopoietin overproduction through increased translation of m-RNA. Unilateral transverse reduction limb defects are usually sporadic and generally thought to be caused by vascular disruptions. Reports of inherited unilateral limb defects are extremely rare. In the present study, we describe a family with segregation of G185T TPO mutation in the 5′ UTR region in 4 subjects with thrombocythemia. Three of these patients also present congenital transverse limb defects. Association of these events gives a strong hint of the in vivo involvement of thrombopoietin in vasculogenesis, confirming the role of TPO in human development of the hemangioblast, the embryonic progenitor of the hematopoietic and endothelial lineages. This is the first report showing that vascular disruptions could be secondary to specific gene derangements.