bluuebunny/crossref_metadata_2025_split huggingface dataset:
Particle Growth and Drop Collection Efficiency of Warm Clouds as Inferred from Joint CloudSat and MODIS Observations
Authors: Suzuki Kentaroh , Nakajima Takashi Y. , Stephens Graeme L. 
Published: May 2010

Abstract
This study describes an approach for combining CloudSat and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite observations to investigate the microphysical processes of warm clouds on the global scale. MODIS column optical thickness is vertically distributed between the cloud top and cloud bottom according to adiabatic and condensational growth assumptions and used as a vertical coordinate system to analyze profiles of CloudSat-observed radar reflectivity. The reflectivity profiles thus rescaled as a function of the in-cloud optical depth clearly depict how the cloud-to-rain particle growth processes take place within the cloud layer and how these processes vary systematically with variations in MODIS-derived effective particle radius. It is also found that the effective radii retrieved using two different wavelengths of MODIS tend to trace the microphysical change of reflectivity profiles in a different way because of the difference in the layer depth that characterizes these two effective radii.
The reflectivity profiles as a function of optical depth are also interpreted in terms of drop collection processes based on the continuous collection model. The slope of the reflectivity change with optical depth provides a gross measure of the collection efficiency factor. The systematic changes of reflectivity profiles with MODIS-derived particle sizes are then interpreted as demonstrating a strong dependency of the collection efficiency on particle size. These results provide a quantitative insight into the drop collection process of warm clouds in the real atmosphere.
Free and Forced Variability of the Tropical Atlantic Ocean: Role of the Wind–Evaporation–Sea Surface Temperature Feedback
Authors: Mahajan Salil , Saravanan R. , Chang Ping 
Published: May 2010

Abstract
The role of the wind–evaporation–sea surface temperature (WES) feedback in the low-frequency natural variability of the tropical Atlantic is studied using an atmospheric global climate model—the NCAR Community Climate Model, version 3 (CCM3)—thermodynamically coupled to a slab ocean model (SOM). The coupled model is modified to suppress the WES feedback and is compared to a control run. Singular value decomposition (SVD) analysis over the tropical Atlantic reveals that the coupled meridional mode of the Atlantic Ocean is amplified in the presence of the WES feedback. In its absence, the meridional mode still exists, but with a weaker amplitude. A feedback mechanism that involves the near-surface specific humidity is proposed to sustain the weaker Atlantic meridional mode in the absence of the WES feedback. Similar analysis of coupled model integrations when forced with an artificial El Niño–Southern Oscillation (ENSO)-like SST cycle in the Pacific reveals that in the presence of the WES feedback, the meridional mode is the preferred mode of response of the tropical Atlantic to ENSO forcing. In the absence of the WES feedback, the tropical Atlantic response is unlike the meridional mode and the effects of tropospheric warming and subsidence dominate. Regression analysis over the tropical Atlantic reveals that the meridional mode response to ENSO peaks in the spring and begins to decay in the fall in the coupled model in the presence of the WES feedback. The WES feedback also appears to be responsible for the northward migration of the ITCZ during ENSO events.
A Coupled Dynamical Ocean–Energy Balance Atmosphere Model for Paleoclimate Studies
Authors: Ritz Stefan P. , Stocker Thomas F. , Joos Fortunat 
Published: May 2010

Abstract
The Bern3D coupled three-dimensional dynamical ocean–energy balance atmosphere model is introduced and the atmospheric component is discussed in detail. The model is of reduced complexity, developed to perform extensive sensitivity studies and ensemble simulations extending over several glacial–interglacial cycles. On large space scales, the modern steady state of the model compares well with observations. In a first application, several 800 000-yr simulations with prescribed orbital, greenhouse gas, and ice sheet forcings are performed. The model shows an increase of Atlantic meridional overturning circulation strength at glacial inceptions followed by a decrease throughout the glaciation and ending in a circulation at glacial maxima that is weaker than at present. The sensitivity of ocean temperature to atmospheric temperature, Atlantic meridional overturning circulation (AMOC), and Antarctic bottom water (AABW) strength is analyzed at 23 locations. In a second application the climate sensitivities of the modern and of the Last Glacial Maximum (LGM) state are compared. The temperature rise for a doubling of the CO2 concentration from LGM conditions is 4.3°C and thus notably larger than in the modern case (3°C). The relaxation time scale is strongly dependent on the response of AABW to the CO2 change, since it determines the ventilation of the deep Pacific and Indian Ocean.
Notes on a Catastrophe: A Feedback Analysis of Snowball Earth
Authors: Roe Gerard H. , Baker Marcia B. 
Published: May 2010

AbstractThe language of feedbacks is ubiquitous in contemporary earth sciences, and the framework of feedback analysis is a powerful tool for diagnosing the relative strengths of the myriad mutual interactions that occur in complex dynamical systems. The ice albedo feedback is widely taught as the classic example of a climate feedback. Moreover, its potential to initiate a collapse to a completely glaciated snowball earth is widely taught as the classic example of a climate “tipping point.” A feedback analysis of the snowball earth phenomenon in simple, zonal mean energy balance models clearly reveals the physics of the snowball instability and its dependence on climate parameters. The analysis can also be used to illustrate some fundamental properties of climate feedbacks: how feedback strength changes as a function of mean climate state; how small changes in individual feedbacks can cause large changes in the system sensitivity; and last, how the strength and even the sign of the feedback is dependent on the climate variable in question.
Decadal Variability in a Central Greenland High-Resolution Deuterium Isotope Record and Its Relationship to the Frequency of Daily Atmospheric Circulation Patterns from the North Atlantic Region
Authors: Rimbu Norel , Lohmann Gerrit 
Published: May 2010

Abstract
The variability of an annual resolution deuterium time series from central Greenland is investigated in connection with the variability in the frequency of daily atmospheric circulation patterns in the North Atlantic region. Statistical analysis reveals that a large part of the decadal variability of the deuterium isotope record is related to decadal variability in the frequency of several identified daily circulation patterns. The study shows that these circulation patterns induce variations in the deuterium record by altering where isotopic fractionation occurs, mainly during the passage of the associated air masses over continental areas. The study identifies three significant periodic components in the deuterium isotope record at ∼12, ∼20, and ∼30 yr. It also shows that the ∼20-yr signal in the deuterium isotope record is related to the variability in the frequency of a winter circulation type. An analysis of six oxygen isotope records from central Greenland reveals decadal variations similar to the deuterium isotope record. The authors argue that high-resolution stable isotope records from Greenland ice cores can be used to obtain information about the frequency of certain daily circulation patterns during past periods.
Assessment of Extreme Quantitative Precipitation Forecasts and Development of Regional Extreme Event Thresholds Using Data from HMT-2006 and COOP Observers
Authors: Ralph F. M. , Sukovich E. , Reynolds D. , Dettinger M. , Weagle S. , Clark W. , Neiman P. J. 
Published: May 2010

Abstract
Extreme precipitation events, and the quantitative precipitation forecasts (QPFs) associated with them, are examined. The study uses data from the Hydrometeorology Testbed (HMT), which conducted its first field study in California during the 2005/06 cool season. National Weather Service River Forecast Center (NWS RFC) gridded QPFs for 24-h periods at 24-h (day 1), 48-h (day 2), and 72-h (day 3) forecast lead times plus 24-h quantitative precipitation estimates (QPEs) from sites in California (CA) and Oregon–Washington (OR–WA) are used. During the 172-day period studied, some sites received more than 254 cm (100 in.) of precipitation. The winter season produced many extreme precipitation events, including 90 instances when a site received more than 7.6 cm (3.0 in.) of precipitation in 24 h (i.e., an “event”) and 17 events that exceeded 12.7 cm (24 h)−1 [5.0 in. (24 h)−1]. For the 90 extreme events {&gt;7.6 cm (24 h)−1 [3.0 in. (24 h)−1]}, almost 90% of all the 270 QPFs (days 1–3) were biased low, increasingly so with greater lead time. Of the 17 observed events exceeding 12.7 cm (24 h)−1 [5.0 in. (24 h)−1], only 1 of those events was predicted to be that extreme. Almost all of the extreme events correlated with the presence of atmospheric river conditions. Total seasonal QPF biases for all events {i.e., ≥0.025 cm (24 h)−1 [0.01 in. (24 h)−1]} were sensitive to local geography and were generally biased low in the California–Nevada River Forecast Center (CNRFC) region and high in the Northwest River Forecast Center (NWRFC) domain. The low bias in CA QPFs improved with shorter forecast lead time and worsened for extreme events. Differences were also noted between the CNRFC and NWRFC in terms of QPF and the frequency of extreme events. A key finding from this study is that there were more precipitation events &gt;7.6 cm (24 h)−1 [3.0 in. (24 h)−1] in CA than in OR–WA. Examination of 422 Cooperative Observer Program (COOP) sites in the NWRFC domain and 400 in the CNRFC domain found that the thresholds for the top 1% and top 0.1% of precipitation events were 7.6 cm (24 h)−1 [3.0 in. (24 h)−1] and 14.2 cm (24 h)−1 [5.6 in. (24 h)−1] or greater for the CNRFC and only 5.1 cm (24 h)−1 [2.0 in. (24 h)−1] and 9.4 cm (24 h)−1 [3.7 in. (24 h)−1] for the NWRFC, respectively. Similar analyses for all NWS RFCs showed that the threshold for the top 1% of events varies from ∼3.8 cm (24 h)−1 [1.5 in. (24 h)−1] in the Colorado Basin River Forecast Center (CBRFC) to ∼5.1 cm (24 h)−1 [3.0 in. (24 h)−1] in the northern tier of RFCs and ∼7.6 cm (24 h)−1 [3.0 in. (24 h)−1] in both the southern tier and the CNRFC. It is recommended that NWS QPF performance in the future be assessed for extreme events using these thresholds.
Scale Dependence of Radar Rainfall Uncertainty: Initial Evaluation of NEXRAD’s New Super-Resolution Data for Hydrologic Applications
Authors: Seo Bong-Chul , Krajewski Witold F. 
Published: May 2010

Abstract
This study explores the scale effects of radar rainfall accumulation fields generated using the new super-resolution level II radar reflectivity data acquired by the Next Generation Weather Radar (NEXRAD) network of the Weather Surveillance Radar-1988 Doppler (WSR-88D) weather radars. Eleven months (May 2008–August 2009, exclusive of winter months) of high-density rain gauge network data are used to describe the uncertainty structure of radar rainfall and rain gauge representativeness with respect to five spatial scales (0.5, 1, 2, 4, and 8 km). While both uncertainties of gauge representativeness and radar rainfall show simple scaling behavior, the uncertainty of radar rainfall is characterized by an almost 3 times greater standard error at higher temporal and spatial resolutions (15 min and 0.5 km) than at lower resolutions (1 h and 8 km). These results may have implications for error propagation through distributed hydrologic models that require high-resolution rainfall input. Another interesting result of the study is that uncertainty obtained by averaging rainfall products produced from the super-resolution reflectivity data is slightly lower at smaller scales than the uncertainty of the corresponding resolution products produced using averaged (recombined) reflectivity data.
The University of South Alabama Mesonet and Coastal Observing System: A Technical and Statistical Overview
Authors: Kimball Sytske K. , Mulekar Madhuri S. , Cummings Shailer , Stamates Jack 
Published: May 2010

AbstractThe University of South Alabama Mesonet consists of 26 sites across the north-central Gulf of Mexico coast. Although the original purpose of the mesonet was monitoring landfalling tropical systems, meteorological data are collected and disseminated every 5 min year-round to serve a multitude of purposes, including weather forecasting, education, and research. In this paper a statistical analysis and like-sensor comparison demonstrates that variables, measured by different sensor types or by sensors at different heights, correlate well. The benefits of sensor redundancy are twofold, offering 1) backup sensors in the case of sensor failure during severe weather and 2) the ability to perform a large number of internal consistency checks for quality control purposes. An oceanographic compliment to the University of South Alabama Mesonet system, which was deployed by NOAA’s Atlantic Oceanographic and Meteorological Laboratory (AOML) to measure surface waves and ocean currents in an area south of Mobile, Alabama, is described. A preliminary comparison of mesonet wind data and ocean wave data show good agreement, offering promising opportunities for future research.
Deployment of a Tethered-Balloon System for Microphysics and Radiative Measurements in Mixed-Phase Clouds at Ny-Ålesund and South Pole
Authors: Lawson R. Paul , Stamnes Knut , Stamnes Jakob , Zmarzly Pat , Koskuliks Jeff , Roden Chris , Mo Qixu , Carrithers Michael , Bland Geoffrey L. 
Published: May 2010

Abstract
A tethered-balloon system capable of making microphysical and radiative measurements in clouds is described and examples of measurements in boundary layer stratus clouds in the Arctic and at the South Pole are presented. A 43-m3 helium-filled balloon lofts an instrument package that is powered by two copper conductors in the tether. The instrument package can support several instruments, including, but not limited to, a cloud particle imager; a forward-scattering spectrometer probe; temperature, pressure, humidity, and wind sensors; ice nuclei filters; and a 4-π radiometer that measures actinic flux at 500 and 800 nm. The balloon can stay aloft for an extended period of time (in excess of 24 h) and conduct vertical profiles up to about 1–2 km, contingent upon payload weight, wind speed, and surface elevation. Examples of measurements in mixed-phase clouds at Ny-Ålesund, Svalbard (79°N), and at the South Pole are discussed. The stratus clouds at Ny-Ålesund ranged in temperature from 0° to −10°C and were mostly mixed phase with heavily rimed ice particles, even when cloud-top temperatures were warmer than −5°C. Conversely, mixed-phase clouds at the South Pole contained regions with only water drops at temperatures as cold as −32°C and were often composed of pristine ice crystals. The radiative properties of mixed-phase clouds are a critical component of radiative transfer in polar regions, which, in turn, is a lynch pin for climate change on a global scale.
Determination of a Consistent Time for the Extratropical Transition of Tropical Cyclones. Part I: Examination of Existing Methods for Finding “ET Time”
Authors: Kofron David E. , Ritchie Elizabeth A. , Tyo J. Scott 
Published: May 2010

Abstract
As a tropical cyclone moves poleward and interacts with the midlatitude circulation, the question of whether it will undergo extratropical transition (ET) and, if it does, whether it will reintensify or dissipate, is a complex problem. Several quantities have been proposed in previous studies to describe extratropical transition including frontogenesis, 500-hPa geopotential heights, and cyclone phase-space parameters. In this study, these parameters are explored for their utility in defining an ET time using the Navy’s Operational Global Assimilation and Prediction System gridded analyses. The 500-hPa geopotential heights and frontogenesis currently do not have objective numerical definitions. Therefore, this study attempts to establish and examine threshold values that may be used to objectively define the ET time. Cyclone phase space already has numerical threshold values that can be examined.
Results show that the 500-hPa geopotential height open wave distinguishes 81 of 82 cases, but it fails to discriminate between transitioning ET and recurving non-ET cases and cannot be determined automatically. The 2D scalar frontogenesis distinguishes 77 of 82 cases but does not discriminate between transitioning ET and recurving non-ET cases. Finally, phase space successfully distinguishes 81 of 82 cases for the “ET time” defined by the asymmetry parameter but is only successful at capturing transitioning ET and recurving non-ET cases properly for 60 of 82 cases. All of the definitions are found to have disadvantages that preclude them from providing consistent guidance for when extratropical transition of a poleward-recurving tropical cyclone is occurring.
Retrospective Forecasts of the Hurricane Season Using a Global Atmospheric Model Assuming Persistence of SST Anomalies
Authors: Zhao Ming , Held Isaac M. , Vecchi Gabriel A. 
Published: May 2010

Abstract
Retrospective predictions of seasonal hurricane activity in the Atlantic and east Pacific are generated using an atmospheric model with 50-km horizontal resolution by simply persisting sea surface temperature (SST) anomalies from June through the hurricane season. Using an ensemble of 5 realizations for each year between 1982 and 2008, the correlations of the model mean predictions with observations of basin-wide hurricane frequency are 0.69 in the North Atlantic and 0.58 in the east Pacific. In the North Atlantic, a significant part of the degradation in skill as compared to a model forced with observed SSTs during the hurricane season (correlation of 0.78) can be explained by the change from June through the hurricane season in one parameter, the difference between the SST in the main development region and the tropical mean SST. In fact, simple linear regression models with this one predictor perform nearly as well as the full dynamical model for basin-wide hurricane frequency in both the east Pacific and the North Atlantic. The implication is that the quality of seasonal forecasts based on a coupled atmosphere–ocean model will depend in large part on the model’s ability to predict the evolution of this difference between main development region SST and tropical mean SST.
Detection of the Heterochirality of a 1:2 Metal/Ph-pybox Complex Ion by ESIMS
Authors: Sato Hirofumi , Suzuki Yoshitomo , Takai Yoshio , Kawasaki Hideya , Arakawa Ryuichi , Shizuma Motohiro 
Published: May 2010

Abstract
The heterochirality of a 1:2 metal/Ph-pybox complex ion was encyclopedically evaluated by ESIMS using pseudo-racemic (R,R)- and (S,S)-Ph-pybox pair, which were unlabeled/labeled by deuterium atoms, respectively. The heterochiral complex was predominantly formed in all investigated 1:2 metal/Ph-pybox complex ions.
Kinetic Analysis of Reduction of Formyl Groups in Chlorophyll d and Pheophytin d
Authors: Sadaoka Kana , Hirai Yuki , Kashimura Shigenori , Saga Yoshitaka 
Published: May 2010

Abstract
Reduction of formyl groups in natural chlorophyll (Chl) d purified from a cyanobacterium, Acaryochloris marina, and its demetalation product, pheophytin (Phe) d, was kinetically analyzed. Chl d exhibited slower reduction kinetics of the formyl group to the hydroxymethyl group by tert-butylamine borane complex than Phe d.
A Novel Protein Gel Route to Synthesize Luminescent Lu3Al5O12:Ce3+ Powders Calcined at Lower Temperature
Authors: Yu Dao , Liu Qingfeng , Liu Qian 
Published: May 2010

Abstract
A novel protein gel method was developed to synthesize composite oxide phosphors, in which ovalbumin was used as gelling agent. By this route, Lu3Al5O12:Ce3+ powders were obtained at 700 °C with a size of less than 50 nm. Under ultraviolet excitation, the emission peak is located around 510 nm. This simple method is applicable to high-throughput synthesis.
Extraordinary Effect of Microwave Irradiation on Asymmetric Catalysis
Authors: Kikuchi Satoshi , Tsubo Tatsuyuki , Ashizawa Tomoko , Yamada Tohru 
Published: May 2010

Abstract
We here report the effect of microwave irradiation on the atropo-enantioselective ring-opening reaction of biaryl lactones with dynamic–kinetic resolution catalyzed by AgBF4–phosphine complexes. The multimode microwave reactor with a cooling system was employed and the fiber-optic sensor was used for measurement of the accurate internal reaction temperature. It was found that the reaction was accelerated by microwave irradiation without any loss of enantioselectivity at almost the same internal temperature as the conventional conditions.
Amino Acid Spin Labels. An Application of Chelation Ability to a Nickel(II) Ion
Authors: Osada Sayaka , Igarashi Kazuki , Nogami Takashi , Ishida Takayuki 
Published: May 2010

Abstract
NN–CH2-substituted l-alanine methyl ester (NNCH2–l-Ala–OMe) and β-alanine ethyl ester (NNCH2–β-Ala–OEt) were prepared, where NN stands for 4,4,5,5-tetramethylimidazolin-1-oxyl 3-oxide. Their nickel(II) perchlorate complexes with a metal/ligand ratio of 1/2 were structurally and magnetically characterized.
Thermodynamic Study of the Solvation States of Acid and Base in a Protic Ionic Liquid, Ethylammonium Nitrate, and Its Aqueous Mixtures
Authors: Kanzaki Ryo , Song Xuedan , Umebayashi Yasuhiro , Ishiguro Shin-ichi 
Published: May 2010

Abstract
Ethylammonium nitrate (EAN) is a typical protic ionic liquid (PIL) known for a long time. In order to investigate acid–base reaction mechanisms in PIL, thermodynamic quantities of a reaction, which corresponds to autoprotolysis in amphoteric solvents, has been determined in neat EAN. Unlike H3O+ and OH− in water, proton donor and acceptor species in EAN are both neutral; this makes acid–base reaction mechanisms in EAN distinct from that in water. EAN–water mixtures have also been studied.
Aspects of the Nonlinear Optical Properties as a Guide to Protonation Sites: A Theoretical Study upon α-Keggin [SiW12O40]4− and [SiV3W9O40]7−
Authors: Yao Chan , Liu Chun-Guang , Yan Li-Kai , Guan Wei , Song Ping , Su Zhong-Min 
Published: May 2010

Abstract
The present study focuses on probing the extent to which nonlinear optical effects act as a guide to protonation sites of α-Keggin heteropolyanions [SiW12O40]4− and [SiV3W9O40]7−. The second-harmonic generation (SHG) values of differently protonated forms predict that the molecular nonlinear optical activity has a close relationship with protonation sites and provides a new potential experimental probe.
Synthesis of Hollow Silica Nanospheres Templated by Micelles of Poly{styrene-b-[3-(methacryloylamino)propyl]trimethylammonium chloride-b-ethylene oxide}
Authors: Liu Jingjing , Liu Dian , Manickam Sasidharan , Yokoyama Yuuichi , Yusa Shin-ichi , Nakashima Kenichi 
Published: May 2010

Abstract
A micelle of poly{styrene-b-[3-(methacryloylamino)propyl]trimethylammonium chloride-b-ethylene oxide} with core–shell–corona architecture in aqueous solutions has been successfully applied to the synthesis of hollow silica nanospheres as a new template. Tetramethoxysilane, phenyltrimethoxysilane, and their mixtures were used as silica precursors and the ratio of the precursor to the template influences the shell thickness of the obtained hollow silica.
Solid-state Solvatochromic Behavior of Reichardt’s Dye Crystals Hybridized with Silica Nanoparticles
Authors: Ichimura Kunihiro , Funabiki Akira , Aoki Ken’ichi 
Published: May 2010

Abstract
The dry bead milling of solvatochromic ET30 with silica nanoparticles gave powdery nanohybrids, which exhibited color changes depending on environmental conditions.