bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ten‐Year Blood Pressure Trajectories, Cardiovascular Mortality, and Life Years Lost in 2 Extinction Cohorts: the Minnesota Business and Professional Men Study and the Zutphen Study
Authors: Tielemans Susanne M. A. J. , Geleijnse Johanna M. , Menotti Alessandro , Boshuizen Hendriek C. , Soedamah‐Muthu Sabita S. , Jacobs David R. , Blackburn Henry , Kromhout Daan 
Published: March 2015

Background

Blood pressure (
BP
) trajectories derived from measurements repeated over years have low measurement error and may improve cardiovascular disease prediction compared to single, average, and usual
BP
(single
BP
adjusted for regression dilution). We characterized 10‐year
BP
trajectories and examined their association with cardiovascular mortality, all‐cause mortality, and life years lost.

Methods and Results

Data from 2 prospective and nearly extinct cohorts of middle‐aged men—the Minnesota Business and Professional Men Study (n=261) and the Zutphen Study (n=632)—were used.
BP
was measured annually during 1947–1957 in Minnesota and 1960–1970 in Zutphen.
BP
trajectories were identified by latent mixture modeling. Cox proportional hazards and linear regression models examined
BP
trajectories with cardiovascular mortality, all‐cause mortality, and life years lost. Associations were adjusted for age, serum cholesterol, smoking, and diabetes mellitus. Mean initial age was about 50 years in both cohorts. After 10 years of
BP
measurements, men were followed until death on average 20 years later. All Minnesota men and 98% of Zutphen men died. Four
BP
trajectories were identified, in which mean systolic BP increased by 5 to 49 mm Hg in Minnesota and 5 to 20 mm Hg in Zutphen between age 50 and 60. The third systolic BP trajectories were associated with 2 to 4 times higher cardiovascular mortality risk, 2 times higher all‐cause mortality risk, and 4 to 8 life years lost, compared to the first trajectory.

Conclusions

Ten‐year
BP
trajectories were the strongest predictors, among different
BP
measures, of cardiovascular mortality, all‐cause mortality, and life years lost in Minnesota. However, average
BP
was the strongest predictor in Zutphen.
Prediction of Maize Yield Response to Climate Change with Climate and Crop Model Uncertainties
Authors: Zhang Yi , Zhao Yanxia , Chen Sining , Guo Jianping , Wang Enli 
Published: March 2015

AbstractProjections of climate change impacts on crop yields are subject to uncertainties, and quantification of such uncertainty is essential for the effective use of the projection results for adaptation and mitigation purposes. This work analyzes the uncertainties in maize yield predictions using two crop models together with three climate projections downscaled with one regional climate model nested with three global climate models under the A1B emission scenario in northeast China (NEC). Projections were evaluated for the Zhuanghe agrometeorological station in NEC for the 2021–50 period, taking 1971–2000 as the baseline period. The results indicated a yield reduction of 13% during 2021–50, with 95% probability intervals of (−41%, +12%) relative to 1971–2000. Variance decomposition of the yield projections showed that uncertainty in the projections caused by climate and crop models is likely to change with prediction period, and climate change uncertainty generally had a larger impact on projections than did crop model uncertainty during the 2021–50 period. In addition, downscaled climate projections had significant bias that can introduce significant uncertainties in yield projections. Therefore, they have to be bias corrected before use.
A Comparison of MODIS-Derived Cloud Fraction with Surface Observations at Five SURFRAD Sites
Authors: An Ning , Wang Kaicun 
Published: March 2015

AbstractClouds determine the amount of solar radiation incident to the surface. Accurately quantifying cloud fraction is of great importance but is difficult to accomplish. Satellite and surface cloud observations have different fields of view (FOVs); the lack of conformity of different FOVs may cause large discrepancies when comparing satellite- and surface-derived cloud fractions. From the viewpoint of surface-incident solar radiation, this paper compares Moderate Resolution Imaging Spectroradiometer (MODIS) level-2 cloud-fraction data with three surface cloud-fraction datasets at five Surface Radiation Network (SURFRAD) sites. The correlation coefficients between MODIS and the surface cloud fractions are in the 0.80–0.91 range and vary at different SURFRAD sites. In a number of cases, MODIS observations show a large cloud-fraction bias when compared with surface data. The variances between MODIS and the surface cloud-fraction datasets are more apparent when small convective or broken clouds exist in the FOVs. The magnitude of the discrepancy between MODIS and surface-derived cloud fractions depends on the satellite’s view zenith angle (VZA). On average, relative to surface cloud-fraction data, MODIS observes a larger cloud fraction at VZA > 40° and a smaller cloud fraction at VZA < 20°. When comparing long-term MODIS averages with surface datasets, Aqua MODIS observes a higher annual mean cloud fraction, likely because convective clouds are better developed in the afternoon when Aqua is observing.
Summertime Potential Evapotranspiration in Eastern Washington State
Authors: Bond Nicholas A. , Bumbaco Karin A. 
Published: March 2015

AbstractThe demands for water in agricultural regions depend on the rate of evapotranspiration (ET). Daily records of potential ET (pET) are available from the late 1980s through the present for five stations in eastern Washington State (George, Harrah, LeGrow, Lind, and Odessa) through the Pacific Northwest Cooperative Agricultural Weather Network (AgriMet) under the auspices of the Bureau of Reclamation. These records reveal a secular increase in the summer (June–August) mean pET over the period 1987–2014. This increase can be attributed largely to an increase in solar irradiance of 20–30 W m−2over the same period. The seasonal mean solar irradiance accounts for approximately 35%–50% of the variance in the interannual variations in seasonal mean pET at the individual stations and for approximately 60% of the variance from a five-station average perspective. The period of analysis includes a mean increase of temperature of about 0.3°C (10 yr)−1, and the variability in temperature relates more to the year-to-year fluctuations in pET than to the overall increase in pET. The time series of surface relative humidity and wind speed exhibit only minor trends. Daily and seasonal mean data for 500-hPa geopotential height and other variables are used to determine aspects of the regional atmosphere associated with periods of high pET. Anomalous ridging aloft and negative anomalies in 925-hPa relative humidity tend to occur over the study area during the summers with the greatest pET. The relationships that are emerging may provide a basis for empirical downscaling of pET from global climate model projections.
Modulation of Midtropospheric CO2 by the South Atlantic Walker Circulation*
Authors: Jiang Xun , Olsen Edward T. , Pagano Thomas S. , Su Hui , Yung Yuk L. 
Published: March 2015

Abstract
Midtropospheric CO2 data from the Atmospheric Infrared Sounder (AIRS) are used in this study to explore the variability of CO2 over the South Atlantic Ocean. It was found that the area-averaged CO2 over the South Atlantic Ocean is less than that over South America by about 1 ppm during December–March. This CO2 contrast is due to the large-scale vertical circulation over this region. During December–March, there is sinking motion over the South Atlantic Ocean. The sinking motion brings high-altitude air with a slightly lower concentration of CO2 to the midtroposphere. Meanwhile, air rising over South America brings near-surface air with a higher concentration of CO2 to the midtroposphere. As a result, the AIRS midtropospheric CO2 concentration is lower over the South Atlantic Ocean than over South America during December–March. The detrended AIRS midtropospheric CO2 difference correlates well with the inverted and detrended 400-hPa vertical pressure velocity difference between the South Atlantic and South America. Results obtained from this study demonstrate the strong impact of large-scale circulation on the vertical distribution of CO2 in the free troposphere and suggest that midtropospheric CO2 measurements can be used as an innovative observational constraint on the simulation of large-scale circulations in climate models.
Decadal Variation of Summer Precipitation over China and Associated Atmospheric Circulation after the Late 1990s
Authors: Xu ZhiQing , Fan Ke , Wang HuiJun 
Published: March 2015

AbstractIn this study, the authors found that the summer precipitation over China experienced different decadal variation features from north to south after the late 1990s. In northeastern and North China and the lower–middle reaches of the Yangtze River, precipitation decreased after 1999, while precipitation experienced a significant reduction over South and southwestern China and a significant increase over the southern parts of Hetao region and Huaihe River valley after 2003. The authors next analyzed the associated decadal variation of the atmospheric circulation and attempted to identify the mechanisms causing the two decadal variations of precipitation. The wind anomalies for the former exhibit a barotropic meridional dipole pattern, with anticyclonic anomalies over Mongolia to northern China and cyclonic anomalies over the southeastern Chinese coast to the northwestern Pacific. For the latter, there is a southeast–northwest-oriented dipole pattern in the middle and lower troposphere, with cyclonic anomalies over the northern parts of the Tibetan Plateau and anticyclonic anomalies over the lower–middle reaches of the Yangtze River to southern Japan. An anomalous anticyclone dominates the upper troposphere over China south of 40°N. The authors further found that the summer sea surface temperature (SST) warming over the tropical Atlantic played an important role in the decadal variation around 2003 via inducing teleconnections over Eurasia. In contrast, the decadal variation around 1999 may be caused by the phase shift of the Pacific decadal oscillation (PDO), as has previously been indicated.
Vertical Redistribution of Oceanic Heat Content
Authors: Liang Xinfeng , Wunsch Carl , Heimbach Patrick , Forget Gael 
Published: March 2015

Abstract
Estimated values of recent oceanic heat uptake are on the order of a few tenths of a W m−2, and are a very small residual of air–sea exchanges, with annual average regional magnitudes of hundreds of W m−2. Using a dynamically consistent state estimate, the redistribution of heat within the ocean is calculated over a 20-yr period. The 20-yr mean vertical heat flux shows strong variations in both the lateral and vertical directions, consistent with the ocean being a dynamically active and spatially complex heat exchanger. Between mixing and advection, the two processes determining the vertical heat transport in the deep ocean, advection plays a more important role in setting the spatial patterns of vertical heat exchange and its temporal variations. The global integral of vertical heat flux shows an upward heat transport in the deep ocean, suggesting a cooling trend in the deep ocean. These results support an inference that the near-surface thermal properties of the ocean are a consequence, at least in part, of internal redistributions of heat, some of which must reflect water that has undergone long trajectories since last exposure to the atmosphere. The small residual heat exchange with the atmosphere today is unlikely to represent the interaction with an ocean that was in thermal equilibrium at the start of global warming. An analogy is drawn with carbon-14 “reservoir ages,” which range from over hundreds to a thousand years.
Is the Tropical Atmosphere in Convective Quasi-Equilibrium?
Authors: Lin Jia-Lin , Qian Taotao , Shinoda Toshiaki , Li Shuanglin 
Published: March 2015

AbstractThe hypothesis of convective quasi-equilibrium (CQE) has dominated thinking about the interaction between deep moist convection and the environment for at least two decades. In this view, deep convection develops or decays almost instantly to remove any changes of convective instability, making the tropospheric temperature always tied to the boundary layer moist static energy. The present study examines the validity of the CQE hypothesis at different vertical levels using long-term sounding data from tropical convection centers. The results show that the tropical atmosphere is far from the CQE with much weaker warming in the middle and upper troposphere associated with the increase of boundary layer moist static energy. This is true for all the time scales resolved by the observational data, ranging from hourly to interannual and decadal variability. It is possibly caused by the ubiquitous existence of shallow convection and stratiform precipitation, both leading to sign reversal of heating from lower to upper troposphere. The simulations by 42 global climate models from phases 3 and 5 of the Coupled Model Intercomparsion Project (CMIP3 and CMIP5) are also analyzed and compared with the observations.
A Method to Estimate the 3D–Time Structure of the Raindrop Size Distribution Using Radar and Disdrometer Data*
Authors: Schleiss Marc , Smith James 
Published: March 2015

AbstractA geostatistical method to quantify the small-scale 3D–time structure of the drop size distribution (DSD) from the ground level up to the melting layer using radar and disdrometer data is presented. First, 3D–time radar reflectivity fields are used to estimate the large-scale properties of a rain event, such as the apparent motion, spatial anisotropy, and temporal innovation. The retrieved quantities are then combined with independent disdrometer time series to estimate the 3D–time variogram of each DSD parameter. A key point in the procedure is the use of a new metric for measuring distances in moving anisotropic rainfall fields. This metric has the property of being invariant with respect to the specific rainfall parameter being considered, that is, it is identical for the radar reflectivity, rain rate, mean drop diameter, drop concentration, or any other weighted moment of the DSD. Evidence is shown of this fact and some illustrations for a stratiform event in southern France and a convective case in the midwestern United States are provided. The proposed framework offers a series of new and interesting applications, including the possibility to compare the space–time structure of different rain events, to interpolate radar reflectivity fields in space–time and to simulate 3D–time DSD fields at high spatial and temporal resolutions.
Available Potential Energy and the General Circulation: Partitioning Wind, Buoyancy Forcing, and Diapycnal Mixing
Authors: Zemskova Varvara E. , White Brian L. , Scotti Alberto 
Published: March 2015

AbstractThe ocean energy cycle is calculated using a new available potential energy (APE) decomposition, which partitions adiabatic buoyancy fluxes from diapycnal mixing, applied to results from the Estimating the Circulation and Climate of the Ocean, Phase II (ECCO2), eddy-permitting ocean state estimate and observed surface buoyancy fluxes from the WHOI OAFlux project. Compared with the traditional Lorenz energy cycle, this framework provides a more accurate estimate of the background potential energy (PE) of the global oceans and the surface generation and interior fluxes of APE. Calculations of the global energy budget using 16 yr of ECCO2 output suggest that the adiabatic portion of the general circulation is maintained by a balance between the mean wind-driven upwelling that increases APE (+0.27 TW) and time-fluctuating processes, including mesoscale eddies, which release APE (−0.27 TW). The APE generated by surface buoyancy fluxes (0.46 TW) is comparable to the generation by the mean winds. The global rate of irreversible mixing (0.46 TW), which balances surface APE generation, is consistent with previous estimates of the diapycnal fluxes associated with maintaining deep stratification (see Munk and Wunsch) and a global diapycnal diffusivity of O(1 × 10−4) m2 s−1. However, the net contribution of diapycnal mixing to the total potential energy is negligible, which suggests that mixing, contrary to one current paradigm, does not place a global demand on kinetic energy dissipation. However, there are regions where mixing is significant, for example, between 3000 and 5000 m (in ECCO2), where mixing increases PE by 0.1 TW. The work provides a new framework for separating adiabatic–diabatic fluxes and for monitoring the global rate of diapycnal mixing rate using measurable surface properties such as SST and heat flux.
Capturing the Transport Variability of a Western Boundary Jet: Results from the Agulhas Current Time-Series Experiment (ACT)
Authors: Beal Lisa M. , Elipot Shane , Houk Adam , Leber Greta M. 
Published: March 2015

AbstractThe volume transport of the Agulhas Current was measured over a 3-yr period by an array of seven current meter moorings and four current- and pressure-recording inverted echo sounders (CPIES) deployed at 34°S. CPIES extended the array farther offshore in order to capture, for the first time, the full Agulhas Current during meander events. Transports derived from CPIES are well correlated with overlapping current meter transports (0.89). The Eulerian mean current is 219 km wide and 3000 m deep, with peak surface speeds of 1.8 m s−1 and a weak northward undercurrent on the continental slope below 1200 m. A new algorithm to capture the western boundary jet transport at each time step T is defined as the poleward transport out to the first maximum of the vertically integrated velocity beyond the half-width of the mean jet. The mean transport of the Agulhas Current jet, so defined, is −84 Sverdrups (Sv; 1 Sv ≡ 106 m3 s−1) with a standard error of 2 Sv. Sampling and instrumental errors are explicitly estimated and amount to an additional 9 Sv. A more traditional estimate, based on net transport integrated to a fixed distance offshore Tbox, gives a mean transport of −77 ± 5 Sv. This transport is 10 Sv greater than an equivalent transport at 32°S, corresponding to a latitudinal increase equal to that predicted by Sverdrup dynamics. The time series of T and Tbox show important differences during solitary meander events and at longer time scales. In terms of an annual cycle, the Agulhas Current appears strongest during austral summer, a similar phase to the Gulf Stream and Kuroshio.
Predictability of the Loop Current Variation and Eddy Shedding Process in the Gulf of Mexico Using an Artificial Neural Network Approach
Authors: Zeng Xiangming , Li Yizhen , He Ruoying 
Published: March 2015

AbstractA novel approach based on an artificial neural network was used to forecast sea surface height (SSH) in the Gulf of Mexico (GoM) in order to predict Loop Current variation and its eddy shedding process. The empirical orthogonal function analysis method was applied to decompose long-term satellite-observed SSH into spatial patterns (EOFs) and time-dependent principal components (PCs). The nonlinear autoregressive network was then developed to predict major PCs of the GoM SSH in the future. The prediction of SSH in the GoM was constructed by multiplying the EOFs and predicted PCs. Model sensitivity experiments were conducted to determine the optimal number of PCs. Validations against independent satellite observations indicate that the neural network–based model can reliably predict Loop Current variations and its eddy shedding process for a 4-week period. In some cases, an accurate forecast for 5–6 weeks is possible.
Air-Deployed Microbuoy Measurement of Temperatures in the Marginal Ice Zone Upper Ocean during the MIZOPEX Campaign
Authors: Bradley Alice C. , Palo Scott , LoDolce Gabriel , Weibel Doug , Lawrence Dale 
Published: March 2015

AbstractAir-deployed microbuoys (ADMBs) were developed as a means of measuring subsurface temperatures in the marginal ice zone (MIZ) over campaign-duration time scales to better understand how MIZ surface layer heat content accelerates melt rates at the edge of the ice pack. ADMBs are small, low-cost buoys deployable from unmanned aircraft and are capable of measuring temperatures to 0.1°C absolute accuracy at the surface, 1-m, and 2-m depth, along with GPS position. Each ADMB contains a microcontroller, GPS, 900-MHz radio, flash electrically erasable programmable read-only memory (EEPROM), battery, and a set of temperature sensors to monitor conditions for up to 10 days. A communications board on an overflying aircraft autonomously deploys each ADMB and collects data from previously deployed ADMBs for analysis. The 2013 Marginal Ice Zone Observations and Processes Experiment (MIZOPEX) campaign deployed ADMBs into the summer melt season MIZ north of Oliktok Point, Alaska, collecting over 400 h of data from two clusters of buoys during the short field campaign. Initial results indicate that SST is a good measure of upper-ocean temperature in the MIZ when conditions are well mixed, but that is often not the case. In areas with higher ice concentration, surface temperatures tend to underestimate the temperature of the subsurface, while in areas of low ice concentration, SSTs overestimate the subsurface temperature.
Assimilating Cloud Water Path as a Function of Model Cloud Microphysics in an Idealized Simulation
Authors: Jones Thomas A. , Stensrud David J. 
Published: March 2015

Abstract
The sensitivity of assimilating satellite retrievals of cloud water path (CWP) to the microphysics scheme used by a convection-allowing numerical model is explored. All experiments use the Advanced Research core of the Weather Research and Forecasting Model (WRF-ARW), with observations assimilated using the Data Assimilation Research Testbed ensemble adjustment Kalman filter and a 40-member ensemble. Three-dimensional idealized supercell simulations are generated from a deterministic WRF nature run started from a homogeneous set of initial conditions. Four cloud microphysics schemes are tested: Lin–Farley–Orville (LFO), Thompson (THOMP), Morrison double-moment (MOR), and Milbrandt–Yau (MY).
For the idealized experiments, assimilating CWP generates a mature supercell after approximately 1 h for all microphysics schemes. Vertical profiles of ensemble covariances show large differences in the relationship between CWP and various hydrometeor mixing ratios. While the differences in overall CWP are small, the experiments generate very different reflectivity analyses of the simulated storm, with MOR and MY underestimating reflectivity by a large margin. Vertical profiles of hydrometeor mixing ratios from each experiment are generally consistent with scheme design, such that the Thompson scheme characterizes the storm top as mostly snow whereas the Milbrandt–Yau scheme characterizes the storm top as mostly ice. The impacts of these differences on 30-min forecasts show that MOR and MY are unable to maintain convection within the model while THOMP and LFO perform somewhat better, though all fail to capture the divergent movement of the storm split in the nature run.