Retrieval of vertical air motion in precipitating clouds using Mie scattering and comparison with in situ measurements

The article of record as published may be located at http://dx.doi.org/10.1175/JAMC-D-16-0158.1For the first time, the Mie notch retrieval technique is applied to airborne cloud Doppler radar observations in warm precipitating clouds to retrieve the vertical air velocity profile above the aircraft. The retrieval algorithm prescribed here accounts for two major sources of bias: aircraft motion and horizontal wind. The retrieval methodology is evaluated using the aircraft in situ vertical air velocity measurements. The standard deviations of the residuals for the retrieved and in situ measured data for an 18-s time segment are 0.21 and 0.24 m s−1, respectively; the mean difference between the two is 0.01 m s−1. For the studied cases, the total theoretical uncertainty is less than 0.19 m s−1 and the actual retrieval uncertainty is about 0.1 m s−1. These results demonstrate that the Mie notch technique combined with the bias removal procedure described in this paper can successfully retrieve vertical air velocity from airborne radar observations with low spectral broadening due to Doppler fading, which enables new opportunities in cloud and precipitation research. A separate spectral peak due to returns from the cloud droplets is also observed in the same radar Doppler spectra and is also used to retrieve vertical air motion. The vertical air velocities retrieved using the two different methods agree well with each other, and the correlation coefficient is as high as 0.996, which indicates that the spectral peak due to cloud droplets might provide another way to retrieve vertical air velocity in clouds when the Mie notch is not detected but the cloud droplets’ spectral peak is discernable.ONR N000140810465

Predictive Value of Pharyngeal Width at Rest (JOSCYL Width) for Aspiration in Elderly People

Objective To develop a new tool for aspiration risk prediction based on pharyngeal width at rest in older adults with symptoms of aspiration. Methods Lateral cervical spine roentgenograms were obtained from 33 older adult patients who complained of dysphagia and from 33 healthy, age-matched controls. Pharyngeal width at rest was measured at two points. We named the average of these two pharyngeal widths ‘JOSCYL Width’, calculated ‘JOSCYL Scale’, and compared these parameters between dysphagia and control groups. Correlations of individual JOSCYL Width and JOSCYL Scale, with Penetration Aspiration Scale (PAS) and Dysphagia Outcome and Severity Scale (DOSS) scores were analyzed for the dysphagia group. To determine optimal cutoff points for predicting aspiration, a receiver operating characteristic curve analysis was performed on JOSCYL Width and JOSCYL Scale. Results Both JOSCYL Width and JOSCYL Scale of the dysphagia group were larger than those of the control group (p<0.001). The correlation between JOSCYL Width and severity of dysphagia was significant for the dysphagia group (PAS p=0.007; DOSS p=0.012). The correlation between JOSCYL Scale and the severity of dysphagia was also significant for the dysphagia group (PAS p=0.009; DOSS p=0.011). Optimal cutoffs for JOSCYL Width and JOSCYL Scale for predicting aspiration were 20.0 mm and 5.9, respectively. Conclusion JOSCYL Width and JOSCYL Scale can be new indicators for predicting aspiration in older adults. They are both precise and easy to use

Cyclin Y inhibits plasticity-induced AMPA receptor exocytosis and LTP

Cyclin Y (CCNY) is a member of the cyclin protein family, known to regulate cell division in proliferating cells. Interestingly, CCNY is expressed in neurons that do not undergo cell division. Here, we report that CCNY negatively regulates long-term potentiation (LTP) of synaptic strength through inhibition of AMPA receptor trafficking. CCNY is enriched in postsynaptic fractions from rat forebrain and is localized adjacent to postsynaptic sites in dendritic spines in rat hippocampal neurons. Using live-cell imaging of a pH-sensitive AMPA receptor, we found that during LTP-inducing stimulation, CCNY inhibits AMPA receptor exocytosis in dendritic spines. Furthermore, CCNY abolishes LTP in hippocampal slices. Taken together, our findings demonstrate that CCNY inhibits plasticity-induced AMPA receptor delivery to synapses and thereby blocks LTP, identifying a novel function for CCNY in post-mitotic cells

Operation of national coordinating service for interhospital transfer from emergency departments: experience and implications from Korea

Background Since 2014, Korea has been operating the National Emergency Medical Situation Room (NEMSR) to provide regional emergency departments (EDs) with coordination services for the interhospital transfer of critically ill patients. The present study aimed to describe the NEMSRs experience and interhospital transfer pattern from EDs nationwide, and investigate the factors related to delayed transfers or transfers that could not be arranged by the NEMSR. Methods This study was a retrospective cross-sectional analysis of the NEMSRs coordination registry from 2017 to 2019. The demographic and hospital characteristics related to emergency transfers were analyzed with hierarchical logistic models. Results The NEMSR received a total of 14,003 requests for the arrangement of the interhospital transfers of critically ill patients from 2017 to 2019. Of 10,222 requests included in the analysis, 8297 (81.17%) successful transfers were coordinated by the NEMSR. Transfers were requested mainly due to a shortage of medical staff (59.79%) and ICU beds (30.80%). Delayed transfers were significantly associated with insufficient hospital resources. The larger the bed capacity of the sending hospital, the more difficult it was to coordinate the transfer (odds ratio [OR] for transfer not arranged = 2.04; 95% confidence interval [CI]: 1.48–2.82, ≥ 1000 beds vs. < 300 beds) and the longer the transfer was delayed (OR for delays of more than 44 minutes = 2.08; 95% CI: 1.57–2.76, ≥ 1000 beds vs. < 300 beds). Conclusions The operation of the NEMSR has clinical importance in that it could efficiently coordinate interhospital transfers through a protocolized process and resource information system. The coordination role is significant as information technology in emergency care develops while regional gaps in the distribution of medical resources widen

Eastern Pacific Emitted Aerosol Cloud Experiment

Aerosol–cloud–radiation interactions are widely held to be the largest single source of uncertainty in climate model projections of future radiative forcing due to increasing anthropogenic emissions. The underlying causes of this uncertainty among modeled predictions of climate are the gaps in our fundamental understanding of cloud processes. There has been significant progress with both observations and models in addressing these important questions but quantifying them correctly is nontrivial, thus limiting our ability to represent them in global climate models. The Eastern Pacific Emitted Aerosol Cloud Experiment (E-PEACE) 2011 was a targeted aircraft campaign with embedded modeling studies, using the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Twin Otter aircraft and the research vessel Point Sur in July and August 2011 off the central coast of California, with a full payload of instruments to measure particle and cloud number, mass, composition, and water uptake distributions. EPEACE used three emitted particle sources to separate particle-induced feedbacks from dynamical variability, namely 1) shipboard smoke-generated particles with 0.05–1-μm diameters (which produced tracks measured by satellite and had drop composition characteristic of organic smoke), 2) combustion particles from container ships with 0.05–0.2-μm diameters (which were measured in a variety of conditions with droplets containing both organic and sulfate components), and 3) aircraft-based milled salt particles with 3–5-μm diameters (which showed enhanced drizzle rates in some clouds). The aircraft observations were consistent with past large-eddy simulations of deeper clouds in ship tracks and aerosol– cloud parcel modeling of cloud drop number and composition, providing quantitative constraints on aerosol effects on warm-cloud microphysics

Challenges and Prospects for Reducing Coupled Climate Model SST Biases in the Eastern Tropical Atlantic and Pacific Oceans: The U.S. CLIVAR Eastern Tropical Oceans Synthesis Working Group

Well-known problems trouble coupled general circulation models of the eastern Atlantic and Pacific Ocean basins. Model climates are significantly more symmetric about the equator than is observed. Model sea surface temperatures are biased warm south and southeast of the equator, and the atmosphere is too rainy within a band south of the equator. Near-coastal eastern equatorial SSTs are too warm, producing a zonal SST gradient in the Atlantic opposite in sign to that observed. The U.S. Climate Variability and Predictability Program (CLIVAR) Eastern Tropical Ocean Synthesis Working Group (WG) has pursued an updated assessment of coupled model SST biases, focusing on the surface energy balance components, on regional error sources from clouds, deep convection, winds, and ocean eddies; on the sensitivity to model resolution; and on remote impacts. Motivated by the assessment, the WG makes the following recommendations: 1) encourage identification of the specific parameterizations contributing to the biases in individual models, as these can be model dependent; 2) restrict multimodel intercomparisons to specific processes; 3) encourage development of high-resolution coupled models with a concurrent emphasis on parameterization development of finer-scale ocean and atmosphere features, including low clouds; 4) encourage further availability of all surface flux components from buoys, for longer continuous time periods, in persistently cloudy regions; and 5) focus on the eastern basin coastal oceanic upwelling regions, where further opportunities for observational–modeling synergism exist

Physical modeling of a prograding delta on a mobile substrate : dynamic interactions between progradation and deformation

The subsurface architecture of a prograding delta on a mobile substrate (e.g., salt) is a product of the complex interplay between deposition and subsidence. Previous studies focused mainly on structural deformation of a salt layer in response to tectonic forcing, leaving the dynamic feedback between sedimentation and subsidence unexplored. We present results from physical experiments of delta progradation on a mobile substrate. Five carefully designed experiments were performed to understand the effects of delta progradation rate on the shape and dimension of salt deformation and associated delta deposition. All of the runs had constant sediment and water discharges, but the water depth and mobile substrate thickness varied from 1 cm to 3 cm and from 2 cm to 4 cm, respectively. The results showed that increasingly deeper water depths slowed the shoreline progradation rate, while increasingly thinner salt thickness accelerated delta progradation. The experimental results also provided a wide range of shoreline advance and subsidence rates that show changes in the shape and dimension of the salt deformation structure. Runs with fast shoreline progradation showed isolated salt domes developed internally on the delta plain and a rough platform pattern along the shoreline due to lobes built by channel flow between upwelled salt structures. However, runs with slow shoreline progradation developed long connected salt ridges around the toe of the delta, limiting sediment transport beyond the ridges. This overall pattern in salt structures is time dependent. As a delta surface grows larger and the shoreline progradational rate autogenically decreases with time, chances to develop isolated salt domes decrease but more connected long salt ridges occur. Physical modeling of a delta on a mobile substrate is important in predicting the mechanism for large-scale salt basin stratigraphy under a high sediment supply that interacts with the substrate.Geological Science

Snow study at Centre for Atmospheric Research Experiments : variability of snow fall velocity, density and shape

In this work, snow data, collected at the Centre for Atmospheric Research Experiments (CARE) site during the winter of 2005/06 as part of the Canadian CALIPSO/CloudSat Validation Project (C3VP) were analyzed with various goals in mind: 1) investigate the effects of surface temperature and system depth on the snow fall velocity and particle size distribution, 2) find the variables that control the relationships between snow fall velocity and size (control variables), 3) retrieve the coefficient and the exponent in the power-law mass-size relations used in snow reflectivity, 4) estimate vertical air motion and 5) describe the shape of snowflakes that can be used in polarimetric studies of snow. It also includes considerable calibration work on the Hydrometeor Velocity and Shape Detector (HVSD); as well as sensitivity testing for radar calibration and Mie-scattering effect on snow density.Snow events were classified into several categories according to the radar echo vertical extent (H), surface and echo top temperatures (T s, Tt), to find their effects on snow fall velocity and particle size distribution. Several case studies, including situations of strong turbulence, were also examined.Simple and multiple correlation analyses between control variables and parameters of the power-law size-velocity relationship were carried out for 13 snow cases having a high R2 between their mean snowflakes fall velocity and the v-D fitted curve, in order to find the control variables of power-law v-D relations. Those cases were all characterized by single layered precipitation with different echo depth, surface and echo top temperatures. Results show that the exponent "b" in v-D power-law relationship has little effect on the variability of snow fall velocity; all control variables (T s, Tt, H) correlate much better to the coefficient "a" than to the exponent "b", leading to a snow fall velocity that can be simulated with a varying coefficient "a" and a fixed exponent "b" (v=aD0.15) with good accuracy. Coefficient "a" and exponent "b" for a generic snow v-D relationship were also examined. The results indicate that coefficient "a" of generic snow represents the most frequent coefficient "a" during the events, while the exponent "b" does not show any representative.Retrieval of the coefficient "a" and exponent "b" in a power-law mass-size relation, which eventually affects the snow reflectivity, was conducted by minimizing the root mean square (RMS) of differences in reflectivity between Vertically pointing McGill X-band Radar (VertiX) and HVSD. Minima of reflectivity differences lay on a diagonal direction of a diagram of the coefficient "a" (x-axis) versus exponent "b" (y-axis). It is shown that as the system deepens, the slope gets less steep. In addition, coefficient and exponent for this mass-size relation change with time, and snow density derived from several combined snow events does not explain the average snow density of the period.A method to retrieve vertical air motion with good accuracy using VertiX and HVSD is suggested. Several snow shape parameters and relations between the area ratio (Ar) and size of snowflakes (Ar-D relation) are investigated with snow dimensions defined in various ways. These Ar-D relations will be used as a guideline in snow density models

Aerosol-Cloud-Precipitation Interactions in the Trade Wind Boundary Layer

This dissertation includes an overview of aerosol, cloud, and precipitation properties associated with shallow marine cumulus clouds observed during the Barbados Aerosol Cloud Experiment (BACEX, March-April 2010) and a discussion of their interactions. The principal observing platform for the experiment was the Cooperative Institute for Remotely Piloted Aircraft Studies (CIRPAS) Twin Otter (TO) research aircraft that was equipped with aerosol, cloud, and precipitation probes, standard meteorological instruments, and a up-looking cloud radar. The temporal variations and vertical distributions of aerosols observed on the 15 flights show a wide range of aerosol conditions that include the most intense African dust event observed at the Barbados surface site during all of 2010. An average CCN varied from 50 cm-3 to 800 cm-3 at super-saturation of 0.6 %, for example. The 10-day backward trajectories show that three distinctive air masses (originality of air mass as well as the vertical structure) dominate over the Eastern Caribbean (e.g., typical maritime air mass, Saharan Air Layer (SAL), Middle latitude dry air) with characteristic aerosol vertical structures. Many clouds in various phases of growth during BACEX are sampled. The maximum cloud depth observed is about less than 3 km and in most of the clouds is less than 1 km. Two types of precipitation features were observed for the shallow marine cumulus clouds with different impacts on boundary layer. In one, precipitation shafts are observed to emanate from the cloud base with evaporation in the sub-cloud layer (stabilize the sub-cloud layer). In the other, precipitation shafts emanate mainly near the cloud top on the downshear side of the cloud and evaporate in the cloud layer, leading to destabilizing the cloud layer and providing moisture to the layer. Only 42-44 % of clouds sampled were purely non-precipitating throughout the clouds; the remainder of the clouds showed precipitation somewhere in the cloud, predominantly closer to the cloud top. The relationship between aerosol (Na), cloud droplets (Nd), and precipitation rates (R) is addressed to explore aerosol-cloud-precipitation interactions. A robust increase in Nd with increase in aerosol concentrations is documented. Further, a strong linear relation between sub-cloud CCN and cloud-base Nd is observed in updrafts. The sensitivity of Nd to changes in vertical velocity perturbations w´ (i.e., dlnNd /dlnw´), is greater in the regimes of high aerosol concentrations, suggesting a slight increase in updrafts (or w´) in polluted conditions can lead to greater increases in Nd. Suppression of precipitation with aerosol is a common feature during BACEX. To quantify this decrease of precipitation toward higher aerosol concentration, the sensitivity of precipitation to changes in aerosol (i.e., precipitation susceptibility S0 ) is examined. S0 exhibits three regimes and peaks at intermediate range of cloud thickness. Further, the removal of Nd , due to the rain (wet scavenging), makes susceptibility stronger overall. In addition to the aerosol feeding clouds from the sub-cloud layer, small cumuli can alter the aerosol properties of their immediate environment through cloud and precipitation processes. In the warm cumuli studied, the depletion of aerosols near cloud field (so-called cloud halos/shell regimes) are notable, and the reduction of aerosols is more significant in precipitating clouds compared with non-and/or light-precipitating clouds. The modification of boundary layer aerosol by cloud processes is also explored. The comparisons of the thermodynamic structures observed over Africa with those at Barbados indicate that layers below the SAL are moistened by surface fluxes and convective processes as the air masses are advected across the Atlantic over 7-10 days

Use of Radar Chaff for Studying Circulations in and around Shallow Cumulus Clouds

Abstract Circulations in and around cumulus clouds are inferred by using a passive tracer (radar chaff) and an airborne cloud radar during the Barbados Aerosol Cloud Experiment (BACEX). The radar chaff elements used for this experiment are fibers that are cut to a length of about ½ of the radar wavelength to maximize radar returns by serving as dipole antennas. The fibers are packed in fiber tubes and are mounted in a dispenser beneath the wing of the aircraft. The chaff was released near the tops and edges of a growing small cumulus cloud. The aircraft then made penetrations of the cloud at lower levels to observe the chaff signals above the aircraft with the zenith-pointing cloud radar. This study shows that the environmental air above the cloud top descends along the downshear side of the cloud edge and is subsequently entrained back into the same cloud near the observation level. The in-cloud flow follows an inverted letter P pattern. The merits and limitations of the chaff method for tracking circulations in and around small cumuli are discussed