An Evaluation of Size-Resolved Cloud Microphysics Scheme Numerics for Use with Radar Observations. Part I: Collision-Coalescence

This study evaluates some available schemes designed to solve the stochastic collection equation (SCE) for collision-coalescence of hydrometeors using a size-resolved (bin) microphysics approach, and documents their numerical properties within the framework of a box model. Comparing three widely used SCE schemes, we find that all converge to almost identical solutions at sufficiently fine mass grids. However, one scheme converges far slower than the other two and shows pronounced numerical diffusion at the large-drop tail of the size distribution. One of the remaining two schemes is recommended on the basis that it is well-converged on a relatively coarse mass grid, stable for large time steps, strictly mass-conservative, and computationally efficient. To examine the effects of SCE scheme choice on simulating clouds and precipitation, two of the three schemes are compared in large-eddy simulations of a drizzling stratocumulus field. A forward simulator that produces Doppler spectra from the large-eddy simulation results is used to compare the model output directly with radar observations. The scheme with pronounced numerical diffusion predicts excessively large mean Doppler velocities and overly broad and negatively skewed spectra compared with observations, consistent with numerical diffusion demonstrated in the box model. Statistics obtained using the recommended scheme are closer to observations, but notable differences remain, indicating that factors other than SCE scheme accuracy are limiting simulation fidelity

Constraining the Models' Response of Tropical Clouds to SST Forcings Using CALIPSO Observations

Here we present preliminary results from the analysis of the low cloud cover (LCC) and cloud radiative effect (CRE) interannual changes in response to sea surface temperature (SST) forcings in two GISS climate models, and 12 other climate models. We further classify them as a function of their ability to reproduce the vertical structure of the cloud response to SST change against 10 years of CALIPSO observations: the constrained models, which match the observation constraint, and the unconstrained models. The constrained models replicate the observed interannual LCC change particularly well (LCC(sub con)=-3.49 1.01 %/K vs. LCC(sub obs)=-3.59 0.28 %/K) as opposed to the unconstrained models, which largely underestimate it (LCC(sub unc) = -1.32 1.28 %/K). As a result, the amount of short-wave warming simulated by the constrained models (CRE(sub con)=2.60 1.13 W/m2/K) is in better agreement with the observations (CRE(sub obs)=3.05 0.28 W/m2/K) than the unconstrained models (CRE(sub con)=0.87 2.63 W/m2/K). Depending on the type of low cloud, the observed relationship between cloud/radiation and surface temperature varies. Over the stratocumulus regions, increasing SSTs generate higher cloud top height along with a large decrease of the cloud fraction below as opposed to a slight decrease of the cloud fraction at each level over the trade cumulus regions. Our results suggest that the models must generate sustainable stratocumulus decks and moist processes in the planetary boundary layer to reproduce these observed features. Future work will focus on defining a method to objectively discriminate these cloud types that can be applied consistently in both the observations and the models

The feasibility of implementing the ICHOM Standard Set for Hip and Knee Osteoarthritis: a mixed-methods evaluation in public and private hospital settings.

Background: There is growing international momentum for standardising patient outcome assessment and using patient-reported outcome measures (PROMs) to capture outcomes that matter to patients. The International Consortium for Health Outcomes Measurement (ICHOM) Standard Sets were developed to capture the outcomes of care for costly conditions including osteoarthritis. This study evaluated the feasibility of implementing the ICHOM Standard Set for Hip and Knee Osteoarthritis in \u27real world\u27 public and private hospital settings. Methods: A mixed-methods design was used to capture comprehensive data on patient outcomes, implementation costs, and the implementation experiences of patients, clinicians and administrative staff. The ICHOM Standard Set was implemented at two hospital sites (1 public, 1 private) in May 2016. Patients undergoing primary hip or knee replacement for osteoarthritis were recruited from pre-admission clinics and a private orthopaedic clinic. Baseline Standard Set data were collected before surgery and at pre-determined post-operative timepoints. Data on the costs of Standard Set implementation were also collected. Semi-structured interviews were conducted with key stakeholders ( Results: The cost of Standard Set implementation and ongoing data collection for 17 months totalled $AUD94,955. Preference data (collected prior to completing the Standard Set) revealed that most participants preferred paper-based (83%) or web-based questionnaire completion (14%), with only a small proportion preferring iPad-based completion (3%). Several PROMs within the Standard Set were responsive to change (effect size range 0.19-0.85), with significant improvements in important health outcomes identified 6 weeks after surgery. Patient interviews showed a variable understanding of why patient-reported data collection is undertaken; however, patients perceived that PROMs provided relevant information to treating clinicians, and that the burden of questionnaire completion was minimal. Staff interviews revealed that PROMs are considered valuable, dedicated personnel are required to support data collection, gaps in information technology resources must be addressed, and that the Standard Set offers benefits beyond what currently-used measures provide. Conclusion: The Standard Set can be feasibly implemented in hospital settings, but with important caveats around staffing and technical support, consideration of patient preferences, and promotion of active clinician engagement

Establishing cross-discipline consensus on contraception, pregnancy and breast feeding-related educational messages and clinical practices to support women with rheumatoid arthritis: An Australian Delphi study

Objective: Recognising the need for a best-practice and consistent approach in providing care to women with rheumatoid arthritis (RA) in relation to (1) general health, (2) contraception, (3) conception and pregnancy, (4) breast feeding and (5) early parenting, we sought to achieve cross-discipline, clinical consensus on key messages and clinical practice behaviours in these 5 areas. Design: 3-round eDelphi study. In round 1, panellists provided free-text responses to open-ended questions about care for women with RA across the 5 areas. Subsequently, panellists refined and scored the synthesised responses, presented as metathemes, themes and detailed elements. Where =5% of panellists did not support a theme in a given round, it was removed. Setting: Panel of practicing Australian rheumatologists (n=22), obstetricians/obstetric medicine physicians (n=9) and pharmacists (n=5). Results: 34 (94.4%) panellists participated in all 3 rounds. The panel supported 18 themes across the 5 areas (support/strongly support: 88.2-100%) underpinned by 5 metathemes. Metathemes focused on coordination in information delivery, the mode and timing of information delivery, evidence underpinning information, engagement of the right health professionals at the right time and a non-judgemental approach to infant feeding. Themes included practices for primary prevention of chronic disease and their sequelae, the importance of contraception and planning pregnancy and breast feeding, close monitoring of medications, supporting mental wellbeing, managing disease activity and providing practical support for early parenting. Conclusions: A cross-disciplinary clinical panel highly supported key information and clinical practices in the care for women with RA across the continuum of contraception to early parenting within a whole-person, chronic disease management approach

Cirrus microphysics and radiative transfer: Cloud field study on October 28, 1986

The radiative properties of cirrus clouds present one of the unresolved problems in weather and climate research. Uncertainties in ice particle amount and size and, also, the general inability to model the single scattering properties of their usually complex particle shapes, prevent accurate model predictions. For an improved understanding of cirrus radiative effects, field experiments, as those of the Cirrus IFO of FIRE, are necessary. Simultaneous measurements of radiative fluxes and cirrus microphysics at multiple cirrus cloud altitudes allows the pitting of calculated versus measured vertical flux profiles; with the potential to judge current cirrus cloud modeling. Most of the problems in this study are linked to the inhomogeneity of the cloud field. Thus, only studies on more homogeneous cirrus cloud cases promises a possibility to improve current cirrus parameterizations. Still, the current inability to detect small ice particles will remain as a considerable handicap

Cirrus microphysics and radiative transfer: A case study

During the Cirrus Intensive Field Operations of FIRE, data collected by the NCAR King Air in the vicinity of Wausau, WI on October 28 were selected to study the influence of cirrus cloud microphysics on radiative transfer and the role of microphysical approximations in radiative transfer models. The instrumentation of the King Air provided, aside from temperature and wind data, up-and downwelling broadband solar and infrared fluxes as well as detailed microphysical data. The aircraft data, supplied every second, are averaged over the 7 legs to represent the properties for that altitude. The resulting vertical profiles, however, suffer from the fact that each leg represents a different cloud column path. Based on the measured microphysical data particle size distributions of equivalent spheres for each cloud level are developed. Accurate radiative transfer calculations are performed, incorporating atmospheric and radiative data from the ground and the stratosphere. Comparing calculated to the measured up- and downwelling fluxes at the seven cloud levels for both the averaged and the three crossover data will help to assess the validity of particle size and shape approximation as they are frequently used to model cirrus clouds. Once agreement is achieved the model results may be applied to determine, in comparison to a cloudfree case, the influence of this particular cirrus on the radiation budget of the earth atmosphere system

A Model for Particle Microphysics, Turbulent Mixing, and Radiative Transfer in the Stratocumulus-Topped Marine Boundary Layer and Comparisons with Measurements

A detailed 1D model of the stratocumulus-topped marine boundary layer is described. The model has three coupled components: a microphysics module that resolves the size distributions of aerosols and cloud droplets, a turbulence module that treats vertical mixing between layers, and a multiple wavelength radiative transfer module that calculates radiative heating rates and cloud optical properties. The results of a 12-h model simulation reproduce reasonably well the bulk thermodynamics, microphysical properties, and radiative fluxes measured in an approx. 500-m thick, summertime marine stratocumulus cloud layer by Nicholls. However, in this case, the model predictions of turbulent fluxes between the cloud and subcloud layers exceed the measurements. Results of model simulations are also compared to measurements of a marine stratus layer made under gale conditions and with measurements of a high, thin marine stratocumulus layer. The variations in cloud properties are generally reproduced by the model, although it underpredicts the entrainment of overlying air at cloud top under gale conditions. Sensitivities of the model results are explored. The vertical profile of cloud droplet concentration is sensitive to the lower size cutoff of the droplet size distribution due to the presence of unactivated haze particles in the lower region of the modeled cloud. Increases in total droplet concentrations do not always produce less drizzle and more cloud water in the model. The radius of the mean droplet volume does not correlate consistently with drizzle, but the effective droplet radius does. The greatest impacts on cloud properties predicted by the model are produced by halving the width of the size distribution of input condensation nuclei and by omitting the effect of cloud-top radiative cooling on the condensational growth of cloud droplets. The omission of infrared scattering produces noticeable changes in cloud properties. The collection efficiencies for droplets less than 30-micrometers radius, and the value of the accommodation coefficient for condensational droplet growth, have noticeable effects on cloud properties. The divergence of the horizontal wind also has a significant effect on a 12-h model simulation of cloud structure. Conclusions drawn from the model are tentative because of the limitations of the 1D model framework. A principal simplification is that the model assumes horizontal homogeneity, and, therefore, does not resolve updrafts and downdrafts. Likely consequences of this simplification include overprediction of the growth of droplets by condensation in the upper region of the cloud, underprediction of droplet condensational growth in the lower region of the cloud, and underprediction of peak supersaturations