What causes the spread of model projections of ocean dynamic sea-level change in response to greenhouse gas forcing?

Sea levels of different atmosphere-ocean general circulation models (AOGCMs) respond to climate change forcing in different ways, representing a crucial uncertainty in climate change research. We isolate the role of the ocean dynamics in setting the spatial pattern of dynamic sea-level (zeta) change by forcing several AOGCMs with prescribed identical heat, momentum (wind) and freshwater flux perturbations. This method produces a zeta projection spread comparable in magnitude to the spread that results from greenhouse gas forcing, indicating that the differences in ocean model formulation are the cause, rather than diversity in surface flux change. The heat flux change drives most of the global pattern of zeta change, while the momentum and water flux changes cause locally confined features. North Atlantic heat uptake causes large temperature and salinity driven density changes, altering local ocean transport and zeta. The spread between AOGCMs here is caused largely by differences in their regional transport adjustment, which redistributes heat that was already in the ocean prior to perturbation. The geographic details of the zeta change in the North Atlantic are diverse across models, but the underlying dynamic change is similar. In contrast, the heat absorbed by the Southern Ocean does not strongly alter the vertically coherent circulation. The Arctic zeta change is dissimilar across models, owing to differences in passive heat uptake and circulation change. Only the Arctic is strongly affected by nonlinear interactions between the three air-sea flux changes, and these are model specific.Peer reviewe

ACCESS-OM2 v1.0: a global ocean-sea ice model at three resolutions

We introduce ACCESS-OM2, a new version of the ocean–sea ice model of the Australian Community Climate and Earth System Simulator. ACCESS-OM2 is driven by a prescribed atmosphere (JRA55-do) but has been designed to form the ocean–sea ice component of the fully coupled (atmosphere–land–ocean–sea ice) ACCESS-CM2 model. Importantly, the model is available at three different horizontal resolutions: a coarse resolution (nominally 1∘ horizontal grid spacing), an eddy-permitting resolution (nominally 0.25∘), and an eddy-rich resolution (0.1∘ with 75 vertical levels); the eddy-rich model is designed to be incorporated into the Bluelink operational ocean prediction and reanalysis system. The different resolutions have been developed simultaneously, both to allow for testing at lower resolutions and to permit comparison across resolutions. In this paper, the model is introduced and the individual components are documented. The model performance is evaluated across the three different resolutions, highlighting the relative advantages and disadvantages of running ocean–sea ice models at higher resolution. We find that higher resolution is an advantage in resolving flow through small straits, the structure of western boundary currents, and the abyssal overturning cell but that there is scope for improvements in sub-grid-scale parameterizations at the highest resolution

ACCESS-OM2 v1.0: A global ocean-sea ice model at three resolutions

We introduce ACCESS-OM2, a new version of the ocean–sea ice model of the Australian Community Climate and Earth System Simulator. ACCESS-OM2 is driven by a prescribed atmosphere (JRA55-do) but has been designed to form the ocean–sea ice component of the fully coupled (atmosphere–land–ocean–sea ice) ACCESS-CM2 model. Importantly, the model is available at three different horizontal resolutions: a coarse resolution (nominally 1∘ horizontal grid spacing), an eddy-permitting resolution (nominally 0.25∘), and an eddy-rich resolution (0.1∘ with 75 vertical levels); the eddy-rich model is designed to be incorporated into the Bluelink operational ocean prediction and reanalysis system. The different resolutions have been developed simultaneously, both to allow for testing at lower resolutions and to permit comparison across resolutions. In this paper, the model is introduced and the individual components are documented. The model performance is evaluated across the three different resolutions, highlighting the relative advantages and disadvantages of running ocean–sea ice models at higher resolution. We find that higher resolution is an advantage in resolving flow through small straits, the structure of western boundary currents, and the abyssal overturning cell but that there is scope for improvements in sub-grid-scale parameterizations at the highest resolution.This research has been supported by the Australian Research Council (grant nos. LP160100073, CE170100023, FT13101532, DP160103130 and DE170100184), the International Space Science Institute (grant no. 406), and the Australian Antarctic Science (grant nos. 4301 and 4390)

Improving clinician-carer communication for safer hospital care: A study of the 'TOP 5' strategy in patients with dementia

© The Author 2015. Objective: To examine the impact of implementing a clinician-carer communication tool for hospitalized patients with dementia. Design: Surveys were conducted with clinicians and carers about perceptions and experiences. Implementation process and costs were explored through surveys of local staff. Time series analysis was conducted on incident-reported falls, usage of non-regular anti-psychotics and one-to-one nursing. Setting: Twenty-one hospitals in Australia. Participants: Surveyswere returned by 798 clinicians, 240 carers and 21 local liaison staff involved in implementation. Intervention: Implementation of a communication tool over 12 months. Main outcome measures: The process of implementation was documented. Outcome measures included clinician and carer perceptions, safety indicators (incident-reported falls and usage of non-regular anti-psychotics), resource use and costs. Results: Clinicians and carers reported high levels of acceptability and perceived benefits for patients. Clinicians rated confidence in caring for patients with dementia as being significantly higher after the introduction of TOP 5, (M= 2.93, SD= 0.65), than prior to TOP 5 (M= 2.74, SD = 0.75); F(1,712) = 11.21, P < 0.05. When analysed together, there was no change in incident-reported falls across all hospitals. At one hospital with a matched control ward, an average of 6.85 fewer falls incidents per month occurred in the intervention ward compared with the matched control ward (B = -6.85, P < 0.05). Conclusions: Our findings indicate that the use of a simple, low-cost communication strategy for patient care is associated with improvements in clinician and carer experience with potential implications for patient safety. Minimally, TOP 5 represents 'good practice' with a low risk of harm for patients

Evaluation of CMIP6 AMIP climate simulations with the ACCESS-AM2 model

The most recent version of the ACCESS-AM2 atmosphere-only climate model is introduced with results from the CMIP6 Atmospheric Model Intercomparison Project (AMIP) experiments configured with two land-surface models: CABLE and JULES. AMIP simulations are required as part of the CMIP6 core experiments. They are forced by prescribed time-varying observed sea surface temperature and sea-ice variations as well as variations in natural and anthropogenic external forcings. We evaluate the performance of the two configurations using three historical realisations for each. Model biases are estimated both globally and for the Australian region. The model shows close agreement with observed interannual variations of global-mean temperature across the latitude range 65°N–65°S. This is also true for the land-only temperature for 65°N–65°S, and a more stringent test of the model is driven by specified observed sea surface temperatures. Patterns of mean precipitation are simulated reasonably well, although there are biases in the amount and distribution of precipitation, typical of longstanding problems in representing this aspect of the climate. Selected features of the atmospheric circulation are discussed, including air temperatures and wind speeds. For the Australian region, in addition to examining the climatological patterns of temperature and precipitation, important drivers of climate variability are reviewed: El Niño-Southern Oscillation, the Indian Ocean Dipole and the Southern Annular Mode. In general, the correlation patterns for precipitation simulated by ACCESS-AM2 are somewhat weaker than in observations, although the ensemble means show better agreement than individual ensemble members. Overall, the two different land-surface schemes perform similarly. ACCESS-AM2 has reduced root mean square errors for both temperature and precipitation of around 15–20% at the global scale compared to the older CMIP5 versions of the model: ACCESS 1.0 and ACCESS 1.3

Improving clinician-carer communication for safer hospital care: a study of the &apos;TOP 5&apos; strategy in patients with dementia International Journal for Quality in Health

Abstract Objective: To examine the impact of implementing a clinician-carer communication tool for hospitalized patients with dementia. Design: Surveys were conducted with clinicians and carers about perceptions and experiences. Implementation process and costs were explored through surveys of local staff. Time series analysis was conducted on incident-reported falls, usage of non-regular anti-psychotics and one-to-one nursing. Setting: Twenty-one hospitals in Australia. Participants: Surveys were returned by 798 clinicians, 240 carers and 21 local liaison staff involved in implementation. Intervention: Implementation of a communication tool over 12 months. Main outcome measures: The process of implementation was documented. Outcome measures included clinician and carer perceptions, safety indicators (incident-reported falls and usage of non-regular anti-psychotics), resource use and costs. Results: Clinicians and carers reported high levels of acceptability and perceived benefits for patients. Clinicians rated confidence in caring for patients with dementia as being significantly higher after the introduction of TOP 5, (M = 2.93, SD = 0.65), than prior to TOP 5 (M = 2.74, SD = 0.75); F(1,712) = 11.21, P &lt; 0.05. When analysed together, there was no change in incident-reported falls across all hospitals. At one hospital with a matched control ward, an average of 6.85 fewer falls incidents per month occurred in the intervention ward compared with the matched control ward (B = −6.85, P &lt; 0.05). Conclusions: Our findings indicate that the use of a simple, low-cost communication strategy for patient care is associated with improvements in clinician and carer experience with potential implications for patient safety. Minimally, TOP 5 represents &apos;good practice&apos; with a low risk of harm for patients

A CMIP6-based multi-model downscaling ensemble to underpin climate change services in Australia

A multi-scenario, multi-model ensemble of simulations from regional climate models is outlined to provide the core data source for a set of climate projections and a climate change service. A subset of realisations from CMIP6 Global Climate Models (GCMs) are selected for downscaling by Regional Climate Models (RCMs) under a ‘sparse matrix’ framework using the CORDEX guidelines for Shared Socio-economic Pathways that feature low emissions (SSP1-2.6) and high emissions (SSP3-7.0). The subset excludes poor performing models, with performance assessed by the climatology over a large Indo-Pacific domain and an Australian-specific domain, the simulation of atmospheric circulation and teleconnections to major drivers, then incorporating other evaluation from the literature. The models are selected to be relatively independent by simply choosing one model from each ‘family’ where possible. The projected change in temperature and rainfall in climatic regions of Australia in the selected models are broadly representative of that from the whole CMIP6 ensemble, after deliberately treating models with very high climate sensitivity separately. A limited but carefully constructed ensemble will not represent statistically balanced estimates but can be used effectively under a ‘storylines’ style approach and can maximise representativeness within limits. The resulting ensemble can be used as a key data source for the future climate component of climate services in Australia. The ensemble will be used in conjunction with CMIP6 and large ensembles of GCM simulations as important context, and targeted ‘convective permitting resolution’ modelling, deep learning models and emulators for added insights to inform climate change planning in Australia