Here we present a description of the UKCA StratTrop chemical mechanism, which is used in the UKESM1 Earth system model for CMIP6. The StratTrop chemical mechanism is a merger of previously ...well-evaluated tropospheric and stratospheric mechanisms, and we provide results from a series of bespoke integrations to assess the overall performance of the model.
There is a clear need for the development of modelling frameworks for both climate change and air quality to help inform policies for addressing these issues simultaneously. This paper presents an ...initial attempt to develop a single modelling framework, by introducing a greater degree of consistency in the meteorological modelling framework by using a two-step, one-way nested configuration of models, from a global composition-climate model (GCCM) (140 km resolution) to a regional composition-climate model covering Europe (RCCM) (50 km resolution) and finally to a high (12 km) resolution model over the UK (AQUM). The latter model is used to produce routine air quality forecasts for the UK. All three models are based on the Met Office's Unified Model (MetUM). In order to better understand the impact of resolution on the downscaling of projections of future climate and air quality, we have used this nest of models to simulate a 5-year period using present-day emissions and under present-day climate conditions. We also consider the impact of running the higher-resolution model with higher spatial resolution emissions, rather than simply regridding emissions from the RCCM. We present an evaluation of the models compared to in situ air quality observations over the UK, plus a comparison against an independent 1 km resolution gridded dataset, derived from a combination of modelling and observations, effectively producing an analysis of annual mean surface pollutant concentrations. We show that using a high-resolution model over the UK has some benefits in improving air quality modelling, but that the use of higher spatial resolution emissions is important to capture local variations in concentrations, particularly for primary pollutants such as nitrogen dioxide and sulfur dioxide. For secondary pollutants such as ozone and the secondary component of PM10, the benefits of a higher-resolution nested model are more limited and reasons for this are discussed. This study highlights the point that the resolution of models is not the only factor in determining model performance – consistency between nested models is also important.
Introduction: Incisional negative pressure wound therapy (iNPWT) has been applied to bilateral breast reduction patients and shown a reduction in surgical complications. However, its effects on ...opioid use and hospitalisation length in this patient group has not been investigated.Methods: In this single surgeon retrospective cohort study, 52 patients who underwent bilateral breast reduction were analysed, with 23 patients in the iNPWT cohort and 29 in the standard-of-care (SOC) wound dressing cohort. Hospitalisation length, postoperative opioid use and surgical site complications were compared between cohorts. Mean (range) follow-up time was 369.15 (77-1329) days.Results: Hospitalisation length in days was significantly less in the iNPWT cohort (1.35) than the SOC cohort (2.03). Total ward opioid use was significantly reduced in the iNPWT cohort (45.50mg) compared to the SOC cohort (62.50mg). Discharge opioid prescription was significantly reduced in the iNPWT cohort (125.50mg) compared to the SOC cohort (230.00mg). The number of surgical site complications was significantly different between the groups (p=0.014).Discussion: This study suggests the use of iNPWT in bilateral breast reduction provides significant benefit through the reduction of hospitalisation, complications and opioid use. Conclusion: This is the first study to provide evidence for iNPWT in bilateral breast reduction in reducing postoperative opioid use and hospitalisation. It supports current literature showing a reduction in surgical site complications using iNPWT in bilateral breast reduction.
Intercontinental Transport of Ozone and Precursors (ITOP) (part of International Consortium for Atmospheric Research on Transport and Transformation (ICARTT)) was an intense research effort to ...measure long‐range transport of pollution across the North Atlantic and its impact on O3 production. During the aircraft campaign plumes were encountered containing large concentrations of CO plus other tracers and aerosols from forest fires in Alaska and Canada. A chemical transport model, p‐TOMCAT, and new biomass burning emissions inventories are used to study the emissions long‐range transport and their impact on the troposphere O3 budget. The fire plume structure is modeled well over long distances until it encounters convection over Europe. The CO values within the simulated plumes closely match aircraft measurements near North America and over the Atlantic and have good agreement with MOPITT CO data. O3 and NOx values were initially too great in the model plumes. However, by including additional vertical mixing of O3 above the fires, and using a lower NO2/CO emission ratio (0.008) for boreal fires, O3 concentrations are reduced closer to aircraft measurements, with NO2 closer to SCIAMACHY data. Too little PAN is produced within the simulated plumes, and our VOC scheme's simplicity may be another reason for O3 and NOx model‐data discrepancies. In the p‐TOMCAT simulations the fire emissions lead to increased tropospheric O3 over North America, the north Atlantic and western Europe from photochemical production and transport. The increased O3 over the Northern Hemisphere in the simulations reaches a peak in July 2004 in the range 2.0 to 6.2 Tg over a baseline of about 150 Tg.
High resolution simulations at 4.4 km and 1.5 km resolution have been performed for 12 historical tropical cyclones impacting Bangladesh. We use the European Centre for Medium-Range Weather ...Forecasting 5
generation Re-Analysis (ERA5) to provide a 9-member ensemble of initial and boundary conditions for the regional configuration of the Met Office Unified Model. The simulations are compared to the original ERA5 data and the International Best Track Archive for Climate Stewardship (IBTrACS) tropical cyclone database for wind speed, gust speed and mean sea-level pressure. The 4.4 km simulations show a typical increase in peak gust speed of 41 to 118 knots relative to ERA5, and a deepening of minimum mean sea-level pressure of up to -27 hPa, relative to ERA5 and IBTrACS data. The downscaled simulations compare more favourably with IBTrACS data than the ERA5 data suggesting tropical cyclone hazards in the ERA5 deterministic output may be underestimated. The dataset is freely available from https://doi.org/10.5281/zenodo.3600201 .
East African aridification during the past 8 million years is frequently invoked as a driver of large-scale shifts in vegetation
and the evolution of new animal lineages, including hominins
. ...However, evidence for increasing aridity is debated
and, crucially, the mechanisms leading to dry conditions are unclear
. Here, numerical model experiments show that valleys punctuating the 6,000-km-long East African Rift System (EARS) are central to the development of dry conditions in East Africa. These valleys, including the Turkana Basin in Kenya, cause East Africa to dry by channelling water vapour towards Central Africa, a process that simultaneously enhances rainfall in the Congo Basin rainforest. Without the valleys, the uplift of the rift system leads to a wetter climate in East Africa and a drier climate in the Congo Basin. Results from climate model experiments demonstrate that the detailed tectonic development of Africa has shaped the rainfall distribution, with profound implications for the evolution of African plant and animal lineages.
BackgroundTo describe the characteristics and outcomes of patients admitted to Intensive Care following vascular surgery, and their subsequent usage of Intensive Care resources, over a 15‐year period ...in Australia and New Zealand.MethodsThis was a retrospective, bi‐national study of 69 676 adult patients admitted to 179 Intensive Care Unit (ICUs) following vascular surgery between January 2005 and December 2019, using the Australian and New Zealand Intensive Care Society Adult Patient Database.ResultsThe proportion of ICU bed days used by vascular surgery patients decreased during the study period from 3.6% in 2005 to 2.9% in 2019 (P < 0.001). The cohort had a median age of 73 years, and were most frequently admitted after a carotid endarterectomy (22%) or elective open aneurysm repair (20%). A total of 5.2% of patients did not survive to discharge. Mean annual adjusted mortality decreased during the study period from 6.1% in 2005 to 3.7% in 2019 (P < 0.001). Multiple factors were associated with higher mortality, including gender, hospital case volume and hospital type.ConclusionsBetween 2005 and 2019 survival for vascular surgery patients requiring ICU admission in Australia and New Zealand improved. During the same time the proportion of ICU bed days used by these patients decreased.
Background
To describe the characteristics and outcomes of patients admitted to Intensive Care following vascular surgery, and their subsequent usage of Intensive Care resources, over a 15‐year ...period in Australia and New Zealand.
Methods
This was a retrospective, bi‐national study of 69 676 adult patients admitted to 179 Intensive Care Unit (ICUs) following vascular surgery between January 2005 and December 2019, using the Australian and New Zealand Intensive Care Society Adult Patient Database.
Results
The proportion of ICU bed days used by vascular surgery patients decreased during the study period from 3.6% in 2005 to 2.9% in 2019 (P < 0.001). The cohort had a median age of 73 years, and were most frequently admitted after a carotid endarterectomy (22%) or elective open aneurysm repair (20%). A total of 5.2% of patients did not survive to discharge. Mean annual adjusted mortality decreased during the study period from 6.1% in 2005 to 3.7% in 2019 (P < 0.001). Multiple factors were associated with higher mortality, including gender, hospital case volume and hospital type.
Conclusions
Between 2005 and 2019 survival for vascular surgery patients requiring ICU admission in Australia and New Zealand improved. During the same time the proportion of ICU bed days used by these patients decreased.
Over a 15‐year period survival to discharge increased for patients admitted to ICU following vascular surgery in 179 units across Australia and New Zealand. During the same period ICU bed‐use by vascular surgery patients decreased.
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