The connected ocean: comparing inter-ocean transport at the surface and at depth

The oceans form a global network of inter-connected basins, with currents transporting a range of tracers such as heat and pollution between them. Although the ocean dynamics play a key role in determining transport between basins, the basins are de ned by arbitrary geographical borders rather than physical connections. This thesis proposes a method of detecting dynamical boundaries and applies it to the ocean surface and interior. To achieve this, probabilistic models are used to summarise the transport described by vast datasets of water-following trajectories. Such models, known as Markov Chain models, have previously been used to map the distribution of plastic pollution yet are known to induce an artificial dispersion. First, a sensitivity analysis of the effect of model parameters on artificial dispersion is performed, to determine the optimal model set-up. Next, a global dataset of observed trajectories is used to detect dynamic transport barriers in two key areas of inter-ocean surface exchange: the Agulhas Current system and the North Atlantic inter-gyre transport barrier. Connectivity maps are introduced as maps of tracer destinations which highlight dynamical segregation between regions. For example, these are used to identify the source region for Agulhas Leakage and one-way equator-ward transport across the Gulf Stream. Using a new method to extract geostrophic motion from a trajectory dataset, the geostrophic contribution to inter-basin transport can be identified. Finally, connectivity maps are produced for the ocean interior using virtual particles released along isopycnals in the eddy-permitting ORCA025 ocean circulation model. The change in connectivity, in the two study regions, between two target isopycnals is the first step in creating a 3D border of the ocean basins. New basin definitions are then explained by transport processes relevant to the region. Future work should establish the link between dynamical boundaries and the distribution of heat and pollution.Open Acces

Seasonal forecast skill of upper-ocean heat content in coupled high-resolution systems

AbstractOcean heat content (OHC) anomalies typically persist for several months, making this variable a vital component of seasonal predictability in both the ocean and the atmosphere. However, the ability of seasonal forecasting systems to predict OHC remains largely untested. Here, we present a global assessment of OHC predictability in two state-of-the-art and fully-coupled seasonal forecasting systems. Overall, we find that dynamical systems make skilful seasonal predictions of OHC in the upper 300 m across a range of forecast start times, seasons and dynamical environments. Predictions of OHC are typically as skilful as predictions of sea surface temperature (SST), providing further proof that accurate representation of subsurface heat contributes to accurate surface predictions. We also compare dynamical systems to a simple anomaly persistence model to identify where dynamical systems provide added value over cheaper forecasts; this largely occurs in the equatorial regions and the tropics, and to a greater extent in the latter part of the forecast period. Regions where system performance is inadequate include the sub-polar regions and areas dominated by sharp fronts, which should be the focus of future improvements of climate forecasting systems

Skill assessment of ECV/EOV from seasonal forecast

Assess the seasonal forecast skill of selected ocean variables - SST, OHC300m, and SSH - from the ensemble of ECMWF and CMCC seasonal forecasts systems contributing to C3

Optimisation of the ActWELL lifestyle intervention programme for women attending routine NHS breast screening clinics

Acknowledgements The authors would like to acknowledge the assistance of Amy Hickman, and Eluned Hughes from Breast Cancer Now, for guidance on practical intervention perspectives, and Jill Hampton in manuscript preparation. Thanks also to all the members of our public advisory group. The Health Services Research Unit, University of Aberdeen, receives core funding from Scottish Government Chief Scientist Office. Funding This work was supported by The Scottish Government, grant number BC/Screening/17/01. The funders provided independent referee reports, which guided some of the study parameters (as described in the text). The funders have read this manuscript. In-kind support was given by Breast Cancer Now for facilitating this study.Peer reviewedPublisher PD

Randomised controlled trial to assess the impact of a lifestyle intervention (ActWELL) in women invited to NHS breast screening

Peer reviewedPublisher PD

Skills of the user-relevant ocean indicators

This document demonstrates the capability of seasonal forecasting systems to predict observable and user-relevant ocean climate indicators

Correction to:A novel approach to increasing community capacity for weight management a volunteer-delivered programme (ActWELL) initiated within breast screening clinics: a randomised controlled trial

Acknowledgements Our thanks to Elizabeth Banks who advised and assisted with many aspects of the study and also to the many women who commented on the development and design of this study including those on our Public Advisory Team (Pamela Deponio, Maggie Taylor and Mary Wotherspoon). Funding This work was supported by The Scottish Government, grant number BC/Screening/17/01. The funders provided independent referee reports which guided the final study design. The funders have read this manuscript. In-kind support was given by Breast Cancer Now for facilitating this study.Peer reviewedPublisher PD

A novel approach to increasing community capacity for weight management a volunteer-delivered programme (ActWELL) initiated within breast screening clinics:a randomised controlled trial

Background: It is estimated that around 30% of breast cancers in post-menopausal women are related to lifestyle. The breast cancer-pooling project demonstrated that sustained weight loss of 2 to 4.5 kg is associated with an 18% lower risk of breast cancer, highlighting the importance of small changes in body weight. Our study aimed to assess the effectiveness a volunteer-delivered, community based, weight management programme (ActWELL) for women with a BMI > 25 kg/m2 attending NHS Scotland Breast Screening clinics. Methods: A multicentre, 1:1 parallel group, randomised controlled trial was undertaken in 560 women aged 50 to 70 years with BMI > 25 kg/m2. On completion of baseline measures, all participants received a breast cancer prevention leaflet. Intervention group participants received the ActWELL intervention which focussed on personalised diet advice and pedometer walking plans. The programme was delivered in leisure centres by (the charity) Breast Cancer Now volunteer coaches. Primary outcomes were changes between groups at 12 months in body weight (kg) and physical activity (accelerometer measured step count). Results: Two hundred seventy-nine women were allocated to the intervention group and 281 to the comparison group. Twelve-month data were available from 240 (81%) intervention and 227 (85%) comparison group participants. Coaches delivered 523 coaching sessions and 1915 support calls to 279 intervention participants. Mean weight change was − 2.5 kg (95% CI − 3.1 to − 1.9) in the intervention group and − 1.2 kg (− 1.8 to 0.6) in the comparison group. The adjusted mean difference was − 1.3 kg (95% CI − 2.2 to − 0.4, P = 0.003). The odds ratio for losing 5% weight was 2.20 (95% CI 1.4 to 3.4, p = 0.0005) in favour of the intervention. The adjusted mean difference in step counts between groups was 483 steps/day (95% CI − 635 to 1602) (NS). Conclusions: A community weight management intervention initiated at breast screening clinics and delivered by volunteer coaches doubled the likelihood of clinically significant weight loss at 12 months (compared with usual care) offering significant potential to decrease breast cancer risk

Skill assessment of seasonal forecasts of ocean variables

There is growing demand for seasonal forecast products for marine applications. The availability of consistent and sufficiently long observational records of ocean variables permits the assessment of the spatial distribution of the skill of ocean variables from seasonal forecasts. Here we use state-of-the-art temporal records of sea surface temperature (SST), sea surface height (SSH) and upper 300m ocean heat content (OHC) to quantify the distribution of skill, up to 2 seasons ahead, of two operational seasonal forecasting systems contributing to the seasonal multi-model of the Copernicus Climate Change Services (C3S). This study presents the spatial distribution of the skill of the seasonal forecast ensemble mean in terms of anomaly correlation and root mean square error and compares it to the persistence and climatological benchmarks. The comparative assessment of the skill among variables sheds light on sources/limits of predictability at seasonal time scales, as well as the nature of model errors. Beyond these standard verification metrics, we also evaluate the ability of the models to represent the observed long-term trends. Results show that long-term trends contribute to the skill of seasonal forecasts. Although the forecasts capture the long-term trends in general, some regional aspects remain challenging. Part of these errors can be attributed to specific aspects of the ocean initialization, but others, such as the overestimation of the warming in the Eastern Pacific are also influenced by model error. Skill gains can be obtained by improving the trend representation in future forecasting systems. In the meantime, a forecast calibration procedure that corrects the linear trends can produce substantial skill gains. The results show that calibrated seasonal forecasts beat both the climatological and persistence benchmark almost at every location for all initial dates and lead times. Results demonstrate the value of the seasonal forecasts for marine applications and highlight the importance of representing the decadal variability and trends in ocean heat content and sea level