Global coral bleaching event detection from satellite monitoring of extreme heat stress

Over the past four decades, coral bleaching events have occurred with increasing frequency and severity, directly linked to increasing ocean temperature due to climate change. For the latter half of that period, satellite monitoring by NOAA Coral Reef Watch in near real-time has provided invaluable insight into bleaching risk. Here, we describe a novel application of those products to develop basin-scale tools for tracking the development of extreme heat events that enable monitoring of global coral bleaching events. Case studies of historical extreme events (1982-2018) across the three tropical ocean basins (Indian, Pacific and Atlantic) were analysed using this basin-scale approach to identify key thresholds of heat stress extent for the definition of global bleaching. Global-scale events are apparent when all three tropical basins experience heat stress in at least 10% of reef-containing locations. An 8-month ‘detection window’ was determined as the optimal period of time through which pixels exposed to heat stress should continue to be counted as part of a basin-scale event to account for seasonal variations across ocean basins. Understanding the broader context of basin-scale conditions can inform management of individual reefs, management networks and other reef stakeholders. Operationalising this product for near real-time delivery will provide an effective communication of the status of coral reefs around the world during an era of unprecedented climate threats

Unprecedented early-summer heat stress and forecast of coral bleaching on the Great Barrier Reef, 2021-2022

The Great Barrier Reef (GBR) is predicted to undergo its sixth mass coral bleaching event during the Southern Hemisphere summer of 2021-2022. Coral bleaching-level heat stress over the GBR is forecast to start earlier than any previous year in the satellite record (1985-present). The National Oceanic and Atmospheric Administration (NOAA) Coral Reef Watch (CRW) near real-time satellite-based heat stress products were used to investigate early-summer sea surface temperature (SST) and heat stress conditions on the GBR during late 2021. As of 14 December 2021, values of instantaneous heat stress (Coral Bleaching HotSpots) and accumulated heat stress over a 12-week running window (Degree Heating Weeks) on the GBR were unprecedented in the satellite record. Further, 89% of GBR satellite reef pixels for this date in 2021 had a positive seven-day SST trend of greater than 0.2 degrees Celsius/week. Background temperatures (the minimum temperature over the previous 29 days) were alarmingly high, with 87% of GBR reef pixels on 14 December 2021 being greater than the maximum SST over that same 29-day period for any year from 1985-2020. The GBR is starting the 2021-2022 summer season with more accumulated heat than ever before, which could have disastrous consequences for the health, recovery, and future of this critical reef system

Semiclassical mode-coupling factorizations of coherent nonlinear optical response

The identification of relevant collective coordinates is crucial for the interpretation of coherent nonlinear spectroscopies of complex molecules and liquids. Using an $\hbar$ expansion of Liouville space generating functions, we show how to factorize multitime nonlinear response functions into products of lower-order correlation functions of collective coordinates, and derive closed expressions for linear, second and third order response functions. In addition to providing systematic quantum corrections, $\hbar$ offers a convenient bookkeeping device even for the purely classical response, since including quantum fluctuations allows to circumvent the expensive computation of stability matrices which is a major bottleneck in Molecular Dynamics (MD) simulations. The existing classical simulation strategies, including Mode-Coupling in $\mathbf{k}$ space and in real-space, Langevin equations, and Instantaneous Normal Modes are compared from a unified viewpoint

Subretinal Implantation of Electrospun, Short Nanowire, and Smooth Poly(ε-caprolactone) Scaffolds to the Subretinal Space of Porcine Eyes

Biodegradable scaffolds play an important adjunct role in transplantation of retinal progenitor cells (RPCs) to the subretinal space. Poly(ε-Caprolactone) (PCL) scaffolds with different modifications were subretinally implanted in 28 porcine eyes and evaluated by multifocal electroretinography (mfERG) and histology after 6 weeks of observation. PCL Short Nanowire, PCL Electrospun, and PCL Smooth scaffolds were well tolerated in the subretinal space in pigs and caused no inflammation and limited tissue disruption. PCL Short Nanowire had an average rate of preserved overlying outer retina 17% higher than PCL Electrospun and 25% higher than PCL Smooth. Furthermore, PCL Short Nanowire was found to have the most suitable degree of stiffness for surgical delivery to the subretinal space. The membrane-induced photoreceptor damage could be shown on mfERG, but the reductions in P1 amplitude were only significant for the PCL Smooth. We conclude that of the tested scaffolds, PCL Short Nanowire is the best candidate for subretinal implantation

Personal technology use amongst stroke patients : understanding the best platforms for the design of health interventions in treatment and rehabilitation

Europe's healthcare systems are under strain with an ageing population contributing to increased risk of strokes. Rapid technology adaption is needed to prevent, rehabilitate and manage symptoms. This paper identifies what technology platforms are most familiar and accessible to stroke patients to guide designers and engineers to develop future interventions. A survey was distributed to 100 inpatients at a stroke unit, identifying patients' accessibility and usage of personal technologies. Results showed that desktop/laptops and smartphones were most used as opposed to tablets and smartwatches. Different technologies were used for different tasks with a notable lack of devices used for personal health. The underlying reasons for this are discussed with recommendations made on what personal technology platforms should be implemented by designers and engineers in technology-based health interventions

Optimal spatiotemporal scales to aggregate satellite ocean color data for nearshore reefs and tropical coastal waters: two case studies

Remotely sensed ocean color data are useful for monitoring water quality in coastal environments. However, moderate resolution (hundreds of meters to a few kilometers) satellite data are underutilized in these environments because of frequent data gaps from cloud cover and algorithm complexities in shallow waters. Aggregating satellite data over larger space and time scales is a common method to reduce data gaps and generate a more complete time series, but potentially smooths out the small-scale, episodic changes in water quality that can have ecological influences. By comparing aggregated satellite estimates of Kd(490) with related in-water measurements, we can understand the extent to which aggregation methods are viable for filling gaps while being able to characterize ecologically relevant water quality conditions. In this study, we tested a combination of six spatial and seven temporal scales for aggregating data from the VIIRS instrument at several coral reef locations in Maui, Hawai‘i and Puerto Rico and compared these with in situ measurements of Kd(490) and turbidity. In Maui, we found that the median value of a 5-pixels, 7-days spatiotemporal cube of satellite data yielded a robust result capable of differentiating observations across small space and time domains and had the best correlation among spatiotemporal cubes when compared with in situ Kd(490) across 11 nearshore sites (R2 = 0.84). We also found long-term averages (i.e., chronic condition) of VIIRS data using this aggregation method follow a similar spatial pattern to onshore turbidity measurements along the Maui coast over a three-year period. In Puerto Rico, we found that the median of a 13-pixels, 13-days spatiotemporal cube of satellite data yielded the best overall result with an R2 = 0.54 when compared with in situ Kd(490) measurements for one nearshore site with measurement dates spanning 2016–2019. As spatiotemporal cubes of different dimensions yielded optimum results in the two locations, we recommend local analysis of spatial and temporal optima when applying this technique elsewhere. The use of satellite data and in situ water quality measurements provide complementary information, each enhancing understanding of the issues affecting coastal ecosystems, including coral reefs, and the success of management efforts

Olive phenology as a sensitive indicator of future climatic warming in the Mediterranean

Experimental and modelling work suggests a strong dependence of olive flowering date on spring temperatures. Since airborne pollen concentrations reflect the flowering phenology of olive populations within a radius of 50 km, they may be a sensitive regional indicator of climatic warming. We assessed this potential sensitivity with phenology models fitted to flowering dates inferred from maximum airborne pollen data. Of four models tested, a thermal time model gave the best fit for Montpellier, France, and was the most effective at the regional scale, providing reasonable predictions for 10 sites in the western Mediterranean. This model was forced with replicated future temperature simulations for the western Mediterranean from a coupled ocean-atmosphere general circulation model (GCM). The GCM temperatures rose by 4·5 °C between 1990 and 2099 with a 1% per year increase in greenhouse gases, and modelled flowering date advanced at a rate of 6·2 d per °C. The results indicated that this long-term regional trend in phenology might be statistically significant as early as 2030, but with marked spatial variation in magnitude, with the calculated flowering date between the 1990s and 2030s advancing by 3–23 d. Future monitoring of airborne olive pollen may therefore provide an early biological indicator of climatic warming in the Mediterranean