Predictability of European winter 2019/20: Indian Ocean dipole impacts on the NAO

Northern Europe and the UK experienced an exceptionally warm and wet winter in 2019/20, driven by an anomalously positive North Atlantic Oscillation (NAO). This positive NAO was well forecast by several seasonal forecast systems, suggesting that this winter the NAO was highly predictable at seasonal lead times. A very strong positive Indian Ocean dipole (IOD) event was also observed at the start of winter. Here we use composite analysis and model experiments, to show that the IOD was a key driver of the observed positive NAO. Using model experiments that perturb the Indian Ocean initial conditions, two teleconnection pathways of the IOD to the north Atlantic emerge: a tropospheric teleconnection pathway via a Rossby wave train travelling from the Indian Ocean over the Pacific and Atlantic, and a stratospheric teleconnection pathway via the Aleutian region and the stratospheric polar vortex. These pathways are similar to those for the El Niño Southern Oscillation link to the north Atlantic which are already well documented. The anomalies in the north Atlantic jet stream location and strength, and the associated precipitation anomalies over the UK and northern Europe, as simulated by the model IOD experiments, show remarkable agreement with those forecast and observed

Tropical rainfall predictions from multiple seasonal forecast systems

We quantify seasonal prediction skill of tropical winter rainfall in 14 climate forecast systems. High levels of seasonal prediction skill exist for year‐to‐year rainfall variability in all tropical ocean basins. The tropical East Pacific is the most skilful region, with very high correlation scores, and the tropical West Pacific is also highly skilful. Predictions of tropical Atlantic and Indian Ocean rainfall show lower but statistically significant scores. We compare prediction skill (measured against observed variability) with model predictability (using single forecasts as surrogate observations). Model predictability matches prediction skill in some regions but it is generally greater, especially over the Indian Ocean. We also find significant inter‐basin connections in both observed and predicted rainfall. Teleconnections between basins due to El Niño–Southern Oscillation (ENSO) appear to be reproduced in multi‐model predictions and are responsible for much of the prediction skill. They also explain the relative magnitude of inter‐annual variability, the relative magnitude of predictable rainfall signals and the ranking of prediction skill across different basins. These seasonal tropical rainfall predictions exhibit a severe wet bias, often in excess of 20% of mean rainfall. However, we find little direct relationship between bias and prediction skill. Our results suggest that future prediction systems would be best improved through better model representation of inter‐basin rainfall connections as these are strongly related to prediction skill, particularly in the Indian and West Pacific regions. Finally, we show that predictions of tropical rainfall alone can generate highly skilful forecasts of the main modes of extratropical circulation via linear relationships that might provide a useful tool to interpret real‐time forecasts

A spatially integrated framework for assessing socioecological drivers of carnivore decline

1. Habitat loss, fragmentation and degradation are key threats to the long-term persistence of carnivores, which are also susceptible to direct persecution by people. Integrating natural and social science methods to examine how habitat configuration/quality and human-predator relations may interact in space and time to effect carnivore populations within human-dominated landscapes will help prioritise conservation investment and action effectively. 2. We propose a socio-ecological modelling framework to evaluate drivers of carnivore decline in landscapes where predators and people coexist. By collecting social and ecological data at the same spatial scale, candidate models can be used to quantify and tease apart the relative importance of different threats. 3. We apply our methodological framework to an empirical case study, the threatened guiña (Leopardus guigna) in the temperate forest ecoregion of southern Chile, to illustrate its use. Existing literature suggests that the species is declining due to habitat loss, fragmentation and persecution in response to livestock predation. Data used in modelling were derived from four seasons of camera-trap surveys, remote-sensed images and household questionnaires. 4. Occupancy dynamics were explained by habitat configuration/quality covariates rather than by human-predator relations. Guiñas can tolerate a high degree of habitat loss (>80% within a home range). They are primarily impacted by fragmentation and land subdivision (larger farms being divided into smaller ones). Ten percent of surveyed farmers (N=233) reported illegally killing the species over the past decade. 5. Synthesis and applications. By integrating ecological and social data into a single modelling framework, our study demonstrates the value of an interdisciplinary approach to assessing the potential threats to a carnivore. It has allowed us to tease apart effectively the relative importance of different potential extinction pressures, make informed conservation recommendations and prioritise where future interventions should be targeted. Specifically for the guiña, we have identified that human-dominated landscapes with large intensive farms can be of conservation value, as long as an appropriate network of habitat patches are maintained within the matrix. Conservation efforts to secure the long-term persistence of the species should focus on reducing habitat fragmentation, rather than human persecution in our study system

Simulating the midlatitude atmospheric circulation: what might we gain from high-resolution modeling of air-sea interactions?

Purpose of Review. To provide a snapshot of the current research on the oceanic forcing of the atmospheric circulation in midlatitudes and a concise update on previous review papers. Recent findings. Atmospheric models used for seasonal and longer timescales predictions are starting to resolve motions so far only studied in conjunction with weather forecasts. These phenomena have horizontal scales of ~ 10–100 km which coincide with energetic scales in the ocean circulation. Evidence has been presented that, as a result of this matching of scale, oceanic forcing of the atmosphere was enhanced in models with 10–100 km grid size, especially at upper tropospheric levels. The robustness of these results and their underlying mechanisms are however unclear. Summary. Despite indications that higher resolution atmospheric models respond more strongly to sea surface temperature anomalies, their responses are still generally weaker than those estimated empirically from observations. Coarse atmospheric models (grid size greater than 100 km) will miss important signals arising from future changes in ocean circulation unless new parameterizations are developed

A Study of the Generative Relationship Between Live Performance and Collective Remembering in Western Australian Settler Society, 1839 to 1899.

This thesis makes a theoretical intervention into debates about the interrelationship of performance with remembering; and analyses performance as a specific instance of distributed collective remembering in colonial Western Australia during the period from 1839 to 1899. It brings new archival data to an analysis of the transmission of British culture through performance events in the colony. This transmission was a double process, in which performance heritage played a significant part in the development of a West Australian identification and sense of place. The first part of the thesis delimits the topic and the interdisciplinary approach I take to it. It then conceptualises the generative links between performance and collective memory in relation to prior philosophical concepts of place and space. It next relates these concepts to social and cultural praxis, culminating with five case studies of colonial Western Australian performances. I argue that colonial performance is symptomatic of a wider modern crisis of remembering that was embedded in specifically Western Australian matrices of gender, class, and race. The case studies analyse the function of microcosmic place-worlds enacted through doublets of imaginative thinking and future remembering, acculturation and cultural amnesia, within colonial performance

Characterization of TolC Efflux Pump Proteins from Pasteurella multocida▿ †

Two TolC homologs, PM0527 and PM1980, were identified for Pasteurella multocida. A pm0527 mutant displayed increased susceptibility to a range of chemicals, including rifampin (512-fold) and acridine orange (128-fold). A pm1980 mutant showed increased susceptibility to rifampin, ceftazidime, and vancomycin

Carboxylesterases (EC 3.1.1). The Molecular Weight and Equivalent Weight of Pig Liver Carboxylesterase

The molecular weight of pig liver carboxylesterase (~88% pure) has been determined as 163,000 (±15,000). The enzyme has two active sites per molecular weight of 163,000 as shown by titration with pnitrophenyl dimethylcarbamate and p-nitrophenyl diethyl phosphate. The enzyme undergoes slow irreversible inactivation at pH 5, but on dilution at pH 7.5, the enzyme dissociates apparently into half-molecules which are active. No evidence has been obtained for the dissociation of the enzyme into species of mol wt ~40,000, either at pH 8 or in 8 M urea

Climatology and convective mode of severe hail in the United Kingdom

Severe or large hail, with diameter ≥20 mm, is a hazard associated with severe convective storms that can cause significant damage. In the UK, the rarity and small footprint of severe hail events makes obtaining well-documented hail reports difficult, and the reports are spread across multiple databases. In this study, three databases of UK severe hail reports are merged for the first time. The combined event set (1979–2022), comprising >800 reports, is used to investigate interannual variability and the seasonal, spatial and size distributions of severe hail. The seasonal cycle peaks in early–mid summer, and the peak month has shifted from June to July since around 2005. The distribution of reported hail size is exponential, with a slower decay (larger hail) during summer. The time of day, basic convective mode (isolated, clustered or linear), and presence or absence of supercellular characteristics are assessed for 274 of the reports since 2006, using composite radar rainrate data. The diurnal cycle is strong year-round, peaking during the late afternoon (1500–1800 UTC). 53% of severe hail events are associated with isolated cells, 33% with clusters, and 14% with linear storms. Around 35% of severe hail-producing storms are probable supercells, increasing to 70% for storms producing ≥40 mm hail. This demonstrates that the prevalence of supercells producing very large hail extends to temperate maritime climates. These results may be of relevance in other regions with a relatively low incidence of severe hail in the present climate. This comprehensive analysis of severe and potentially impactful hail in the UK provides novel insight into its characteristics, enabling improved assessment of climate risk from this hazard. </p