Magnitude and frequency of wind speed shears and associated downdrafts

Data are presented indicating the frequency of occurrence of wind shear and downdrafts together with information on the simultaneous occurrence of these two phenomena. High resolution wind profile measurements recorded at a 150 meter ground winds tower facility were used for the analysis. From instantaneous measurements during horizontal wind speeds of gale-force and below intensity, vertical motion at the 10, 60, and 150 m levels was approximately 60 percent downward and 40 percent upward. At the 18 level the percentages were reversed. Updraft maxima were an order of magnitude or two greater than downdrafts at all levels. Frequency of vertical motion or = 9.7 kts for a year at four levels was 338 occurrences upward and 274 downward. Approximately 90 percent of these updrafts occurred at the 18 m level almost equally during summer and winter, and 65 percent of the downdrafts were at the 150 m level during summer

Stock assessment of the Queensland east coast redthroat emperor (Lethrinus miniatus)

Queensland’s redthroat emperor (Lethrinus miniatus) is a line caught fish forming a single population (stock) on the Queensland east coast. Redthroat emperor are protogynous hermaphrodites (born female, many later changing sex to male). They can grow to 3 kg and 20 years of age. This assessment builds on a previous assessment that estimated the stock was at 70% of unfished biomass in 2004. This stock assessment includes updates to the input data and methods. This stock assessment used a age structured population model with a yearly time step and length based selectivity. The annual data inputs included total fish harvest, standardised catch rates, length structures and conditional age at length data. The model used data from the anticipated start of fishing in 1945 to 2019. In 2019, the stock level was estimated to be 72% unfished biomass and at healthy levels

English economic growth, 1270-1700

We provide annual estimates of GDP for England over the period 1270-1700, constructed from the output side. The GDP data are combined with population estimates to calculate GDP per capita. Sectoral price data and estimates of nominal GDP are also provided. We find per capita income growth of 0.20 per cent per annum, although growth was episodic, with the strongest growth after the Black Death and in the second half of the seventeenth century. Living standards in the late medieval period were well above “bare bones subsistence”, although levels of kilocalorie consumption per head were modest because of the very large share of pastoral production in agriculture

British economic growth : 1270 - 1870

We provide annual estimates of GDP for England between 1270 and 1700 and for Great Britain between 1700 and 1870, constructed from the output side. The GDP data are combined with population estimates to calculate GDP per capita. We find English per capita income growth of 0.20 per cent per annum between 1270 and 1700, although growth was episodic, with the strongest growth during the Black Death crisis of the fourteenth century and in the second half of the seventeenth century. For the period 1700-1870, we find British per capita income growth of 0.48 per cent, broadly in line with the widely accepted Crafts/Harley estimates. This modest trend growth in per capita income since 1270 suggests that, working back from the present, living standards in the late medieval period were well above “bare bones subsistence”. This can be reconciled with modest levels of kilocalorie consumption per head because of the very large share of pastoral production in agriculture

Assessment of the barramundi (Lates calcarifer) fishery in the Southern Gulf of Carpentaria, Queensland, Australia.

Wild-capture barramundi (Lates calcarifer) forms the basis of important commercial, recreational and customary Indigenous fisheries in Queensland, with an estimated harvest of about 700 tonnes in 2015 (Saunders et al. 2016). For stock status assessment, barramundi in Queensland are considered to consist of seven genetically distinct populations. Within the Gulf of Carpentaria (GoC), there are two genetic stocks split at around 13⁰ S - a Northern Gulf of Carpentaria stock and a Southern Gulf of Carpentaria stock. The Gulf of Carpentaria Inshore Fin Fish Fishery harvests barramundi from both these stocks, but the current assessment focuses on the Southern Gulf of Carpentaria (Southern GoC) barramundi stock, which produces, on average, greater than 50% of the annual commercial harvest of barramundi in Queensland and was listed as transitional-depleting in the 2016 Status of Australian Fish Stocks report (Saunders et al. 2016)

Precision spectral manipulation of optical pulses using a coherent photon echo memory

Photon echo schemes are excellent candidates for high efficiency coherent optical memory. They are capable of high-bandwidth multi-pulse storage, pulse resequencing and have been shown theoretically to be compatible with quantum information applications. One particular photon echo scheme is the gradient echo memory (GEM). In this system, an atomic frequency gradient is induced in the direction of light propagation leading to a Fourier decomposition of the optical spectrum along the length of the storage medium. This Fourier encoding allows precision spectral manipulation of the stored light. In this letter, we show frequency shifting, spectral compression, spectral splitting, and fine dispersion control of optical pulses using GEM

Assessment of the barramundi fishery in Queensland, 1989-2007

The barramundi (Lates ca/carifer) is an important target species for commercial, recreational and Indigenous fishers across northern Australia. In Queensland, barramundi stocks from the Gulf of Carpentaria (GoC) and the east coast (EC) are managed separately. Updated assessments of both the Goe and EC stocks are reported here. The assessment used catch and effort information from both commercial (CFISH logbooks) and recreational (RFISH surveys) sources. The data were split into six different strata based on the genetic makeup of the stock, leading to six geographical regions with each having its own aggregated total commercial and recreational catch. The analysis proceeded in two stages. The first stage was a standardisation of the catch rate per unit of effort (CPUE) to obtain an estimate of the relative changes in abundance over time. The second stage was fitting a biomass dynamic model to estimate absolute stock biomass and management parameters such as maximum sustainable yield. The primary conclusion drawn from both the standardisation results and the dynamic modelling results is that the data are of insufficient quality to reliably estimate stock biomass or management parameters. This conclusion is based on a number of factors, including (but not limited to): • large fluctuations in the standardised catch rate, which would be biologically implausible if taken as a reliable index of abundance • an inability to find model parameters that lead to a good fit (unless certain parameters are taken past biologically plausible limits) • large uncertainty in parameters estimated from the surplus production model

Stock assessment of Queensland east coast saddletail snapper (Lutjanus malabaricus), Australia

In Queensland, east coast saddletail snapper (Lutjanus malabaricus) are mostly line-caught by commercial and recreational fishers, with some recreational spearfishing take. Saddletail snapper are believed to be a single stock (population) off Queensland’s east coast. This is the first stock assessment of the Queensland east coast stock. The assessment implemented a two-sex population model fit to age and length data, constructed within the Stock Synthesis modelling framework. The model incorporated data spanning the period from financial years 1988 to 2020 including commercial logbook harvest (1988–2020), recreational, charter and Indigenous survey harvest estimates (2000–2019), length distribution data from boat-ramp surveys (2017–2020) and age-length (2018–2020). Twenty-one model scenarios were run, covering a wide range of modelling assumptions. Base case (preferred) scenario results suggested that biomass declined between 1961 and 2017 to 19% unfished biomass. In 2020, the stock level was estimated to be 23% (13–73% range across scenarios) unfished biomass. The harvest consistent with a biomass ratio of 60%, the Sustainable Fisheries Strategy longer-term target, was estimated at 159 t (146–348 t range across scenarios and all sectors). The recommended harvest in the 2021 financial year is 12 t (0–494 t range across scenarios) to achieve this target by 2040