NOSS altimeter algorithm specifications

A description of all algorithms required for altimeter processing is given. Each description includes title, description, inputs/outputs, general algebraic sequences and data volume. All required input/output data files are described and the computer resources required for the entire altimeter processing system were estimated. The majority of the data processing requirements for any radar altimeter of the Seasat-1 type are scoped. Additions and deletions could be made for the specific altimeter products required by other projects

Multi-physics ensemble snow modelling in the western Himalaya

Combining multiple data sources with multi-physics simulation frameworks offers new potential to extend snow model inter-comparison efforts to the Himalaya. As such, this study evaluates the sensitivity of simulated regional snow cover and runoff dynamics to different snowpack process representations. The evaluation is based on a spatially distributed version of the Factorial Snowpack Model (FSM) set up for the Astore catchment in the upper Indus basin. The FSM multi-physics model was driven by climate fields from the High Asia Refined Analysis (HAR) dynamical downscaling product. Ensemble performance was evaluated primarily using MODIS remote sensing of snow-covered area, albedo and land surface temperature. In line with previous snow model inter-comparisons, no single FSM configuration performs best in all of the years simulated. However, the results demonstrate that performance variation in this case is at least partly related to inaccuracies in the sequencing of inter-annual variation in HAR climate inputs, not just FSM model limitations. Ensemble spread is dominated by interactions between parameterisations of albedo, snowpack hydrology and atmospheric stability effects on turbulent heat fluxes. The resulting ensemble structure is similar in different years, which leads to systematic divergence in ablation and mass balance at high elevations. While ensemble spread and errors are notably lower when viewed as anomalies, FSM configurations show important differences in their absolute sensitivity to climate variation. Comparison with observations suggests that a subset of the ensemble should be retained for climate change projections, namely those members including prognostic albedo and liquid water retention, refreezing and drainage processes

Eriophyid Mites New to Ohio

Author Institution: Department of Zoology and Entomology, Ohio Agricultural Experiment Station, Wooster, Ohi

Laboratory Growth, Reproduction and Life Span of the Pacific Pygmy Octopus, Octopus digueti

Octopus digueti Perrier and Rochebrune, 1894 was reared through its life cycle at 25°C in a closed seawater system using artificial sea water. Two field-collected females produced 231 hatchlings: 193 hatchlings were groupcultured while 24 were isolated at hatching and grown individually to allow precise analyses of growth in length and weight over the life cycle. All octopuses were fed primarily live shrimps. Maturing adults fed at a rate of 4.7% of body weight per day and had a gross growth efficiency of 48%. Growth in weight was exponential for the first 72 days and described best by the equation: WW(g) = .0405e•0646t. The mean growth rate over this period was 6.4% increase in body weight per day (%/d), with no significant difference between male and female growth. From 72 to 143 days, growth was logarithmic and described best by the equation: WW(g) = (6.78 x 1O- 6) t3 .13. Females grew slightly faster than males over this growth phase. During the exponential growth phase, mantle length increased at a mean rate of 2.1% per day, declining to 1.1% per day over the logarithmic phase. No attempt was made to describe mathematically the period of declining growth rate beyond day 143. The primary causes of early mortality in group culture were escapes and cannibalism. Survival was good despite high culture density: 73% survival to date of first egg laying (day 111). Survival was better among the isolated growth-study octopuses: 88% to the date of first egg laying (day 130). Mean life span was 199 days in group-reared octopuses and 221 days in the growth-study octopuses. There was no significant difference between male and female life span. Progeny of the group culture were reared at similar stocking densities and fed predominantly fresh dead shrimp and crab meat. This diet resulted in cannibalism, with only 6% survival to first egg laying on day 128. Fecundity in this group was lower. Octopus digueti is a good candidate for laboratory culture and biological experimentation because of its small size, rapid growth, short life span, and good survival in group culture

Detection of positron-atom bound states through resonant annihilation

A method is proposed for detecting positron-atom bound states by observing enhanced positron annihilation due to electronic Feshbach resonances at electron-volt energies. The method is applicable to a range of open-shell transition metal atoms which are likely to bind the positron: Fe, Co, Ni, Tc, Ru, Rh, Sn, Sb, Ta, W, Os, Ir, and Pt. Estimates of their binding energies are provided.Comment: 5 pages, 1 figure; estimates of binding energies have been adde

Growth of the Eastern Atlantic squid, Loligo forbesi Steenstrup (Mollusca: Cephalopoda)

Loligo forbesi Steenstrup is a commercially and biomedically important species raneing from Scotland to North Africa and from the Azores Islands in the central Atlantic east through the Mediterranean Sea and Red Sea. Eggs were collected from Plymouth. England and from the Azores and the hatchlings were reared to adult size in recirculating seawater systems. Growth data were obtained primarily from mortalities during the course of three culture experiments which lasted 360, 240 and 480 days. Loligo forbesi hatched at a size of 5–9mg (3.0–4.6mm mantle length, ML) and grew to a maximum size of 124g (155 mm ML) in 413 days. In all experiments, growth was exponential in form for at least the first 3 months at rales of 5.8, 5.1 and 3.6% body weight per day (BW/d) at mean temperatures of 14.1, 14.0 and 13.1°C respectively. In one short-term experiment, month-old squids grew at 8.0% BW/d at 17.4°C. Growth beyond 3 months was slower and either logarithmic (as described by the power function) or exponential in form. Growth rates gradually declined to 1–2% BW/d, Analyses of mantle length growth confirmed the wet weight results. There was no evidence of sexual dimorphism in the laboratory populations, which were of small size, and the length-weight (L-W) relationships were found to be similar to those of field populations. Growth rates during the exponential growth phase appeared very sensitive to temperature, with a 1°C difference changing growth rate by 2% BW/d and producing a three-fold difference in weight at 90 days post-hatching. These dramatic effects of temperature on adult size and lifespan in nature are discussed. It is hypothesized that the small size of mature laboratory-reared squids was due to low culture temperatures during the first 3 months

Effect of temperature on laboratory growth, reproduction and life span of Octopus bimaculoides

Laboratory culture of 40 Octopus bimaculoides from April 1982 to August 1983 through the full life cycle at 18°C vs 23°C provided information on the growth, reproductive biology and life span of this California littoral octopus. At 18°C, the cephalopods grew from a hatchling size of 0.07 g to a mean of 619 g in 404 d; the largest individual was 872 g. Octopuses cultured at 23°C reached their highest mean weight of 597 g in 370 d; the largest individual grown at this temperature was 848 g after 404 d. Growth data revealed a two-phase growth pattern: a 5 mo exponential phase followed by a slower logarithmic (power function) phase until spawning. At 5 mo octopuses grown at 23°C were over three times larger than their 18°C siblings. However, beyond 6.5 mo, growth rates were no higher at 23°C than at 18°C. At 13.5 mo, the mean weight of the 18°C group surpassed that of the 23°C group. The slope of the length/weight (L/W) relationship was significantly different for the two temperature regimes, with the 23°C octopuses weighing 18% less than their 18°C siblings at a mantle length of 100 mm. Females weighed more than males at any given mantle length. Males grew slightly larger and matured before females. The L/W relationship indicated isometric body growth throughout the life cycle. Higher temperature accelerated all aspects of reproductive biology and shortened life span by as much as 20% (from approximately 16 to 13 mo). O. bimaculoides has one of the longest life cycles among species with large eggs and benthic hatchlings. Extrapolations to field growth are made, and the possible effects of temperature anomalies such as El Niño are discussed