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By linking ice-core volcanic horizons with precisely dated frost damage in bristlecone pines, the authors have revised the dating of the principal Greenland ice-core chronologies back to c. 2000 BC. This revision has implications for establishing an absolute calendar date for the Bronze Age eruption of Thera. Three volcanic horizons (1653, 1627 and 1610 BC) are now coincident with the seventeenth-century BC radiocarbon dating of Thera, but none of these horizons is likely to result from the Theran eruption. In particular, a volcanic event at c. 1627 BC—a date associated with Thera for over 30 years—can now probably be attributed to the Aniakchak II volcano in Alaska.

Flooding on the Tone River, which drains the largest catchment area in Japan and is now home to 12 million people, poses significant risk to the Greater Tokyo Area. In April 2010, an expert panel in Japan, the Central Disaster Prevention Council, examined the potential for large-scale flooding and outlined possible mitigation measures in the Greater Tokyo Area. One of the scenarios considered closely mimics the pattern of flooding that occurred with the passage of Typhoon Kathleen in 1947 and would potentially flood some 680 000 households above floor level. Building upon that report, this study presents a Geographical Information System (GIS)-based data integration approach to estimate the insurance losses for residential buildings and contents as just one component of the potential financial cost. Using a range of publicly available data – census information, location reference data, insurance market information and flood water elevation data – this analysis finds that insurance losses for residential property alone could reach approximately 1 trillion JPY (US$ 12.5 billion). Total insurance losses, including commercial and industrial lines of business, are likely to be at least double this figure with total economic costs being much greater again. The results are sensitive to the flood scenario assumed, position of levee failures, local flood depths and extents, population and building heights. The Average Recurrence Interval (ARI) of the rainfall following Typhoon Kathleen has been estimated to be on the order of 200 yr; however, at this juncture it is not possible to put an ARI on the modelled loss since we cannot know the relative or joint probability of the different flooding scenarios. It is possible that more than one of these scenarios could occur simultaneously or that levee failure at one point might lower water levels downstream and avoid a failure at all other points. In addition to insurance applications, spatial analyses like that presented here have implications for emergency management, the cost-benefit of mitigation efforts and land-use planning.

In 2012 Plummer et al., in presenting the volcanic chronology of the Antarctic Law Dome ice core, chose to list connections to acid layers in other ice cores and also possible chronological coincidences between ice acid dates and the precise dates of frost damage, and/or reduced growth in North American bristlecone pines. We disagree with the chronological links indicated by Plummer et al. for the period before AD 700, and in this paper we show that a case can be made that better linkages between ice acid and tree ring effects occur for this period if the ice chronologies are systematically moved forward by around 7 years, consistent with a hypothesis published by Baillie in 2008. In the paper we seek to explore the proposition that frost damage rings in North American bristlecone pines are a very useful indicator of the dates of certain large explosive volcanic eruptions; the dating of major eruptions being critical for any clear understanding of volcanic forcing. This paper cannot prove that there is an error in the Greenland Ice Core Chronology 2005 (GICC05), and in equivalent ice chronologies from the Antarctic, however, it does provide a coherent argument for an apparent ice dating offset. If the suggested offset were to prove correct it would be necessary to locate where the error occurs in the ice chronologies and in this regard the dating of the increasingly controversial Icelandic Eldgjá eruption in the AD 930s, and the China/Korean Millennium eruption which occurs some 7 years after Eldgjá, may well be critical. In addition, if the offset were to be substantiated it would have implications for the alleged identification of tephra at 429.3 m in the Greenland GRIP core, currently attributed to the Italian volcano Vesuvius and used as a critical zero error point in the GICC05 chronology.

Fire, an ever present hazard in Australia, causes approximately 100 fatalities and over 3000 injuries per annum. Significant resources are allocated to mitigate the risk. In this study, we estimate the total cost of fire in Australia for 2005 at AUD$12,000 million or 1.3% of GDP. Comparable studies in the UK, USA, Canada, Denmark and New Zealand are reviewed and show that the cost in these countries ranges between 0.8 and 2% of GDP. Breaking the Australian total down into its component parts, we find that 57% relates to costs in anticipation of fire, 29% for response activities and that the remaining 14% results from the consequences of fire. This estimate shows that the investment in mitigation (86% of the total costs) is over five times the consequences (14%) and raises questions as to whether the current system adopted in Australia is economically efficient.

Hailstorms occur frequently in metropolitan Sydney, in the eastern Australian State of New South Wales, which is especially vulnerable due to its building exposure and geographical location. Hailstorms challenge disaster response agencies and pose a great risk for insurance companies. This study focuses on the Sydney hailstorm of 14 April 1999 – Australia's most expensive insured natural disaster, with supporting information from two other storms. Comparisons are drawn between observed hailstone sizes, radar-derived reflectivity and damage data in the form of insurance claims and emergency calls. The "emergency response intensity" (defined by the number of emergency calls as a proportion of the total number of dwellings in a Census Collection District) is a useful new measure of the storm intensity or severity experienced. The area defined by a radar reflectivity ≥55 dBZ appears to be a good approximation of the damage swath on ground. A preferred area for hail damage is located to the left side of storm paths and corresponds well with larger hailstone sizes. Merging hail cells appear to cause a substantially higher emergency response intensity, which also corresponds well to maximum hailstone sizes. A damage threshold could be identified for hailstone sizes around 2.5 cm (1 cm), based on the emergency response intensity (insurance claims). Emergency response intensity and claims costs both correlate positively with hailstone sizes. Higher claim costs also occurred in areas that experienced higher emergency response intensities.

Auckland, New Zealand’s most populous Region is centred on the Auckland volcanic field (AVF), which contains an estimated 49 small-volume basaltic volcanoes. Although these volcanoes are considered monogenetic, a number of centres may have been active either simultaneously or within a short period of time. After reviewing the characteristics of the field, known vent locations and a provisional eruption sequence were used to estimate likely eruption locations for the next event. The term event is used here to describe a short period of activity comprising one or more eruptions. Point pattern analysis and temporal consideration allow vents related by location and age to be grouped, suggesting that as few as 18 separate events may have produced the AVF. Probability distributions describing previous event attributes were used to generate Monte Carlo simulations, each defining likely vent locations for the next AVF event. Simulations were based on the assumption that distance from Rangitoto, the youngest volcano in the field, to the next event is best approximated using distances between the centroids of previous consecutive events. The maximum extent of the field is constrained only by faulting on its eastern side. The simulations show that 69% of events involved at least one eruption centred either on land or within 1 km of the coast. These events would result in substantial damage to buildings and infrastructure, significant business interruption and, potentially, loss of life. A simple risk assessment is presented considering only spatial eruption probability contingent upon a future event and building density within a 2 km grid. Work in progress aims to develop a more realistic assessment of risk for the region.

Thin film Ba0.5Sr0.5TiO3 (BST) capacitors of thickness ∼ 75 nm to ∼ 1200 nm, with Au top electrodes and SrRuO3 (SRO) or (La, Sr)CoO3 (LSCO) bottom electrodes were fabricated using Pulsed Laser Deposition. Implementing the “series capacitor model,” bulk and interfacial capacitance properties were extracted as a function of temperature and frequency. ‘Bulk’ properties demonstrated typical ceramic behaviour, displaying little frequency dependence and a permittivity and loss peak at 250 K and 150 K respectively. The interfacial component was found to be relatively temperature and frequency independent for the LSCO/BST capacitors, but for the SRO/BST configuration the interfacial capacitance demonstrated moderate frequency and little temperature dependence below T ∼ 300 K but a relatively strong frequency and temperature dependence above T ∼ 300 K. This was attributed to the thermal activation of a space charge component combined with a thermally independent background. The activation energy for the space char...

Thin film Au/Ba0.5Sr0.5TiO3/SrRuO3 capacitor structures, with a thickness of dielectric varying between ∼70 and ∼950 nm, were deposited on {001} MgO single-crystal substrates using pulsed laser deposition. Low-field dielectric measurements were performed as a function of temperature and frequency. At all temperatures and frequencies, the dielectric response as a function of thickness was found to adhere reasonably well to the so-called “series capacitor model,” from which nominal “bulk” and “interfacial” capacitance components could be extracted. The bulk component showed weak frequency dependence but strong temperature dependence, with a peak in permittivity and dielectric loss around 250 K and 150 K, respectively. Well above 250 K, reasonable Curie–Weiss behavior was evident. Overall, the extracted bulk component behaved much as would be expected in real bulk ceramics or single crystals lending confidence as to the general applicability of the series capacitor model. The functional behavior of the extra...

Thin film parallel-plate capacitor structures with Ba0.5Sr0.5TiO3 as the dielectric layer were fabricated using pulsed-laser deposition. The thickness of the dielectric was varied between 7.5 nm and 1.4 μm. Low-field measurements of the dielectric constant showed the system to possess a nonzero interfacial capacitance. Since there is considerable debate about the origin of interfacial capacitance, further functional analysis was performed: zero-field dielectric susceptibility information was extracted using Landau–Ginzburg–Devonshire fitting of saturated polarization loops. This analysis revealed that the zero-field dielectric susceptibility extracted from P–E loops does not possess a finite interfacial component. The origin of interfacial capacitance therefore disappears (albeit temporarily) after a significant field has been applied and then removed during the P–E loop measurement cycle.

Various attempts have been made to link tree-ring and ice-core records, something vital for the understanding of the environmental response to major volcanic eruptions in the past. Here we demonstrate that, by taking note of the spacing between events, it is possible to clarify linkages between tree-response, as witnessed by frost rings in bristlecone pines from Western North America and volcanic acid deposition in ice cores. The results demonstrate that in the 6th and 7th centuries of the current era, and presumably for all earlier dates, the key European ice chronologies from the North Greenland Ice Core Project, namely Dye3, GRIP, NGRIP and NEEM appear to have been wrongly dated by 7 years, with the ice dates being too old. Similar offsets are observed for the Antarctic Law Dome and West Antarctic Ice Sheet Divide WDC06A ice-core chronologies that have been linked to the Greenland record. Importantly, the results clarify which frost rings in bristlecone pines are related to volcanic activity and which may be the result of other causes. In addition, it is possible to show that ice core researchers have used inappropriate linkages to tree effects to justify their chronology.

Methods are needed to measure the surface fluxes of sensible ( H ) and latent heat ( E ) at large scales. A promising method is scintillometry. Over pasture, a near-infrared scintillometer was most sensitive to temperature fluctuations whilst a microwave scintillometer was unduly affected by both humidity fluctuations and correlated temperature–humidity fluctuations. Slower changes in path-averaged humidity caused additional signal variance and an overestimation of H and E . Log-amplitude spectra of the microwave scintillometer signal showed inertial-convective subrange behavior. In combination, path-averaged E and H could be determined over 3 km. Independent corroborative measurements of H and E were made at the path midpoint using the eddy covariance technique. For sensible heat, agreement was within 4% over a measured range 0–300 W m −2 , with a residual standard deviation of 45 W m −2 . Latent heat agreed at best to within 12% over the range 0–450 W m −2 (residual standard deviation of 94 W m −2 ) and an offset of 30 W m −2 .

Barium strontium titanate (Ba0.5Sr0.5TiO3–BST) thin film capacitor structures were made using pulsed laser deposition, and their functional properties were monitored with varying temperature. It was found that poling at low temperature could induce distinct differences in the behavior of the dielectric constant and loss tangent, on heating. In relatively thick BST films (>∼650nm), poling the sample at 80K produced a change from a single broad anomaly to one in which three distinct anomalies could be observed. The temperatures of these anomalies (∼140, ∼200, and ∼260K) were close to those known to be associated with phase transitions in bulk. Monitoring changes in polarization loops with temperature confirmed the likelihood that the dielectric anomalies observed were indeed the result of phase transitions in the films. Unusually, though, when the films were poled at 150K, and then cooled to 80K prior to collection of dielectric data on heating, the dielectric anomaly around 140K was completely suppressed. ...

Physical principles and design criteria for a large-aperture scintillometer conceived at the NOAA Wave Propagation Laboratory in Boulder, Colorado are presented. This instrument measures intensity fluctuations of a collimated beam of incoherent light at spatial wavelengths within the inertial subrange. Together with measurements of mean windspeed and rule-of-thumb estimates of the surface roughness, these optical scintillation measurements yield sensible heat flux and friction velocity ( u ∗ ) via a simple iterative procedure. A maximum path-length of some 1.7 km is calculated for near-surface measurements (1–2 m height) of the path-averaged sensible heat flux ( H ) and this range increases with increasing height as z 1 2 A field test over pasture with a transmitter-receiver separation of 350 m gave estimates of H and u ∗ within 7 and 1% of those determined directly by eddy-correlation. Over the measured ranges (0 H −2 and 0.05 ∗ m s −1 ), residual standard deviations were 25 W m-2 and 0.04 m s −1 . Given these results, the ability of the large-aperture scintillometer to provide estimates of fluxes over homogeneous surfaces seems assured.

It has been suggested in Part I of this paper that, after a dryland-to-irrigated transition, the surface sensible and latent heat fluxes may exhibit little change with downstream distance from the leading edge. It was argued that such step changes in surface fluxes could be caused by a feedback mechanism between surface resistance and changing saturation deficit. A simple model was derived for describing the streamwise change in surface resistance leading to such a step change in flux. The aim of the present paper is to test these assumptions against experimental data acquired specifically for this purpose. Measurements were performed over a transition between dryland and irrigated barley. Eddy covariance determinations of sensible heat flux at a height of 1 m showed little variation downwind of the transition and, once corrected from the footprint effect, exhibited patterns roughly compatible with a step change in surface flux. Transects of radiative temperature, and air temperature and humidity above the crop, also showed downwind changes in good agreement with the expected variation. The most convincing results were obtained from measurements of stomatal and canopy resistance, whose downwind variation was close to that required by a step change in evapotranspiration.

Previous experimental and theoretical studies have examined the possible use of thermal-infrared measurements of surface temperature to estimate sensible heat flux from homogeneous surfaces. In extending the methodology suggested by Lagouarde and McAneney to larger scales, it is necessary to consider the effect of spatial variability. Over a heterogeneous mixture of surfaces, statistical errors are possible due to spatially-correlated changes in windspeed, surface roughness and surface temperature. Errors due to the latter two variables are investigated here at the 1 km2 scale of the NOAA AVHRR using two specific case studies. Errors due to correlated variations in windspeed and surface roughness, and windspeed and surface temperature, are also estimated. The results suggest that all these errors are generally negligible if application is restricted to surfaces having a maximum crop height of around I m. Given this qualification,estimates of regional scale sensible heat fluxes seem feasible using...

Line-averaged measurements of the structure parameter of refractive index (C 2 ) were made using a semiconductor laser diode scintillometer above two markedly different surfaces during hours of positive net radiation. The underlying vegetation comprised in the first instance a horizontally homogeneous, pasture sward well-supplied with water, and in the second experiment, a sparse thyme canopy in a semi-arid environment. Atmospheric stability ranged between near neutral and strongly unstable (−2≤ζ≤0). The temperature structure parameterC 2 computed from the optical measurements over four decades from 0.001 to 2 K2 m−2/3 agreed to within 5% of those determined from temperature spectra in the inertial sub-range of frequencies. Spectra were obtained from a single fine thermocouple sensor positioned near the midway position of the 100m optical path and at the beam propagation height (1.5m). With the inclusion of cup anemometer measurements, rule-of-thumb assumptions about surface roughness, and Monin-Obukhov similarity theory, path-averaged optical scintillations allow calculation of surface fluxes of sensible heat and momentum via a simple iterative procedure. Excellent agreement was obtained between these fluxes and those measured directly by eddy correlation. For sensible heat, agreement was on average close to perfect over a measured range of 0 to 500 W m−2 with a residual standard deviation of 30 W m−2. Friction velocities agreed within 2% over the range 0–0.9 m s−1 (residual standard deviation of 0.06 m s−1). The results markedly increase the range of validation obtained in previous field experiments. The potential of this scintillation technique and its theoretical foundation are briefly discussed.

Surface energy budget investigations of a range of agricultural surfaces in France and the African Sahel demonstrate consistent linear relationships between daily totals of sensible heat flux (H d) and the difference between a once-a-day radiative measurement of surface temperature and the maximum air temperature at a height of 2 m. Surface temperature was measured with nadir-viewing radiothermometers near 1400 h (LST). The average residual standard error in the estimate ofH d was 0.6 mm of equivalent evaporation. An equation for the daily sensible heat flux (H d) having a form analogous to Dalton's evaporation formula was derived from surface energy budget considerations. This equation discriminates well between relatively homogeneous, low-cover surfaces where surface exchange characteristics can be assumed to be simple fractions of the height of the roughness elements. By contrast, data from two other crops with discontinuous plant cover suggest a much reduced sensitivity to canopy architecture. This result is not unreasonable if scalar transport were controlled by the thermal conductivity of a layer of still air close to ground level which is sheltered by the plant canopy. There is scope for further experimental and theoretical work on this matter.

Near-neutral measurements of the turbulent wind field within and above a sequence of 15 parallel windbreaks on a flat pastoral site are presented. The windbreak fences each had a porosity of 60% and were equally-spaced at 6 times their height (h = 2 m). The following conclusions seem justified for wind directions within 10 ° of the normal to the array: The measurements show the practical difficulty of simultaneously reducing both mean windspeeds and turbulence levels with repeated windbreaks at conventional spacings for horticultural applications.

Kiwifruit crop loading relationships published for pergola-trained vines in Hawkes Bay are shown to hold over a wider climatic range, several seasons and for T-bar training systems. Absorption of solar radiation by the vertical foliage ‘walls’ on the T-bar would reduce differences in total energy absorption between T-bar and pergola systems and contribute to the fact that training system was not, in itself, a significant determinant of yield. Relationships between harvest yield (Y) and fruit number (N) m−2 of orchard allocated per female vine, and mean fruit weight (μ) in g, can be described by: (1) Y=Y max ( N (N+K) ) and (2) Y= Nμ 1000 where K is a constant equal to 95.25 fruit m−2 of orchard and Ymax equals 13.48 kg m−2. After accounting for male vines, the latter figure corresponds to a maximum possible yield of 126 tonnes ha−1. Equation (1) expresses the potential productivity of kiwifruit, given currently available genetic material and good management. Combining eqns. (1) and (2) with a normal parameterisation of harvest fruit size distributions, allows returns from a range of crop loading regimes to be calculated directly. Using this approach, New Zealand grower returns (1986/1987 prices) are shown to be optimised for an average fruit weight of 90 g which corresponds to a crop load of approximately 50 fruit m−2. This information can be used by growers to develop pruning and thinning strategies that maximise returns rather than yield and also by industry to set price schedules that encourage the production of fruit in the most marketable size ranges.

An instrument designed for easy field measurements of kiwifruit volume or weight is described. Volume (or weight) calculated from a single length measurement has a resolution of ± 1 cm3 (g) permitting individual fruit growth to be monitored on a weekly basis. The assumption that the density of kiwifruit is 1 gm/cm3 is shown to be a very good approximation. Variations in fruit shape cause the average error in a single measurement to be 8%. Data collected are displayed with resolutions of 1 cm3 (g) for operator verification and are transferable to a portable personal computer to simplify data storage and analysis and to minimise handling errors. With this arrangement, a single operator can measure over 2 500 fruit in 4 h. The use of fruit growth information for assessing orchard practices such as irrigation management and for the early prediction of harvest fruit size in relation to target yield is discussed.

A series of experiments has been undertaken to understand more about the fundamental origin of the thickness-induced permittivity collapse often observed in conventional thin film ferroelectric heterostructures. The various experiments are discussed, highlighting the eventual need to examine permittivity collapse in thin film single crystal material. It has been seen that dielectric collapse is not a direct consequence of reduced size, and neither is it a consequence of unavoidable physics associated with the ferroelectric-electrode boundary. Research on three-dimensional shape-constrained ferroelectrics, emphasizing self-assembled structures based on nanoporous alumina templates and on FIB-milled single crystals, is also presented, and appears to represent an exciting area for ongoing research.

International audience; Hailstorms occur frequently in metropolitan Sydney, in the eastern Australian State of New South Wales, which is especially vulnerable due to its building exposure and geographical location. Hailstorms challenge disaster response agencies and pose a great risk for insurance companies. This study focuses on the Sydney hailstorm of 14 April 1999 ? Australia's most expensive insured natural disaster, with supporting information from two other storms. Comparisons are drawn between observed hailstone sizes, radar-derived reflectivity and damage data in the form of insurance claims and emergency calls. The "emergency response intensity" (defined by the number of emergency calls as a proportion of the total number of dwellings in a Census Collection District) is a useful new measure of the storm intensity or severity experienced. The area defined by a radar reflectivity ?55 dBZ appears to be a good approximation of the damage swath on ground. A preferred area for hail damage is located to the left side of storm paths and corresponds well with larger hailstone sizes. Merging hail cells appear to cause a substantially higher emergency response intensity, which also corresponds well to maximum hailstone sizes. A damage threshold could be identified for hailstone sizes around 2.5 cm (1 cm), based on the emergency response intensity (insurance claims). Emergency response intensity and claims costs both correlate positively with hailstone sizes. Higher claim costs also occurred in areas that experienced higher emergency response intensities.

X-ray analysis of ferroelectric thin layers of Ba1/2Sr1/2TiO3 with different thickness reveals the presence of internal strain gradients across the film thickness and allows us to propose a functional form for the internal strain profile. We use this to calculate the direct influence of strain gradient, through flexoelectric coupling, on the degradation of the ferroelectric properties of thin films with decreasing thickness, in excellent agreement with the observed behaviour. This work highlights the link between strain relaxation and strain gradients in epitaxial films, and shows the pressing need to avoid strain gradients in order to obtain thin ferroelectrics with bulk-like properties., 4 pages, 3 embedded figures (1 color), revTex4

International audience; The potential of the LAS (large aperture scintillometry) method for measuring sensible heat flux (H) directly integrated over a two-field composite surface is evaluated. We describe a field experiment performed within the Alpilles/ReSeDa project in the south-east of France over a composite surface made up of wheat and bare soil (451 and 216 m long respectively) using two 0.15-m diameter scintillometers mounted at heights of 2.05 and 4.54 m. When compared against reference values obtained by the eddy correlation technique, LAS-measured sensible heat flux reveals a systematic overestimation of about 10%. A simple model describing the integration of the scintillometer signal along the beam for a two-field composite surface is described. A simulation of the experiment confirms that the bias observed isrelated to non-linearities in the integration process in relation with thebell-shape sensitivity curve of the instrument to the structure parameter for the refractive index it measures. The model is used to test the sensitivity of the LAS-derived H values to the composition of the pathlength (ratio of both surfaces) and to the contrast in sensible heat flux and roughness length between the two fields. Sensitivity tests to the aggregation scheme for roughness length (two of them are tested) and to the measurement height are also presented. The composition of the surface in combination with the contrast in sensible heat flux (in direct relation with the contrast in latent heat flux) explains most of the bias, with possible deviations ranging from -50 up to 80 W m-2. A tentative semi-empirical method for correcting the bias is suggested, which only requires a crude estimate of the contrast in component sensible heat fluxes along the pathlength.

International audience; The Penman-Monteith equation (PM) provides a direct and logical route to explaining rates of crop water consumption without the need of resorting to the artificiality of a reference crop and ill-defined crop factors. However as an operational irrigation tool, the PM is often impractical because of uncertainties about stomatal behaviour and turbulent transport. While recent progress is providing better descriptions of these processes, it is questionable whether such detail is always warrented for practical irrigation. Another option for evaporation prediction is the Priestley and Taylor equation (PT). This approach enjoys reasonable empirical support in humid regions and our efforts here are devoted to better defining its limits of applicability. We begin by presenting previously published and new evidence in support of Priestley and Taylors' value of 1.26 for the coefficient α indicating proportionality between evaporation rate and available energy. While α may depart from this value depending on windspeed and saturation deficit, it is shown to be fairly insensitive to both over a reasonable range of conditions. A daytime mean saturation deficit of 10 g m–3 is suggested as a likely upper limit for the range of applicability of the PT; below this limit, the extra data inputs required for the PM will not be rewarded with a better estimate of evaporation. In arid regions and under stable conditions, fluxes well beyond the PT estimate have been measured and no simple prediction alternative to the PM exists.

Ba0.5Sr0.5TiO3 (BST) thin-film capacitor structures with various thicknesses, (50–1200nm) and different strain conditions (on lanthanum strontium cobalt oxide La0.5Sr0.5CoO3 and strontium ruthenate SrRuO3 buffer layers) were made using pulsed laser deposition, and characterized by x-ray diffraction. The out-of-plane lattice parameter was followed as a function of temperature within the 100–300K temperature interval. The phase sequence (cubic-tetragonal-orthorhombic-rhombohedral) known to exist in the bulk analog is shown to be strongly affected by both the stress conditions imposed by the buffer layer and the thickness of the BST film itself. Thus, no phase transition was found for the in-plane compressed BST films. On the stress-free BST films, on the contrary, more phase transitions were observed. It appeared that the complexity of structural phase transitions increased as the film thickness in this system was reduced.

The transpiration of 2 kiwifruit vines grown within sheltered orchards in the Nelson locality was estimated in late summer by measuring their water uptake for 2 days following excision. Total daily transpiration by vines with vertically projected canopy areas of 16–17 m2 varied between 80 and 100 liters of water per day (4.8–6.1 mm/day) and ranged from 1.6 to 2.4 times the equilibrium evaporation rate. Stomatal conductances on excised vines were lower than those of adjacent uncut vines after the first day. Since transpiration estimates using the Penman-Monteith formula agreed well with the measured water uptake by cut vines, this equation was used to predict the transpiration of adjacent intact vines. Advective enhancement of evaporation contributed between 21 and 49% of the daytime water use despite the presence of multiple, closely spaced shelterbelts. Transpiration continued throughout the night as a consequence of incomplete stomatal closure, so that in total, advected energy was responsible ...

An in situ device for determining the soil water potential by measuring the dewpoint temperature depression is described. A saturated ceramic plug is used to provide hydraulic contact between the soil and an air-tight measuring chamber housing a four-terminal thermojunction. The ceramic and the thermojunction references are thermally clamped to the copper body of the instrument in order that temperature differences between the vapor source (the internal evaporating surface of the ceramic) and the reference junctions are minimal. Thus, the device reduces the major source of error that plague conventional soil psychrometers in the presence of temperature gradients. A hygrometer placed perpendicular to an imposed thermal gradient in a soil column recorded a maximum zero offset voltage of 0.22 µV as compared with 130 µV from a Wescor psychrometer under the same conditions. Provided the ceramic remains saturated, the response of the hygrometer to changes in soil water matric potential is extremely rapid. Two bean plants (Phaseolus vulgaris L., c.v. “Tender-green”) growing in a 2-liter container of silt loam soil were subjected to wetting and drying cycles in the laboratory. Simultaneous measurements of leaf and soil water potential illustrate the capacity of the soil hygrometers to track changes in soil water matric potential. In the presence of solutes, the instrument is diffusion limited. The time constant for salt equilibration, with our geometry and using KCl as the solute was 23 hours. This is consistent with a diffusion coefficient of 2 to 3 × 10⁻⁶ cm³ sec⁻¹. For this reason the application of this design should be restricted to circumstances where the osmotic contribution to the total water potential is either small or not changing rapidly. These criteria are generally satisfied in the humid regions.

Losses of export-quality kiwifruit (Actinidia chinensis Planch.) attributable to wind damage increased with distance downwind of both natural and artificial windbreaks. These effects occurred on standard ‘T-bar’ trellised vines during a particularly windy season, within shelter spacings which the literature suggest should achieve adequate reductions in windspeed. Distance from the nearest upwind natural shelterbelt explained 57%of the variation in exportable yield per vine. Major losses resulted from frictional marks caused by fruit rubbing against each other and against plant canes. Mean proportions of exportable sized fruit rejected for this reason varied from 3–10%(for rows adjacent and to the lee of natural windbreaks) to 30–44%(3–4 rows downwind of artificial shelter). Trends in foliar damage and vegetative growth were similar to those observed in wind-rub damage. On rows partially shaded by natural shelter, up to 40%of the total fruit load did not reach export size because of poor pollinati...

The rooting patterns of mature kiwifruit (Actinidia chinensis Planch.) vines were observed in 2 soils of contrasting texture — Ohinepanea sand and Levin silt loam. Near the surface of both soils, roots extended laterally 2.2-2.4 m from the base of the stem. In the Bay of Plenty, rooting depths of 3 m have been observed and in the Ohinepanea sand significant moisture extraction occurred to depths exceeding 2.4 m. By contrast, the roots in the Levin soil were restricted to the top 70 cm because of unfavourable subsoil conditions. Some hydraulic characteristics of kiwifruit were measured and provided a basis for examining the relative contributions of plant and soilto- root resistances in the water uptake process. Large xylem vessels up to 0.5 mm in diameter in both roots and stem provide a very low resistance pathway for water movement within the vine. The measured hydraulic conductivities, which varied between 2.7 and 7.2 X 10-7 m2/Pa per s, may be the highest ever reported. Positive root pressure...

An important parameter necessary for describing the microclimate or heat budget at the earth's surface is the quantity of incident solar radiation. However, measurements of radiation on other than a horizontal surface are not normally available. This article provides a set of tables listing the ratio of total daily solar energy received on a surface of given aspect and slope to that received on a horizontal surface at latitude 37° 30' S. By multiplying this figure by the total short wave radiation recorded on a horizontal plane subject to similar cloud and atmospheric conditions, daily or monthly values of solar radiation on a sloping surface may be approximated.

The behaviour of 4-year-old kiwifruit (Actinidia deliciosa (A. Chev.) C. F. Liang & A. R. Ferguson) vines growing in a Springbank soil within the Kerikeri Irrigation Scheme was monitored over the 1982–83 season. Water stress was induced in two vines by withholding irrigation and preventing rainfall recharge. Fruit volume expansion appeared strongly linked to the hydraulic status of the vines and could be described by a simple model whereby fruit either expand at the maximum rate shown on well-watered vines, or not at all if water is limiting. Volume losses resulting from fruit softening after extreme water stress were quickly recovered upon the reapplication of irrigation and could be ignored for modelling the influence of water stress on harvest yields. In the absence of rainfall or irrigation, the readily available moisture in this soil is capable of maintaining unrestricted fruit volume expansion for 10 days in mid summer. This result is extrapolated to other soils within the Irrigation Scheme...

An irrigation experiment was conducted on young kiwifruit vines over two seasons to examine effects of water stress on fruit development. Vines were grown outdoors in a sandy, rooting medium enclosed within a polythene-lined trench with removable surface covers to enable strict control of the water supply. Measurements of fruit growth, leaf water potential, and stomatal conductance were made throughout the season in conjunction with periods of water stress imposed at different times, and for varying durations. Fruit development was very responsive to water stress with mean fruit size per vine at harvest varying from 60 to 130 cm3 as a result of various stress treatments. Fruit expansion ceased when predawn leaf water potentials fell below −0.1 MPa. Upon rewatering, leaf turgor was regained within 24 h even after severe, prolonged stress. Any turgor loss associated with fruit softening was quickly made up, and thereafter fruit growth continued at the same rate concurrently exhibited on continuously well-watered vines. Suggesting that stomatal conductance did not follow the rapid recovery of leaf water potentials and fruit expansion may be more closely linked to water supply than to the concurrent rate of photosynthesis. Despite the large range in mean fruit size, the shape of the fruit size distribution at harvest was not affected by water stress and it is concluded that harvest yields can be adequately modelled by assuming a normal distribution with a fixed standard deviation.

The distribution of fruit weight at harvest from 0.5 ha blocks of kiwifruit in the Kerikeri district is shown to closely approximate a Normal distribution with a constant standard deviation of 20.5 g. The standard deviation changed less than 2 g between seasons despite wide variations in the mean fruit weight with crop loading and vine age. This Normal approximation provides a mathematically convenient assumption which should be considered when modelling the influence of management practices on yield or the effect of industry pricing schedules on grower returns.