Miracle-dz/UniFAR-FTUs huggingface dataset:
Substorm growth and expansion onset as observed with ideal ground-spacecraft THEMIS coverage

[1] We present a fortuitous case of an isolated substorm on 29 March 2009, observed by the Time History of Events and Macroscale Interaction during Substorms (THEMIS) probes clustered at ∼11–14 RE with simultaneous coverage by the THEMIS ground network. The four probes are at roughly the same radial and azimuthal location, with one probe staying near the neutral sheet during entire growth phase and during the ensuing transition to the substorm expansion phase. Prior to substorm onset, THEMIS observed the damping of earthward convection and development of an embedded tail current sheet with half thickness ≤ 0.15 RE and current density ∼20 nA/m2, while the total magnetic field closest to the neutral sheet was below 2 nT. Tail activity was observed to start prior to substorm onset tailward of the THEMIS probes (<−14 RE) with the gradual increase of earthward flow and total pressure in front of an earthward moving bursty bulk flow event (BBF). There was no evidence of an outward propagating rarefaction wave prior to BBF onset. Peak flow was accompanied by two short dipolarization pulses, followed by a sharp reduction of the total pressure (up to 30–50%) and a decrease in the lobe magnetic field. By analyzing the lobe field waveforms, we infer their reconnection origin and argue that different onset-related magnetotail phenomena discussed in past literature (BBFs, bubbles, current disruption, nightside flux transfer events, earthward traveling convection regions) are views of the same dissipative structure formed by reconnection, when it is observed from different vantage points. Although the first ionospheric signatures of the substorm were observed near the equatorward edge of the auroral oval, the adaptive magnetospheric model maps the breakup to the tail current sheet at 15–20 RE, consistent with other estimates of the substorm onset location available in our case. The event provides definite evidence in favor of tail reconnection within a thin current sheet as the primary substorm initiation process. It also demonstrates that actual changes of tail current magnitude in the magnetotail can be an order of magnitude larger, compared to the magnitude of 3-D current inferred from ground observations.
Fracture sealing of quartzite under a temperature gradient: experimental results

Veined lithologies are formed by fracturing and sealing processes, with the veins representing former fluid conduits through the rock. Although detailed fieldwork and numerical simulations have provided a better understanding of vein growth, few studies have attempted to seal fractures and generate veins experimentally. In this pilot study, we subjected fractured quartzite to temperature gradients of 45–125 °C under hydrothermal conditions in a static fluid, with the aim of precipitating secondary quartz in the cooler portions of the fracture. Results show that secondary quartz precipitates due to the imposed temperature gradient, causing the initial fracture to seal locally. Although no systematic sealing pattern was observed along the fracture, samples subjected to higher temperatures exhibit a smaller fracture width and appear to have reacted more extensively. Electron microprobe mapping visualizes the spatial distribution of secondary quartz, which contains elevated concentrations of aluminium.
Global ship track distribution and radiative forcing from 1 year of AATSR data

One year of ENVISAT‐AATSR (Advanced Along Track Scanning Radiometer) satellite data is analyzed to derive a global distribution of ship tracks and their radiative forcing (RF). Ship tracks are changes in cloud reflectance, visible in satellite data, and result from the emission of aerosols and their precursors by ships into the clean marine boundary layer. An algorithm is presented that extracts scenes dominated by low clouds over the oceans that are susceptible to be affected by ship emissions. These selected cloud scenes are used to examine ship tracks on a global scale via visual analysis. The results show a high temporal variability of ship track occurrence with peak values in July. They also show a high spatial variability with peak values in the North Pacific Ocean and on the west coast of southern Africa, correlated with high ship traffic and frequent low cloud occurrence in regions of cold upwelling ocean currents. The analysis of backscattered radiation at top of the atmosphere (TOA) compared to the surrounding area reveals enhanced backscattering with values between 0 and 100 Wm−2. For particular regions on the west coast of North America, the annual mean RF due to ship tracks estimated by the changes in backscattered radiation at TOA can be up to −50 mWm−2. The global annual mean RF due to ship tracks is small (−0.4 to −0.6 mWm−2) and negligible compared to previous global model estimates on the total indirect aerosol effect and RF contributions of other ship emissions.
A study into the techno-economic feasibility of photovoltaic and wind generated electricity for enhancement of sustainable livelihoods on Likoma Island in Malawi

This research investigated the techno-economic feasibility of increasing hours of electricity services on Likoma Island in Malawi; making use of solar photovoltaic and wind power in order to enhance sustainable livelihood. Likoma Island grid is operated independent of the mainland grid; and the island is supplied electricity by diesel generators which are scheduled for only 14 hours per day. The limited hours of electricity supply constrains the delivery of essential services and hinders people from achieving sustainable livelihoods. The research used empirical and modelled data of solar irradiance and hub height wind speed, photovoltaic and wind energy systems costs, diesel-generator operation costs, energy needs, energy use patterns, electricity demand profile, and prevailing socioeconomic conditions. Diesel, photovoltaic, and wind based energy systems feeding the Island s grid; and autonomous photovoltaic and wind energy systems for selected essential institutions were modelled and simulated using the Hybrid Optimization Model for Electric Renewables. Energy system solutions are proposed indicating cost factors and opportunities for the enhancement of sustainable livelihoods. The thesis argues that with the financial resources committed to the prevailing 14-hours supply of electricity by diesel generators, it is feasible to provide Likoma Island with electricity for 24 hours every day by photovoltaic and wind based energy systems. A deployment model which uses excess energy from the modelled photovoltaic and wind power systems to serve non-grid loads and livelihood activities which are difficult to account for when sizing embedded renewable energy systems has been developed. The findings provide cost projections of photovoltaic and wind energy systems relative to diesel generators upon which investment and policy decisions can be made. Microscale wind maps at 10 m, 25 m, 40 m and 50 m have been developed for identification of potential wind turbine sites. Empirical socioeconomic data which are essential for the design of delivery mechanisms for renewable energy systems have been generated. The deployment model proposed by the research gives new insights into holistic ways of enhancing sustainable energy access in low-income communities. The interdisciplinary insights provided by this thesis can be applied in other countries and communities with similar socioeconomic contexts to Likoma Island.
Edinburgh Research Explorer Experimentally determined postspinel transformation boundary in Mg2SiO4 using MgO as an internal pressure standard and its geophysical implications

[ 1 ] We have determined the postspinel transformation boundary in Mg 2 SiO 4 by combining quench technique with in situ pressure measurements, using multiple internal pressure standards including Au, MgO, and Pt. The experimentally determined boundary is in general agreement with previous in situ measurements in which the Au scale of Anderson et al. [1989] was used to calculate pressure: Using this pressure scale, it occurs at significantly lower pressures compared to that corresponding to the 660-km seismic discontinuity. In this study, we also report new experimental data on the transformation boundary determined using MgO as an internal standard. The results show that the transition boundary is located at pressures close to the 660-km discontinuity using the MgO pressure scale of Speziale et al. [2001] and can be represented by a linear equation, P (GPa) = 25.12 (cid:1) 0.0013 T ( (cid:1) C). The Clapeyron slope for the postspinel transition boundary is precisely determined and is significantly less negative than previous estimates. Our results, based on the MgO pressure scale, support the conventional hypothesis that the postspinel transformation is responsible for the observed 660-km seismic discontinuity.
Comparison of Growth Characteristics and Ginsenosides Content of 6-Year-Old Ginseng (Panax ginseng C. A. Meyer) by Drainage Class in Paddy Field

**Ginseng Research Division, Department of Herbal Crop Research, NIHHS, RDA, Eumseong 369-873, Korea. **Horticultural and Herbal Crop Environment Division, NIHHS, RDA, Suwon 440-706, Korea.ABSTRACT : To develop the practical cultivation for paddy field, we investigated the properties of paddy soil, growth char-acteristics and ginsenoside content of 6-year-old ginseng, Cheonpung variety between poor drainage class (PDC) and imper-fect drainage class (IDC). Groundwater level in PDC showed monthly small changes of 20~30㎝, while IDC showedmonthly great changes of 28~71 ㎝ depending on rainfall. Soil moisture content in PDC and IDC was 17.2%, 22.5%, respec-tively. Air temperature in IDC was lower than 0.3 ℃, while soil temperature was higher than 0.8 ℃ compare to PDC, respec-tively. Main soil color of PDC was grayish olive, while IDC was brownish olive. PDC showed yellowish mottles only atunderground of 20~40㎝, while IDC showed that at underground of 30~90㎝. IDC showed lower pH, EC, potassium, cal-cium and magnesium content, but higher organic matter, phosphate, and iron content than that of PDC, respectively. All ofEC, organic matter, potassium, calcium, and magnesium content were decreased, but iron content was increased at the sub-soil layers of PDC. All of EC, organic matter, phosphorus, and potassium content were decreased, but calcium and magne-sium content were increased at the subsoil layers of IDC. Root yield in IDC was more increased by 33% than that of PDC.The moisture content and rusty ratio of ginseng root in IDC were lower than that of PDC. Ginsenoside content in IDC washigher than that of PDC because the ratio of lateral and fine root showing relatively high content of ginsenoside was higherin IDC than that of PDC.Key Words : Panax ginseng, Poor Drainage Class, Imperfect Drainage Class, Paddy Soil, Root Yield, Ginsenoside
Investigation of physical and bathymetric characteristics of Lakes Abaya and Chamo, Ethiopia, and their management implications

The purpose of this study was to investigate the physical parameters of Lakes Abaya and Chamo in the Ethiopian rift lakes system, including such physical characteristics as depth, water resources capacity, hydrology, water balances, and impacts of water use and degradation of their watersheds. These parameters have not previously been studied for these two lakes to any significant extent. This study describes the bathymetry survey undertaken for these two lakes, and the morphometric characteristics derived from it. This study is part of a research project developed to provide further details on such parameters as hydrology, water quality, sediment inflows and deposition, lake hydrodynamics and consumptive water uses. The bathymetric survey was conducted, utilizing a combination of global positioning system (GPS) and echo sounder. To calculate the morphometric characteristics, the background lake map was digitized, and the surveyed primary data were developed as digital values. The digital values were interpolated, generating grids of the elevation surface. The elevation area and elevation volume curves (capacity curves) of the two lakes were developed from the digital values, describing the water resources capacity of the lake water basins. The results of this study increase our understanding of the water resources of these two lakes, as well as provide better understanding of their vulnerability to human activities because of their shallow depths. Immediate application of the results, as a basis for continuation of this study, also is highlighted.
Energetics of a global ocean circulation model compared to observations

The majority of the eddy kinetic energy (EKE) in the ocean is found on scales of 50 km to 500 km, encompassed by mesoscale eddies and the meanders and rings of the boundary currents. Mesoscale eddies play a critical role in the dynamics of the ocean circulation with instabilities of the strong mean currents generating eddies in the upper ocean. Interactions between eddies transfer energy from the upper ocean to the deep ocean where eddies interact with bottom topography to generate abyssal mean flows and eddies transfer momentum back to the mean currents. The kinetic energy in a global Hybrid Coordinate Ocean Circulation Model (HYCOM) is compared with long‐term observations from surface drifters, geostrophic currents from satellite altimetry, subsurface floats and deep current meter moorings. HYCOM, configured at 1/12.5° (∼9 km, typical of the present generation of high resolution models), is deficient in EKE in both the upper and abyssal ocean (depths greater than 3000 m) by ∼21% and ∼24% respectively compared to surface drifting buoys and deep current meters. Increasing the model resolution to 1/25° (∼4.4 km) or injecting mesoscale eddies through the assimilation of surface observations in a 1/12.5° model increases the surface and the abyssal EKE to levels consistent with the observations. In these models, the surface (abyssal) EKE is increased by 23% (51%) and 15% (46%) for the higher resolution or data‐assimilative models, respectively, compared to the 1/12.5° non‐assimilative model. While data assimilation increases the EKE in both the upper and abyssal ocean, the kinetic energy of the mean flow in the upper ocean is decreased in the data‐assimilative hindcast.
Compressive Strength Properties of Snow

Abstract The compressive strength of snow cylinders was investigated as a function of the age of the snow from which the cylinders were made, the snow particle size and the age of the cylinders. The results show that the compressive strength is reduced if the snow is older, if the particle size is smaller, or if the cylinders are younger. The variation with age of the cylinders can be represented by an equation similar to that for a first-order chemical reaction. The effect of adding small quantities of various gases to the atmosphere in which the cylinders were kept was also investigated; carbon dioxide and methane had no measurable effect, but ammonia lowered the strength of the cylinders. All the strength measurements were carried out at −10° C.
Towards deconfounding hydrological and seasonal temperature variability in the determination of selected limnological variables of a temperate floodplain ecosystem

This paper presents a methodological approach that can aid the assessment of variation in limnological variables in response to hydrological phases and seasonal temperature variation. The investigation was conducted in the Danube River floodplain, Kopački Rit, Croatia. The proposed approach facilitates a more accurate examination of the effects of first factor, while maintaining second factor less variable, and vice versa. Samples were collected in the floodplain channel and lake along a temporal connectivity gradient, and were grouped according to three hydrological phases (isolation, flow pulse and flood pulse) and according to three seasons (spring, summer and autumn). A permutational multivariate analysis of variance was used to analyse the hydrological effects within seasons, as well as seasonal effects within hydrological phases on selected limnological variables: pH, conductivity, dissolved oxygen, nitrites, nitrates, ammonium, total Kjeldahl nitrogen, total phosphorus, chlorophyll a concentrations and ratio of copiotrophic to oligotrophic bacteria. A multivariate data cloud was structured by hydrological phases during all investigated seasons, but not by all seasons during different hydrological phases. The strongest impact of hydrological phases on limnological variables occurred during summer. Seasonal effects were significant during the isolation and the flood pulse phases. The flow pulse phase somehow obscured the effects of seasonal change, resulting in temporal floodplain homogenization. One possible explanation is that water temperature determines potential limnological conditions, whereas hydrology determines actual conditions. Such results must be taken into account if the accurate effects of hydrology and seasonal change are to be assessed in temperate floodplain ecosystems. Copyright © 2014 John Wiley & Sons, Ltd.
Tropical systems from the southwest Indian Ocean making landfall over the Limpopo River Basin, southern Africa: a historical perspective

The study provides perspective on the contribution of landfalling tropical systems (cyclones, depressions, storms and lows) from the southwest Indian Ocean (SWIO) towards rainfall over the eastern interior of southern Africa, over the period 1948–2008. Although these systems contribute to < 10% of the annual rainfall occurring over the region, their relative contribution to local and widespread heavy rainfall events is shown to be highly significant. About 50% of widespread heavy rainfall events over northeastern South Africa are caused by landfalling tropical systems. Fourier analysis performed on the time series of rainfall occurring over northeastern South Africa in association with these systems reveals the existence of a quasi‐18‐year cycle. The cycle coincides with the well‐known quasi‐18‐year Dyer–Tyson cycle in rainfall over the summer rainfall region of South Africa. These results suggest that atmospheric and surface conditions leading to wet phases of the Dyer–Tyson cycle also favour the landfall and subsequent westward movement of tropical systems from the SWIO over southern Africa—and their eventual contribution to rainfall over northeastern South Africa and southern Zimbabwe. Copyright © 2011 Royal Meteorological Society
Chronology of the last deglaciation and Holocene environmental changes in the Sisimiut area, SW Greenland based on lacustrine records

The Sisimiut area was deglaciated in the early Holocene, c. 11 cal. ka BP. At that time the lowlands were inundated by the sea, but the isostatic rebound surpassed the global sea‐level rise, and the lowlands emerged from the sea. The pioneer vegetation in the area consisted of mosses and herbaceous plants. The oldest remains of woody plants (Empetrum nigrum) are dated to c. 10.3 cal. ka BP, and remains of Salix herbacea and Harrimanella hypnoides are found in slightly younger sediments. The maximum occurrence of statoblasts of the bryozoan Plumatella repens from c. 10 to 4.5 cal. ka BP probably reflects the Holocene thermal maximum, which is also indicated in geochemical proxies of the lake sediments. A maximum in organic matter accumulation in one of the three studied lakes c. 3 cal. ka BP can probably be ascribed to a late Holocene short‐duration temperature maximum or a period of increased aridity. Cenococcum geophilum sclerotia are common in the late Holocene, implying increased soil erosion during the Neoglaciation. A comparison with sediment and macrofossil records from inland shows similar Holocene trends and a similar immigration history. It also reveals that there has been a significant gradient throughout the Holocene, from an oceanic and stable climate at the outer coast to a more continental and unstable climate with warmer summers and drier conditions close to the margin of the Greenland ice sheet, where the buffer capacity of the sea is lower.
Thinning of a Ponderosa Pine/Douglas-Fir Forest in South-Central BC: Impacts on Understorey Vegetation

The ponderosa pine and Douglas-fir forests in the Interior of British Columbia, Canada, are facing problems such as forest in-growth mainly due to fire suppression, reducing grazing land area. This study focused on the use of thinning to reduce forest stand density and restore understorey species diversity and increase aboveground biomass productivity. Data were collected over a 4-year period. Species richness and diversity were generally lower under the canopy of ponderosa pine and Douglas-fir trees than outside the canopy. Species diversity was reduced by thinning at one site but unaffected by thinning at the other. Total understorey biomass increased up to 80% within 3 to 4 years after thinning. Depending on site and year, biomass production of one or more plant groups, such as forb, shrub, or graminoid, increased. Reduction in litter depth was observed at both sites due to the removal and/or reduction of needle sources. Variations in species composition existed among blocks and between sites, suggesting greater sampling size may be needed in future research to better capture the spatial variability. Thinning reduces stand density and thereby reduces fuel load and enhances understorey species productivity.
Ocean wind fields retrieved from radar‐image sequences

[1] The dependency of radar backscatter on the surface wind field is investigated using a nautical X-band radar operating at grazing incidence and horizontal polarization in transmit and receive. This resulted in development of an algorithm for wind retrieval from nautical radar image sequences. The algorithm consists of two parts: In the first part, wind directions are extracted from wind-induced streaks that are in line with the mean surface wind direction. These streaks are visible in the temporal integrated radar images at scales between 100 and 500 m. The orientation of the streaks is determined from the local gradients, which are derived from the radar images smoothed and reduced to the appropriate scales. In the second part, wind speeds are derived from the backscatter of the temporal integrated radar image sequence and the radar retrieved wind direction. The dependency of the radar backscatter on the local surface wind and geometry of the radar is parameterized by training a neural network. The algorithm is applied to radar image sequences acquired by a nautical X-band radar mounted aboard an offshore platform in the North Sea. The radar-derived winds are validated by comparison to in situ wind data measured at the platform. The comparison of wind directions resulted in a correlation of 0.99 with a standard deviation of 14.2°; for wind speeds the correlation is 0.97 with a standard deviation of 0.85 m s−1. In contrast to traditional offshore wind sensors, the retrieval of the wind field from the backscatter of the ocean surface makes the system independent of the sensors motion and installation height and reduces the effects due to platform-induced blockage and turbulence effects.