Miracle-dz/UniFAR-FTUs huggingface dataset:
Polar cap index as a proxy for hemispheric Joule heating

The polar cap (PC) index measures the level of geomagnetic activity in the polar cap based on magnetic perturbations from overhead ionospheric currents and distant field‐aligned currents on the poleward edge of the nightside auroral oval. Because PC essentially measures the main sources of energy input into the polar cap, we propose to use PC as a proxy for the hemispheric Joule heat production rate (JH). In this study, JH is estimated from the Assimilative Mapping of Ionospheric Electrodynamics (AMIE) procedure. We fit hourly PC values to hourly averages of JH. Using a data base approximately three times larger than studies, we find a quadratic relationship between JH and PC, differentiated by season. A comparison during the November 1993 storm interval with earlier reported methods using the AE index and the cross polar cap potential, shows that the PC‐based Joule heating estimate is as equally accurate. Thus the single station PC index appears to provide a quick estimate of, and is an appropriate proxy for, the hemispheric Joule heating rate.
Spatio-temporal reflectance fusion via unmixing: accounting for both phenological and land-cover changes

Owing to technical limitations the acquisition of fine spatial resolution images (e.g. Landsat data) with frequent (e.g. daily) coverage remains a challenge. One approach is to generate frequent Landsat surface reflectances through blending with coarse spatial resolution images (e.g. Moderate Resolution Imaging Spectroradiometer, MODIS). Existing implementations for data blending, such as the Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM) and Enhanced STARFM (ESTARFM), have their shortcomings, particularly in predicting the surface reflectance characterized by land-cover-type changes. This article proposes a novel blending model, namely the Unmixing-based Spatio-Temporal Reflectance Fusion Model (U-STFM), to estimate the reflectance change trend without reference to the change type, i.e. phenological change (e.g. seasonal change in vegetation) or land-cover change (e.g. conversion of a vegetated area to a built-up area). It is based on homogeneous change regions (HCRs) that are delineated by segmenting the Landsat reflectance difference images. The proposed model was tested on both simulated and actual data sets featuring phenological and land-cover changes. It proved more capable of capturing both types of change compared to STARFM and ESTARFM. The improvement was particularly observed on those areas characterized by land-cover-type changes. This improved fusion algorithm will thereby open new avenues for the application of spatio-temporal reflectance fusion.
Some Observations on the Dinosaur Tracks at Münchehagen (Lower Cretaceous), Germany

Dinosaur tracks at the Dinosaurier-Freilichtmuseum Munchehagen are well-known and are the reason the site is designated part of the German National Monument system. Although both sauropod and ornithopod tracks have been described in some detail, additional observations are presented herein. These include observations on the gauge and heteropody of sauropods and evidence for quadrupedal progression by ornithopods. Theropod tracks are also recorded in the region at this time and have proven to be taxonomically controversial. Most of the in situ tracks on the “main” surface are those of sauropods preserved on a single large ripple-marked sandstone bedding plane. The sauropod tracks are nearly parallel but the trackmakers were evidently going in two different directions and therefore not travelling together. The presence of ornithopod tracks in close stratigraphic proximity to the main sauropod track layer, (and perhaps on the same layer) is interesting and raises questions about the close spatial and tempora.
Paired windward and leeward biogeochemical time series reveal consistent surface ocean CO2 trends across the Hawaiian Ridge

Sustained time series have provided compelling evidence for progressive acidification of the surface oceans through exchange with the growing atmospheric reservoir of carbon dioxide. However, few long‐term programs exist, and extrapolation of results from one site to larger oceanic expanses is hampered by the lack of spatial coverage inherent to Eulerian sampling. Since 1988, the Hawaii Ocean Time‐series program has sampled CO2 system variables nearly monthly at Station ALOHA, a deep ocean site windward and 115 km north of the island of Oahu. Surface measurements have also been made at Station Kahe, a leeward site 12 km from the island and on the opposite side of the Hawaiian Ridge. Despite having different physical settings, the sites exhibit identical rates of surface pCO2 increase and hydrogen ion accumulation, suggesting that atmospheric forcing dominates over local dynamics in determining the CO2 trend in the surface waters of the North Pacific subtropical gyre.
Trajectory Similarity Learning with Auxiliary Supervision and Optimal Matching

Trajectory similarity computation is a core problem in the field of trajectory data queries. However, the high time complexity of calculating the trajectory similarity has always been a bottleneck in real-world applications. Learning-based methods can map trajectories into a uniform embedding space to calculate the similarity of two trajectories with embeddings in constant time. In this paper, we propose a novel trajectory representation learning framework Traj2SimVec that performs scalable and robust trajectory similarity computation. We use a simple and fast trajectory simplification and indexing approach to obtain triplet training samples efficiently. We make the framework more robust via taking full use of the sub-trajectory similarity information as auxiliary supervision. Furthermore, the framework supports the point matching query by modeling the optimal matching relationship of trajectory points under different distance metrics. The comprehensive experiments on real-world datasets demonstrate that our model substantially outperforms all existing approaches.
Diurnal restratification and turbulence in the oceanic surface mixed layer: 2. Modeling

We find that daytime restratification of the remnant layer is important to modeling both the decay of convective turbulence during the day and convective deepening the following night. Penetrating solar insolation accounted for about 60% of the observed restratification of the remnant layer. Of the other processes supplying the remaining restratification, we believe lateral advection is the most important and sets a limit on the capabilities of one-dimensional mixed-layer models. In the morning, with the end of convective forcing, there was an initial period lasting nearly an hour, similar to the convective time scale, during which e in the remnant layer remained nearly constant. After that, turbulence in the remnant layer could be modeled in accordance with a balance between e and the storage term for turbulent kinetic energy (TKE). Energy storage is computed using q2 = (el/C)2/3, where l = 0.84LO, the Ozmidov scale, matches observed overturning scales during most of the decay. Calculating LO for the observed linearly increasing stratification gives a modified exponential form for the decay. A value of C = 0.04 gives the best fit. This decay lasted about 5 hours, until 〈e〉 reached ≈ 5 × 10−10 W kg−1. Then for the remainder of the restratification period, dissipation and production of TKE due to vertical shear appeared to be approaching a balance.
Sea‐surface temperature and salinity product comparison against external in situ data in the Arctic Ocean

Sea-surface temperature and salinity (SST/S) in the Arctic Ocean (AO) are largely governed by sea-ice and continental runoff rather than evaporation and precipitation as in lower latitude oceans, and global satellite analyses and models which incorporate remotely observed SST/S may be inaccurate in the AO due to lack of direct measurements for calibrating satellite data. For this reason, we are motivated to validate several satellite sea-surface temperature (SST) data products and SST/S models by comparing gridded data in the AO with oceanographic records from 2006 to 2013. Statistical analysis of product-minus-observation differences reveals that the satellite SST products considered have a temperature bias magnitude of less than 0.5 °C compared to ship-based CTD measurements, and most of these biases are negative in sign. SST/S models also show an overall negative temperature bias, but no common sign or magnitude of salinity bias against CTD data. Ice tethered profiler (ITP) near-surface data span the seasons of several years, and these measurements reflect a sea-ice dominated region where the ocean surface cannot be remotely observed. Against this data, many of the considered models and products show large errors with detectable seasonal differences in SST bias. Possible sources of these errors are discussed, and two adjustments of product SST on the basis of sea-ice concentration are suggested for reducing bias to within less than 0.01 °C of ITP near-surface temperatures.
BINOCULAR VISION AND NOCTURNAL ACTIVITY IN OILBIRDS (STEATORNIS CARIPENSIS) AND PAURAQUES (NYCTIDROMUS ALBICOLLIS): CAPRIMULGIFORMES

Visual field characteristics were measured using an ophthalmoscopic reflex technique in Oil- birds (Steatornis caripensis) and Pauraques (Nyctidromus albicollis). Despite these birds' apparent frontal-eyed appearance, their functional binocular fields are relatively small with a maximum width of 38o and vertical extent of 100o in Oilbirds, and 25o x 110o in Pauraques. Maximum width occurred 10o above the horizontal in both species. In Pauraques, the blind area behind the head equals 89o and the monocular retinal field equals 148o. The apparent (optical) binocular field is 65o wide, compared with the functional (retinal) field approx. 25o. The binocular fields in these highly nocturnal birds are similar to those of strongly diurnal species. This supports the hypothesis that binocularity in birds is concerned with the contra lateral projec- tion of each eye rather than achieving disparate images of the same object from two eyes. These contra lat- eral projections result in a section of the field in each eye that provides a symmetrically expanding optic flow field, rather than a basis for the extraction of higher order information from disparate images. Accepted 30 September 2003.
Continuous day and night aerosol optical depth observations in the Arctic between 1991 and 1999

[1] Ground-based measurements of total aerosol optical depth (AOD), e.g., tropospheric and stratospheric aerosol, have been established at the Koldewey station in Ny-Alesund, Spitzbergen (Norway, 78.95°N, 11.93°E), since 1991. The basic instrumentation is a multichannel photometer using sunlight. New instruments have been developed to extend the measurement period to polar night. The new instruments are a Sun and Moon photometer (1995) and a star photometer (1996). The instruments and applied methods for aerosol optical depth retrieval for Sun, Moon, and star measurements are briefly discussed. The year-round measurements made it possible to study in detail the interannual and seasonal variations of total AOD in the Arctic. The seasonal variation and the long-term trend of tropospheric aerosol optical depth are discussed, taking into account the stratospheric AOD measured by the Stratospheric Aerosol and Gas Experiment (SAGE II). The lowest tropospheric aerosol optical depth values occur in late summer and fall. Each year, strong Arctic haze events were recorded not only during spring but also in late winter as the first star photometer measurements clearly show. Five-day backward trajectories were used to analyze possible sources for high tropospheric AOD. Elevated tropospheric aerosol optical depth appears for northeasterly, easterly, or westerly winds. Finally, the long-term changes of tropospheric AOD have been assessed. A small positive trend of the tropospheric aerosol optical depth is found for the vicinity of Spitzbergen during the measurement period.
The nature and origin of pegmatites in a fluorine-rich leucogranite, East Kemptville Tin Deposit, Nova Scotia, Canada

ABSTRACT Pegmatites at the East Kemptville Sn-Zn-Cu-Ag deposit occur within a F- and P-rich, 370 Ma topaz-muscovite leucogranite, the most evolved phase of the chemically zoned Davis Lake Pluton. Structural observations and geochronology indicate that the leucogranite intruded into an active shear/fault zone environment. Pegmatites are preferentially located near the roof zone of the intrusion and include: (1) quartz-feldspar pods (≤ 1–2 m) aligned parallel to a foliation in the leucogranite. Such pegmatites have marginal aplites or may be cored by aplites; (2) aplite-pegmatite zones with well-developed crenulate and unidirectional solidification textures; and (3) muscovite-bordered miarolitic cavities lined with quartz-feldspar ± cassiterite. Associated with areas of pegmatites are irregular- to cuspate-shaped zones enriched in muscovite. Mineralogically the pegmatites are simple, consisting of clear to black quartz, albite, microcline perthite and muscovite; topaz may be enriched in aplites coring pegmatites and coarse euhedral cassiterite is rare. Chemically the leucogranites marginal to pegmatites are similar to the host leucogranite, but some aphanitic felsic dykes indicate extreme differentiation, as reflected by REE depletion and P-enrichment. Enrichment of pegmatitic feldspar in P2O5 (to 1 wt. %) indicates that melts contained 2–3 wt. % P2O5, whereas muscovite chemistry (to 5 wt. % F) reflects the F-rich nature of the melt. Trace and REE contents of pegmatitic feldspars are consistent with local segregation of volatile-rich melts to form pegmatites rather than extreme crystal-chemical fractionation. Fluid inclusion studies of pegmatitic quartz and cassiterite indicate the presence of a highly saline brine (40 wt. % eq. NaCl; Na > K > Fe > Mn > Ca > Sr) of magmatic origin. Isochores modelled for a 40 wt. % eq. NaCl fluid constrain pegmatite formation at 550–600°C, thus the depressed solidus is consistent with the volatile-rich (F, P, H2O) nature of the melt. Stable isotopes demonstrate that a magmatic fluid (δ18OH2O = +5·5 to +10‰, δDH2O = −33 to −41‰ for 450–500°C) equilibrated with the pegmatites and the system cooled abruptly at c. 425°C. The low volume of pegmatite at East Kemptville suggests that the melt was not near volatile saturation, instead pegmatite generation is interpreted to have resulted from rapid decompression related to the active shear zone setting of the granite. Although feldspar chemistry reflects a local segregation model, the chemistry of aphanitic dyke rocks indicates that the leucogranite did evolve into a more fractionated melt. The local presence of cassiterite in pegmatites and miarolitic cavities indicates that locally, saturation of Sn occurred, but not throughout the EKL where elevated Sn contents are attributed to infiltration of mineralising fluids (i.e. deuteric alteration).
Magnetic study of magnetite in the Tagish Lake meteorite

Abstract— The saturation magnetization, saturation remanent magnetization, the coercive, and remanent coercive force were determined at room and liquid nitrogen temperatures for three pieces of the Tagish Lake meteorite. The results are compared to similar data for four other chondrites (Allende, Murray, Orgueil, and Murchison). The data suggests that the Tagish Lake meteorite is magnetically homogeneous, and is not as magnetically hard as the comparison chondrites. The magnetization measurements indicate that it contains about 10–11% multi‐domain magnetite. Magnetic susceptibility measurements on all the samples from 77 K to room temperature showed a Verwey transition for all the samples which contain a significant amount of multi‐domain magnetite. The coercive force data further indicate that the magnetite in Tagish Lake is multi‐domain and that the grain size is small and approximately 4–9 μm.
Automatic detection of anisotropic features on rock surfaces

Surface roughness is an important rock property that is measured for structural geology and engineering purposes. We have developed an automatic technique to detect anisotropic features on rock faces based on fractal analysis. The analysis method has been applied to synthetic surfaces, and to digitally mapped point clouds of natural rock surfaces shaped by weathering, fault wear, and mining. We illustrate the technique using field examples from Permian sandstones containing brittle shear zones in northeast England, the surface of a neotectonic fault in Turkey, Proterozoic quartzite from central Australia, and Devonian Quartzite in an aggregate quarry in Germany. Roughness analysis of these natural examples suggests that a significant change of roughness value, anisotropy, and anisotropy direction can exist across scale. Our analysis method represents a step toward developing a toolkit to automatically detect and interpret surface characteristics from digitally acquired data sets. It has widespread potential for applications in rock engineering and the geosciences.
Kamil Crater (Egypt): Ground truth for small-scale meteorite impacts on Earth

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Simplified procedures for the evaluation of settlements in sands due to earthquake shaking

Simplified methods of analysis are proposed for estimating probable settlements in either saturated or unsaturated sand deposits subjected to earthquake shaking. It is suggested that the primary factors controlling induced settlement are the cyclic stress ratio and maximum shear strain induced in saturated sands by the earthquake shaking and the cyclic strains induced in dry or partially saturated sands, together with the SPT N-value of the sand and the magnitude of the earthquake. Charts are presented for estimating settlements using these parameters, and the results are shown to compare favorably with settlements observed at six sites for which good data on settlements have been observed.
Central Appalachians forest ecosystem vulnerability assessment and synthesis: a report from the Central Appalachians Climate Change Response Framework project

Forest ecosystems in the Central Appalachians will be affected directly and indirectly by a changing climate over the 21st century. This assessment evaluates the vulnerability of forest ecosystems in the Central Appalachian Broadleaf Forest-Coniferous Forest-Meadow and Eastern Broadleaf Forest Provinces of Ohio, West Virginia, and Maryland for a range of future climates. Information on current forest conditions, observed climate trends, projected climate changes, and impacts on forest ecosystems was considered by a multidisciplinary panel of scientists, land managers, and academics in order to assess ecosystem vulnerability to climate change. Appalachian (hemlock)/northern hardwood forests, large stream floodplain and riparian forests, small stream riparian forests, and spruce/fir forests were determined to be the most vulnerable. Dry/mesic oak forests and dry oak and oak/pine forests and woodlands were determined to be least vulnerable. Projected changes in climate and the associated impacts and vulnerabilities will have important implications for economically valuable timber species, forest-dependent wildlife and plants, recreation, and long-term natural resource planning.
Reynolds Stresses and Secondary Circulation in a Stratified Rotating Shear Flow

Abstract A transverse secondary circulation should result from vertical mixing of momentum in a stratified shear flow influenced by the earth's rotation. A rigidly mounted acoustic Doppler current profiler was deployed at the bottom of Juan de Fuca Strait, a stratified estuary on the west coast of North America, for 21 days, to examine this dynamical process and its variation over a spring–neap tidal cycle. The data demonstrate a significant fortnightly modulation of the estuarine exchange flow, with stronger along-channel flow, less dynamic stability, and much greater cross-strait currents at neap tide than at spring tide. Reliable estimates of the Reynolds stresses in the stratified shear flow away from boundaries were also obtained. They were small except for several days around neap tide when they were associated with times of reduced Richardson number. These stresses are not related in any simple way (such as with a smooth, positive, eddy viscosity) to the shear of the mean flow but do have a pattern.
Migrant Labor Markets and the Welfare of Rural Households in the Developing World: Evidence from China

In this paper, the authors examine the impact of reductions in barriers to migration on the consumption of rural households in China. The authors find that increased migration from rural villages leads to significant increases in consumption per capita, and that this effect is stronger for poorer households within villages. Household income per capita and non-durable consumption per capita both increase with out-migration, and increase more for poorer households. The authors also establish a causal relationship between increased out-migration and investment in housing and durable goods assets, and these effects are also stronger for poorer households. The authors do not find robust evidence, however, to support a connection between increased migration and investment in productive activity. Instead, increased migration is associated with two significant changes for poorer households: increases both in the total labor supplied to productive activities and in the land per capita managed by the household. In examining the effect of migration, we pay considerable attention to developing and examining our identification strategy.