Miracle-dz/UniFAR-FTUs huggingface dataset:
Relationships between ice breakup dates of lakes and local air temperature on the Eurasian continent

Ice breakup dates on lakes are related to the local air temperature, and are useful for understanding the local climate. However, little study has been done on lakes on the Eurasian continent. Therefore, an ice breakup date estimation method, using water temperature trend and threshold surface temperature and aided by satellite remote sensing, was developed in our previous study in order to obtain the ice breakup dates for these lakes. The spatial distribution of ice breakup dates was also determined from the ice breakup dates on 18 Eurasian lakes from 2001 to 2003. The current paper reports the time series of the ice breakup dates, and establishes the relationships between ice breakup date and local air temperature. First, we estimated the ice breakup dates for Lake Khanka, which lies in the east of the Eurasian continent, over a period between 1984 and 2003, using advanced very high resolution radiometer (AVHRR) data. The results show that the ice breakup dates vary across a span of 10 to 20 days over a cycle of 5 to 10 years. According to the annual analysis, the ice breakup period does not become any earlier during the 20 years of the estimates. The observed data for Lake Baikal show a similar picture, although low correlation coefficients suggest that there is no strong relationship between the ice breakup dates for these lakes. Second, for each year, the ice breakup dates on Lake Khanka were plotted against the air temperature at Vladivostok, located about 160 km south of Lake Khanka. This analysis helps us to understand that a day change in ice breakup date represents a 0.3°C change in the mean air temperature in the month prior to the ice breakup date. A similar relationship was also derived between the ice breakup dates over 3 years on 17 Eurasian lakes and the air temperature derived from an observatory near to each lake.
High‐precision Pb‐Sr‐Nd‐Hf isotopic characterization of USGS BHVO‐1 and BHVO‐2 reference materials

The recent development of multiple‐collector inductively coupled plasma mass spectrometry (MC‐ICP‐MS) and increasing use of the technique have created the need for well‐characterized rock standards, especially for isotopic systems where no internal fractionation correction can be applied. This paper presents a careful leaching experiment on the U.S. Geological Survey (USGS) reference materials BHVO‐1 and BHVO‐2 (Hawaiian basalts) and documents the evidence for contamination of the rock powders during processing. This contamination accounts for the difference in Pb isotopic ratios of BHVO‐1 and BHVO‐2 as well as for their lack of homogeneity both in Pb isotopic compositions and in some trace element contents.
Crustal and upper mantle structure of southeast Tibet from Rayleigh wave tomography

[1] We have applied the two-plane wave inversion technique to fundamental mode Rayleigh waves in southeast Tibet. Phase velocity variations are obtained at 15 periods from 20 to 143 s and are used to construct three-dimensional shear wave velocity structure. A low-velocity zone is imaged in the middle crust of southeast Tibet, in which velocity perturbation varies from −4% to 3%. The slow area might be associated with high temperature and partial melt and can flow ductilely, while the high-velocity region could be relatively cold and mechanically strong enough to pass crustal strain, implying that coherent lithospheric deformation is possible with the presence of complicated crustal flow. Strong negative anomalies in the shallow crust are imaged at 92°E, correlating with the location of a north-south rift zone. A fast mantle lid to a depth of ∼120 km is present beneath most of the study area. The lithosphere is significantly slower in the central part of the study area than in the west and east. To the east of 96°E, a subvertical high-velocity zone is imaged at 120–240 km depths under the Bangong-Nujiang Suture (BNS), which is more like the subduction of the Asian lithosphere. We interpret the high-velocity anomalies to the south of the BNS as the subducted Indian lithosphere and those to the north as the Asian lithosphere. A vertical low-velocity column is observed in the central part of the region from the lower crust to the midupper mantle, which is probably in part responsible for the rift at 92°E. The slow anomaly is likely associated with asthenosphere upwelling following the opening of a slab window that could have developed when the slab was torn apart vertically because of the significant change of subducting direction at the eastern syntaxis.
Surface Temperature Related Variations in Tropical Cirrus Cloud as Measured by SAGE II

Abstract Data from the Stratospheric Aerosol and Gas Experiment II (SAGE II) solar occultation satellite instrument have been used to study the properties of tropical cloud over the altitude range 10.5–18.5 km. By virtue of its limb viewing measurement geometry, SAGE II has good vertical resolution and sensitivity to subvisual cloud not detectable by most other satellite instruments. The geographical distribution and temporal variation of the cloud occurrence have been examined over all longitudes on timescales from less than 1 day to that of the El Nino-Southern Oscillation (ENSO) cycle. Significant variations in cloud occurrence are found on each of these scales and have been compared with the underlying surface temperature changes. Maximum cloud occurs over the warm pool region of the Pacific Ocean, with secondary maxima over the South American and Central African landmasses, where the percentage of cloud occurrence in the upper troposphere can exceed 75%. Cloud occurrence at all altitudes within the T.
He+ and other unusual ions in the solar wind: A systematic search covering 1972–1980

Following the recent discovery of large fluxes of He/sup +/ in the solar wind, a systematic search of solar wind energy/change (E/Q) spectra was initiated, using plasma data from IMP 7, IMP 8, ISEE 1, and ISEE 3 that covered the time period from October 1972 to February 1980. A technique of vertically stacking successive E/Q spectra made it possible to detect systematic trends in the spectra that were indicative of ion species beyond the He/sup + +/ peak down to the one count level. A search of nearly 8 years of data yielded only three distinct events identifiable levels of He/sup +/. These events occurred on July 29, December 1, and December 4, 1977, all within 1 year and during the rising phase of solar cycle 21. We believe more events would have been detected if the instruments had been more sensitive and tracking more complete. Two of the events occurred within driver gas, following interplanetary shocks, while the third event occurred in a noncompressive density enhancement (NCDE). For all three the abundances of various minor ions, including He/sup + +/, were enhanced in comparison to normal solar wind abundances. One unusual feature found in these three He/sup +/more » events, in contrast to normal solar wind, was the appearance of ionization states corresponding to both warm and very cold coronal freezing-in conditions within the same plasma. In addition to the unusual appearances of large fluxes of He/sup +/ ions, iron ions ranging from Fe/sup +10/ to Fe/sup +5/ were observed. Evidence was found for the appearance of C/sup +4/ ion, and in one event the data can be interpreted as containing O/sup +2/ and O/sup +3/ at detectable levels. One of the phenomenological results following from these observations is that certain unusual transient events eject both hot and unusually cold coronal plasma mixed and coexisting on the same magntic field lines. « less
Detection of changes in glacial run‐off in alpine basins: examples from North America, the Alps, central Asia and the Andes

Atmospheric warming and enhanced melting of glaciers is already resulting in changes in the glacial contribution to run‐off in mountain basins around the world. The enhanced melting of glaciers leads at first to increased run‐off and discharge peaks and an increased melt season, while in the longer time frame glacier wasting can be so severe that it results in decreased run‐off. Glacier basins with a decreasing run‐off trend have been observed in south‐central British Columbia, at low elevations in the Swiss Alps and in the central Andes of Chile, which is probably a combined effect of reduced melt from seasonal snow cover as the snow line rises, and relevant glacier area losses. In contrast, significant run‐off increases are reported in Alberta, north‐western British Columbia and Yukon in Canada, in highly glacierized basins in the Swiss and Austrian Alps, the Tianshan Mountains and Tibet in central Asia and in the tropical Andes of Peru. The run‐off increase within these basins is closely related to observed temperature rise, indicating that there is an unequivocal signal of enhanced glacier melting under the present warming trends. In future warming scenarios, glacier run‐off should start to decrease even in high‐altitude basins, affecting water availability. Copyright © 2008 John Wiley & Sons, Ltd.
Particle densities, velocities and size distributions in large avalanches from impact-sensor measurements

Abstract In winter 1998/99, high-frequency pressure measurements with 10 cm sensors mounted 1–19 m above ground were carried out in the upper run-out zone of the avalanche test site at Vallée de la Sionne, Switzerland. Two large dry-snow avalanches clearly revealed a three-layered structure, with surprisingly low pressures in the suspension (or powder-snow) layer. The height of the saltation layer varied between 1 and > 3 m. From the duration, impulse and frequency of single-particle impacts (observed in the saltation layer and intermittently in the dense flow),particle-size and velocity distribution functions as well as strongly varying saltation-layer densities were found. With improved methods for peak detection and correction for grazing impacts, pressure measurements will become premier tool for testing granular flow models.
Recent slowdown of tropical upper tropospheric warming associated with Pacific climate variability

Observed upper tropospheric temperature over the tropics (TTUT) shows a slowdown in warming rate during 1997–2011 despite the continuous warming projected by coupled atmosphere‐ocean general circulation models (AOGCMs). This observation‐model discord is an underlying issue regarding the reliability of future climate projections based on AOGCMs. To investigate the slowdown, we conducted ensemble historical simulations using an atmospheric general circulation model (AGCM) forced by observed sea surface temperature both with and without anthropogenic influences. The historical AGCM run reproduced a muted TTUT change over the central Pacific (CP) found in multiple observations, while the multi‐AOGCM mean did not. Recent tropical Pacific cooling, which is considered natural variability, contributes to the muted trend over the CP and the resultant slowdown of TTUT increase. The results of this study suggest that difficulties in simulating the recent “upper tropospheric warming hiatus” do not indicate low reliability of AOGCM‐based future climate projections.
Lightning and precipitation history of a microburst‐producing storm

Quantitative measurements of the lightning and precipitation life-cycle of a microburst-producing storm are described. The storm produced 116 total flashes of which only 6 were discharges to ground. The initial discharge occurred during a period of vigorous vertical development, approximately 4-6 min after small hail was first indicated by radar. The peak flash rate of 23 flashes min−1 occurred only 7-8 min later, 4 min prior to microburst onset, in conjunction with the peak in storm mass, vertically integrated liquid water content, echo volume, and cloud height. An abrupt decrease in the total flash rates is associated with storm collapse and serves as a precursor to the arrival of the maximum microburst outflows at the surface. Ice-phase precipitation is shown to be an important factor in both the formation of the strong downdraft and the electrification of the storm.
A study of the morphology of ionospheric storms

A study was made of the variations of the maximum electron number density in the ionospheric F2 layer during magnetic storms. Fifty-one strong storms and 58 weak storms were studied. The data were collected during the ten-year period 1946–1955, at 38 ionospheric stations between 60.4°N and 60.4° geomagnetic latitudes. The ionospheric stations were put into eight zones according to their geomagnetic latitudes. Storm-time variations in the maximum electron number density (Dst) and disturbance daily variations during each six-hour period (DS) were obtained for each of the eight zones. The Dst variation in higher middle-latitudes was characterized by an initial short increase followed by a much larger decrease, the amplitude of the decrease being accentuated in summer. In the equatorial region, however, the phase of the variation was the opposite of that in higher latitudes. There was generally an increase after an initial short decrease, with no seasonal effect. The Dst variation at intermediate latitudes resembled that at higher latitudes in summer and that at the equatorial region in winter, with the average over all seasons being relatively flat. The diurnal component of the DS variation for each six-hour period indicated, on the harmonic dial, a change in the clockwise sense except in the equatorial region. The maximum amplitude of the diurnal component of the mean of the DS variations showed a gradual decrease from higher toward lower latitudes, with a subsequent increase in the equatorial region. A remarkable change of the phase of the diurnal component also occurred from higher toward lower latitudes.
Deep Currents in the Gulf of Mexico

Abstract Direct current measurements using moored arrays have been made below 1000 m in the eastern, central and western Gulf of Mexico basin. The major low frequency velocity fluctuations in the lower 1000 to 2000 m of the water column in the three regions have the characteristics of topographic Rossby waves (TRWs). Spectral peaks are observed at periods of about 25 days and 40 to 100 days. Motions are highly coherent with depth. Variances increase toward the bottom despite the very weak stratification of the deep waters of the Gulf. Wave-lengths are about 150–250 km and phase propagation is offshore with energy propagation westward. A group velocity of about 9 km day−1 could be directly estimated from significantly coherent signals between eastern and western arrays. This value is consistent with estimates derived from the dispersion relation and is higher than the westward translation speed of 3 to 6 km day−1 of the large anticyclonic eddies shed from the Loop Current. It appears that a major source of.
Wind stress and surface roughness at air‐sea interface

Based on the compiled data of thirty independent oceanic observations, this article systematically presents the wind-stress coefficient, the surface roughness, and the boundary layer flow regime at the air-sea interface under various wind conditions. The air flow near the water surface is shown to be aerodynamically rough or in the transition region except at a very low wind velocity (U10 < 3 m/sec). Both the wind-stress coefficient and the surface roughness are found to increase with the wind velocity when U10 is less than 15 m/sec and to reach a saturated value for U10 greater than 15 m/sec. From the oceanic wave observations, the presence of this discontinuity at U10 = 15 m/sec is found to be due to an increase in the wind velocity (measured at the significant wave amplitude above the mean water level) beyond the average wave phase velocity. This finding provides a well-defined separation for the often quoted terms ‘light’ and ‘strong’ winds. The compiled data also show that the surface roughness is governed by the amplitude of the short gravity waves. Charnock's relationship is shown to be applicable to most of the oceanic data and Charnock's proportionality constant is determined, η/(u*2/g) = 0.0156. Finally, two approximate formulas for the windstress coefficient C10 = 0.5 × U101/2 × 10−3 for light wind and C10 = 2.6 × 10−3 for strong wind are suggested for oceanic applications.
Modelling the impact and potential mitigation of cold water pollution on Murray cod populations downstream of Hume Dam, Australia

A one‐dimensional hydrodynamic reservoir model is coupled with a stochastic fish population model to examine the impacts of cold water pollution (CWP) on the Australian freshwater fish, Murray cod, downstream of Hume Dam, Australia. Mitigation of CWP through the introduction of selective withdrawal capabilities to access near‐surface water is predicted to increase discharge temperatures during the crucial spring‐early summer post‐spawning period by 4–6°C for normal operating conditions, that is, a full reservoir in early spring. No improvement in discharge temperature was predicted for drought conditions characterized by relatively low storage levels in early spring. The predicted temperature increase using selective withdrawal increased the predicted average minimum female population abundance by 30–300% depending on the assumed spawning behaviour. Increased discharge temperatures appear to be achievable and are expected to reduce the stress currently impacting Murray cod populations due to CWP during crucial post‐spawning periods. This provides evidence that mitigation of this problem may assist in rehabilitating Murray cod populations in the Murray River downstream of Hume Dam. Copyright © 2007 John Wiley & Sons, Ltd.
An Endogenously Clustered Factor Approach to International Business Cycles

Factor models have become useful tools for studying international business cycles. Block factor models [e.g., Kose, Otrok, and Whiteman (2003)] can be especially useful as the zero restrictions on the loadings of some factors may provide some economic interpretation of the factors. These models, however, require the econometrician to predefine the blocks, leading to potential misspecification. In Monte Carlo experiments, we show that even small misspecifica- tion can lead to substantial declines in t. We propose an alternative model in which the blocks are chosen endogenously. The model is estimated in a Bayesian framework using a hierarchi- cal prior, which allows us to incorporate series-level covariates that may influence and explain how the series are grouped. Using similar international business cycle data as Kose, Otrok, and Whiteman, we find our country clusters differ in important ways from those identified by geography alone. In particular, we find that similarities in institutions (e.g., legal systems, language diversity) may be just as important as physical proximity for analyzing business cycle comovements.
Plucking as an Effect of Water-Pressure Variations at the Glacier Bed

A rapid displacement of glaciers occurs at times when the water supply from melting or lake drainage surmounts the capacity of the subglacial drainage system. It is explained by the hydraulic action of water at high pressure in cavities which open up on the lee side of undulations or steps of the glacier bed. It is suggested that, because of pressure-induced temperature fluctuations, rock fragments may freeze on to the glacier sole and be lifted out into an opening cavity. Laboratory experiments have shown that small pressure fluctuations of a few bars* only are sufficient for rock slabs of a considerable thickness to be moved in this way.
The global water balance

This paper was originally prepared— in English as well as Russian— as ‘The Water Balance of the Continents of the World and the Method of Studying It’ (Vodnii Balans Materikov Zemnovo Shara i. Metod Polozhennii v Osnovu Yevo Izucheniya) for the Working Meeting on Water Balance Maps of the Continents of the World, held during the Fifteenth General Assembly of the International Union of Geodesy and Geophysics, in Moscow in August 1971. It has been edited only very lightly for the IHD Bulletin.
Not all folds and thrusts in the Yangtze foreland thrust belt are related to the Dabie Orogen: Insights from Mesozoic deformation south of the Yangtze River

The Yangtze foreland fold‐and‐thrust belt is located between the Mesozoic Dabie collisional orogen and the Mesozoic Jiangnan intraplate orogen in east‐central China. Three regional deformation events are recognized in the Dabie Orogen north of the Yangtze River. The earliest regional deformation (D1) corresponded to a southeastward compression that occurred during the subduction of the South China Plate below the North China Plate. Top‐to‐the‐southeast shearing coeval with Late Permian–Early Triassic blueschist facies metamorphism, was possibly associated with the development of regional gneissosity in the Dabie complexes and flat‐ramp‐style thrusts within the Neoproterozoic–Palaeozoic sedimentary cover, north of the Yangtze River. The main ductile deformation (D2) is also characterized by southeast‐verging overturned and recumbent folds, coeval with the early stage of exhumation of the high‐pressure rocks. A top‐to‐the‐SW thrusting and WNW‐striking open folds belong to a separate, later deformation phase, D3. Previous 40Ar–39Ar mica dates ranging between 245 and 205 Ma suggest Late Permian–Early Jurassic ages for the D1 to D3 events. The foreland folds and thrusts related to these deformations in the Dabie Orogen flank the eastern and western ‘limbs’ of the Dabie Orogen but are absent in the front of it. In contrast to the deformation north of the Yangtze River, the deformation of Neoproterozoic–Palaeozoic sedimentary cover in the Jiangnan Orogen south of the Yangtze River is generally characterized by north‐verging folding and top‐to‐the‐north thrusting from Triassic to Jurassic times. Based on the differences of deformation and structural polarity between the south and north areas of the Yangtze River, we propose that the Yangtze foreland fold‐and‐thrust belt in the direct front of the Dabie Orogen is unrelated to the Dabie Orogen but resulted from the Jiangnan Orogen. Copyright © 2010 John Wiley & Sons, Ltd.
Fractal Mapping of Pore and Solid Attributes

Soil structure depends on its genesis and consists of highly variable pore and solid networks. Several internal and external factors affect the attributes of these networks, with water being the most aggressive agent. In this study, we used selected fractal parameters (called descriptors) to quantify the basic topological attributes—compactness and connectedness—as well as lacunarity and roughness of porous materials, with special attention to sampling error and population variance dynamics. Four microhorizons were sampled from a 1.0‐ by 1.0‐ by 1.6‐m monolith during a long‐term drying period under controlled conditions. A comparative fractal analysis of selected multitemporal (11 mo) and multiscale (50×, 500×, 1000×, and 5000×) scanning electron microscopy (SEM) images was accomplished for the following layers with contrasting texture or structure: loam topsoil, pure basaltic compacted sand, and two amorphous lacustrine clays. The scale invariance (self‐similarity) of pore and solid networks was documented. A complex relationship was found between the descriptor mean values and corresponding variances. Simple power‐law relations were established between the standard deviation (and variance) and layer depth, as well as scale and sampling time. Pearson's r correlation criterion was applied to measure the degree of association between multiobjective fractal descriptors. Systematic and standardized fractal analysis of multiscale images is recommended for the statistical quantitative description of complex and dynamic pore and solid networks.