Miracle-dz/UniFAR-FTUs huggingface dataset:
The Effect Of Rheology On Seasonal Sea-Ice Simulations

On the seasonal time scales relevant to numerical investigations of climate, the rheology used in large-scale sea ice models significantly affects the ice thickness build-up and ice velocity fields. Plastic rheologies with a normal flow rule have been used to-date in seasonal dynamic thermodynamic simulations. These rheologies have proved useful in simulating discontinuous slip near the coast while still supplying relatively robust velocity fields in the central Arctic Basin. However, as indicated by limited numerical sensitivity studies with different types of elliptical yield curves, the amount of shear strength significantly affects the ice build-up and can possibly cause a stoppage of the ice outflow through Fram Strait. In addition to the shear strength issue, there is also the possibility that non-normal flow rule rheologies, such as the Mohr Coulomb failure criterion used in soil mechanics, may cause somewhat different types of flow patterns, especially in the Fram Strait region. However, to date no seasonal simulations with such non-normal flow rule rheologies have been carried out. In order to investigate the role of different rheologies on the large-scale flow patterns in the Arctic Basin, a more general numerical scheme than that of Hibler (1979) is developed, which allows the simulation of the dynamic thermodynamic behavior of sea ice with a wide variety of different non linear rheologies. Using this numerical scheme, comparative simulations are carried out to seasonal equilibrium with several variations of the Mohr Coulomb rheology and compared to the more standard Elliptical yield curve results. In particular, the main control Mohr Coulomb case is a capped rheology in which the shear strength is taken to be proportional to the compressive stress. In this capped case only shear flow is allowed until a maximum allowable compressive stress is reached. This cap strength is parameterized to be a function of the ice thickness and compactness. For comparison, a simulation with a very large cap strength is also carried out, and an experiment with a similar compressive cap but much lower shear strength. Overall the results are analyzed to determine the sensitivity of the ice build-up to flow rule and shear strength magnitude. In addition special attention is given to the character of the flow and stoppage (if any) through Fram Strait.
Spectral Characteristics of the Response of the Meridional Overturning Circulation to Deep-Water Formation

Abstract The response of the upper limb of the meridional overturning circulation to the variability of deep-water formation is investigated analytically with a linear, reduced-gravity model in basins of simple geometry. The spectral characteristics of the model response are first derived by prescribing white-noise fluctuations in the meridional transport at the northern boundary. Although low-frequency basin modes are solutions to the eigenproblem, they are too dissipative to be significantly excited by the boundary forcing, and the thermocline depth response has a red spectrum with no prevailing time scale other than that of a high-frequency equatorial mode, only flattening at the millennial time scale because of vertical diffusivity. The meridional transport is asymmetric about the equator because the northern part of the basin is directly influenced by the boundary forcing while the southern part is mostly set in motion by long Rossby waves. This results in the equator acting as a low-pass filter for .
Modelling how vegetation cover affects climate change impacts on streamflow timing and magnitude in the snowmelt‐dominated upper Tuolumne Basin, Sierra Nevada

We investigated, through hydrologic modelling, the impact of the extent and density of canopy cover on streamflow timing and on the magnitude of peak and late summer flows in the upper Tuolumne basin (2600–4000 m) of the Sierra Nevada, California, under current and warmer temperatures. We used the Distributed Hydrology Soil Vegetation Model for the hydrologic modelling of the basin, assuming four vegetation scenarios: current forest (partial cover, 80% density), all forest (uniform coverage, 80% density), all barren (no forest) and thinned forest (partial cover, 40% density) for a medium‐high emissions scenario causing a 3.9 °C warming over a 100‐year period (2001–2100). Significant advances in streamflow timing, quantified as the centre of mass (COM) of over 1 month were projected for all vegetation scenarios. However, the COM advances faster with increased forest coverage. For example, when forest covered the entire area, the COM occurred on average 12 days earlier compared with the current forest coverage, with the rate of advance higher by about 0.06 days year−1 over 100 years and with peak and late summer flows lower by about 20% and 27%, respectively. Examination of modelled changes in energy balance components at forested and barren sites as temperatures rise indicated that increases in net longwave radiation are higher in the forest case and have a higher contribution to melting earlier in the calendar year when shortwave radiation is a smaller fraction of the energy budget. These increases contributed to increased midwinter melt under the forest at temperatures above freezing, causing decreases in total accumulation and higher winter and early spring melt rates. These results highlight the importance of carefully considering the combined impacts of changing forest cover and climate on downstream water supply and mountain ecosystems. Copyright © 2013 John Wiley & Sons, Ltd.
Reciprocal Lowstand Clastic and Highstand Carbonate Sedimentation, Subsurface Devonian Reef Complex, Canning Basin, Western Australia: Chapter 6

Integrated sequence analysis of seismic and well data of the Givetian to Tournaisian sedimentary succession on the outer margin of the Lennard Shelf and adjacent Fitzroy Trough has recognized 18 third-order stratigraphic sequences in a major transgressive-regressive facies cycle. A Givetian phase of crustal extension initiated the transgressive-regressive cycle. The cycle terminated in the Tournaisian, following a phase of slow thermal subsidence. The transgressive half-cycle comprises at least four third-order sequences; an initial Frasnian-Givetian sequence followed by three backstepping Frasnian sequences. The regressive half-cycle comprises 14 basinward-advancing third-order sequences. A period of tectonic uplift and erosion immediately prior to the Frasnian-Famennian boundary resulted in a major basinward shift in coastal onlap in the initial stages of the regressive half-cycle. Systems tracts and facies are partitioned according to their position on the transgressive-regressive cycle; in the transgressive half-cycle, lowstand deposits are subdued and transgressive and highstand deposits accentuated. In the regressive half-cycle, lowstand deposits are accentuated and provide a foundation for the overlying transgressive and highstand deposits. The extent of basinward highstand progradation was limited by the break point of their underlying lowstand deposits. Sequence and systems tract geometries, their stacking patterns, and component facies define two distinct styles of sedimentation: (1) a Givetian to early Famennian, reef-rimmed platform complex; and (2) a late Famennian to Tournaisian mixed carbonate and siliciclastic ramp complex. The reef complex demonstrates marked reciprocal sedimentation. During lowstands, terrigenous sediments by-passed the exposed platform to be deposited in End_Page 157------------------------ the basin as basin floor fans, slope fans, and prograding complexes. During transgressions and highstands, carbonate sediments were deposited on the platform, allodapic carbonate particles were shed into proximal marginal-slope settings, and clastics were trapped on the inner platform. Lowstand carbonate production occurred locally in areas starved of terrigenous clastic influx. The recognition of relative sea-level cycles in these strata has led to a subsurface model of reef development, which provides new insights into the third-order cyclicity within the larger Pillara and Nullara cycles recognized from previous outcrop studies. The outcrop model of backstepping and advancing reef complexes emphasizes transgressive and highstand depositional systems, and fails to recognize phases o lowstand deposition.
Stability and the conservation of mass in drainage basin evolution

Drainage basin evolution is modeled as the time development of an initial surface subject to conservation of sediment and water and a transport law qs = F(S, q) connecting the sediment flux qs with the local slope S and the discharge of surface water q. Two models are presented. The first is appropriate to a smooth surface on which no discrete channels have formed, and the second is appropriate to a family of V-shaped valleys, each containing a separate stream of negligible width. For the first model, some solutions are presented that describe the evolution of a long ridge for which the profile is independent of one spatial coordinate. The stability of such surfaces is then discussed. It is shown that, if F/q < ∂F/∂q, disturbances of small amplitude and small lateral scale will grow rapidly and presumably will lead to the formation of closely spaced channels directed down the slope, whereas, if F/q ≥ ∂F/∂q, such channels will tend to disappear. For a surface eroding without change of shape, convex portions are stable, and concave segments are unstable. The second model is less well developed, since conservation principles alone are insufficient to determine its evolution without some additional postulate describing the sideways migration of individual streams. It is shown how, if each stream moves so that the sediment fluxes entering from its two side slopes remain equal, a system of similar parallel valleys is unstable, and neighbors will tend to coalesce on a time scale comparable to that for erosion through a layer as thick as a valley is deep.
Future changes in the distribution of daily precipitation totals across North America

Shape and scale parameters of the two‐parameter gamma distribution were estimated for daily distributions of precipitation at individual grid‐points in two General Circulation Models (HadCM2 and CSM). Maps of changing parameter distributions under anthropogenic forcing show the extent to which future precipitation scenarios for North America are consistent with observed trends in the 20th century. The scale parameter is found to be more variable, both spatially and temporally, than the shape parameter. Patterns of changes in mean wet‐day amounts are strongly correlated with changes in the scale parameter. While the two models show quite different results for the spatial patterns of change, both indicate that the proportion of total precipitation derived from extreme and heavy events will continue to increase relative to moderate and light precipitation events.
Cardiovascular risk factors and kidney function among automobile mechanic and their association with serum heavy metals in Southwest Nigeria: A cross-sectional study

Introduction The burden of cardiovascular disease (CVD) is huge due to its associated morbidity, mortality and adverse socio-economic impact. Environmental pollution as a risk factor contributes significantly to the burden of CVD, especially in the low and middle income countries. One of the effective strategies to reduce CVD burden is to prevent or detect cardiovascular risk factors early in at-risk population. This study determined some cardiovascular risk factors, kidney function, and their association with heavy metals among automobile mechanics. Method This was a cross-sectional study involving 162 automobile mechanics and 81 age and sex matched controls. Serum levels of lead, cadmium and some cardiovascular risks were assessed and compared in the two groups. Associations between serum lead, cadmium and some cardiovascular risks were determined using correlation analysis. P value of <0.05 was taken as significant. Results The mean ages of the automobile mechanics and controls were 47.27±9.99 years and 48.94±10.34 years, respectively. The prevalence of elevated serum cadmium was significantly higher in the automobile mechanics (25.9% vs 7.9%; p = <0.001). The significant cardiovascular risk factors in the automobile mechanics vs controls were elevated total cholesterol (32.1% vs 18.5%; p = 0.017), hyperuricemia (20.4% vs 1.2%; p = <0.001), elevated blood glucose (16.0% vs 4.9% p = 0.013); and alcohol use (55.1% vs 30.0%; p = 0.001). Among the automobile mechanics, there were significant positive correlations between serum cadmium, atherogenic index of plasma (AIP) (p = 0.024; r = 0.382) and triglyceride (p = 0.020; r = 0.391). Significant positive correlation was found between serum lead and neutrophil gelatinase associated lipocalin (NGAL) (p = <0.001; r = 0.329). There were significant positive correlation between serum cadmium level, AIP (p = 0.016; r = 0.373) and TG (p = 0.004; r = 0.439); between serum lead and NGAL in all the study participants (p = 0.005; r = 0.206). Conclusion Automobile mechanics have notable exposure to heavy metals and a higher prevalence of some cardiovascular risk factors. Health education and sensitisation as well as policies that would regulate exposure of persons to heavy metals should be implemented in Nigeria.
Awareness and knowledge of physicians and residents on the non-sexual routes of human papilloma virus (HPV) infection and their perspectives on anti-HPV vaccination in Jordan

Background and objectives Although penetrative sex is the most common route of HPV infection, there is strong evidence of non-sexual modes of transmission. As the first of its kind, this study aimed to investigate the knowledge and awareness of Jordanian physicians on such routes. Methods A questionnaire was conducted among a national Jordanian sample of physicians from Jordanian health sectors. The survey included questions assessing participants’ knowledge on HPV, non-sexual routes of infection and HPV vaccines. Physicians’ attitudes towards HPV screening and vaccination were covered. Statistical analysis was carried out using SAS 9.4, ANOVA, post-hoc Tukey-Honest test and Kruskal-Wallis test. All significant differences were set at α = 0.05. Results A total of 412 participants completed the survey. Physicians showed a huge deficit in knowledge on nonsexual routes of HPV transmission. They agreed that the most and least common routes of non-sexual transmission are skin to mucosa (64%) and contaminated water (15%), respectively. Females showed significantly better knowledge in all aspects of HPV transmission and vaccination (p<0.0001) and more positive attitudes towards HPV screening and vaccination compared to males (p = 0.03). Age group ≤ 25 and academic physicians demonstrated higher knowledge on HPV vaccines compared to their counterparts in non-academic places (p = 0.002). Specialty and experience seemed to have no impact on knowledge or attitudes of participants. Higher knowledge physicians had more positive attitude towards vaccination and screening compared to lower knowledge fellows (p<0.001). Conclusions The noteworthy findings of this study is the extremely low level of knowledge on non-sexual routes of HPV infection among Jordanian physicians. Increasing the level of awareness of physicians and healthcare workers on these routes and their association with cervical and other cancers through university curricula and other reliable sources is strongly recommended.
Seismically induced modification of lunar surface features

The formation of large impact craters and basins produced not only large volumes of ejecta but also catastrophic seismic waves. Theoretical models, extrapolation of terrestrial explosion data, and extrapolation of lunar impact data suggest surface displacements of 1-10 m at four crater radii from a Copernicus-size impact (4 x 10 to the 30th power ergs). Independent estimates of impact-generated stresses indicate that regions within 4 crater radii of an impact will receive shock waves with pressures exceeding 1 kbar. Greater areas also may receive shock effects as elastic waves following deep ray paths transform into shock waves near the surface. Additional seismic energy will be generated by impacts from secondary ejecta. The resulting large and long-lasting surface movement may contribute to the subdued appearance of the continuous ejecta blanket and secondary craters around large impact craters and to the degradation of small craters outside these zones.
Observed Atmospheric Response to Cold Season Sea Ice Variability in the Arctic

AbstractThe relation between weekly Arctic sea ice concentrations (SICs) from December to April and sea level pressure (SLP) during 1979–2007 is investigated using maximum covariance analysis (MCA). In the North Atlantic sector, the interaction between the North Atlantic Oscillation (NAO) and a SIC seesaw between the Labrador Sea and the Greenland–Barents Sea dominates. The NAO drives the seesaw and in return the seesaw precedes a midwinter/spring NAO-like signal of the opposite polarity but with a strengthened northern lobe, thus acting as a negative feedback, with maximum squared covariance at a lag of 6 weeks. Statistical significance decreases when SLP is considered in the whole Northern Hemisphere but it increases when North Pacific SIC is included in the analysis. The maximum squared covariance then occurs after 8 weeks, resembling a combination of the NAO response to the Atlantic SIC seesaw and the Aleutian–Icelandic low seesaw-like response to in-phase SIC changes in the Bering and Okhotsk Seas, w.
Quantitative metrics that describe river deltas and their channel networks

[1] Densely populated river deltas are losing land at an alarming rate and to successfully restore these environments we must understand the details of their morphology. Toward this end we present a set of five metrics that describe delta morphology: (1) the fractal dimension, (2) the distribution of island sizes, (3) the nearest-edge distance, (4) a synthetic distribution of sediment fluxes at the shoreline, and (5) the nourishment area. The nearest-edge distance is the shortest distance to channelized or unchannelized water from a given location on the delta and is analogous to the inverse of drainage density in tributary networks. The nourishment area is the downstream delta area supplied by the sediment coming through a given channel cross section and is analogous to catchment area in tributary networks. As a first step, we apply these metrics to four relatively simple, fluvially dominated delta networks. For all these deltas, the average nearest-edge distances are remarkably constant moving down delta suggesting that the network organizes itself to maintain a consistent distance to the nearest channel. Nourishment area distributions can be predicted from a river mouth bar model of delta growth, and also scale with the width of the channel and with the length of the longest channel, analogous to Hack's law for drainage basins. The four delta channel networks are fractal, but power laws and scale invariance appear to be less pervasive than in tributary networks. Thus, deltas may occupy an advantageous middle ground between complete similarity and complete dissimilarity, where morphologic differences indicate different behavior.
Ecological ReGional Ocean Model with vertically resolved sediments (ERGOM SED 1.0): coupling benthic and pelagic biogeochemistry of the south-western Baltic Sea

Abstract. Sediments play an important role in organic matter mineralisation and nutrient recycling, especially in shallow marine systems. Marine ecosystem models, however, often only include a coarse representation of processes beneath the sea floor. While these parameterisations may give a reasonable description of the present ecosystem state, they lack predictive capacity for possible future changes, which can only be obtained from mechanistic modelling. This paper describes an integrated benthic–pelagic ecosystem model developed for the German Exclusive Economic Zone (EEZ) in the western Baltic Sea. The model is a hybrid of two existing models: the pelagic part of the marine ecosystem model ERGOM and an early diagenetic model by Reed et al. (2011). The latter one was extended to include the carbon cycle, a determination of precipitation and dissolution reactions which accounts for salinity differences, an explicit description of the adsorption of clay minerals, and an alternative pyrite formation pathway. We present a one-dimensional application of the model to seven sites with different sediment types. The model was calibrated with observed pore water profiles and validated with results of sediment composition, bioturbation rates and bentho-pelagic fluxes gathered by in situ incubations of sediments (benthic chambers). The model results generally give a reasonable fit to the observations, even if some deviations are observed, e.g. an overestimation of sulfide concentrations in the sandy sediments. We therefore consider it a good first step towards a three-dimensional representation of sedimentary processes in coupled pelagic–benthic ecosystem models of the Baltic Sea.
Global climate signals and equatorial SST variability in the Indian, Pacific and Atlantic oceans during the 20th century

Oceanic global and individual basin (i.e., Indian, Pacific and Atlantic oceans) sea surface temperature (SST) and sea level pressure (SLP) are analyzed jointly, using MTM/SVD technique. Besides global and individual secular variability, differences in low‐frequency climate signals are evidenced: that is, an inter‐decadal signal dominates in the Indian and Pacific oceans, while a quasi‐decadal signal dominates in the Pacific and Atlantic oceans. Two inter‐annual global and individual climate signals dominate: i.e., ENSO and quasi‐biennial (QB). Moreover, significant correlations are found between three known equatorial SST indices (i.e., IO1 in Indian Ocean, NINO3 in Pacific Ocean, and ATL2 in Atlantic Ocean), and SST time‐series obtained by summing‐up only global lead‐frequency signals identified here: i.e., 0.74, 0.82, and 0.56 respectively. These results should help improving long‐term climate numerical forecasts and mitigating societal impacts by using observed specific equatorial SSTs time‐series, in a climate change context.
Mitigation of Distance-Dependent Errors for GPS Network Positioning

The effect of the atmosphere has been identified as the major problem of long-baseline carrier phase positioning. The effect of the ionosphere, however, can be neutralised with dual-frequency observations. Thus, the effect of the troposphere is the challenge of precise positioning and needs to be mitigated in some way. The network-based approach provides a nondispersive correction that can be useful in reducing this effect. Applying the correction to the ionosphere-free combination improves the ambiguity resolution and hence guarantees higher accuracy. In addition, dispersive and non-dispersive corrections can be separately applied to the computation of the receiver position.
WINTER OCEAN/SEA ICE INTERACTIONS STUDIED IN THE EAST ANTARCTIC

An experiment to identify changes in water mass properties as a result of sea ice growth and deformation was conducted in a 110×110 km region of the Antarctic pack ice near 64°S, 140°E in August 1995. This was the first intensive winter-time study in this region, which is thought to be high in ice production and active in bottom water formation [Foster, 1995; Gordon and Tchernia, 1972]. The information gathered is important in understanding the role sea ice plays in the climate system and for developing and validating combined ocean-ice-atmosphere models.