Miracle-dz/UniFAR-FTUs huggingface dataset:
Constraining Land Surface and Atmospheric Parameters of a Locally Coupled Model Using Observational Data

Abstract In coupled land surface–atmosphere modeling, the possibility and benefits of constraining model parameters using observational data bear investigation. Using the locally coupled NCAR Single-column Community Climate Model (NCAR SCCM), this study demonstrates some feasible, effective approaches to constrain parameter estimates for coupled land–atmosphere models and explores the effects of including both land surface and atmospheric parameters and fluxes/variables in the parameter estimation process, as well as the value of conducting the process in a stepwise manner. The results indicate that the use of both land surface and atmospheric flux variables to construct error criteria can lead to better-constrained parameter sets. The model with “optimal” parameters generally performs better than when a priori parameters are used, especially when some atmospheric parameters are included in the parameter estimation process. The overall conclusion is that, to achieve balanced, reasonable model performance .
Calculating pH from EC and SAR values in salinity models and SAR from soil and bore water pH and EC data

Currently used soil salinity models do not contain a mechanism for including exchangeable sodium effects on soil pH. A method is needed that allows pH calculation from the sodium adsorption ratio (SAR) or exchangeable sodium percentage (ESP) and electrical conductivity (EC) data. This study developed a simple method for calculating saturated soil paste and aqueous solution pH from SAR (or ESP) and EC data and compared the results with measured values from a number of soils and subsurface waters. The equation pH =A+{B*(SAR)1/2/(1+C*EC)} estimated soil pH from EC and SAR or ESP values. When rewritten as: SAR or ESP={(pH-A)(1 + C*EC)/B)2, the SAR or ESP was estimated from pH and EC data. By using shallow bore (well) water and soil extract data from the Murray Basin, values were determined for the scalar terms A, B and C. These values differed among subsurface water and soil types, however, the range of each scalar was reasonably small. It was found that a range of at least 2.5 pH units in the calibration data was necessary to obtain reliable regression between predicted and measured pH and SAR or ESP values. When these conditions were met, the predicted results were satisfactory. These relationships provide a method for pH calculation in soil salinity models which takes into account soil EC and sodium effects. They also provide a rapid field method to estimate SAR or ESP from easily obtainable EC and pH data. Further research is needed to define the factors that determine the values of A, B and C.
A Reconsideration of the Coastal Landslides at Folkestone Warren, Kent

Synopsis The coastal landslides of Folkestone Warren, involving the Chalk and the Gault. are among the most important in southern England. In the first part of the Paper, their geology, hydrology and history are described and the relevance of these to an understanding of the landslides is explored. All the deep-seated landslides in the Warren recorded during the past two centuries are shown to have occurred within the period of seasonally high ground-water levels in the slipped masses, from December to March. The initiation of the present landslides probably took place between 3500 and 500 b.c. The Warren landslides have not hitherto been considered in terms of effective stresses. The Paper presents such analyses for the deep-seated renewals of movement on non-circular slip surfaces which occurred in 1915, 1937 and 1940. The results are consistent in showing that, in all three landslides, the average strengths mobilized in the Gault on the slip surfaces approximated to the residual and are bounded by the .
Cell nuclei segmentation in noisy images using morphological watersheds

A major problem in image processing and analysis is the segmentation of its components. Many computer vision tasks process image regions after segmentation, and the minimization of errors is then crucial for a good automatic inspection system. This paper presents an applied work on automatic segmentation of cell nuclei in digital noisy images. One of the major problems when using morphological watersheds is oversegmentation. By using an efficient homotopy image modification module, we prevent oversegmentation. This module utilizes diverse operations, such as sequential filters, distance transforms, opening by reconstruction, top hat, etc., some in parallel, some in cascade form, leading to a new set of internal and external cell nuclei markers. Very good results have been obtained and the proposed technique should facilitate better analysis of visual perception of cell nuclei for human and computer vision. All steps are presented, as well as the associated images. Implementations wee done in the Khoros system using the MMach toolbox.
Least-squares Wave-equation AVP Imaging of 3D Common Azimuth Data

This paper summarizes our experience with 2D/3D leastsquares amplitude versus Angle (AVA) migration. AVA imaging can be posed as a linear inverse problem. This provides several advantages. First, we are able to incorporate model space weighting operators that improve amplitude fidelity in common angle gathers. In addition, the influence of improperly sampled data can be diminished. The latter leads to the attenuation of acquisition footprints.
Nitrous acid formation in the urban atmosphere: Gradient measurements of NO2 and HONO over grass in Milan, Italy

[1] The source of nitrous acid, HONO, in the troposphere remains uncertain, even after two decades of research. It is currently believed that HONO is formed by heterogeneous conversion of NO2 on either the ground or the aerosol surface. While this conversion has been studied in the laboratory, few atmospheric studies have been reported. Here we present the first simultaneous determination of the vertical gradients and fluxes of HONO, its precursor NO2, and SO2 over a flat grass surface in the polluted atmosphere. The measurements were performed in Milan, Italy, during the Limitation of Oxidant Production/Pianura Padana Produzione di Ozono (LOOP/PIPAPO) study in summer 1998, using differential optical absorption spectroscopy. While deposition of NO2 onto the ground was frequently observed, heterogeneous HONO formation was much smaller than expected. We can explain our observation by a mechanism that consists of a combination of NO2 and HONO deposition, and a heterogeneous conversion of NO2 to HONO on the ground. The compensation point for deposition and formation of HONO is characterized by a HONO/NO2 ratio of ∼0.03, indicating that only one HONO molecule is released into the gas phase for every 33 NO2 molecules deposited. Our measurements also show that direct emission of HONO is an important source in strongly polluted areas.
Earliest Arenig Radiolarians from the Cow Head Group, Western Newfoundland

Abstract Radiolarians have been recovered from lowermost Arenigian rocks of the Cow Head Group in Gros Morne National Park, Newfoundland. Two new faunal assemblages include eight families, 13 genera, and 25 species. Among these, the family Neoaspiculumidae, the genus Neoaspiculum, and 11 species, Beothuka aitchisoni, B. grosmornensis, B. stougei, B. stellata, Neoaspiculum cancellium, N. headense, N. transformum, N. laxum, N. amplum, Proventocitum cylindricum, and P. piriforme, are new. This study elucidates the reason for the significant difference in species composition between pre-Arenigian and Arenigian radiolarian faunas. This difference does not appear to be due to mass extinction, but rather to phylogenetic evolution: most radiolarian families that flourished during pre-Arenig time were gradually but significantly reduced by the earliest Arenig. Characteristic features of the earliest Arenig assemblages that distinguish them from their Tremadocian predecessors are 1) the development of a distinctive skeletal constructional element referred to as “bandage” structure that evolved through modification of a mesh of thin bars and 2) the appearance of multiple concentric shells including a proloculus (or a microsphere), which developed from a primitive three-dimensionally interwoven meshwork or spongy shell wall. These forms, represented by beothukids, antygoporids, and inaniguttids, are rare but they appear to originate in the earliest Arenig. Transitional characteristics among those forms are developed in the Neoaspiculumidae, which flourished during the earliest Arenig. The precise biostratigraphic age of one of the assemblages was determined with the recovery of the index condont Prioniodus adami Stouge and Bagnoli, 1988 from strata belonging to the Tetragraptus approximatus Graptolite Zone, which is at the base of the Arenigian.
Crustal structure of the Cape Verde Swell : insights into the flexural response of the lithosphere to loading

Throughout the ocean basins many broad regions of anomalously shallow topography exist that do not fit the widely accepted model of conductive plate cooling and subsidence as a function of lithospheric age. These ‘swells’ often coincide with positive geoid, Free-air gravity and heat flow anomalies as well as groups of ocean islands and seamounts. Various mechanisms have been proposed to explain how this anomalous topography is isostatically supported at depth, including increased crustal buoyancy and dynamic asthenospheric support. The Cape Verde Swell is the largest oceanic mid-plate swell on Earth at ~1800 km in diameter, with a crest ~2.2 km high, and positive geoid, gravity and heat flow anomalies of 8 m, 30 mGal and 10-15 mW m-2, respectively. These characteristics and its location on the slow-to-stationary African Plate, which concentrates the volcanism and associated geophysical anomalies within a relatively small areal extent, makes the Cape Verde Swell an ideal location to test the various proposed mechanisms for swell support. Wide-angle seismic refraction data along an ~474 km profile, extending from the Cape Verde Swell crest, is analysed and modelled to produce a 2-D velocity-depth model of the crustal structure. The resulting model reveals no widespread thickening of the lower oceanic basement, despite evidence for localised thickening beneath the islands from other studies. Subsequent 3-D ‘whole plate’ lithospheric flexure modelling reveals that, on a regional scale, the plate is stronger than expected based on its age, with some evidence for localised weakening around the islands. Overall, the results of this study suggest that the anomalously shallow topography of the Cape Verde Swell is primarily maintained by a dynamic upwelling of hot, low density material impinging on the base of the lithosphere. Over time, conduction from this hot column has thermally rejuvenated the lithosphere on a local scale, leading to additional uplift, melting and volcanism associated with the islands.
Flood Forecasting Using ANN, Neuro-Fuzzy, and Neuro-GA Models

Flood forecasting at Jamtara gauging site of the Ajay River Basin in Jharkhand, India is carried out using an artificial neural network (ANN) model, an adaptive neuro-fuzzy interference system (ANFIS) model, and an adaptive neuro-GA integrated system (ANGIS) model. Relative performances of these models are also compared. Initially the ANN model is developed and is then integrated with fuzzy logic to develop an ANFIS model. Further, the ANN weights are optimized by genetic algorithm (GA) to develop an ANGIS model. For development of these models, 20 rainfall–runoff events are selected, of which 15 are used for model training and five are used for validation. Various performance measures are used to evaluate and compare the performances of different models. For the same input data set ANGIS model predicts flood events with maximum accuracy. ANFIS and ANN model perform similarly in some cases, but ANFIS model predicts better than the ANN model in most of the cases.
Synoptic-Scale Dual Structure of Precipitable Water along the Eastern Pacific ITCZ

AbstractUsing 10-yr high-resolution satellite and reanalysis data, the synoptic-scale dual structure of precipitable water (PW), in which the southern and northern bands straddled at the ITCZ produce zonally propagating meridional dipoles, is observed over the eastern Pacific (EP) during boreal summer and fall. Composites indicate that the PW dipole, concurrent with the dipole-like filtered divergence, has a shift to the west of the anomalously cyclonic circulation. The vertical structure of filtered meridional wind is characterized by a wavenumber-1 baroclinic mode, and the vertical motion has two peaks situated at 850 and 300 hPa, respectively. To the east of the PW dipole, the shallow convection is embedded within the deep convection, forming a multilevel structure of meridional wind on the ITCZ equatorward side. To the west of the PW dipole, the deep convection tends to be suppressed because of the invasion of midlevel dry air advected by northerly flows. The generation and propagation of the dual PW .
CAN THE ALUMINUM AND TITANIUM CONTENTS OF OCEAN SEDIMENTS BE USED TO DETERMINE THE PALEOPRODUCTIVITY OF THE OCEANS

In the central equatorial Pacific, settling particles collected with sediment traps have Al/Ti values greater than those of a typical crustal source. The Al/Ti values of the sediment trap material are not well correlated with either the flux of organic carbon or with total particle mass, suggesting that this ratio cannot be used as a simple index of paleoproductivity. However, the Al/Ti values of some trap samples are more than 3 times the ratio for typical crustal materials, indicating a noncrustal source of excess Al. Numerical analysis using linear programming indicates that the excess Al is associated with opal and that this biological component carries as much as 1200 ppm of Al. Because of the low particulate fluxes of lithogenic material in the equatorial Pacific and the relatively high opal content of equatorial sediment trap material, opal appears to be the predominant conveyor of Al to the equatorial sediments. Our sediment trap Al/Ti values are similar to ratios previously measured in equatorial sediments, suggesting that measurements of this element pair in ocean sediments may be an indicator of opal rain to the seafloor. The particle-reactive nature of Al and Ti means their ratios in sediments may be relatively insensitive to opal preservation or other diagenetic processes. However, the Al/Ti values of raining particles are highly sensitive to the relative proportion of opal and lithogenic material. Where opal/lithogenic ratios are less than 20, the Al/Ti values are indistinguishable from a crustal source ratio. In addition, the amount of excess Al associated with opal in settling particles may be a function of the concentration of Al in the water column and of the processes that fractionate dissolved Al and Ti. These issues must be evaluated before the Al/Ti values of ocean sediments can be used as a reliable proxy of opal flux to the seafloor.
Outflow of Summertime Arctic Sea Ice Observed by Ice Drifting Buoys and Its Linkage with Ice Reduction and Atmospheric Circulation Patterns

Drifting buoys deployed near the North Pole in the 2000s revealed that sea-ice export from the Arctic Ocean through the Fram Strait was large in 2005. The relationship between ice drift and sea-level pressure (SLP) showed that the mean SLP from June to September is conducive to continuous sea-ice drift offshore from Siberia. A record minimum of the ice extent in 2005 is partly explained by the strongest SLP gradient across the Transpolar Drift Stream for the recent 27 years from 1979. The SLP pattern regressed on the linear trends of ice extent is characterized by cyclonic circulation anomalies along the Eurasian coast, which tend to enhance the SLP gradient across the Transpolar Drift Stream. The large export of freshwater and sea ice in 2005 could increase the salinity of the upper ocean and lead to development of the mixed layer and suppression of sea-ice growth during the subsequent winter.
About connections

Despite the attention attracted by “connectomics”, one can lose sight of the very real questions concerning “What are connections? ” In the neuroimaging community, “structural” connectivity is ground truth and underlying constraint on “functional” or “effective” connectivity. It is referenced to underlying anatomy; but, as increasingly remarked, there is a large gap between the wealth of human brain mapping and the relatively scant data on actual anatomical connectivity. Moreover, connections have typically been discussed as “pairwise”, point x projecting to point y (or: to points y and z), or more recently, in graph theoretical terms, as “nodes” or regions and the interconnecting “edges”. This is a convenient shorthand, but tends not to capture the richness and nuance of basic anatomical properties as identified in the classic tradition of tracer studies. The present short review accordingly revisits connectional weights, heterogeneity, reciprocity, topography, and hierarchical organization, drawing on concrete examples. The emphasis is on presynaptic long-distance connections, motivated by the intention to probe current assumptions and promote discussions about further progress and synthesis.
On Solving the Flow Equation in Unsaturated Soils by Optimization: Horizontal Infiltration

Recently, integral methods have been developed that provide accurate approximations to the diffusion equation with rapidly varying diffusivity, but require in general some numerical iteration. In the present paper, a new analytical approach is developed which yields optimal approximations without any numerical iteration. The method is applied to the problem of one-dimensional horizontal infiltration of water in soils. In that case it is shown that the sorptivity is an invariant, which can be expressed in terms of the sum of two integrals involving the diffusivity. The analytical results are in excellent agreement with numerical calculations for Yolo light clay.
Medroxyprogesterone acetate alters the vaginal microbiota and microenvironment in women and increases susceptibility to HIV-1 in humanized mice

ABSTRACT The hormonal contraceptive medroxyprogesterone acetate (MPA) is associated with increased risk of human immunodeficiency virus (HIV), via incompletely understood mechanisms. Increased diversity in the vaginal microbiota modulates genital inflammation and is associated with increased HIV-1 acquisition. However, the effect of MPA on diversity of the vaginal microbiota is relatively unknown. In a cohort of female Kenyan sex workers, negative for sexually transmitted infections (STIs), with Nugent scores <7 (N=58 of 370 screened), MPA correlated with significantly increased diversity of the vaginal microbiota as assessed by 16S rRNA gene sequencing. MPA was also significantly associated with decreased levels of estrogen in the plasma, and low vaginal glycogen and α-amylase, factors implicated in vaginal colonization by lactobacilli, bacteria that are believed to protect against STIs. In a humanized mouse model, MPA treatment was associated with low serum estrogen, low glycogen and enhanced HIV-1 susceptibility. The mechanism by which the MPA-mediated changes in the vaginal microbiota may contribute to HIV-1 susceptibility in humans appears to be independent of inflammatory cytokines and/or activated T cells. Altogether, these results suggest MPA-induced hypo-estrogenism may alter key metabolic components that are necessary for vaginal colonization by certain bacterial species including lactobacilli, and allow for greater bacterial diversity in the vaginal microbiota. This article has an associated First Person interview with the first author of the paper. Summary: MPA may increase susceptibility to HIV-1 in sex workers through the suppression of endogenous estrogen, reducing vaginal glycogen and α-amylase levels, which increases bacterial diversity, potentially reducing protective bacterial species such as lactobacilli.
Interactions between tropospheric chemistry and climate model temperature and humidity biases

Temperature and humidity climatologies from the Met Office Hadley Centre climate model, HadGAM1, show a strong cold bias of up to 5 K in the extra‐tropical upper troposphere/lower stratosphere and a dry bias of up to 20% in the tropical lower and mid troposphere. Removing the temperature bias alone has little effect on tropospheric ozone or methane lifetime. Removing the humidity bias alone causes a reduction in both the global annual mean tropospheric ozone burden of greater than 2% and the methane lifetime of 3.6–4.2%. The impact of removing both biases together is similar to that of removing the humidity bias alone. The choice of reanalysis product (ERA‐40 or NCEP) to calculate the biases does not greatly affect the results. Radiative feedback from ozone and methane reduced some of the climate model biases without any significant change to the performance of the chemistry.
Simulation of rainfall-underground outflow responses of a karstic watershed in Southwest China with an artificial neural network

Karstic aquifers in Southwest China are largely located in mountainous areas and groundwater level observation data are usually absent. Therefore, numerical groundwater models are inappropriate for simulation of groundwater flow and rainfall-underground outflow responses. In this study, an artificial neural network (ANN) model was developed to simulate underground stream discharge. The ANN model was applied to the Houzhai subterranean drainage in Guizhou Province of Southwest China, which is representative of karstic geomorphology in the humid areas of China. Correlation analysis between daily rainfall and the outflow series was used to determine the model inputs and time lags. The ANN model was trained using an error backpropagation algorithm and validated at three hydrological stations with different karstic features. Study results show that the ANN model performs well in the modeling of highly non-linear karstic aquifers.
Physical properties of Arctic versus subarctic snow: Implications for high latitude passive microwave snow water equivalent retrievals

Two unique observational data sets are used to evaluate the ability of multi‐layer snow emission models to simulate passive microwave brightness temperatures (TB) in high latitude, observation sparse, snow‐covered environments. Data were utilized from a coordinated series of 18 sites measured across the subarctic Northwest Territories and Nunavut, Canada in April 2007 during a 1000 km segment of a 4200 km snowmobile traverse from Fairbanks, Alaska to Baker Lake, Nunavut (~64°N). In April 2011, a network of 22 high Arctic sites was sampled across a 60 × 60 km study area on the Fosheim Peninsula, Ellesmere Island (~80°N). In comparison to sites across the subarctic, high Arctic snow was more spatially variable, thinner (site averages between 15 and 25 cm versus 30 to 40 cm), colder (−25°C versus −10°C), composed of fewer layers, had a proportionally higher fraction of wind slabs (storing 57% of the snow water equivalent (SWE) versus 15%), with these slabs comparatively denser (often exceeding 450 g/cm3, compared to 350 g/cm3 in the subarctic). The physical snow measurements were used as inputs to snow emission model simulations. The radiometric difference between simulations of “typical” arctic and subarctic snow reached 30 K at 37 GHz. Sensitivity analysis showed that this TB difference could be partitioned between the effects of physical temperature (~5 K between −25°C and −10°C), wind slab density (~5 K between 0.40and 0.35 g/cm3), and vertical depth hoar fraction (~20 K between 70% and 30% vertical fraction of total snow depth). Model simulations at the satellite scale (625 km2) were produced using the observational spread for snow depth and snow stratigraphy. The range of TB from simulations with varied stratigraphy extended unrealistically far below the magnitude of satellite measured TB, illustrating that the snow depth first guess is very important for SWE retrieval schemes that are based on forward emission model simulations.