J. A. Rial

An outsider's review of the astronomical theory of the climate: Is the eccentricity-driven insolation the main driver of the ice ages?

Abstract Although the astronomical theory of the climate (also known as the “Milankovitch” theory) explains a number of key features of the paleoclimate time series (especially frequency and phase distribution) in terms of orbital influence on the waxing and waning of ice sheets, it still faces several important unresolved challenges. In this review, we discuss five main challenges we believe the theory must resolve in order to survive: (1) The large amplitude of the ∼100 ky ice age cycles; (2) the switch from 41-ky- to 100-ky-long glaciations around 0.9 Ma BP; (3) the absence of significant spectral power at 413 ky over the past 1.2 Ma; (4) the variation in glacial cycle duration in the last 800 ky; and (5) the presence of non-orbital spectral peaks in the climate record. But in spite of these problems, we conclude that the Milankovitch theory may still be a viable one; at least in the original sense of Hays et al. [Science 194 (1976) 1121], that orbital changes somehow influenced the ice ages. Many investigators, ourselves included, appear to see the impact of orbital forcing in the data, clear evidence of astronomical forcing, as well as evidence which suggests that the climate system responds nonlinearly to all Milankovitch (orbital) frequencies.

Shear-wave splitting and reservoir crack characterization: the Coso geothermal field

Abstract This paper aims to improve current understanding of the subsurface fracture system in the Coso geothermal field, located in east-central California. The Coso reservoir is in active economic development, so that knowledge of the subsurface fracture system is of vital importance for an accurate evaluation of its geothermal potential and day-to-day production. To detect the geometry and density of fracture systems we applied the shear-wave splitting technique to a large number of high-quality seismograms from local microearthquakes recorded by a permanent, 16-station, down-hole, 3-component seismic array running at 480 samples/s. The analysis of shear-wave splitting (seismic birefringence) provides parameters directly related to the strike of the subsurface fractures and their density (number of cracks per unit volume), and, consequently, is an important technique to outline zones of high permeability. Three major fracture directions N10–30W, N0–20E, and N40–50E, of which the first and the second are the most prominent, were identified from the seismograms recorded by the 16-station down-hole array. All orientations are consistent with the known strike of local sets of faults and fractures in local wells and at the surface, as well as with previous analyses of seismic anisotropy in the region. The high quality of the recordings has allowed us to launch an unprecedented investigation into the characteristics of the temporal variations in crack polarization and crack density in a producing geothermal environment. Preliminary results point to significant temporal changes in shear-wave time delays, probably influenced by temporal changes in crack density within a period of 5 years (1996–2000). They are tentatively interpreted as due to a local ∼3% increase in shear-wave velocity in the southwestern part of the field during 1999.

Shear‐wave splitting: A diagnostic tool to monitor fluid pressure in geothermal fields

An experiment on the uses of shear-wave splitting as an imaging tool in fracture-controlled geothermal reservoirs was conducted at Krafla, Iceland. Fifteen days after the beginning of the seismic recording the injection was stopped for eleven days and then restarted, a sequence designed to determine whether shear-wave splitting measurements can detect the transient response of the subsurface crack system to changes in fluid pressure. It was observed that time delays between the fast and slow split shear waves changed significantly and promptly with the stoppage and resumption of injection. Large time delays occurred only during injection, decreased substantially during the stoppage phase, and increased again as injection restarted. Comparisons of these results with similar observations at the Coso geothermal field in California strongly suggest that the time delay of split shear waves can be a useful proxy to monitor fluid pressure in the cracks and changes in crack density.

On the origin of the long period sawtooth shape of the Late Pleistocene paleoclimate Records: The first derivative of the Earth's orbital eccentricity

The first time derivative of the earths orbital eccentricity function is sawtooth shaped, and closely mimics the ∼100,000 yr cycles of the oxygen isotope δ18O time series (the proxy for global ice volume change) of the last ∼800,000 yr. Conversely, numerical integration of the datas variance closely reproduces the orbital eccentricity function for the same interval. Such long-lived, strong correlation does not appear to be coincidental, is consistent with the physics of ice sheets and with the time history of their advance and retreat.

Synchronization of polar climate variability over the last ice age: in search of simple rules at the heart of climate's complexity

Evidence is presented supporting the hypothesis of polar synchronization, which states that during the last ice age, and likely in earlier times, millennial-scale temperature changes of the north and south Polar Regions were coupled and synchronized. The term synchronization as used here describes how two or more coupled nonlinear oscillators adjust their (initially different) natural rhythms to a common frequency and constant relative phase. In the case of the Polar Regions heat and mass transfer through the intervening ocean and atmosphere provided the coupling. As a working hypothesis, polar synchronization brings new insights into the dynamic processes that link Greenlands Dansgaard-Oeschger (DO) abrupt temperature fluctuations to Antarctic temperature variability. It is shown that, consistent with the presence of polar synchronization, the time series of the most representative abrupt climate events of the last glaciation recorded in Greenland and Antarctica can be transformed into one another by a π/2 phase shift, with Antarctica temperature variations leading Greenlands. This, plus the fact that remarkable close simulations of the time series are obtained with a model consisting of a few nonlinear differential equations suggest the intriguing possibility that there are simple rules governing the complex behavior of global paleoclimate.

FR waves: A second fault-guided mode with implications for fault property studies

Previous work has shown that earthquake S-waves can become fault zone guided-waves. We present observational evidence for a second type of earthquake-generated, fault-guided seismic wave, apparently involving coupled P- and S-waves. Our data are from a fault located in igneous rocks in Owens Valley, California. In analogy to standard Love and Rayleigh waves, we suggest that purely S-type modes be indicated on seismograms by F L and the new coupled P- and S-type by F R . Since F R waves are sensitive to both the local P- and S-wave velocities, their presence implies unique conditions in and near the fault. Modeling of our seismograms suggests a differential reduction in these velocities, with a larger change in bulk modulus than in shear modulus. We propose that this reduction is due to unsaturated fractures within the core of the fault. We view F R waves as a new tool for detecting and characterizing highly fractured fault zones, providing important information on the relation of earthquakes and subsurface fluid conduits.

Application of the wavelet transform in detecting multiple events of microearthquake seismograms

The Wavelet Transform (WT) is employed here to discriminate multiple events contained in microearthquake seismograms. The WT decomposes the signal into well localized time-frequency compartments (or “Heisenberg boxes”) that display the energy distribution over the time and frequency domains simultaneously, therefore providing a useful technique to characterize dispersion and attenuation of a seismic signal, as well as to identify multiple interfering events. This letter suggests that the WT could provide a useful tool to analyze complicated seismic signals, especially to detect the multiple events contained in microearthquake seismograms.

Synchronization of the climate system to orbital eccentricity insolation and the 100ky problem

C rays, produced by high-energy extra-solar events, ionize the earth’s atmosphere. Ionized aerosol particles can combine and form “seed” particles for cloud formation. In addition, cosmic-ray ionization increases the atmospheric conductivity. Variations of these quantities would be expected to have an effect on climate, and they do vary. The solar corona has a temperature of one million degrees and is continually “boiling off,” producing “the solar wind.” The solar wind is plasma that fills the solar system to a distance of about 90 times the earth-sun distance. The cosmic rays that fill the galaxy must do work against the solar wind to reach the earth’s orbit and hence lose intensity. The work done is measured in hundreds of megavolts. The intensity of the solar wind, and hence the intensity of cosmic-rays at earth orbit varies irregularly over an approximately 11-year cycle and sometimes, falls to deep minima. The 17th century “Maunder Minimum,” when solar modulation, the energy necessary to reach earth orbit, fell nearly to zero, was accompanied by what has been known as the “Little Ice Age,” causing much hardship in Europe. This is evidence that changes in cosmic-rays intensity can be associated with an impact on climate. Another important climatological consideration due to cosmic-ray impacts on the terrestrial atmosphere is the production of 1.5 million-year Be-10 by the spallation process. Radioactive Be-10 is used to date sections of Greenland and Antarctic ice cores to analyze past climates. Calculations of these quantities from basic principles are presented.Floods are becoming increasingly common in Nepal resulting in a huge loss of life and damage to settlements, agriculture land and infrastructures in various parts of the country. Most recent research findings suggest that climate change has accelerated the intensity and frequency of flood hazards in most parts of the country. Communities are however, making use of options that increase their preparedness for these flood hazards. The random sampling (for household survey), focus group discussion, key informant interviews and field observations were employed for data collection. Based on field data, this paper intends to assess the indigenous knowledge on flood forecasting and flood management practices at the community level those are being in practiced in the plain region of West Rapti River Basin of Nepal and its relevance under climate change induced flood disaster. The research findings indicate that there are some very effective local flood forecasting practices such as identifying the position of clouds; monitoring the extent of rainfall in upper catchments; analyzing the mobility of ants; analyzing the magnitude of thunderstorms and wind blows; analyzing the magnitude of hotness; and hearing strange sounds from river/torrents. Synthesis and analysis of these indicators helps communities to prepare for potential flood events. These include preparation of search and rescue related materials; the creation of small drainage structures in each plot of land and storage of the valuable material at a safer location; and being psychologically prepared for floods. This paper argues that these indigenous flood forecasting and management practices could be particularly useful for migrants, who are in flood prone areas but are not familiar with those practices.T of past earth system states are preserved in an array of biogeochemical archives. Extracting information from these archives produces valuable data that reveal time progression of environmental conditions. Covarying measurements entice cause-effect explanations, but establishing causal relationships from observational studies requires a rigorous epistemology. Correlation is necessary for hypothesizing a causal relationship, but insufficient for forming conclusions. Common-cause explanations, such as independent orbital forcing of correlated measurements, must be rejected based on characteristics of the data. Determining amplitude and phase response over a range of frequencies provides a test of cause-effect scenarios: measured cause must precede proportionate effect in a manner consistent with direct forcing theory. Amplitude and phase persistence (coherence) through time provides a method for quantifying probabilistic confidence in a cause-effect conclusion. In this presentation, methods are described, and then applied to ice core proxies for air temperature and atmospheric carbon dioxide concentration.T ‘100ky problem’ (1ky=1000 years) of the astronomical theory of the ice ages questions how the almost negligible ~100ky eccentricity forcing could power the ten massive glaciations of the last million years while the stronger ~400ky eccentricity forcing is nearly absent from the proxy records. Further, the astronomical theory does not explain how, without change in forcing, climatic oscillations switched from 41ky to 100ky at the mid-Pleistocene transition (MPT) 1.2 million years ago (1.2 Ma), or what caused the strong climatic response at the marine isotope stage (MIS) 11, the presence of power at frequencies absent in the external forcing, or the timing of glacial terminations. To resolve these inconsistencies many explanations have been put forward, from internal climatic oscillations without external forcing to external forcing other than the Milankovitch cycles, but the ultimate cause(s) remain elusive. I will introduce a unifying explanation that resolves all the above inconsistencies through a single process: nonlinear synchronization of the climate system’s internal oscillations to the eccentricity forcing. Synchronization is a fundamental nonlinear phenomenon and one basic mechanism of self-organization in complex system. The evidence suggests that after at least four million years of slow evolution, the climate system first synchronized to eccentricity at ~1.2Ma and has remained synchronized ever since. Synchronization powered the late Pleistocene glaciations, forced the frequency switch at the MPT, and caused the strong short-lived response at the MIS11 (~400ka).The study was conducted in July 2011 to June 2012 at the Isabela State University watershed experimental. Primary goal is to evaluate the performance and adaptability of the Water Erosion Prediction Project (WEPP) model in estimating the rate of soil erosion and run-off under upland rice cultivation. The research involves establishment of automatic weather station, small farm reservoir and erosion plots with three conservation management as treatments. Analysis was undertaken to characterize rainfall events in terms of amount, intensity, duration and frequency in relation to erosion data. Comparison of actual and simulated data and sensitivity analysis of scenarios for different types of rainfall, slope, and conservation practices were made. Validation result demonstrated statistical acceptability of the WEPP model. Actual and simulated data indicated that 50% soil loss is reduced when contour planting with hedgerow are practiced. The rate of sedimentation is linearly affected by increasing slopes and length, such that, the rate of soil removal ranges 1.2 t/ha to 48.46 t/ha across treatments at 10%-50% slope and 10 m-40 m slope length. The model can be use to develop decision support tools for conservation, optimization and utilization of farm resources in agricultural watershed units to improved productivity of upland areas in sustainable way.E though anomalous behaviors of liquid water around 4oC have long been studied by many different authors up to now, it is not still cleared what thermodynamic mechanisms induce them. The thermodynamic properties of substances are determined by inter-particle interactions. We analyze what characteristics of pair potential cause density anomaly using a thermodynamically Self-Consistent Ornstein-Zernike Approximation (SCOZA). The SCOZA is known to provide a very good description of the overall thermodynamics and a remarkably accurate critical point and coexistence curve. We consider a fluid of spherical particles with a pair potential given by a hard-core repulsion plus a Lennard-Jones type tail (HC-LJ system). We show that the soft-repulsion near the hard-core contact determines the behavior of excess internal energy which plays a crucial role in the anomalous behaviors of the system. Our results show that even though such models as second critical point hypothesis, a twostate model, liquid-liquid phase transition model, clathrate model, network model, and orientation-dependent potential would be important to some properties of water, those are not the immediate cause of the density anomaly in liquid water. We present also a core-softened potential which reproduces experimentally measured density-temperature curve in the wide temperature range much better compared to other models presented up to now. Although our study is restricted to liquid phases of water, it provides us with important insights into the thermodynamic properties of solid water. Makoto Yasutomi, J Earth Sci Climate Change 2013, 4:4 http://dx.doi.org/10.4172/2157-7617.S1.009S green tea (GT) and Peppermint (PM) teabags were used as adsorbents of dyes to purify aqueous solutions. Basic Yellow 57 (BY) and Crystal Violet (CV) were chosen as model dyes due to their widespread use in the scientific and cosmetics industries. Equilibrium parameters such as pH, mass of adsorbent, initial dye concentration, salinity and presence of heavy metals were studied to maximize the adsorption of the dyes from aqueous solution in discontinuous experiments at room temperature. Experimental data indicate that adsorption of BY is maximized at pH 6, with optimum adsorbent masses of 100 mg and 75 mg for GT and PM respectively. The adsorbents also reached their highest adsorption in the absence of salts and heavy metal with maximum initial concentrations of 0.085 g/L and 0.2 g/L for GT and PM, respectively. On the other hand, CV was greatly adsorbed at pH 4 with adsorbent masses of 75 mg and 25 mg of GT and PM, respectively. Both adsorbents were able to adsorb CV dye concentrations of up to 0.075 g/L. The presence of salts and heavy metals also had negative effects on the adsorption. Finally, desorption of the dyes were studied to recycle the adsorbents in repetitive adsorption cycles. BY was surprisingly desorbed by using diluted HCl and ethanol solutions, while CV showed better desorption in front of ethanol and acetone solutions. We believe this “clean” technology will educate us to take advantage of inexpensive waste materials to improve water quality.Sulphur is essential in healthy plant and crop yields. Rapidly, largely due to emission controls, soils are becoming depleted in sulphur. Soils also act as a significant carbon sink but suggest that soil carbon is largely released back into the atmosphere. Here we examine the potential of soil microorganisms in the sequestration of atmospheric CO2 whilst examining the role sulphur has to play on the fixation of CO2. Agricultural soils were incubated in a carbon dioxide incubation chamber (ECIC) for 12 weeks where CO2 or CO2 was added at 400 ppm. One sample-soil A-had elemental sulphur added as a supplement. Total microbial DNA obtained from CO2 and CO2 experiments were subjected to Isopycnic centrifugation. Labelled DNA fractions and total microbial DNA extractsfollowing incubationwere subjected to Pyrosequencing. RubisCO genes were quantified by qPCR over the course of the experiment. Phospholipid fatty acid analysis and DGGE was used to monitor the microbial community structure over the duration of the experiment. To track the fate of labelled carbon into the soil throughout the incubation NMR analysis was performed on soil samples at defined time points. We established that the addition of sulphur to soil, as a fertilizer, has a significant impact on the microbial community structure. The sequestration of atmospheric CO2 by soil microorganisms was stimulated through the addition of sulphur whilst Rubis CO gene copy numbers increased significantly following its addition to soil.This project aims at detecting variabilities and trends in outputs of a three dimensional hydro dynamical numerical model based on a version of the Princeton Ocean Model (POM), covering the region between 85°S-30°N and 70°W-25°E, with 0.5° x 0.5° resolution. Surface data of temperature and salinity, from Climate Forecast System Reanalysis (CFSR), together with meteorological data of winds and surface fluxes, generated by reanalyzes of NCEP / NCAR global model, were analyzed and used as model forcing. The temperature salinity data, meteorological data and the model results cover the period from 1980 to 2009 (30 years). The model was validated through comparisons of outputs with oceanic buoy data from the project PIRATA. Model results and sea surface temperature data from PIRATA display strong correlations, both in the annual and higher frequencies signals. Harmonic and statistical analyses of selected points, applied to meteorological parameters, sea surface elevation, temperature, salinity and currents provide information on the variabilities and trends in the Tropical and South Atlantic Ocean, in the period 1980-2009. Biography Joseph Harari has completed his M.Sc. in Physical Oceanography in 1978, Ph.D. in Meteorology in 1985 and postdoctoral studies in Physical Oceanography in 1991, from the University of Sao Paulo (SP, Brazil). His research is on Numerical Modeling applied to the ocean dynamics and he is an Associate Professor in the Postgraduate Programs in Oceanography and in the Post Graduate Program in Environmental Sciences, at the University of Sao Paulo (SP, Brazil).

On the bipolar origin of Heinrich events

Evidence obtained from ice cores from Greenland and Antarctica indicates the presence of interactions between the polar climates, but, until recently, it has not been clear what the interactions are. Here we show that analysis under the previously established hypothesis of polar synchronization potentially connects the presence and possible energy source of the Heinrich (H) events and ice-rafted debris (IRD) events. These events appear to be related to the dynamic linkage between the polar climates, as they are not revealed in analysis of the records from a single pole. The H events and IRDs discovered in the North Atlantic along with coeval Southern Ocean events appear to drive or be driven by bipolar climate oscillations.

Real-time fracture monitoring in Engineered Geothermal Systems with seismic waves

As proposed, the main effort in this project is the development of software capable of performing real-time monitoring of micro-seismic activity recorded by an array of sensors deployed around an EGS. The main milestones are defined by the development of software to perform the following tasks: • Real-time micro-earthquake detection and location • Real-time detection of shear-wave splitting • Delayed-time inversion of shear-wave splitting These algorithms, which are discussed in detail in this report, make possible the automatic and real-time monitoring of subsurface fracture systems in geothermal fields from data collected by an array of seismic sensors. Shear wave splitting (SWS) is parameterized in terms of the polarization of the fast shear wave and the time delay between the fast and slow shear waves, which are automatically measured and stored. The measured parameters are then combined with previously measured SWS parameters at the same station and used to invert for the orientation (strike and dip) and intensity of cracks under that station. In addition, this grant allowed the collection of seismic data from several geothermal regions in the US (Coso) and Iceland (Hengill) to use in the development and testing of the software.