Manifestations of motions of the Earth’s pole in the El Niño–Southern Oscillation rhythms

We analyze autocorrelations and power spectra of the time series of monthly mean data characterizing sea surface temperature anomalies in the equatorial Pacific in the years 1920–2013 and show that the rhythms of El Niño–Southern Oscillation can be interpreted as the responses of the climate system to the external quasi-periodic forcing generated by the motions of the Earth’s pole. We conclude that the ENSO phenomenon has no prediction limits.

     

Relation between the variations in the global surface temperature,El Niño/La Niña phenomena,and the Atlantic Multidecadal Oscillation

We analyzed directed couplings between the variations in the global surface temperature and modes of the natural climatic variability: the El NiñoLa Niña (ENSO) quasi-periodical phenomena and the long-period Atlantic Mutidecadal Oscillation (AMO) based on the data for 1870–2014. According to the quantitative estimates based on the monthly and annual mean data, the initial data, and the 10-year mean remote data, the most pronounced impact of the ENSO on the global surface temperature and the AMO was found. A weaker bidirectional coupling between the global surface temperature and the AMO is also pronounced. The analysis using running windows revealed an alternating effect of the ENSO and AMO on the variations in the global surface temperature related to the AMO phases.     

Anomalous Winters in Regions of Northern Eurasia in Different Phases of the El Niño Phenomena

Doklady Earth Sciences - Estimates of the probability of warm and cold winters in regions of Northern Eurasia are obtained from data for eight decades, depending on El Niño phenomena. The...     

Protons of Radiation Belts as a Source of Hydrogen in the Earth’s Atmosphere

Doklady Earth Sciences - A scenario is proposed for replenishing the Earth’s exosphere with atomic hydrogen of cosmic origin. An assessment was made, and the coincidence of the total atomic...     

Evolution of manganese ore genesis in the earth’s geological history and the role of the biosphere

The formation of manganese rocks and ores occurred during the whole geological history of the Earth. Five metallogenic epochs (Early to Middle Proterozoic, Late Proterozoic, Early to Middle Paleozoic, Late Paleozoic, and Meso-Cenozoic) and 7 very important phases (Early, Middle, and Late Proterozoic, Early to Middle Paleozoic, Late Paleozoic, Late Mesozoic, and Meso-Cenozoic) can be distinguished. The phases of manganese ore genesis at many stratigraphic levels are closely related to the global climatic and tectonic reconstructions (the breakup of the continent of Gondwana and periods of glaciations and aridization) and biotic events (mass extinction of organisms). Based on carbon isotopic composition in manganese carbonates, participation of oxidized organic carbon is established.     

Adventures in Data Analysis: The TAO Array and the 1997–1998 El Ni?o

Traditional undergraduate education in earth sciences does not emphasize data acquisition, analysis, or assessment. However, arrival of the information age dictates that earth sciences graduates be imbued with fundamental skills to organize, evaluate and process large data sets. Fortunately, the proliferation of remotely sensed data and its availability via the Internet provides many opportunities for earth science educators to meet these needs. Exercises to introduce students to data analysis have been designed utilizing data from the Tropical Atmosphere–Ocean (TAO) Array and the 1997–1998 El Niño episode in the tropical Pacific Ocean. The TAO Array is a grid of 69 buoys moored across the equatorial Pacific Ocean (8°N to 8°S and 95°W to 143°E) recording environmental data relevant to El Niño—Southern Oscillation (ENSO) processes. Data from the TAO Array is available in near-real-time (http://www.pmel.noaa.gov/toga-tao/realtime.html) or as archived ASCII files (http://www.pmel.noaa.gov/toga-tao/data-delivery.html) providing daily (sometimes hourly) records of environmental parameters for each buoy in the grid. Student exercises in data analysis begin with downloading data from buoy locations, parsing the data into spreadsheets, and organizing data by environmental parameter into yearly and monthly data sets. Analyses of reconstructed data include calculations of long-term averages of environmental parameters, seasonal climatologies, monthly climatologies and calculation of long-term, seasonal, and monthly anomalies. Finally, monthly anomaly maps produced by students are loaded sequentially into GIF-animation software to create time-series images illustrating the progress and development of the 1997–1998 El Niño event.     

Numerical modeling to predict the spread of landslide of schist’s area under climatic event of Ain El Hammam (Algeria)

The several reactivations of the landslide of Ain El Hammam (AEH) after each important weather event compel us to look closely at its triggering factors and predict its mechanisms and its evolution at the longer term. In this sense, the prediction of the slope behavior becomes necessary. This paper presents a numerical model of the AEH landslide using Plaxis® software. This model considers hydraulic effects such as precipitation and pore pressure even in the unsaturated parts. Soil and rock behaviors are described with proper elasto-plastic models named Hardening Soils and Jointed Rocks. The first model takes into account hardening on isotropic and deviatoric mechanism as well as a non-associated flow rule. The second model considers a non-isotropic elasticity with perfect plasticity along with given sliding directions. The hydraulic and mechanical models are coupled with an effective stress concept. To detect unstable areas in the landslide, we developed a Matlab® program to take into account the Hill’s bifurcation criterion, which is based on sign of the second-order work. It has been proved that this criterion allows detecting all failure modes that can appear in rate-independent materials and especially the ones that develop before the plasticity limit criterion. From such computations, we can predict the shape and position of slip surface responsible of the actual ground movement of the slope. To validate the numerical results, analysis of field measurement is included. We use high resolution of electrical tomography to delineate the geometry and position of failure surface and approve our results.     

Meteotsunamis in the northeastern Gulf of Mexico and their possible link to El Niño Southern Oscillation

Analysis of 20-year time series of water levels in the northeastern Gulf of Mexico has revealed that meteotsunamis are ubiquitous in this region. On average, 1–3 meteotsunamis with wave heights >0.5 m occur each year in this area. The probability of meteotsunami occurrence is highest during March–April and June–August. Meteotsunamis in the northeastern Gulf of Mexico can be triggered by winter and summer extra-tropical storms and by tropical cyclones. In northwestern Florida most of the events are triggered by winter storms, while in west and southwest Florida they appear both in winter and summer. Atmospheric pressure and wind anomalies (periods <6 h) associated with the passage of squalls originated the majority of the observed meteotsunami events. The most intense meteotsunamigenic periods took place during El Niño periods (1997–1998, 2009–2010 and 2015–2016). Meteotsunamis were also active in 2005, a year characterized by exceptionally intense tropical cyclone activity. Meteotsunami incidence varied yearly and at periods between 2 and 5 years. Results from cross-wavelet analysis suggested that El Niño and meteotsunami activity are correlated at annual and longer-period bands.     

Geochemical characteristics of sediments from Lake El’gygytgyn,Chukotka Peninsula,as indicators of climatic variations for the past 350 ka

This paper presents data on the inorganic geochemical characteristics of the sediments from Hole LZ1024 (Lake El’gygytgyn, Chukotka, 67°30′ N 172°08′ E). It is demonstrated how these data are associated with climatic variations during isotope stages 1–9. The sediments of the warm stages are characterized by elevated contents of SiO₂, CaO, Na₂O, K₂O, and Sr and low concentrations of TiO₂, Al₂O₃, MgO, and Fe₂O₃. It has been established that the geochemical parameters correlate with global climatic variations.     

Simple statistical equivalents of Penman–Monteith formula’s parameters in the absence of non-basic climatic factors

The Penman?CMonteith (PM) method is the most recommended method for estimating reference evapotranspiration (ET_o). The PM equation requires several parameters to be available, either measured or computed. Some of these parameters are conventionally calculated by some slightly sophisticated formulas, especially for handy calculations. This paper aimed to derive some simpler statistical equivalents to these formulas. Simplifications were performed to the formulas of the saturation vapor pressure e _o[T], slope of vapor pressure (?), atmospheric pressure (P), the psychrometric constant (??), wind speed correction, the long-wave radiation, R _nl; the sunset hour angle, ?? _s; and the extraterrestrial radiation, R _a. For the first five parameters, the parameter-independent factor was analyzed for its extremes, then fitted by interpolation to a simpler equivalent formula. The last three parameters were fitted to simpler form through data from the FAO-CLIMWAT database. Each of the simplified formulas was compared to the conventional one; some correlation indices were applied to validate the new formulas. The ET_o was calculated for all stations in the CLIMWAT database by both simplified and conventional formulas. All the correlation results were excellent, with a minimum correlation coefficient of 0.9966. The simplified formulas were proven to be equivalent in performance, with almost no loss in accuracy but simpler in form and faster in execution in the online database applications.     

An experimental study of the partitioning of a rare earth element (Gd) in the system diopside—aqueous vapour

The partitioning of Gd in the experimental system diopside-aqueous vapor as a function of temperature, pressure, composition of the phases, time, grain size, solid-liquid ratio and Gd concentration has been investigated. A radioactive tracer measurement was used to determine Gd concentration in the separated phases. Diposides were reacted with aqueous vapor containing tracer Gd and reversibility was tested by reacting Gd-doped diopsides with pure aqueous vapor. Equilibration of Gd between the bulk of the diopside and the liquid was found to be limited by the slow rate of Gd diffusion in diopside, maximum value of D = 2 × 10^?15cm²sec^?1 at 800°C and 1 kb. Depending on whether the diopside was previously synthesized or synthesized from an oxide mix during the experiment, Gd concentrations were zoned in the crystal such that higher concentrations existed at the edges or center, respectively. Equilibrium is difficult to achieve in these experiments, but at the optimum experimental conditions for equilibration, the Gd diopside-aqueous vapor distribution coefficient is 20 ± 6 (800°C, 1 kb) in approximate agreement with previous results of 55 ± 23. Changing the composition of the aqueous vapor indicated that possible mechanisms for Gd substitution included coupling of Gd³⁺ with H⁺ or Na⁺ replacing 2Ca²⁺, or substitution of 2Gd³⁺ for 3Ca²⁺ with formation of a cation vacancy.     

Interannual variations in length of day with respect to El Niño - Southern Oscillation’s impact (1962–2015)

The objective of research done in this study is to examine the variability of the length of day (LOD) and to investigate its correlation with ENSO (El Niño-Southern oscillation) episodes. For this purpose, the LOD time series (1962–2015), from the International Earth Rotation and Reference Systems Service (IERS), is investigated using the Singular Spectrum Analysis (SSA) technique. The results show that the LOD time series is very complex and is composed of several components: the long-term trend explains 95.97% of the original series, the annual harmonic 1.76% and the semi-annual 1.35%. Considering sea surface temperature anomalies (SSTA) index over the Niño3, Niño4 and Niño3.4 regions, Southern Oscillation Index (SOI) and Multivariate ENSO Index (MEI), the residuals signal, that represents only 0.92% of the initial LOD series, indicate a significant correlation with ENSO occurred during 1965–66, 1972–73, 1982–83 and 1997–98 El Niño events and 1970–71, 1973–74, 1988–89, 2007–08, 2010–11 La Niña ones. This is a pertinent result that suggests that LOD variability is at least partly related to ENSO phenomena.     

Evolution of silica accumulation in the earth’s history and its relation to biota development

Two branches of silica rockevolution related to oceans and continental blocks have been outlined. The boundaries of changes in types of silica rocks, their formation, and development of the organic world were established: (i) the beginning of the Phanerozoic was related to transformation from microbial to biogenic silica deposition (or to a change in the influence of microbial activity on silica accumulation); (ii) cessation of the formation of cherts enriched in organic matter, which was synchronized with land colonization by organisms in the Devonian, and (iii) an explosive style of global silica accumulation related to the appearance and development of diatoms, which correlates with appearance of angiosperm plants in tropical forests.     

About the variability in thunderstorm and rainfall activity over India and its association with El Niño and La Niña

Thunderstorms are of much importance in tropics, as this region is considered to have central role in the convective overturn of the atmosphere and play an important role in rainfall activity. It is well known that El Niño and La Niña are well associated with significant climate anomalies at many places around the globe. Therefore, an attempt is made in this study to analyze variability in thunderstorm days and rainfall activity over Indian region and its association with El Niño and La Niña using data of thunderstorm day’s for 64 stations well distributed all over India for the period 1981–2005 (25 years). It is seen that thunderstorm activity is higher and much variable during pre-monsoon (MAM) and southwest monsoon (JJAS) than the rest of the year. Positive correlation coefficients (CCs) are seen between thunderstorms and rainfall except for the month of June during which the onset of the southwest monsoon sets over the country. CCs during winter months are highly correlated. Composite anomalies in thunderstorms during El Niño and La Niña years suggest that ENSO conditions altered the patterns of thunderstorm activity over the country. Positive anomalies are seen during pre-monsoon (MAM) and southwest monsoon months (JAS) during La Niña years. Opposite features are seen in southwest monsoon during El Niño periods, but El Niño favors thunderstorm activity during pre-monsoon months. There is a clear contrast between the role of ENSO during southwest monsoon and post-monsoon on thunderstorm activity over the country. Time series of thunderstorms and precipitation show strong association with similarities in their year-to-year variation over the country.