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Victor Manuel Naumovich Velasco Herrera

Victor Manuel Naumovich Velasco Herrera
Institute of Geophysics of the National Autonomous University of Mexico (UNAM) · Space Sciences

32.27
 · 
PhD

About

116
Publications
27,060
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735
Citations
Introduction
Skills and Expertise
Research Experience
January 2000 - present
Geophysics of the National Autonomous University of Mexico (UNAM)
Position
  • Researcher

Publications

Publications (116)
Article
Full-text available
The so-called Ground Level Enhancement events are sporadic relativistic solar particles measured at ground level by a network of cosmic ray detectors worldwide. These sporadic events are typically assumed to occur by random chance. However, we find that by studying the last 56 ground level enhancement events reported from 1966 through 2014, these e...
Article
A new time-frequency method of analysis, based on the generalization of Einstein's cross-functions, is introduced. • The method is relevant for n > 2 time series. • We test our algorithm for the study of solar activity variations. We introduce the method of multiple cross-wavelet algorithm, hereafter also as Einstein's cross functions, for the time...
Article
Full-text available
h i g h l i g h t s: We present a new method to estimating TSI between the years 1000 and 2100. We found a grand minimum for the 21st century. We found conspicuous periodicities of 11 and 120 years. The solar activity grand minima periodicity is of 120 years. To decide when the solar activity is high or low, we using the power of the TSI. a b...
Article
Full-text available
Climatology of Aerosol Optical Depth (AOD), Single Scattering Albedo (SSA), and aerosol particle-size distribution were analyzed using a 15-year (1999–2014) dataset from AErosol RObotic NETwork (AERONET) observations over the Mexico City (MC) basin. The atmosphere over this site is dominated by two main aerosol types, represented by urban/industria...
Article
Full-text available
Observed changes in Northern Hemisphere snow cover from satellite records were compared to those predicted by all available Coupled Model Intercomparison Project Phase 5 ("CMIP5") climate models over the duration of the satellite's records, i.e., 1967-2018. A total of 196 climate model runs were analyzed (taken from 24 climate models). Separate ana...
Article
The present study reports the synchronization between the chromospheric and photometric variability at timescale of about 1.6-1.8 year as observed for the young, rapidly rotating solar analog HD 30495. In addition, HD 30495 may be presenting evidence of surface differential rotation at timescales of about 11-day and 21-day, as well as the sunspot-l...
Conference Paper
Full-text available
The new reference solarimetric network for Mexico is presented, actually 10 stations has been installed around the country with a climatic regionalization, the three principal solar parameters are measured (bean, diffuse and global radiation) in all the stations, and spectral parameters in some stations (long wave radiation, UVB and illuminance)
Chapter
Full-text available
Background: In preterm neonates, the cardiovascular and cerebral vascular control is immature, making the brain vulnerable to an increased incidence of hypoxic and hyperoxic episodes. Aim: The aim of the study was to apply the recently developed multiple Einstein's cross wavelet analysis (MECWA) to quantify the coupling of fluctuations of periph...
Article
Full-text available
Among the several GLE (Ground Level Enhancements) that have presumptuously occurred in the period 2012-2015 the 17th May 2012 is that which is more widely accepted to be a GLE, in view of the high number of high latitude Neutron Monitor (NM) stations that have registered it. In spite of the small amplitude, it was the more prominent of the predicte...
Article
BACKGROUND: In preterm neonates, the cardiovascular and cerebral vascular control is immature, making the brain vulnerable to an increased incidence of hypoxic and hyperoxic episodes. AIM: The aim of the study was to apply the recently developed multiple Einstein's cross wavelet analysis (MECWA) to quantify the coupling of fluctuations of periphera...
Article
Full-text available
The stability of Earth's critical zone is intimately linked with erosion, weathering and vegetation type and density. Therefore, it affects global biogeochemical processes which in turn affect the global climate by absorbing and reflecting solar radiation, and by altering fluxes of heat, water vapour, carbon dioxide and other trace gases through va...
Article
Full-text available
We analysed a his­tor­i­cal cat­a­logue of me­te­oroid falling dur­ing the last 400 years. We re­port here for the first time the syn­chro­niza­tion be­tween ob­served me­te­ors and so­lar barycen­tric pa­ra­me­ters in 19.6 and 13.2 years pe­ri­od­ic­i­ties us­ing a new mul­ti­ple cross wavelet. The group of mod­er­ated num­ber of me­te­ors is dis­...
Article
Full-text available
The Sun is the principal energy source for the Earth's life and variation of this energy can contribute to a global food surplus or a world food deficit. The estimation of Solar Energy for the 21st century is one of the current concerns of contemporary scientific approaches in this field of Sun study, since the possible occurrence of a solar defici...
Article
Total solar irradiance is the primary energy source of the Earth’s climate system and therefore its variations can contribute to natural climate change. This variability is characterized by, among other manifestations, decadal and secular oscillations, which has led to several attempts to estimate future solar activity. Of particular interest now...
Chapter
Full-text available
The international journal of Pattern Recognition in Physics was a good journal that might have become a renowned forum for important scientific papers. Its termination due to a straightforward conclusion on solar variability in relation to climate change is not only to be regretted as an unreasonable constraint on academic freedom but also excoriat...
Data
This article explores the Sun's influence on the hydrological cycle in southern South America (SSA) at the range of interannual-to-multidecadal scales from the early 1900s to 2011. The solar variability is described by the sunspot number (SSN) index. The hydrological cycle is examined by using annual mean discharges of the Paraná River (PAR) and th...
Article
Full-text available
Key Message An improved quantification of variations in bark microrelief is presented that uses wavelets on a circular domain from data acquired using the LaserBark™ automated tree measurement system. Abstract An important metric of canopy structure, bark microrelief affects both the hydrology and biogeochemistry of forests. Increased bark microrel...
Data
Full-text available
We report on the existence and nature of Holocene solar and climatic variations on centennial to millennial time-scales. We introduce a new solar activity proxy, based on nitrate (NO 3 −) concentration from the Talos Dome ice core, East Antarctica. We also use a new algorithm for computing multiple-cross wavelet spectra in time–fre-quency space tha...
Book
Full-text available
The Sun’s activity constantly varies in characteristic cyclic patterns. With new material and new analyses, we reinforce the old proposal that the driving forces are to be found in the planetary beat on the Sun and the Sun’s motions around the center of mass. This is a Special Issue published on Pattern Recognition in Physics where various aspects...
Data
Full-text available
The idea that planetary effects may modulate, or even control solar variability is old; having been investigated by Rudolf Wolf from 1859 until his death in 1893. Many further efforts to measure and explain the possible mechanisms for planetary solar effects have been made by researchers at frequent intervals through the years. Despite this it has...
Data
Key Message An improved quantification of variations in bark microrelief is presented that uses wavelets on a circular domain from data acquired using the Laser-Bark TM automated tree measurement system. Abstract An important metric of canopy structure, bark microrelief affects both the hydrology and biogeochemistry of forests. Increased bark micro...
Chapter
Full-text available
In a collection of research papers devoted to the problem of solar variability and its origin in plan-etary beat, it is demonstrated that the forcing function originates from gravitational and inertial effects on the Sun from the planets and their satellites. This conclusion is shared by nineteen co-authors.
Data
In this work we make an analysis of significant periodicities shown by phenomena linked to solar activity such as coronal hole area, radio emission in the 10.7 cm band and sunspots. We use the wavelet method that gives information in the frequency and time domains. Of particular interest are the mid-term periodicities (1 2 yrs). Over the whole peri...
Article
Full-text available
The measurement of solar B band Ultraviolet radiation (UVB) should be considered a priority in Mexico due to implications on public health throughout the country (total population, 108 million), but this is not carried out at present. Installed sensors cover only 0.12% of the country. However, there are alternative methods for estimating UVB radiat...
Article
Full-text available
The measurement of solar B band Ultraviolet radiation (UVB) should be considered a priority in Mexico due to implications on public health throughout the country (total population, 108 million), but this is not carried out at present. Installed sensors cover only 0.12% of the country. However, there are alternative methods for estimating UVB radiat...
Chapter
The analysis of the cosmic rays is a tool to study the solar magnetic field. The galactic cosmic rays flux is modulated by the change in interplanetary magnetic field and the barycentre motion of the solar system. Since there is no direct observational data to study the cosmic rays variability over a long-time scale, proxy data such as cosmogenic r...
Article
Full-text available
Cosmogenic isotopes have frequently been employed as proxies of ancient cosmic ray fluxes. On the basis of periodicities of the 10 Be time series (using data from both the South and North Poles) and the 14 C time series (with data from Intercal-98), we offer evidence of the existence of cosmic ray fluctuations with a periodicity of around 30 years....
Article
Full-text available
Using modern wavelet analysis techniques, we have made an attempt to search for oscillations of intensity of galactic cosmic rays (GCR), sunspot numbers (SS) and magnitudes of coronal index (CI) implying that the time evolution of those oscillations may serve as a precursor of Ground Level Enhancements (GLEs) of solar cosmic rays (SCR). From total...
Article
Full-text available
The potential oceanic influence on southernmost South American precipitation since 1930 is analyzed in this study. The aim is to define oceanic characteristics that can produce wetter or drier conditions over the mentioned region on different time scales. Results suggest important precipitation-oceanic links in decadal and interdecadal oscillations...
Article
In this work we attempt to determine characteristic signatures of Ground Level Enhancements (GLE's) of Relativistic Solar Particle for the task of prognostic goals: first, in addition of the multipleyears periodicities, among the periodicities found here there are the short to term (ST) periodicities, in the order of days (all of them harmonics of...
Article
Full-text available
The reconstruction and prediction of solar activity is one of the current problems in dynamo theory and global climate modeling. We estimate the Total Solar Irradiance for the next hundred years based on the Least Square Support Vector Machine. We found that the next secular solar minimum will occur between the years 2003 and 2063 with an average o...
Article
The 20th century surface air temperature (SAT) records of China from various sources are analyzed using data which include the recently released Twentieth Century Reanalysis Project dataset. Two key features of the Chinese records are confirmed: (1) significant 1920s and 1940s warming in the temperature records, and (2) evidence for a persistent mu...
Article
Full-text available
In this work we study the mid-term periodicities (MTPs), between 1 and 2 years, of the sunspot groups and the flare index (FI), by separating the data into hemispheres and spectral bands (SBs) according to the most significant periodicities presented by these phenomena. We found that the MTP of sunspot groups has a diminished power during the Moder...
Article
Using different approaches and techniques of wavelet analysis we analyze variations (oscillations) of galactic cosmic rays, solar spot number, and coronal index of solar activity before ground level enhancements of solar cosmic rays. Obtained results are discussed in frames of recent ideas about periodicity phenomena in the photosphere, and corona...
Article
Full-text available
A linear dependence between ozone depletion on the 11 years cycle of Cosmic Rays (CR) has been often debated in the literature. At first instance, the more elemental corroboration is by means of the correlation coefficient (r). Calculations corresponding to the relevant data gives a value r = 0.5216. Since this low value is not completely conclusiv...
Article
In this work, we attempt to determine characteristic signatures of Ground Level Enhancements (GLE's) of Relativistic Solar Particle (RSP) for the following tasks: (1) the study of common periodicities between RSP and solar activity processes at different layers of the solar atmosphere. Among the periodicities found here there are the Ultra short-te...
Article
Full-text available
We study the specific influence of African dust on each one of the categories of Atlantic hurricanes. By applying wavelet analysis, we find a strong decadal modulation of African dust on Category 5 hurricanes and an annual modulation on all other categories of hurricanes. We identify the formation of Category 5 hurricanes occurring mainly around th...
Article
Full-text available
The Antarctic region in which severe ozone depletion has taken place is known as the ozone hole. This region has two basic indicators: the area, where the ozone abundance is low (size), and the quantity of ozone mass deficit (depth). The energetic particles that penetrate deeply into the atmosphere and galactic cosmic rays (GCR) modify the ozone ab...
Article
The analysis of the sunspots series is a tool to study the solar magnetic field and the solar dynamo. Since there are no direct observational data to study the solar variability over long time scales we need to rely on proxy data such as cosmogenic isotopes. In this paper we have done a reconstruction of sunspot time series during the period 1-1600...
Article
In this work, we make an analysis of the synchronization of the layers of the solar atmosphere. using different indexes such as sunspot, solar flare index and others. We use the wavelet transformed spectral analysis to find the significant periodicities of these series. In particular, we found .27 days, 152 2 days, and 11 yrs. The later one modulat...
Article
Full-text available
The purpose of this work is to create a parallel micro-platform, that simulates the virtual movements of a space exploration in 3D. One of the innovations presented in this design consists of the application of a lever mechanism for the transmission of the movement. The development of such a robot is a challenging task very different of the industr...
Article
On December 7th 1995, the Galileo mission began the study the jovian system. Among the results that his mission has obtained, it is the evidence of the existence of a liquid water ocean beneath the icy crust of Europa. Liquid water is one of the main factors that make life possible, so then life might exist in Europa. Some of the scenes that have b...
Article
In the present paper the algorithms of optimum handling of fields of own radio thermal radiation are synthesized and the outcomes of researches of behaviors of limiting errors of measurement of parameters of water in Mars surface. These data can be received at the rate of potential exactitudes, defined by Rao-Kramer's inequality or diagonal element...
Article
Here we apply cross-wavelet, the global wavelet spectra and a new wavelet coherency signal-noise method to theavailable data of African Dust for the period 1966-2004 and Database of hurricanes, from the National Weather Service (http:// weather.unisys. com/ hurricane/). Hurricane data was transformed into a series of Pulses Width modulation (PWM) o...
Article
The nature of the climatic change response to solar variability in different time scale. The wavelet analysis applied to paleoclimatic proxy data of large scale atmospheric phenomena (Pacific Decadal Oscillation and Southern Oscillation Index) has revealed coherence between the climatic oscillations and the solar phenomena (the cosmogenic isotope 1...
Article
The direct impact of solar variability on climate has been widely studied through different so-lar indexes. Biological processes also impact climate and are deeply affected by solar activity. For example, the Marine phytoplankton emissions into the atmosphere have been proposed to change cloud albedo through cloud formation. The wavelet analysis ap...
Article
One of the main questions in the study of solar variability is to know if the Solar Dynamo and the Shchwabe cycle were present or absent, before and during the Maunder minimum. Unfortunately, there is not a complete theory of the Solar Dynamo that explains the origin of the observed solar magnetic fields, their properties, their evolution and how t...
Article
We analyze the ice winter severity index on the Baltic region since 1501-1995. We found that the variability of this index is modulated among other factors by the secular solar activity. The little ice ages that have appeared in the North Hemisphere occurred during periods of low solar activity. Seemingly our star is experiencing a new quiet stage...
Article
Using different techniques of Wavelet Analysis, particularly, cross-wavelet coherence and the Global Wavelet Spectrum, we analyze data of intensity of 70 GLE's of the solar cycles 17 -23 vs data of the solar corona. We have found common periodicities of short period (2.8, 5.2 and 27 days), medium period (0.5, 1.2, 1.8, 3.2) as well as a the 4.6 and...
Article
The direct impact of solar activity on climate has been widely studied through Total Solar Irradiance (TSI). Biological processes also impact climate and are deeply affected by TSI. Marine phytoplankton emissions into the atmosphere have been proposed to change cloud albedo through cloud formation. In this work, we use wavelet analysis to investiga...
Article
In this work we make an analysis of significant periodicities shown by phenomena linked to solar activity such as coronal hole area, radio emission in the 10.7 cm band and sunspots. We use the wavelet method that gives information in the frequency and time domains. Of particular interest are the mid-term periodicities (1–2 yrs). Over the whole peri...
Article
The intensity time me profiles of Relativistic Solar Protons (RSP) in the period 1942 to 2006 were analyzed by means of the Morlet Spectral technique: the periodicities of their time series were determined. Furthermore, RSP time series together with those of several solar activity indexes were analyzed by means of the Wavelet Coherence spectral met...
Article
Full-text available
Recently it has been suggested that there exist specific changes in the cosmic ray intensity and some solar and geomagnetic parameters during the days, preceding the hurricane appearances over the North Atlantic Ocean. To understand better these phenomena, data for all hurricanes born not only over the Atlantic but also over the Pacific waters in t...
Article
Full-text available
The nature of the climatic response to solar variability is assessed over a long-time scale. The wavelet analysis applied to paleoclimatic proxy data of large scale atmospheric phenomena (North Atlantic Oscillation, Atlantic Multidecadal Oscillation, Pacific Decadal Oscil-lation and Southern Oscillation Index) has revealed coherence between the cli...
Article
Full-text available
In order to sustain previous results regarding the Correlational Analysis between Tropical Cyclones and Cosmophysical phenomena, namely Galactic Cosmic Rays (CR) and Solar Activity (SS), we extend here such analysis by means of the Coherence Morlet Wavelet spectral analysis. Then, the aim of this work is to find incident cosmophysical periodicities...
Article
The nature of the climatic response to solar variability is assessed over a long-time scale. The sun has long been suspected to influence decade-to century climate changes. One of the principal difficulties in quantifying the role of the sun in climate change has been the absence of long-term measurements of both, the climatic and solar activity ph...
Article
The origin, behavior and evolution of the solar magnetic field is one of the main challenges of observational and theoretical solar physics. Up to now the Dynamo theory gives us the best approach to the problem. However, it is not yet able to predict many features of the solar activity, which seems not to be strictly a periodical phenomenon. Among...
Article
In this work we report an analysis of various indices of solar magnetic variability of closed and open field, concentrating particularly in the quasi-biennial peridicities (1.7-2.5 years). The wavelet technique is used in the time series of the solar indices to find the significant periodicities of our study, we also use other wavelet analysis alre...
Article
The Intensity Time Profile and Energy Spectra of Relativistic Solar Protons (RSP) in the period 1942-2007 were analyzed by means of the Morlet Spectral method: the periodicities of their time series were determined. Besides, RSP data together with several solar activity indexes were analyzed by means of the Wavelet Coherence Spectral technique, wit...
Article
We have done a Wavelet Spectral Analysis of the daily, monthly and annual series of Sunspots; the obtained results show that the 5.5 years (quasi-quinquennial) periodicity is systematically present in the spectrum of the secular maxima of solar activity. Such periodicity is attenuated or disappears during the secular minima: e.g. the Maunder, Dalto...
Article
The analysis of the sunspots series is a tool to study the solar magnetic field and the solar dynamo. Since there are no direct observational data to study the solar variability over long time scales we need to rely on proxy data such as cosmogenic isotopes. By applying the Wavelet transform spectral analysis to the cosmogenic isotope 14 C, we have...
Article
In this paper, we make an analysis of significant periodicities shown by phenomena linked to different cosmophysical indexes such as solar flare index, cosmic ray flux intensity and others. We use the wavelet transformed spectral analysis to find the significant periodicities of these series. In particular, we found that when the periodicities are...