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1.
With a view to difficulties with explaining the physical mechanism of solar forcing on the Earth’s climate, we applied a new approach of determining and quantifying an influence of solar-related events on water vapor variability by correlating the total electron content (TEC) and precipitable water vapor (PWV), both derived from ground-based GPS observations. In this study, ionospheric TEC and atmospheric PWV values are employed as solar activity and terrestrial climate parameters, respectively. Three-year GPS data at five stations in Antarctica are analyzed on a daily mean basis. Results show significant correlation between TEC and PWV differences during storms-affected days. The high correlation between the daily mean values of TEC and PWV, both of which follow the seasonal signals and subsisting downward trend, suggests an influence of solar activity on climate variability in Antarctica. These quantities are determined by changes of the upper-atmosphere level, which varies in conformity with the zenith angle of the Sun.  相似文献   

2.
Predicting global climate change is a great challenge and must be based on a thorough understanding of how the climate system components behave. Precipitable water vapor (PWV) is one of the key components in determining and predicting the global climate system. It is well known that the local surface temperature and pressure have a direct influence on the production of PWV. However, the influence of solar activity on atmospheric dynamics and their physical mechanisms is still an open debate, where past studies are focused at mid-latitude regions. A new method of determining and quantifying the solar influence on PWV based on GPS observations to correlate the GPS PWV and total electron content (TEC) variations is proposed. Observed data from Scott Base (SBA) and McMurdo (MCM) stations from 2003 to 2005 have been used to study the response of PWV to solar activity. In the analysis, the effects of local conditions (wind speed and relative humidity) on the distribution of PWV are investigated. Results show significant correlation between PWV and solar activity for four geomagnetic storms, with correlation coefficients of 0.74, 0.77, 0.64 and 0.69, which are all significant at the 95% confidence level. There was no significant correlation between TEC and PWV changes during the absence of storms. On a monthly analysis, a strong relationship exists between PWV and TEC during storm-affected days, with correlation coefficients of 0.83 and 0.89 (99% confidence level) for SBA and MCM respectively. These indicate a statistically significant seasonal signal in the Antarctic region, which is very active (higher) during the summer and inactive (lower) for the winter periods.  相似文献   

3.
There have been a number of investigations for examining the possible link between long-term climate variability and solar activity. A continuous δ18O record of peat cellulose covering the past 6 000 years and the response of climate variation inferred from the proxy record to solar forcing are reported. Results show that during the past 5 000 years the abrupt climate variations, including 17 warming and 17 cooling, and a serious of periodicities, such as 86, 101, 110, 127, 132, 140, 155, 207, 245, 311, 820 and 1 050 years, are strikingly correlative to the changes of solar irradiation and periodicity. These observations are considered as further evidence for a close relationship between solar activity and climate variations on time scales of decades to centuries.  相似文献   

4.
Direct and indirect data on variations in cosmic rays, solar activity, geomagnetic dipole moment, and climate from the present to 10–12ka ago (the Holocene Epoch), registered in different natural archives (tree rings, ice layers, etc.), have been analyzed. The concentration of cosmogenic isotopes, generated in the Earth’s atmosphere under the action of cosmic ray fluxes and coming into the Earth archives, makes it possible to obtain valuable information about variations in a number of natural processes. The cosmogenic isotopes 14C in tree rings and 10Be in ice layers, as well as cosmic rays, are modulated by solar activity and geomagnetic field variations, and time variations in these concentrations gives information about past solar and geomagnetic activities. Since the characteristics of natural reservoirs with cosmogenic 14C and 10Be vary with climate changes, the concentrations of these isotopes also inform about climate changes in the past. A performed analysis indicates that cosmic ray flux variations are apparently the most effective natural factor of climate changes on a large time scale.  相似文献   

5.
Information about variations in solar activity and climate on the time intervals from 130 years to four–five last centuries, including results of instrumental measurements (Wolf numbers, actinometry, thermometry) and indirect indicators (ice core acidity, NO 3 ? ion concentration in polar ice, temperature tree-ring reconstructions), has been analyzed for the Northern Hemisphere and its high-latitude part. It has been obtained that the observed relation between secular variations in solar activity and near-Earth temperature resulted from the effect of the corresponding variation in aerosol transparency of the stratosphere on terrestrial climate. It has been also indicated that long-term variations in the aerosol content of the stratosphere can, in turn, be related to secular cycles in atmospheric ionization caused by variations in fluxes of ionizing cosmic particles.  相似文献   

6.
A large number of individual enstatite crystals of the gas-rich aubrites Khor Temiki, Staroe Pesyanoe and Bustee was analyzed for implanted helium and for steep gradient ion tracks in order to investigate the relation between solar flare irradiation and solar wind implantation with extreme local resolution. Irradiated and non-irradiated crystals coexist within the gas-rich phases of the aubrites investigated. Statistically in a given meteorite the proportion of crystals with implanted solar wind is similar to the proportion of solar flare irradiated crystals. It varies from aubrite to aubrite in the sequence of their bulk contents of trapped rare gases.For nine enstatites, tracks and rare gases were subsequently measured within the same crystal. The results support the intimate association of solar flare tracks and implanted He. The4He-surface concentrations of irradiated crystals vary between <5 × 10?7 and 10?4 cm3 STP/cm2.The absence of saturation effects together with the low degree of elemental gas fractionation indicates very short solar wind exposure times (< 100 yr) rather than strong diffusion losses. The evidence from tracks and rare gases can be understood in terms of an early simultaneous irradiation of aubritic crystals by solar wind and solar flare particles on top of a regolith-covered parent body.  相似文献   

7.
Seasonal variations in the auroral E-region neutral wind for different solar activity periods are studied. This work is based on neutral wind data obtained over 56 days between 95–119 km altitude under geomagnetic quiet conditions (Ap<16) during one solar cycle by the European Incoherent Scatter radar located in northern Scandinavia. In general, the meridional mean wind shifts northward, and the zonal mean wind increases in eastward amplitude from winter to summer. The zonal mean wind blows eastward in the middle and lower E-region for each season and for each solar condition except for the equinox, where the zonal mean wind blows westward at and below 104 km. Solar activity dependence of the mean wind exists during the winter and equinox seasons, while in summer it is less prominent. Under high solar activity conditions, the altitude profiles of the horizontal mean winds in winter and the equinoxes tend to resemble those in summer. The horizontal diurnal tide is less sensitive to solar activity except during summer when the meridional amplitude increases by ∼10 m s−1 and the corresponding phase shifts to a later time period (1–2 h) during high solar activity. Seasonal dependence of the semidiurnal tide is complex, but is found to vary with solar activity. Under low solar activity conditions the horizontal semidiurnal amplitude shows seasonal dependence except at upper E-region heights, while under high solar activity conditions it becomes less sensitive to seasonal effects (except for the meridional component above 107 km). Comparisons of mean winds with LF and UARS observations are made, and the driving forces for the horizontal mean winds are discussed for various conditions.  相似文献   

8.
We study the cosmic ray modulation during different solar cycles and polarity states of the heliosphere. We determine (a) time lag between the cosmic ray intensity and the solar variability, (b) area of the cosmic ray intensity versus solar activity modulation loops and (c) dependence of the cosmic ray intensity on the solar variability, during different solar activity cycles and polarity states of the heliosphere. We find differences during odd and even solar cycles. Differences during positive and negative polarity periods are also found. Consequences and implications of the observed differences during (i) odd and even cycles, and (ii) opposite polarity states (A<0 and A>0) are discussed in the light of the modulation models, including drift effects.  相似文献   

9.
Such high-resolution indirect data on solar activity as the 14C and 10Be cosmogenic isotopes have been considered. The long-term solar activity cyclicity during the last millennium with periods of approximately 90 and 210 years, which can be related to substantial climatic warming and cooling events in this millennium, has been established based on an analysis of these data. It has been indicated that long-term recent climate warming can result from the effect of the ∼90- and ∼210-year solar cycles on the climatic system, which is characterized by the nonlinear dynamics.  相似文献   

10.
This paper presents a qualitative analysis of the properties and particular examples of strong (10% < |δfoF2| < 30%) and very strong (|δfoF2| > 30%) fluctuations in the critical frequency of the F2 layer (foF2) of the quiet ionosphere at midlatitudes under low solar activity according to the Irkutsk station data for 2007–2008. It is found that strong day-to-day fluctuations in foF2 are mainly related to changes in thermospheric parameters, which have a nature of planetary waves and tides. Evidently, very strong day-to-day fluctuations in foF2 are caused by superposition of the effects in the ionosphere caused by changes in the thermospheric parameters and those related to a complex of processes of solar wind interaction with the magnetosphere, including the effects caused by the reversal of the vertical component of the solar wind magnetic field southwards. The increase in foF2 during nighttime hours in winter up to values typical for the daytime maximum in foF2 is the brightest example of very strong changes in foF2 in the quiet ionosphere.  相似文献   

11.
Isotopic anomalies in Mo and Zr have recently been reported for bulk chondrites and iron meteorites and have been interpreted in terms of a primordial nucleosynthetic heterogeneity in the solar nebula. We report precise Zr isotopic measurements of carbonaceous, ordinary and enstatite chondrites, eucrites, mesosiderites and lunar rocks. All bulk rock samples yield isotopic compositions that are identical to the terrestrial standard within the analytical uncertainty. No anomalies in 92Zr are found in any samples including high Nb/Zr eucrites and high and low Nb/Zr calcium-aluminum-rich inclusions (CAIs). These data are consistent with the most recent estimates of <10−4 for the initial 92Nb/93Nb of the solar system. There exists a trace of isotopic heterogeneity in the form of a small excess of r-process 96Zr in some refractory CAIs and some metal-rich phases of Renazzo. A more striking enrichment in 96Zr is found in acetic acid leachates of the Allende CV carbonaceous chondrite. These data indicate that the r- and s-process Zr components found in presolar grains were well mixed on a large scale prior to planetary accretion. However, some CAIs formed before mixing was complete, such that they were able to sample a population of r-process-enriched material. The maximum amount of additional r-process component that was added to the otherwise well-mixed Zr in the molecular cloud or disk corresponds to ∼0.01%.  相似文献   

12.
It is uncertain whether the solar cycle 24 will have a high or a low sunspot maximum number. In its last revision the Solar Cycle 24 Prediction Panel indicates that the low prediction is the most likely. Also, solar cycle 25 is considered to present an equal or lower activity than cycle 24. In order to assess the possible effect of the solar activity on temperature, in the present work we attempt to model the tendency of the Northern Hemisphere temperature for the years 2009–2029, corresponding to solar cycles 24 and 25, using a thermodynamic climate model. We include as forcings the atmospheric carbon dioxide (CO2) and the solar activity by means of the total solar irradiance, considering that the latter has not only a direct effect on climate, but also an indirect one through the modulation of the low cloud cover. We use two IPCC-2007 CO2 scenarios, one with a high fossil consumption and other with a low use of fossil sources. Also we consider higher and lower solar activity conditions. We found that in all the performed experiments the inclusion of the solar activity produces a noticeable reduction in warming respect to the IPCC-2007 CO2 scenarios. Such reduction goes between ～14% and ～44%. In order to evaluate the efficiency of the TCM, we use the root mean square (RMS) between the observed and model temperatures for the period 1980–2003. We find that the RMS for the experiment using the CO2 as the only forcing is 0.06 °C,while for the experiment that includes also the solar activity it is higher, 0.13 °C.  相似文献   

13.
The solar prominence radiation spectrum has been simulated in close H and K lines of ionized calcium and hydrogen line H? convenient for processing in CCD observations. Equations of radiation transfer and statistical equilibrium in absence of LTE are solved for a model of homogeneous plane layer, taking into account the partial frequency redistribution for a 20-level continuum model of hydrogen atoms and a 5-level continuum model of calcium ions. The ratio of the integral intensities s = E(H Ca II)/E(H?) and t = E(K)/E(H) Ca II is calculated for a model grid (pressure 0.001 < P < 1.0 dyn/cm2, temperature 4000 < T < 20000 K). The s(T, P) and t(T, P) constructed diagnostic charts for solar prominences are obtained for the first time with allowance for the influence of the Ly?? line on the ionization of Ca II ions.  相似文献   

14.
Previous studies on the relationship between polar motion and water mass change have mainly concentrated on the excitation of polar motion via global terrestrial water storage changes(TWSC). In view of the uneven distribution of global terrestrial water storage, the relationship between regional water mass change and polar motion needs to be further explored owing to the lack of documented results. In addition, given the uncertainty in the estimation of TWSC, it is required to develop appropriate indices to describe water mass change from different perspectives. The Amazon River basin(referred to Amazon hereafter), containing the world's largest river, located at around the 90°W longitude, is selected as the study area. Water vapor flux, precipitation, runoff and TWSC are selected as the indices of water mass changes to reveal the relationship between polar motion and water mass change in this giant basin. The Mann-Kendall(M-K) method, the accumulated anomaly analysis method and the curvature method are used to identify the abrupt change points; the least squares method is used to estimate the trends,and the Fast Fourier Transform(FFT) and the Ensemble Empirical Mode Decomposition(EEMD) are used to perform a periodic analysis, for all the above indices. It is shown that, of all the indices from 1948 to 2011, water vapor flux is the most closely related index to polar motion. In detail, precipitation and water vapor flux contain beat periods of polar motion; water vapor flux,precipitation and polar motion have a common M-K test abrupt change point(occurring in ca. 1968) at the 0.05 significance level; water vapor flux has a similar accumulated anomaly curve with that of polar motion; and water vapor flux is more highly correlated with polar motion than most other indexes. It is found, just like global TWSC, the χ2 component of the excitation via water vapor flux and water storage change in the Amazon follows that of observed polar motion; χ1 does not follow. However, the pattern in the Amazon that the χ2 component of the excitation by water follows that of observed polar motion is at a more significant level than in global. Finally, the new index termed Location of Vapor-based Inter Tropical Convergence Zone(LVITCZ) we proposed to describe the annual mean latitudinal location of water mass change shows a more close and visual relationship between water mass change and polar motion than other chosen indices do.  相似文献   

15.
We analyze the longest temperature series from Prague, Bologna and Uccle. We partition daily minimum and maximum temperatures and their differences in two subsets as a function of high vs low solar activity, using the superimposed epochs method. Differences display patterns with significant amplitudes and time constants ～3 months. These are recognized in all stations and are stable against a change in the analyzed period. Amplitude of variations is ～1 °C. Differences between average annual values corresponding to high vs low activity periods are also ～1 °C. Solar activity may account for these long-term temperature variations. These variations also present local characteristics, which may render identification of a global correlation delicate. We discuss possible physical mechanisms by which solar variation could force climate changes (e.g. through solar activity itself, the EUV part of the solar flux, cosmic rays, the downward ionosphere-earth current density, etc.).  相似文献   

16.
Data on the concentrations of the cosmogenic 10Be isotope and Na+ and Ca2+ ions, as well as on ice accumulation rates in central Greenland, obtained by the GISP2 collaboration were studied in a time interval spanning about 40 000 recent years. Joint analysis of the indicated glacial and chemical paleoseries demonstrated that in a period from 12 008 to 24 008 years ago, the 10Be flux variations were most free of influence of climate and changes in the geomagnetic dipole moment. As a consequence, this time interval is most suitable for studying periodicities of purely solar nature. Statistical analysis of the 10Be flux data has revealed significant variations with periods of 500–800 years and 1300–1600 years in the time interval from 12 008 to 17 008 years ago. This evidence favors the existence of the appropriate cycles of solar activity in the mentioned epoch. Similar periodicities are also revealed in the time interval from 3288 to 8008 years ago.  相似文献   

17.
A joint analysis of paleodata on variations in cosmic ray fluxes, solar activity, geomagnetic field, and climate during the period from ～10000 to ～100000 years ago has been performed. Data on the time variations in the concentration of 14C and 10Be cosmogenic isotopes, which are generated in the Earth’s atmosphere under the action of cosmic ray fluxes modulated by solar activity and geomagnetic field variations, were used to detect variations in solar activity and the geomagnetic dipole. Information about climate changes has been obtained mainly from variations in the concentration of stable isotopes in the natural archives. A performed analysis indicates that the variations in cosmic ray fluxes under the action of variations in the geomagnetic field and solar activity are apparently one of the most effective natural factors of long-term climate changeability on a large time scale.  相似文献   

18.
An 8-m continuous sediment core, approximately 250-ky-old at the bottom, from Academician Ridge in Lake Baikal, has been analyzed for the stable isotopes of carbon, nitrogen and sulfur, in order to study the paleoclimatic and paleobiological changes that occurred in the Eurasian continental interior. These isotopic changes are closely related to changes in vertical lake-water circulation between glacial and interglacial periods. Sedimentary organic carbon in cool periods is more enriched in 13C (−23.8‰ on average) than that in warm periods (−27.0‰ on average). The 13C-enrichment of organic carbon suggests a decrease of land-derived organic matter influx to the lake, less precipitation, and loss of terrestrial vegetation around Lake Baikal in cool periods. Pyrite in high total sulfur/total organic carbon (TS/TOC) layers shows strong depletion in 34S (−20.8‰ to −32.4‰) during climate transitions from glacial to interglacial periods at the beginning of oxygen isotope stages (OIS) 1, 5 and 7. The 34S-depleted pyrite indicates augmentation of dissimilatory sulfate reduction by sulfate reducing bacteria (SRB) at the sediment-water interface. Enhancement of aqueous sulfate concentrations and limitation of oxygen circulation to the surface sediments might also occur in the climate transition periods. The δ15N values of total nitrogen increase abruptly by ∼2‰ just after the δ34S negative peaks, which may result from low nutrient concentrations in the euphotic zone associated with water circulation changes in Lake Baikal.  相似文献   

19.
We investigate here the fluctuations in the total, open and closed solar magnetic flux (SMF) for the period 1971–1999 by means of the maximum entropy method in the frequency range 5×10−9–10−7 Hz (6 yr to 120 days). We use monthly data for the total, open and closed magnetic solar fluxes. Periodicities found in the series are similar showing that there is some relationship between the fluxes. The most important finding of this work is the existence of fluctuations at around 1.3 and 1.7 yr in the SMF with alternating importance during consecutive even and odd solar cycles. These fluctuations are directly related with variations present in cosmic rays, solar wind parameters and geomagnetic activity indexes. A quasi-triennial periodicity previously found in sunspots and other solar phenomena is also of importance. The SMF is generated by the action of the solar dynamo; therefore, it is through the magnetic flux that the solar dynamo influences several heliospheric phenomena.  相似文献   

20.
Numerous studies of interrelations between solar activity and global climate changes report contradictory conclusions. The topic as such is too complex, and manifestations of the studied relationship appear to differ in time and space, and sometimes are even of the opposite sense, In this study the data on air temperature and precipitation totals from Hurbanovo, one of the oldest meteorological observatories in Europe, are used to study their evolution within the interval 1871–1995, covering solar cycles 12–22, The variability of the meteorological elements mentioned is compared with that of the sunspot number and aa index of geomagnetic activity. The sensitivity of climate changes to variable solar forcing is presented as a comparison of extreme (maximum/minimum) activity conditions. Harmonic components with periods close to the length of the solar secular and solar magnetic cycles were found in climate evolution profiles.  相似文献   

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