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1.
In this paper we
introduce the results of our investigations for some new methods of the automatic
observation forecast、data
processing and research,IncludingAutomatic
forecast and capture of solar flare events;A method in drawing light curves of solar flares with high
accuracy;A method for
the automatic observation of solar active regions etc. 相似文献
2.
Two parameters,the smoothed sunspot numbers in the eleventh month during
rising phase of the current cycle and the length month of the minimum period (R<14),are selected to predict the
maximum-value of sunspot number of cycle 23 in this paper. The predicted maximum-values of
smoothed sunspot number are 115<Ri<149 and 114<Ri<146 also predicted by
statistical method. The peak-time will be from September,1999 to March,2000,and the end-time will be from August,2006 to April,2008. 相似文献
3.
A correlation between
the coronal mass ejection(CME) and the meter wavelength radio bursts is analyzed in this
paper. It is found that type Ⅱ and type Ⅳ bursts
have very good correlation with CME. Noise storms occur several tens minutes before the
onset of the moving type Ⅳ bursts. A sudden stop of noise storms can be used as a sign to foresee the
possibility of a following CME. The three kinds of the moving type Ⅳ
also introduced in this present papersolated source type,the expanding-arc moving Ⅳ type and the advancing front
type. 相似文献
4.
The article analysizes
the current situation and opportunity of the development of radioheliograph in China. It
provides an idea to construct the radioheliograph by three stepsfrom small sized,to middle sized,then tobig sized. Each step is to construct a complete
radioheliograph. The article also analysizes some important technical performance,such as diameter of element
antenna,overall
pointing error and observing frequency. 相似文献
5.
Using the characteristic
values of sunspot number variations during the descent and ascent of solar cycles,a neural network is designed to
make long-term predications of the ascending period and the maximum smoothed monthly mean
sunspot number for the Solar Cycle 23. Moreover,the factor of geomagnetic disturbance is also added as an
input. The trained and tested results from Solar Cycle 12 to 22 have been obtained.
Finally,the
predictions of the ascending period and the maximum smoothed monthly mean sunspot number
are given for Solar Cycle 23. 相似文献
6.
《地球物理学进展》1999,14(1):32
In the paper,the effects of short-term
prediction techniques of solar activity of the World Warning Agency (W) and Beijing
Astronomical Observatory in 1970s(B7) and 1990s(B9) were analyzed statistically by the
standard of the effects of the persistance prediction technique(CH) in the same periods of
time. A Q-index evaluating effects of prediction has been put forward;the index indicates the synthesis of positive effects of
correct forecasts and negative effects of false forecasts. Against the persistence
prediction (CH),the
effects of WWA prediction (W),BAO prediction using 1970s' technique (B7) and 1990s' technique (B9) during the
same periods of time as (CH) have been evaluated by the Q-index. Based on the above,we have advanced a concrete
scientific way to improve the short-term prediction technique. Especially,we have raised that in order to
improve prediction technique,the results of persistence prediction should become the basic component of
short-term prediction of solar activity;namely,present prediction of forecasting the levels of solar
activity should be transformed to forecast the coming change of solar activity levels with
the aim of using the effects of persistence prediction fully. 相似文献
7.
Usually,because of the Starkbroadening
for the spectrum lines,the half widths of hydrogen higher Balmer emission lines of the solar flare
increase with the principal quantum number N. Their variation curve,as observed before,has a minimum value near N=8 or 9. However,a curve for the solar flare which
occurred at the limb of solar disk on June 12,1982shows an all-time decline with increasing N. How to
explain this phenomena remains to be discussed. 相似文献
8.
An introduction to the
instrumonts to be used for solar radio observations in Beijing in Solar Cycle 23 is made
in this paper. They are 10cm solar radio telescope which has been used for a long time,and 1.0～2.0GHz,2.6～3.8GHz and 5.2～7.6GHz spectrometers. The former two spectrometers has
passed a test,showing
high guality,and the
5.2～7.6GHz one will
be in operation from 1999. It is believed that highl gualified data should be obtained in
the next solar cycle. 相似文献
9.
In this paper,5 proton events and corresponding
active regions in the descending phase of Solar Cycle 22(1993～1995) are analysed. The result shows that (1)The proton
flares in 1993～1995
occurred mainly in the longitudy zone of 140～270 degree. (2)4 of 5 events (80%) studied have their
small magnetic fluxes to disappear in their magnetic flux regions with a major polarity,one day before the event. (3)It
is 60% of the event studied to show characteristic of the merging of 2 or greater than 2
magnetic fluxes with similar polarity in their active regions,one day before of the proton
event. The results are possibly useful for the short-term prediction of proton events. 相似文献
10.
A Solar and interplanetary observational system composed of
two artificial planets and the earth is suggested for the solar-terrestrial study and
prediction.The two planets should move along the earth's orbit around the sun. The angle
distance between the two planets and between them with the earth is 120°. This system can
be used to improve greatly the short-term,midiu-mterm solar activity predictions and monitor an
earth-toward coronal mass ejection,giving an accurate warning of a solar-terrestrial
disturbance. Observational data obtained by this system would be very useful in a model
work of solar wind and an evolution study of structures in solar atmosphere such as solar
active regions and magnetic fields with various scales. 相似文献
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Gtz Schroth Luciana Ferreira Da Silva Marc‐Andree Wolf Wenceslau Geraldes Teixeira Wolfgang Zech 《水文研究》1999,13(10):1423-1436
The partitioning of rain water into throughfall, stemflow and interception loss when passing through plant canopies depends on properties of the respective plant species, such as leaf area and branch angles. In heterogeneous vegetation, such as tropical forest or polycultural systems, the presence of different plant species may consequently result in a mosaic of situations with respect to quantity and quality of water inputs into the soil. As these processes influence not only the water availability for the plants, but also water infiltration and nutrient leaching, the understanding of plant effects on the repartitioning of rain water may help in the optimization of land use systems and management practices. We measured throughfall and stemflow in a perennial polyculture (multi‐strata agroforestry), monocultures of peach palm (Bactris gasipaes) for fruit and for palmito, a monoculture of cupuaçu (Theobroma grandiflorum), spontaneous fallow and primary forest during one year in central Amazonia, Brazil. The effect on rain water partitioning was measured separately for four useful tree species in the polyculture and for two tree species in the primary forest. Throughfall at two stem distances, and stemflow, differed significantly between tree species, resulting in pronounced spatial patterns of water input into the soil in the polyculture system. For two tree species, peach palm for fruit (Bactris gasipaes) and Brazil nut trees (Bertholletia excelsa), the water input into the soil near the stem was significantly higher than the open‐area rainfall. This could lead to increased nutrient leaching when fertilizer is applied close to the stem of these trees. In the primary forest, such spatial patterns could also be detected, with significantly higher water input near a palm (Oenocarpus bacaba) than near a dicotyledonous tree species (Eschweilera sp.). Interception losses were 6·4% in the polyculture, 13·9 and 12·3% in the peach palm monocultures for fruit and for palmito, respectively, 0·5% in the cupuaçu monoculture and 3·1% in the fallow. With more than 20% of the open‐area rainfall, the highest stemflow contributions to the water input into the soil were measured in the palm monocultures and in the fallow. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
18.
M. N. French R. L. Bras W. F. Krajewski 《Stochastic Environmental Research and Risk Assessment (SERRA)》1992,6(1):27-45
A procedure for short-term rainfall forecasting in real-time is developed and a study of the role of sampling on forecast ability is conducted. Ground level rainfall fields are forecasted using a stochastic space-time rainfall model in state-space form. Updating of the rainfall field in real-time is accomplished using a distributed parameter Kalman filter to optimally combine measurement information and forecast model estimates. The influence of sampling density on forecast accuracy is evaluated using a series of a simulated rainfall events generated with the same stochastic rainfall model. Sampling was conducted at five different network spatial densities. The results quantify the influence of sampling network density on real-time rainfall field forecasting. Statistical analyses of the rainfall field residuals illustrate improvement in one hour lead time forecasts at higher measurement densities. 相似文献
19.
M. A. Kahn 《洁净——土壤、空气、水》2000,28(2):95-101
Red tide, a recurrent phenomenon has become conspicuous in several Kashmir lake ecosystems since 1991. The responsible organism (Euglena pedunculata), a rare flagellate rediscovered in the Kashmir Himalaya (Khan 1993) caused first and unprecedented red tide outbreak, constituting a maximum of 96% of resident numerical phytoplankton density in Dal Lake. At present, conflicting hypotheses exist on the generation of causal assemblage(s) imparting redness to waters: Jeeji Bai (1991) linked its origin to acid precipitation – a fallout of burning oil‐fields during the Gulf War – whilst Khan (1993) holds local factor(s) responsible. Field/experimental studies support the latter contention that the influx of untreated sewage, in unison with warm temperatures, high levels of PhAR, iron and interruption to hydrological flow‐pattern together with absence/or reduction in grazing activity created conducive environmental milieu for red tide outbreak. Dal Lake “red tide” drifted the bloom‐inoculum to other waters, including Lake Wular, where additional ecological niches were carved out, threatening the aesthetic value and biological diversity of Kashmir lakes. Ecological monitoring indicates frequent seasonal red tide occurrence in Dal Lake (including summer‐autumn event of 1998) which testifies its unabated eutrophication status. Further studies are needed on ecological adaptability and biogeographic distribution of this rare and unique red tide‐causing flagellate. 相似文献
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