A correlation study between ozone and volcanic activity

A cross-correlation study for time-lags of ±5 yrs between eleven ground based ozone stations (1957–1985) for = 40°N–75° N and = 30° E-114° W and five volcanic emissivity indices has shown their close connection: significant correlations well above 90% were obtained. Intepretation of these positive/negative correlations () was based on the global wind circulation (aided also by a 2-D, 3-D representation between, , ), and the types of volcanic aerosols leading to heterogeneous chemical reactions with ozone.     

The distribution of solar flares and probable relations to biological effects

We have compared the monthly distribution of the total number of flares to the monthly mortality from cardiovascular and myocardial infarctions for the time period 1974–1983, and computed correlation coefficients. Periodicities of 3 and 5 months (150 days) have been found in both distributions.     

A spectroscopic study of solar spicules in Hα, Hβ and K

Simultaneous spectra of spicules in H, H and the Ca ii K have been analyzed. These spectra were obtained with the échelle spectrograph of Sacramento Peak Observatory and have a resolution of 1.5 s of arc. Data include absolute intensities, velocities, linewidths and the optical depth at the center of H. Electron densities range between 6 × 10¹⁰cm^–3 and 1.2 × 10¹¹cm^–3, while the range of the electron temperature is between 12000K and 15000K at a height of 5400 km above the limb. The analysis of the variation of the line of sight velocity across spicules shows that their rotation is very small. There is very good correlation in the structure of all three lines.     

Periodicities of the number of solar flares for the period 1966–1988

In the present paper a study is made of the mean monthly number of grouped solar flaresf for the time period 1966–1988. Corresponding dataF were taken from the catalogue published by Coffey (1989). Periodicities of 140, 120, 48, 18, 12, and 11 months as well as shorter periodicities of the order of 6 and 3 months for the solar flares have been found. The emphasis is given as far as it concerns the period of 48 months, i.e., 4 years which is for the first time revealed by the present investigation.     

A method predicting the earthquake-induced landslide risk by back analyses of past landslides and its application in the region of the Wenchuan 12/5/2008 earthquake

The work considers critical slopes located at regions with high danger and proposes a method which approximately predicts the risk of earthquake-induced excessive movement of these slopes, in the case where relevant soil strength data along their slip surface do not exist. The method utilizes (1) simplified constitutive equations predicting soil response along slip surfaces and (2) a multi-block sliding system model, both recently proposed. It involves the following steps: (a) collect relevant topographic information and laboratory test results of past landslides at the region of interest, (b) (i) analyze the relevant laboratory tests to estimate the soil constitutive parameters and (ii) estimate the mobilized residual soil strength by back analysis of relevant past landslides, (c) select constitutive model parameters for future applications at the region based on step (b) and validate them based on analysis of the triggering of the past landslides and (d) apply the selected constitutive model parameters in critical slopes in the region under consideration to predict not only whether triggering occurs, but also the post-triggering slide deformation. The paper, after describing in detail the proposed method, applies it at the Wenchuan region, where the 12th May 2008 earthquake triggered many landslides. During the application, four ring shear test results and twelve landslides of the 12th May 2008 earthquake were considered. The application was successful and the following were observed: (i) in the back analyses, the multi-block model predicted reasonably well the final configuration of all slides, (ii) apart from two significantly larger back-estimated values of the residual soil strength, small scatter existed in the other back-estimated values and (iii) the selected model parameters were duly validated under step (c). Furthermore, as the back-estimated friction angle of most landslides was less than 18°, and the materials along the slip surface have a Liquid Limit value less than 25 %, it is inferred that some, or all of the slip surface during these slides, was sheared in an undrained manner.     

Rocket sonde-derived stratospheric temperature changes associated with a major solar cosmic ray event

A significant cooling of the upper stratosphere at high latitudes following the major solar proton event of August 1972 is reported. The observed cooling is consistent with a decrease in upper stratospheric ozone after the same proton event that has been reported by Heath,et al. (1977). It is also in agreement with the cooling predicted by tentative model calculations of radiative equilibrium temperature changes following the deozonizing effect of nitric oxides produced at high latitudes by solar protons.     

Examining the physical meaning of the bank erosion coefficient used in meander migration modeling

Widely used models of meander evolution relate migration rate to vertically averaged near-bank velocity through the use of a coefficient of bank erosion (E). In applications to floodplain management problems, E is typically determined through calibration to historical planform changes, and thus its physical meaning remains unclear. This study attempts to clarify the extent to which E depends on measurable physical characteristics of the channel boundary materials using data from the Sacramento River, California, USA. Bend-average values of E were calculated from measured long-term migration rates and computed near-bank velocities. In the field, unvegetated bank material resistance to fluvial shear (k) was measured for four cohesive and noncohesive bank types using a jet-test device. At a small set of bends for which both E and k were obtained, we discovered that variability in k explains much of the variability in E. The form of this relationship suggests that when modeling long-term meander migration of large rivers, E depends largely on bank material properties. This finding opens up the possibility that E may be estimated directly from field data, enabling prediction of meander migration rates for systems where historical data are unavailable or controlling conditions have changed. Another implication is that vegetation plays a limited role in affecting long-term meander migration rates of large rivers like the Sacramento River. These hypotheses require further testing with data sets from other large rivers.     

Possible periodicities of high-speed solar plasma

We have made a statistical analysis of the monthly numbers of high-velocity solar wind streamers observed by the time period 1964–1978.The following periods have been found: