The global distribution of total ozone: TOMS satellite measurements

The general behavior of total ozone by season and latitude was known before 1930 through the pioneering observations by G. M. B. Dobson. The ozone record at Oxford and other European stations was dominated by an annual cycle and by irregular short term fluctuations. The amplitude and phase of the annual cycle were determined at representative latitudes in both hemispheres. However, the short term variations appeared to be of meteorological origin, although the specific cause could not be identified. Data from the Total Ozone Mapping Spectrometer (TOMS) on the Nimbus 7 spacecraft, with global coverage at an average spatial resolution of 66 km, can now be used to completely map the total ozone field. These maps demonstrate that troughs and ridges in the upper troposphere are responsible for the large, short term ozone variations found at middle latitudes, while in the troplcs, the steady, low ozone levels show broad scale structure associated with the Hadley circulation.     

Measurements of the vertical distribution of ozone by ground-based microwave techniques at the Bordeaux Observatory during the June 1981 intercomparison campaign

Spectra of the ozone emission line at 110.832 GHz were obtained by a ground-based technique using radio microwaves at the Bordeaux Observatory, France, during the Intercomparison Ozone Campaign on 19 and 26 June 1981. From the spectra, it is possible to obtain altitude profiles of the ozone concentration by a model-fitting computation method which is briefly described.The resulting profiles are given, which can be compared with other observations in the same altitude range.     

On the influence of the aerosols for satellite measurements of ozone at the thermospheric base

The dust layer at an altitude of about 80 km causes the attenuation of the light of the stars during the OAO-2 satellite observations near the horizon. This is compared with absorption due to ozone near to 2400 A in the spectral range, using ozone concentration measured by the OAO-2 satellite.     

Measurement of the vertical ozone distribution by means of an in situ gas phase chemiluminescence ozonometer during the intercomparison ozone campaign,Gap, France,June 1981

Two vertical ozone profiles have been obtained above Gap (France), with an instrument using a gas phase chemiluminescence technique. Data are given for each 0.5 km. The absolute uncertainty on the measurements increase with altitude from 8% of mixing ratio at 16 km to, at most, 15% at 38 km. Uncertainty analysis leads to an incompressible 6%. The integrated column content between 16 km and flight ceiling is also given.     

Ground-based measurements of the methane distribution on Titan

Using spectra taken with NIRSPEC (Near Infrared Spectrometer) and adaptive optics on the Keck II telescope, we resolved the latitudinal variation of the 3ν₂ band of CH₃D at 1.56 μm. As CH₃D is less abundant than CH₄ by a factor of 50±10×10^-5, these CH₃D lines do not saturate in Titan’s atmosphere, and are well characterized by laboratory measurements. Thus they do not suffer from the large uncertainties of the CH₄ lines that are weak enough to be unsaturated in Titan. Our measurements of the methane abundance are confined to the latitude range of 32°S-18°N and longitudes sampled by a 0.04″ slit centered at ∼195°W. The methane abundance below 10 km is constant to within 20% in the tropical atmosphere sampled by our observations, consistent with the low surface insolation and lack of surface methane [Griffith, C.A., McKay, C.P., Ferri, F., 2008. Astrophys. J. 687, L41-L44].     

High resolution absorption cross-section measurements of ozone at 195 K in the wavelength region 240–350 nm

Cross-sections of the Hartley-Huggins bands of 03 at the temperature 195 K have been obtained from photoabsorption measurements at column densities in the range 2 × 10¹⁷?1 × 10²¹ cm^?2 throughout the wavelength region 240–350 nm with a 6.65 m photoelectric scanning spectrometer equipped with a 2400 lines mm^?1 grating and operated at an instrumental width (FWHM) of 0.003 nm. The assumptions made in putting the measured relative cross-sections on an absolute basis are discussed. Fine structure in the cross-section observed in the Huggins bands is illustrated in the region 323–327 nm where shallow features of width 0.01–0.02 nm occur superposed on a stronger apparent continuum exhibiting broader wavy structure.     

Convective vortices on Mars: a reanalysis of Viking Lander 2 meteorological data, sols 1-60

Dust devil data from Mars is limited by a lack of data relating to diurnal dust devil behaviour. Previous work looking at the Viking Lander meteorological data highlighted seasonal changes in temporal occurrence of dust devils and gave an indication of typical dust devil diameter, size, and internal dynamics. The meteorological data from Viking Lander 2 for sols 1 to 60 have been revisited to provide detailed diurnal dust devil statistics. Results of our analysis show that the Viking Lander 2 experienced a possible 38 convective vortices in the first 60 sols of its mission with a higher occurrence in the morning compared to Earth, possibly as a result of turbulence generated by the Lander body. Dust devil events have been categorised by statistical confidence and intensity. Some initial analysis and discussion of the results is also presented. Assuming a similar dust loading to the vortices seen by Mars Pathfinder, it is estimated that the amount of dust lofted in the locality of the Lander is approximately 800 ± 10 kgsol⁻¹km⁻².     

Limits on radiative decays of solar neutrinos from measurements during a total solar eclipse

During the 1999 total solar eclipse we intended to search for photons emitted by a possible radiative decay of the heavier component of solar neutrinos, using two telescopes: an airborne one, and another at mountain altitude, in Romania(the NOTTE experiment). The weather conditions did not allow us to perform the measurements. Alternatively, we analyzed a video tape of the eclipse offered to us by a local television, obtaining some qualitative estimations on the neutrino lifetimes. We present also a first report on the observations made 21 June 2001, from Zambia. This revised version was published online in July 2006 with corrections to the Cover Date.     

Measurements of the ozone vertical distribution (0–25 km): Comparison of various instruments,Gap—Observatoire de Haute-Provence June 1981

A tentative comparison is made between the various instruments operated at Gap and at the Observatoire de Haute-Provence to measure the ozone vertical distribution up to 25 km during the Intercomparison Ozone Campaign. This includes comparison of the three ozonosondes carried on the same payload during the stratospheric open air balloon flights on 19 June and 25/26 June 1981, comparison between Brewer Mast sondes and electrochemical concentration cells on 19 and 26 June. A specific comparison has been made between a ground-based lidar and ECC sondes launched at the same location on 20/21 June 1981. Also compared are the ozone distributions as monitored between 12 June and 20 June 1981 by two ground-based instruments : lidar (active sounding) or Dobson spectrometer using the Umkehr method. Analysis of the various data set are performed in terms of relative variations observed and potential causes of discrepancies.     

Brightness distribution at the base of a coronal hole

A coronal hole was observed for three days of its passage near the central meridian of the Sun. Spectrograms containing strong lines of ionized calcium were obtained. The central intensities of the Ca II H, K, and λ849.8 nm lines in the region of the coronal hole and in the quiet-Sun region outside its boundaries were measured. Only the line profiles that were confidently identified as being undisturbed even by weak flocculi were selected. All profiles were averaged in each of the two chromospheric network components (network and cell), and the average profiles were calculated using all of the available data (network+cell). Small differences were found between the central intensities of the Ca II H and K lines inside and outside the coronal hole, with the hole being brighter than the quiet region. A detailed statistical analysis shows that these small differences are real at high confidence levels owing to the large sample sizes. A difference of the same sign is slightly noticeable in the infrared line, but its confidence level is less than 90%. The chromosphere in the coronal hole is brightened by the cell alone; in the network, the chromospheric foot of the coronal hole does not differ from the quiet region. Comparison with the results of other authors obtained from observations in higher atmospheric layers suggests that the network also contains a brightness peak that subsequently gives way to a characteristic depression, but it lies higher than that in the cell.     

Determinations of the cosmological deceleration parameter based on various quasar subsets

Published determinations of the deceleration parameter qo based on various selected subsets are reviewed and a uniform re-determination is made according to a procedure given in /1/.The resulting q₀-values from 8 largely independant samples of radio quasars all fall within the 4σ range obtained in /1/, namely, 1.0 ? q₀ ? 3.5. The most important assumption made is that the characteristic luminosity of radio quasars is independant of the cosmic epoch. Thus, unless radio quasars at earlier times were much more luminous than the later ones, the universe is probably closed.     

The radial brightness distribution of the Sun at 3.2 mm as determined from the June 30, 1973 total solar eclipse and a reanalysis of the March 7, 1970 total solar eclipse

The radial brightness distribution of the Sun at 3.2 mm is recalculated for the 7 March, 1970 total solar eclipse by an improved method. The results from the first contact of the 30 June, 1973 total eclipse are also analyzed. Limb brightening is apparent for the 1970 eclipse when all four contacts are averaged. The 1973 eclipse indicates strong limb brightening, although the detailed shape differs from the 1970 eclipse.     

The simulation of atmospheric ozone distribution with a 2-D model and validation against LIARS and TOMS data

A two-dimensional model of radiative, dynamical and photochemical processes in the atmosphere has been developed and used for the simulation of ozone distribution. The results of numerical simulations are compared with LIARS and TOMS measurements. The comparison shows that the overall agreement between simulated and LIARS stratospheric ozone data is within 5–15% for almost all of the stratosphere except for the high latitudes of the winter hemisphere. This kind of disagreement is a common problem for all 2-D models, which cannot resonably reproduce planetary and gravity wave breaking processes over high latitudes. Validation of the simulated total ozone against TOMS data also shows a good overall agreement. The the total ozone difference between the 2-D model results and TOMS measurements is within 5–10% in both Northern and Southern hemispheres during all seasons except 40°S-60°S from June to October. In this region, the difference between simulated and TOMS total ozone is 30%.     

Implications of bias evolution on measurements of the integrated Sachs–Wolfe effect: errors and biases in parameter estimation

The subject of this paper is a quantification of the impact of uncertainties in bias and bias evolution on the interpretation of measurements of the integrated Sachs–Wolfe (ISW) effect, in particular on the estimation of cosmological parameters. We carry out a Fisher matrix analysis for quantifying the degeneracies between the parameters of a dark energy cosmology and bias evolution, for the combination of the PLANCK microwave sky survey with the EUCLID main galaxy sample, where bias evolution   b ( a ) = b ₀+ (1 − a ) b_a   is modelled with two parameters b ₀ and   b_a   . Using a realistic bias model introduces a characteristic suppression of the ISW spectrum on large angular scales, due to the altered distance-weighting functions. The errors in estimating cosmological parameters if the data with evolving bias is interpreted in the framework of cosmologies with constant bias are quantified in an extended Fisher formalism. We find that the best-fitting values of all parameters are shifted by an amount comparable to the statistical accuracy: the estimation bias in units of the statistical accuracy amounts to 1.19 for Ω_m, 0.27 for σ₈ and 0.72 for w for bias evolution with   b_a = 1  . Leaving   b_a   open as a free parameter deteriorates the statistical accuracy, in particular on Ω_m and w .     

Fluctuations of energetic particle flux during solar cycle based on measurements in the solar wind,in the magnetosphere,and at Earth

We present the results of our studies of the cosmic-ray fluctuations in the frequency range 10⁻⁴−1.67 × 10⁻³ Hz based on energetic particle flux measurements on spacecraft in the solar wind, in the magnetosphere, and at Earth in the 11-year solar cycle. The cosmic-ray fluctuation spectrum is shown to have an 11-year modulation related to the solar cycle. A different behavior of the level of energetic particle fluctuations measured in different regions of space is observed for cosmic rays of different origins. We conclude that the new, previously unknown phenomenon of 11-year modulation of the cosmic-ray fluctuation spectrum has been established. A possible explanation of this phenomenon is given.     

Fluctuations of brightness and vertical velocity at various heights in the photosphere

In a spectrogram of exceptionally high spatial resolution, brightness and velocity fluctuations in seven weak to medium-strong Fe i lines have been measured and analyzed. Heights of formation of these lines have been computed using the Harvard-Smithsonian Reference Atmosphere (Gingerich et al., 1972), taking into account departures from LTE.The results show that granular velocity fluctuations decrease with increasing height up to the vicinity of the temperature minimum. If extrapolated downward to the height of formation of the continuum, the rms velocity fluctuation is 0.8 km s^-1 with an estimated error of ± 0.2 km s^-1.The correlation of continuum brightness fluctuations with velocity fluctuations decreases rapidly with height, and even becomes slightly negative at h > 160 km. This finding is consistent with the picture of the granulation consisting of convective elements overshooting into a stable atmosphere.On leave from Fraunhofer Institut, Freiburg, F.R.G.