HALOE science investigation

The Halogen Occulation Experiment (HALOE) gas response test simulations were completed using the HALOE spectroscopic instrument model. A new series of programs were written for routine repetitive runs of the spectroscopic model to make it more user friendly for certain studies. Some of the limitations of the model were eased for atmospheric studies. Atmospheric signal profiles were calculated for inclusion in the electronic model programs. Analysis of additional spectral bands of CO2 in the 3 micron region was continued. A program of measurement of the air broadened halfwidths of spectral lines in the nu (sub 3) fundamental band of CH4 was started and over 40 lines measured

Gaussian quadrature exponential sum modeling of near infrared methane laboratory spectra obtained at temperatures from 106 to 297 K

Transmission measurements made on near-infrared laboratory methane spectra have previously been fit using a Malkmus band model. The laboratory spectra were obtained in three groups at temperatures averaging 112, 188, and 295 K; band model fitting was done separately for each temperature group. These band model parameters cannot be used directly in scattering atmosphere model computations, so an exponential sum model is being developed which includes pressure and temperature fitting parameters. The goal is to obtain model parameters by least square fits at 10/cm intervals from 3800 to 9100/cm. These results will be useful in the interpretation of current planetary spectra and also NIMS spectra of Jupiter anticipated from the Galileo mission

Strong electronic correlations in Lix_xZnPc organic metals

Nuclear magnetic resonance, electron paramagnetic resonance and magnetization measurements show that bulk Li$_x$ZnPc are strongly correlated one-dimensional metals. The temperature dependence of the nuclear spin-lattice relaxation rate $1/T_1$ and of the static uniform susceptibility $\chi_S$ on approaching room temperature are characteristic of a Fermi liquid. Moreover, while for $x\simeq 2$ the electrons are delocalized down to low temperature, for $x\to 4$ a tendency towards localization is noticed upon cooling, yielding an increase both in $1/T_1$ and $\chi_s$. The $x$-dependence of the effective density of states at the Fermi level $D(E_F)$ displays a sharp enhancement for $x\simeq 2$, at the half filling of the ZnPc lowest unoccupied molecular orbitals. This suggests that Li$_x$ZnPc is on the edge of a metal-insulator transition where enhanced superconducting fluctuations could develop.Comment: 5 pages, 4 figure

Universality of rain event size distributions

We compare rain event size distributions derived from measurements in climatically different regions, which we find to be well approximated by power laws of similar exponents over broad ranges. Differences can be seen in the large-scale cutoffs of the distributions. Event duration distributions suggest that the scale-free aspects are related to the absence of characteristic scales in the meteorological mesoscale.Comment: 16 pages, 10 figure

The pursuit of isotopic and molecular fire tracers in the polar atmosphere and cryosphere

We present an overview of recent multidisciplinary, multi-institutional efforts to identify and date major sources of combustion aerosol in the current and paleoatmospheres. The work was stimulated, in part, by an atmospheric particle \u27sample of opportunity\u27 collected at Summit, Greenland in August 1994, that bore the 14C imprint of biomass burning. During the summer field seasons of 1995 and 1996, we collected air filter, surface snow and snowpit samples to investigate chemical and isotopic evidence of combustion particles that had been transported from distant fires. Among the chemical tracers employed for source identification are organic acids, potassium and ammonium ions, and elemental and organic components of carbonaceous particles. Ion chromatography, performed by members of the Climate Change Research Center (University of New Hampshire), has been especially valuable in indicating periods at Summit that were likely to have been affected by the long range transport of biomass burning aerosol. Univariate and multivariate patterns of the ion concentrations in the snow and ice pinpointed surface and snowpit samples for the direct analysis of particulate (soot) carbon and carbon isotopes. The research at NIST is focusing on graphitic and polycyclic aromatic carbon, which serve as almost certain indicators of fire, and measurements of carbon isotopes, especially 14C, to distinguish fossil and biomass combustion sources. Complementing the chemical and isotopic record, are direct \u27visual\u27 (satellite imagery) records and less direct backtrajectory records, to indicate geographic source regions and transport paths. In this paper we illustrate the unique way in which the synthesis of the chemical, isotopic, satellite and trajectory data enhances our ability to develop the recent history of the formation and transport of soot deposited in the polar snow and ice

Atlas of high resolution infrared spectra of carbon dioxide, February 1983

A long path, low pressure laboratory spectrum of carbon dioxide is presented for the spectral region 1830 to 2010/cm. The data were recorded at 0.01/cm resolution and room temperature with the Fourier transform spectrometer in the McMath solar telescope complex at Kitt Peak National Observatory. A list of positions and assignments is given for the 1038 lines observed in this region. A total of 30 bands and subbands of 12C16O2, 13C16O2, 12C16O18O, 12C16O17O, and 13C16O18O were observed

Atlas of high resolution infrared spectra of carbon dioxide

An atlas of long-path room-temperature absorption spectra of carbon dioxide is presented for the spectral intervals 1830-2100 cm, 2395-2680 cm, and 3140-3235 cm. The spectral data were recorded at high signal to noise with the 0.01 cm resolution Fourier transform interferometer. The spectra were obtained with pressures between 1 and 10 Torr of CO2 and with total paths between 24 and 384 meters. A compilation of the measured line positions and the assignments derived from the analysis are presented. Of the 3336 lines in the atlas, 94 percent were identified as CO2 lines or as residual lines H2O and CO. Calculated positions are presented for the carbon dioxide lines; a total of 52 bands of C-12O2-16, C-13O2-16, C-12O-16O-18, C-12O-16O-17, and C-13O-16O18 were identified. The weakest carbon dioxide lines marked in the atlas have intensities of approximately 0.5 x 10 to the negative 26th power cm/molecule at room temperature