The atmospheric effects of stratospheric aircraft. Report of the 1992 Models and Measurements Workshop. Volume 3: Special diagnostic studies

This Workshop on Stratospheric Models and Measurements (M&M) marks a significant expansion in the history of model intercomparisons. It provides a foundation for establishing the credibility of stratospheric models used in environmental assessments of chlorofluorocarbons, aircraft emissions, and climate-chemistry interactions. The core of the M&M comparisons involves the selection of observations of the current stratosphere (i.e., within the last 15 years): these data are believed to be accurate and representative of certain aspects of stratospheric chemistry and dynamics that the models should be able to simulate

On the observed changes in upper stratospheric and mesospheric temperatures from UARS HALOE

Temperature versus pressure or <I>T(p)</I> time series from the Halogen Occultation Experiment (HALOE) of the Upper Atmosphere Research Satellite (UARS) have been extended and re-analyzed for the period of 1991–2005 and for the upper stratosphere and mesosphere in 10-degree wide latitude zones from 60 S to 60 N. Even though sampling from a solar occultation experiment is somewhat limited, it is shown to be quite adequate for developing both the seasonal and longer-term variations in <I>T(p)</I>. Multiple linear regression (MLR) techniques were used in the re-analyses for the seasonal and the significant interannual, solar cycle (SC-like or decadal-scale), and linear trend terms. Plots of the amplitudes and phases for the interannual (QBO and subbiennial) terms are provided. A simple SC-like term of 11-yr period was fitted to the time series residuals after accounting for the seasonal and interannual terms. Highly significant SC-like responses were found for both the upper mesosphere and the upper stratosphere. The phases of these SC-like terms were checked for their continuity with latitude and pressure-altitude; the larger amplitude responses are directly in-phase with that of standard proxies for the solar flux variations. The analyzed, max minus min, responses at low latitudes are of order 0.5 to 1 K, while at middle latitudes they are as large as 3 K in the upper mesosphere. Highly significant, linear cooling trends were found at middle latitudes of the middle to upper mesosphere (−1.5 to −2.0 K/decade), at tropical latitudes of the lower mesosphere (about −0.5 K/decade), and at 2 hPa (of order −1 K/decade). Both the diagnosed solar cycle responses and trends from HALOE for the mid to upper mesosphere at middle latitudes are larger than simulated with most models, perhaps an indication of decadal-scale dynamical forcings that are not being simulated so well

The Nimbus 7 LIMS (Limb Infrared Monitor of the Stratosphere) water vapor measurements

Earth orbital instruments, designed to measure the vertical and spatial distribution of atmospheric water vapor is discussed. Specifically, the operation of the Limb Infrared Monitor of the Stratosphere (LIMS) experiment is examined. The LIMS is a six channel limb scanning radiometer that was launched aboard Nimbus 7 in 1978. Profiles of stratospheric and mesospheric temperature, water vapor, and various other constituents were obtained by inverting the LIMS radiance measurements. This same technique was used in 1981 to analyze the data returned from another limb scanning radiometer aboard the Solar Mesosphere Explorer

Biochemical And Functional Studies Of Histone Deacetylase 3 In Metabolic Tissues

Organismal physiology is built upon the foundation of molecular processes. A central axis to maintaining homeostasis in vivo is at the level of gene regulation. Tissue specific gene expression is created at the level of epigenetics, where proteins guided by tissue specific DNA binding proteins create a chromatin landscape for precise gene programs. Understanding these molecular processes is of vital importance to understand the underpinning pathologies, such as metabolic syndrome, which are a growing medical concern and require greater research efforts in order to tackle its challenges. A major epigenetic regulator is histone deacetylase 3 (HDAC3), which is a core member of the nuclear receptor corepressor (NCoR) complex. This ubiquitously expressed chromatin associated protein complex functions to repress target gene transcription. Here we address the functional role of HDAC3 in β-cells of adult mice. An HDAC3 β-cell specific knockout was generated using the MIP-CreERT transgenic mouse model and while HDAC3 β-cell specific deletion did not increase total pancreatic insulin content, the mice demonstrated markedly improved glucose tolerance and increased glucose-stimulated insulin secretion. Cistromic and transcriptomic analyses of pancreatic islets revealed that HDAC3 regulated multiple genes that contribute to glucose-stimulated insulin secretion. Furthermore, using mass spectrometry in conjunction of cistromic analyses of interactors we have characterized the interactome of HDAC3 and detailed its function in mammalian liver. We identified PROX1 as an abundant interactor which is corecruited with HDAC3 by HNF4a in liver to corepress gene transcription important for maintenance of lipid homeostasis. Lastly, as we continue to explore the protein-protein interaction networks of these critical factors, novel tools are proving to be invaluable to their investigation. The advent of CRISPR-Cas9 genome editing has allowed for reliable and simple design and generation of mouse models. Therefore we have employed this technology to generate a variety of epitope tagged mouse models with the goal of comparing their tissue specific interactomes. This body of work includes a wide breadth of biological techniques that have succeeded in advancing knowledge of HDAC3 function in vivo, vital to our understanding of molecular pathology in diabetes and obesity

Acceptance Corrections and Extreme-Independent Models in Relativistic Heavy Ion Collisions

Kopeliovich's suggestion [nucl-th/0306044] to perform nuclear geometry (Glauber) calculations using different cross sections according to the experimental configuration is quite different from the standard practice of the last 20 years and leads to a different nuclear geometry definition for each experiment. The standard procedure for experimentalists is to perform the nuclear geometry calculation using the total inelastic N-N cross section, which results in a common nuclear geometry definition for all experiments. The incomplete acceptance of individual experiments is taken into account by correcting the detector response for the probability of measuring zero for an inelastic collision, which can often be determined experimentally. This clearly separates experimental issues such as different acceptances from theoretical issues which should apply in general to all experiments. Extreme-Independent models are used to illustrate the conditions for which the two methods give consistent or inconsistent results.Comment: 4 pages, 1 figure, published in Physical Review

Lidar backscattering measurements of background stratospheric aerosols

A comparative lidar-dustsonde experiment was conducted in San Angelo, Texas, in May 1974 in order to estimate the uncertainties in stratospheric-aerosol backscatter for the NASA Langley 48-inch lidar system. The lidar calibration and data-analysis procedures are discussed. Results from the Texas experiment indicate random and systematic uncertainties of 35 and 63 percent, respectively, in backscatter from a background stratospheric-aerosol layer at 20 km

A diagnostic model for studying daytime urban air quality trends

A single cell Eulerian photochemical air quality simulation model was developed and validated for selected days of the 1976 St. Louis Regional Air Pollution Study (RAPS) data sets; parameterizations of variables in the model and validation studies using the model are discussed. Good agreement was obtained between measured and modeled concentrations of NO, CO, and NO2 for all days simulated. The maximum concentration of O3 was also predicted well. Predicted species concentrations were relatively insensitive to small variations in CO and NOx emissions and to the concentrations of species which are entrained as the mixed layer rises

Stratospheric models and measurements: A critical comparison

The stated objectives of the High Speed Research Program/Atmospheric Effects of Stratospheric Aircraft (AESA) initiative are to support research in the atmospheric sciences that will improve the basic understanding of the circulation and chemistry of the stratosphere and lead to interim assessments of the impact of a projected fleet of HSCT's on the stratosphere. Three model comparison workshops have been conducted, so far, in support of this goal. These workshops have been focused on the differences between models used to calculate the atmospheric effects of the proposed aircraft emissions. It is now possible to test these models against atmospheric data

On the Observed Changes in Upper Stratospheric and Mesospheric Temperatures from UARS HALOE

Temperature versus pressure or T(p) time series from the Halogen Occultation Experiment (HALOE) on the Upper Atmosphere Research Satellite (UARS) have been extended and re-analyzed for the period of 1991-2005 and for the upper stratosphere and mesosphere in 10-degree wide latitude zones from 60S to 60N. Even though sampling from a solar occultation experiment is somewhat limited, it is shown to be quite adequate for developing both the seasonal and longer-term variations in T(p). Multiple linear regression (MLR) techniques were used in the re-analyses for the seasonal and the significant interannual, solar cycle (SC-like or decadal-scale), and linear trend terms. A simple SC-like term of 11-yr period was fitted to the time series residuals after accounting for the seasonal and interannual terms. Highly significant SC-like responses were found for both the upper mesosphere and the upper stratosphere. The phases of these SC-like terms were checked for their continuity with latitude and pressure-altitude, and in almost all cases they are directly in-phase with that of standard proxies for the solar flux variations. The analyzed, max minus min, responses at low latitudes are of order 1 K, while at middle latitudes they are as large as 3 K in the upper mesosphere. Highly significant, linear cooling trends were found at middle latitudes of the middle to upper mesosphere (about -2 K/decade), at tropical latitudes of the middle mesosphere (about -1 K/decade), and at 2 hPa (or order -1 K/decade)