Modeling the effect of plume-rise on the transport of carbon monoxide over Africa and its exports with NCAR CAM

International audienceWe investigated the effects of fire-induced plume-rise on the predicted export of carbon monoxide (CO) over Africa during SAFARI 2000 using the NCAR Community Atmosphere Model (CAM) with a CO tracer and plume-rise parameterization scheme. The plume-rise parameterization scheme simulates the consequences of strong buoyancy of hot gases emitted from biomass burning, including both dry and cloud-associated (pyrocumulus) lofting. The scheme was first adapted from a regional model. The current implementation of the plume-rise parameterization scheme into the global model provides an opportunity to examine the effect of plume-rise on long-range transport. The CAM simulation with the plume-rise parameterization scheme shows a substantial improvement of the agreements between the modeled and aircraft-measured vertical distribution of CO over southern Africa biomass burning area. The plume-rise mechanism plays a crucial role in lofting biomass burning pollutants to the middle troposphere. In the presence of deep convection we found that the plume-rise mechanism results in a decrease of CO concentration in the upper troposphere. The plume rise depletes the boundary layer, and thus leaves lower concentrations of CO to be lofted by the deep convection process. The effect of the plume-rise on free troposphere CO concentration is more important for the source area (short-distance transport) than for remote areas (long-distance transport). The plume-rise scheme also increases the CO export fluxes from Africa to the Atlantic and Indian Oceans. These results further confirm and extend previous findings in a regional model study. Effective lofting of large concentration of CO by the plume-rise mechanism also has implication for local air quality forecast in areas affected by other fire-related pollutants

Long-Term Stability of an Area-Reversible Atom-Interferometer Sagnac Gyroscope

We report on a study of the long-term stability and absolute accuracy of an atom interferometer gyroscope. This study included the implementation of an electro-optical technique to reverse the vector area of the interferometer for reduced systematics and a careful study of systematic phase shifts. Our data strongly suggests that drifts less than 96 $\mu$deg/hr are possible after empirically removing shifts due to measured changes in temperature, laser intensity, and several other experimental parameters.Comment: 4 pages, 4 figures, submitted to PR

Data mining: a tool for detecting cyclical disturbances in supply networks.

Disturbances in supply chains may be either exogenous or endogenous. The ability automatically to detect, diagnose, and distinguish between the causes of disturbances is of prime importance to decision makers in order to avoid uncertainty. The spectral principal component analysis (SPCA) technique has been utilized to distinguish between real and rogue disturbances in a steel supply network. The data set used was collected from four different business units in the network and consists of 43 variables; each is described by 72 data points. The present paper will utilize the same data set to test an alternative approach to SPCA in detecting the disturbances. The new approach employs statistical data pre-processing, clustering, and classification learning techniques to analyse the supply network data. In particular, the incremental k-means clustering and the RULES-6 classification rule-learning algorithms, developed by the present authors’ team, have been applied to identify important patterns in the data set. Results show that the proposed approach has the capability automatically to detect and characterize network-wide cyclical disturbances and generate hypotheses about their root cause

P-P Total Cross Sections at VHE from Accelerator Data

Comparison of P-P total cross-sections estimations at very high energies - from accelerators and cosmic rays - shows a disagreement amounting to more than 10 %, a discrepancy which is beyond statistical errors. Here we use a phenomenological model based on the Multiple-Diffraction approach to successfully describe data at accelerator energies. The predictions of the model are compared with data On the basis of regression analysis we determine confident error bands, analyzing the sensitivity of our predictions to the employed data for extrapolation. : using data at 546 and 1.8 TeV, our extrapolations for p-p total cross-sections are only compatible with the Akeno cosmic ray data, predicting a slower rise with energy than other cosmic ray results and other extrapolation methods. We discuss our results within the context of constraints in the light of future accelerator and cosmic ray experimental results.Comment: 26 pages aqnd 11 figure

Sensing endogenous seasonality in the case of a coffee supply chain

Rogue seasonality, or endogenously generated cyclicality (in variables), is common in supply chains and known to adversely affect performance. This paper explores a technique for sensing rogue seasonality at a supply chain echelon level. A signature and index based on cluster profiles of variables, which are meant to sense echelon-level generation and intensity of rogue seasonality, respectively, are proposed. Their validity is then established on echelons of a downstream coffee supply chain for five stock keeping units (SKUs) with contrasting rogue seasonality generation behaviour. The appropriateness of spectra as the domain for representing variables, data for which is daily sampled, is highlighted. Time-batching cycles which could corrupt the sensing are observed in variables, and the need to therefore filter them out in advance is also highlighted. The knowledge gained about the echelon location, intensity and time of generation of rogue seasonality could enable timely deployment of specific mitigation actions

Ornamental plants, 1979: a summary of research

An analysis of production costs for containerized nursery products / David E. Hahn, Jerry L. Robertson, and Elton M. Smith -- Monoterpene investigations with creeping juniper cultivars (Juniperus horizontalis Moench.) / Thomas A. Fretz -- Woody flora in Hokkaido adaptable to the north central United States / Makoto Kawase -- An evaluation of microfoam on plant quality following overwintering of container-grown woody ornamentals / Christopher F. Rizzo, Elton M. Smith, and Thomas A. Fretz -- Evaluation of winter barrels as a heat source in woody ornamental winter storage structures / Christopher F. Rizzo, Elton M. Smith, and Thomas A. Fretz_ -- Effective utilization of applied fertilizer in relation to multiple flushes of growth on 'Helleri' holly / C. H. Gilliam and R. D. Wright -- Tissue nitrogen changes during a growth flush on 'Helleri' holly / C. H. Gilliam and R. D. Wright -- Controlling winter annual and perennial weeds in field-grown Cotoneaster divaricata / Elton M. Smith and Sharon A. Treaster -- Evaluation of oxadiazon for weed control in container-grown nursery stock / Thomas A. Fretz and Wendy J. Sheppard -- A 10-year evaluation of flowering crabapple susceptibility to apple scab in Ohio / Elton M. Smith -- Fungicides for the control of diseases of ornamental plants: results of 1977 trials / C. C. Powell and James A. Chatfield -- An evaluation of fungicides on container-grown woody ornamentals during winter storage under microfoam / Christopher F. Rizzo, Elton M. Smith, and Thomas A. Fretz -- Resistance of maple cultivars and species to verticillium wilt: a preliminary report / H. A. J. Hoitink, T. D. Sydnor, and C. L. Wilso

Nucleation and Growth of Β′-SiAlON

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65495/1/j.1151-2916.1994.tb07042.x.pd