Investigate the impacts of assimilating satellite rainfall estimates on rainstorm forecast over southwest United States

Using the MM5-4DVAR system, a monsoon rainstorm case over southern Arizona (5-6 August 2002) was investigated for the influence of assimilating satellite rainfall estimates on precipitation forecasts. A set of numerical experiments was conducted with multiple configurations including using 20-km or 30-km grid distances and none or 3-h or 6-h assimilation time windows. Results show that satellite rainfall assimilation can improve the rainstorm-forecasting pattern and amount to some extent. The minimization procedure of 4DVAR is sensitive to model spatial resolution and the assimilation time window. The 3-h assimilation window with hourly rainfall data works well for the 6-h forecast, and for 12-h or longer forecasts, a 6-h assimilation window will be requested. Copyright 2004 by the American Geophysical Union

Highlights of the TEXONO Research Program on Neutrino and Astroparticle Physics

This article reviews the research program and efforts for the TEXONO Collaboration on neutrino and astro-particle physics. The ``flagship'' program is on reactor-based neutrino physics at the Kuo-Sheng (KS) Power Plant in Taiwan. A limit on the neutrino magnetic moment of \munuebar < 1.3 X 10^{-10} \mub} at 90% confidence level was derived from measurements with a high purity germanium detector. Other physics topics at KS, as well as the various R&D program, are discussedComment: 10 pages, 9 figures, Proceedings of the International Symposium on Neutrino and Dark Matter in Nuclear Physics (NDM03), Nara, Japan, June 9-14, 200

Multi-level higher order QMC Galerkin discretization for affine parametric operator equations

We develop a convergence analysis of a multi-level algorithm combining higher order quasi-Monte Carlo (QMC) quadratures with general Petrov-Galerkin discretizations of countably affine parametric operator equations of elliptic and parabolic type, extending both the multi-level first order analysis in [\emph{F.Y.~Kuo, Ch.~Schwab, and I.H.~Sloan, Multi-level quasi-Monte Carlo finite element methods for a class of elliptic partial differential equations with random coefficient} (in review)] and the single level higher order analysis in [\emph{J.~Dick, F.Y.~Kuo, Q.T.~Le~Gia, D.~Nuyens, and Ch.~Schwab, Higher order QMC Galerkin discretization for parametric operator equations} (in review)]. We cover, in particular, both definite as well as indefinite, strongly elliptic systems of partial differential equations (PDEs) in non-smooth domains, and discuss in detail the impact of higher order derivatives of {\KL} eigenfunctions in the parametrization of random PDE inputs on the convergence results. Based on our \emph{a-priori} error bounds, concrete choices of algorithm parameters are proposed in order to achieve a prescribed accuracy under minimal computational work. Problem classes and sufficient conditions on data are identified where multi-level higher order QMC Petrov-Galerkin algorithms outperform the corresponding single level versions of these algorithms. Numerical experiments confirm the theoretical results

Influences of Model Parameterization Schemes on the Response of Rainfall to Soil Moisture in the Central United States

The sensitivities of soil moisture impacts on summer rainfall in the central United States to different commonly used cumulus parameterization and surface flux schemes are examined using the PSU-NCAR MMS under different atmospheric and soil moisture conditions. The cumulus convection schemes used are the Kuo and Grell parameterization schemes, while the surface-moisture flux schemes used are the aerodynamic formulation and the Simple Biosphere (SiB) Model. Results show that a transient increase in soil moisture enhanced total rainfall over the simulation domain. The increase in soil moisture enhanced local rainfall when the lower atmosphere was thermally unstable and relatively dry, but it decreased the rainfall when the atmosphere was humid and lacked sufficient thermal forcing to initiate deep convection. Soil moisture impacts were noticeably stronger for the Kuo scheme, which simulated lighter peak rainfall, than those for the Grell scheme, which simulated heavier peak rainfall. The greater sensitivity to soil moisture exhibited by the Kuo scheme than either the Grell or explicit scheme implies that it exaggerated the role of soil moisture. This difference was related to how each scheme partitioned rainfall between convective and stable forms, and possibly to each scheme\u27s closure assumptions. Adding details to the surface-moisture flux schemes had a secondary influence on soil moisture impacts on rainfall within a 24-h period

Collaborative Piano Student Recital, November 17, 1993

This is the concert program of the Collaborative Piano Student Recital on Wednesday, November 17, 1993 at 8:00 p.m., at the Concert Hall, 855 Commonwealth Avenue. Works performed were Sonata for Piano and Violin, Op. 30 No. 3 by Ludwig van Beethoven, Chanson triste by Henri Duparc, Extase by H. Duparc, L'invitation au voyage by H. Duparc, Allerseelen by Richard Strauss, Nacht by R. Strauss, Zueignung by R. Strauss, Von ewiger Liebe by Johannes Brahms, O kühler Wald by J. Brahms, and "Song to the Moon" from "Rusalka" by Antonin Dvorák. Digitization for Boston University Concert Programs was supported by the Boston University Humanities Library Endowed Fund

A preference for a non-zero neutrino mass from cosmological data

We present results from the analysis of cosmic microwave background (CMB), large scale structure (galaxy redshift survey) and X-ray galaxy cluster (baryon fraction and X-ray luminosity function) data, assuming a geometrically flat cosmological model and allowing for tensor components and a non-negligible neutrino mass. From a combined analysis of all data, assuming three degenerate neutrinos species, we measure a contribution of neutrinos to the energy density of the universe, Omega_nu h^2=0.0059^{+0.0033}_{-0.0027} (68 per cent confidence limits), with zero falling on the 99 per cent confidence limit. This corresponds to ~4 per cent of the total mass density of the Universe and implies a species-summed neutrino mass \sum_i m_i =0.56^{+0.30}_{-0.26} eV, or m_nu~0.2 eV per neutrino. We examine possible sources of systematic uncertainty in the results. Combining the CMB, large scale structure and cluster baryon fraction data, we measure an amplitude of mass fluctuations on 8h^{-1} Mpc scales of sigma_8=0.74^{+0.12}_{-0.07}, which is consistent with measurements based on the X-ray luminosity function and other studies of the number density and evolution of galaxy clusters. This value is lower than that obtained when fixing a negligible neutrino mass (sigma_8=0.86^{+0.08}_{-0.07}). The combination of CMB, large scale structure and cluster baryon fraction data also leads to remarkably tight constraints on the Hubble constant, H_0=68.4^{+2.0}_{-1.4} km/s/Mpc, mean matter density, Omega_m =0.31\pm0.02 and physical baryon density, Omega_b h^2=0.024\pm0.001, of the Universe.Comment: Final version. MNRAS, in press (9 pages, 6 figures, 1 table). Includes small modification to the neutrino mass calculation and comment on quintessence. Conclusions unchange