Modeling the temperature of the polar mesopause region: Part II—Intra-seasonal monthly oscillations     

Hans G. Mayr  John G. Mengel  Frank T. Huang  Scott M. Bailey 《Journal of Atmospheric and Solar》2009,71(3-4):508-517

Measurements show that the polar mesospheric clouds (PMC) can vary, in the zonal mean, with periods around 1 month [Bailey et al., 2005. Observations of polar mesospheric clouds by the Student Nitric Oxide Explorer. J. Geophys. Res. 110, D13203, doi:10.1029/2004JD005422]. This observation has been the impetus for the present paper, where we describe corresponding temperature oscillations generated by the Numerical Spectral Model (NSM). Our numerical results are taken from the 3D and 2D versions of the NSM, which produce inter-annual and long-term variations in the polar mesopause region, as discussed in the accompanying paper (Part I). In the NSM, the intra-seasonal temperature variations with periods around 2 months are generated by the meridional winds that in turn are accelerated by the momentum deposition from small-scale gravity waves (GW) propagating north/south. The wave-driven dynamical process underlying the oscillations is intrinsically non-linear like that generating the quasi-biennial oscillation (QBO). Our analysis demonstrates that the seasonal annual and semi-annual variations excite the oscillation frequencies through non-linear cascading.  相似文献   

Comparison of polar mesospheric cloud measurements from the Cloud Imaging and Particle Size experiment and the solar backscatter ultraviolet instrument in 2007     

Susanne Benze  Cora E. Randall  Matthew T. DeLand  Gary E. Thomas  David W. Rusch  Scott M. Bailey  James M. Russell  William McClintock  Aimee W. Merkel  Chris Jeppesen 《Journal of Atmospheric and Solar》2009,71(3-4):365-372

We compare measurements from the Aeronomy of Ice in the Mesosphere (AIM) Cloud Imaging and Particle Size (CIPS) experiment to the NOAA-17 solar backscatter ultraviolet (SBUV/2) instrument during the 2007 Northern Hemisphere polar mesospheric cloud (PMC) season. Daily average Rayleigh scattering albedos determined from identical footprints from the CIPS nadir camera and SBUV/2 agree to better than ～5% throughout the season. Average PMC brightness values derived from the two instruments agree to within ±10%. PMC occurrence frequencies are on average ～5% to nearly a factor of two higher in CIPS, depending on latitude. Agreement is best at high latitudes where clouds are brighter and more frequent. The comparisons indicate that AIM CIPS data are valid for scientific analyses. They also show that CIPS measurements can be linked to the long time series of SBUV/2 data to investigate long-term variability in PMCs.  相似文献   

Integrating a calibrated groundwater flow model with error-correcting data-driven models to improve predictions     

Yonas K. Demissie  Albert J. Valocchi  Barbara S. Minsker  Barbara A. Bailey 《Journal of Hydrology》2009,364(3-4):257-271

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A modelling study of the effects of neutral air winds on electron content at mid-latitudes in winter     

G.C. Sethia  G.J. Bailey  R.J. Moffett  J.K. Hargreaves 《Planetary and Space Science》1984,32(5):535-542

A modelling study of the effects of neutral air winds on the electron content of the mid-latitude ionosphere and protonosphere in winter has been made. The theoretical models are based on solutions of time dependent momentum and continuity equations for oxygen and hydrogen ions. The computations are compared with results from slant path observations of the ATS-6 radio beacon made at Lancaster (U.K.) and Boulder, Colorado (U.S.A.).It is found that the magnitude of the poleward neutral air wind velocity has a strong effect on the general magnitude of the electron content, but that the daily pattern of electron content variation is relatively insensitive to changes in the magnitude and phase of the wind pattern. These results are in contrast with the behaviour reported previously (Sethia et al., 1983) for summer conditions. However, the night-time electron content is increased by advancing the phase of the neutral air wind and decreased by retarding it. It appears that day-to-day variations in the electron content pattern in winter cannot be explained as effects of changing neutral air winds, which again contrasts with the findings for summer. As in summer, the wind has a major effect on the filling of the protonosphere, but in opposite sense.It is argued that the effect of the neutral air wind on the ionospheric and the protonospheric electron contents depends on the duration of the poleward wind in relation to daylight and on whether or not the wind reverses direction whilst the ionosphere is sunlit.  相似文献   

Impacts of multiple stressors on annual recruitment in striped bass (Morone saxatilis) in the Sacramento-San Joaquin estuary     

Howard C. Bailey  Carol Digiorgio  David E. Hinton 《Marine environmental research》1996,42(1-4)

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Annual variations in water storage and precipitation in the Amazon Basin   总被引：1，自引：0，他引：1  

John W. Crowley  Jerry X. Mitrovica  Richard C. Bailey  Mark E. Tamisiea  James L. Davis 《Journal of Geodesy》2008,82(1):9-13

We combine satellite gravity data from the gravity recovery and climate experiment (GRACE) and precipitation measurements from the National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center’s (CPC) Merged Analysis of Precipitation (CMAP) and the Tropical Rainfall Measuring Mission (TRMM), over the period from mid-2002 to mid-2006, to investigate the relative importance of sink (runoff and evaporation) and source (precipitation) terms in the hydrological balance of the Amazon Basin. When linear and quadratic terms are removed, the time-series of land water storage variations estimated from GRACE exhibits a dominant annual signal of 250 mm peak-to-peak, which is equivalent to a water volume change of ~1,800 km³. A comparison of this trend with accumulated (i.e., integrated) precipitation shows excellent agreement and no evidence of basin saturation. The agreement indicates that the net runoff and evaporation contributes significantly less than precipitation to the annual hydrological mass balance. Indeed, raw residuals between the de-trended water storage and precipitation anomalies range from ±40 mm. This range is consistent with stream-flow measurements from the region, although the latter are characterized by a stronger annual signal than our residuals, suggesting that runoff and evaporation may act to partially cancel each other.  相似文献   

Errors in the gerdien measurement of atmospheric electric conductivity     

Dr. R. V. Anderson  J. C. Bailey  H. Tammet 《Meteorology and Atmospheric Physics》1991,46(1-2):101-112

Summary The measurement of conductivity has been an essential part of most atmospheric electricity research programs during the past century. This measurement is known to be vulnerable to a variety of potentially significant errors which can be separated into those resulting from diffusion of ions and those produced by electrical forces. Diffusion errors are caused by inlet tubing, screens, and inlet covers; and electrically produced errors may result from the effect of the accelerating potential or the potential of the apparatus itself. Detection and quantification of these errors has been the subject of several past studies which are discussed in detail. In this paper, a series of measurements and theoretical analyses is described in which the effects of each error mechanism are isolated, measured, and analyzed, and in which prior error reduction schemes are tested. It is shown that diffusive losses in inlet ducting and structures can be significant, and analytical estimations of these losses are presented which agree well with the measurements. The losses produced by electrical forces may also be significant even when plausible ameliorative measures are taken, and operating constraints to avoid this error source are developed. Past measurements of diffusive loss are found to be consistent with these results except in one case where improper operating conditions are indicated.With 11 FiguresRetired.  相似文献   

The provenance and evolution of comets     

M. E. Bailey 《Earth, Moon, and Planets》1995,71(3):57-68

The process of comet formation through the hierarchical aggregation of originally submicron-sized interstellar grains to form micron-sized particles and then larger bodies in the protoplanetary disc, culminating in the formation of planetesimals in the disc extending from Jupiter to beyond Neptune, is briefly reviewed. The planetesimal theory for the origin of comets implies the existence of distinct cometary reservoirs, with implications for the immediate provenance of observed comets (both long-period and short-period) and their evolution as a result of planetary perturbations and physical decay, for example splitting and sublimation. The principal mode of cometary decay and collisional interaction with the terrestrial planets is through the formation and evolution of streams of cometary debris and hitherto undiscovered families of cometary asteroids. Recent dynamical results, in particular the sungrazing and sun-colliding end-state for short-period comet and asteroid orbits, are briefly discussed.  相似文献   

Climate policy strength compared: China,the US,the EU,India, Russia,and Japan     

Hugh Compston  Ian Bailey 《Climate Policy》2016,16(2):145-164

The few systematic international comparisons of climate policy strength made so far have serious weaknesses, particularly those that assign arbitrary weightings to different policy instrument types in order to calculate an aggregate score for policy strength. This article avoids these problems by ranking the six biggest emitters by far – China, the US, the EU, India, Russia, and Japan – on a set of six key policy instruments that are individually potent and together representative of climate policy as a whole: carbon taxes, emissions trading, feed-in tariffs, renewable energy quotas, fossil fuel power plant bans, and vehicle emissions standards. The results cast strong doubt on any idea that there is a clear hierarchy on climate policy with Europe at the top: the EU does lead on a number of policies but so does Japan. China, the US, and India each lead on one area. Russia is inactive on all fronts. At the same time climate policy everywhere remains weak compared to what it could be.

Policy relevance

This study enables climate policy strength, defined as the extent to which the statutory provisions of climate policies are likely to restrict GHG emissions if implemented as intended, to be assessed and compared more realistically across space and time. As such its availability for the six biggest emitters, which together account for over 70% of global CO₂ emissions, should facilitate international negotiations (1) by giving participants a better idea of where major emitters stand relative to each other as far as climate policy stringency is concerned, and (2) by identifying areas of weakness that need action.  相似文献   

The steepness and shape of wind waves     

Richard J. Bailey  Ian S. F. Jones  Yoshiaki Toba 《Journal of Oceanography》1991,47(6):249-264

Variations are found in the shape and the steepness of wind-generated surface gravity waves between very young waves, such as seen in a laboratory tank, and larger waves of various wave ages encountered at sea as the result of wind stress over larger fetches. These differences in the characteristic shape of wind waves are presented as a function of the wave age. The wave steepness is also expressed as a function of wave age, the measurement of which is consistent with the 3/2-power law connecting wave height and characteristic period, normalized by the air friction velocity.  相似文献