Jovian Auroral Ion Precipitation: Field-Aligned Currents and Ultraviolet Emissions

2018 ◽  
Author(s):  
S. J. Houston ◽  
N. Ozak ◽  
J. Young ◽  
T. E. Cravens ◽  
D. R. Schultz
Keyword(s):  
Precipitation Field ◽  
Ultraviolet Emissions

scholarly journals Modeling the Variability of Drop Size Distributions in Space and Time

2007 ◽  
Vol 46 (6) ◽  
pp. 742-756 ◽  
Author(s):  
Gyu Won Lee ◽  
Alan W. Seed ◽  
Isztar Zawadzki
Keyword(s):  
Drop Size ◽  
Temporal Structure ◽  
Space Time ◽  
Cascade Model ◽  
Time Variability ◽  
Size Distributions ◽  
Precipitation Field ◽  
Stochastic Fluctuations ◽  
Taylor Hypothesis ◽  
Drop Size Distributions

Abstract The information on the time variability of drop size distributions (DSDs) as seen by a disdrometer is used to illustrate the structure of uncertainty in radar estimates of precipitation. Based on this, a method to generate the space–time variability of the distributions of the size of raindrops is developed. The model generates one moment of DSDs that is conditioned on another moment of DSDs; in particular, radar reflectivity Z is used to obtain rainfall rate R. Based on the fact that two moments of the DSDs are sufficient to capture most of the DSD variability, the model can be used to calculate DSDs and other moments of interest of the DSD. A deterministic component of the precipitation field is obtained from a fixed R–Z relationship. Two different components of DSD variability are added to the deterministic precipitation field. The first represents the systematic departures from the fixed R–Z relationship that are expected from different regimes of precipitation. This is generated using a simple broken-line model. The second represents the fluctuations around the R–Z relationship for a particular regime and uses a space–time multiplicative cascade model. The temporal structure of the stochastic fluctuations is investigated using disdrometer data. Assuming Taylor hypothesis, the spatial structure of the fluctuations is obtained and a stochastic model of the spatial distribution of the DSD variability is constructed. The consistency of the model is validated using concurrent radar and disdrometer data.

Westward-propagating Rossby modes in idealized GCMs

2021 ◽  
Author(s):  
Pablo Zurita-Gotor ◽  
Isaac M. Held
Keyword(s):  
General Circulation ◽  
Surface Friction ◽  
General Circulation Models ◽  
Convective Heating ◽  
Smoothing Algorithm ◽  
Precipitation Field ◽  
Background Spectrum ◽  
Spectral Peaks ◽  
Nonlinear Smoothing ◽  
State Of Rest

AbstractThis work investigates the characteristics of westward-propagating Rossby modes in idealized global general circulation models. Using a nonlinear smoothing algorithm to estimate the background spectrum and an objective method to extract the spectral peaks, the 4 leading meridional modes can be identified for each of the first 3 zonal wavenumbers, with frequencies close to the predictions from the Hough modes obtained by linearizing about a state of rest. Variations in peak amplitude for different modes, both within a simulation and across simulations, may be understood under the assumption that the forcing of the modes scales with the background spectrum. Surface friction affects the amplitude and width of the peaks but both remain finite as friction goes to zero, which implies that some other mechanism, arguably nonlinear, must also contribute to the damping of the modes. Although spectral peaks are also observed for the precipitation field with idealized moist physics, there is no evidence of mode enhancement by the convective heating. Subject to the same friction, the amplitude of the peaks are very similar in the dry and moist models when both are normalized by the background spectra.

Sensitized Ce3+and Gd3+Ultraviolet Emissions by Tm3+in Colloidal LiYF4Nanocrystals

2009 ◽  
Vol 15 (38) ◽  
pp. 9660-9663 ◽  
Author(s):  
Venkataramanan Mahalingam ◽  
Rafik Naccache ◽  
Fiorenzo Vetrone ◽  
John A. Capobianco
Keyword(s):  
Ultraviolet Emissions

Mechanism of photoluminescence quenching in visible and ultraviolet emissions of ZnO nanowires decorated with gold nanoparticles

2019 ◽  
Vol 58 (5) ◽  
pp. 051005 ◽  
Author(s):  
Keshuang Zheng ◽  
Zhipeng Zhang ◽  
Ximiao Wang ◽  
Runze Zhan ◽  
Huanjun Chen ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Zno Nanowires ◽  
Photoluminescence Quenching ◽  
Ultraviolet Emissions

About 335 nm Ultraviolet Emissions Obtained from Simple Metal–Insulator–Semiconductor Light‐Emitting Tunnel Diodes

2020 ◽  
pp. 2000524
Author(s):  
Chen-Sheng Lin ◽  
Duncan W. E. Allsopp ◽  
Kate Cavanagh ◽  
Hei Chit Leo Tsui ◽  
Ling-Shan Yu ◽  
...  
Keyword(s):  
Tunnel Diodes ◽  
Simple Metal ◽  
Metal Insulator ◽  
Metal Insulator Semiconductor ◽  
Light Emitting ◽  
Ultraviolet Emissions

Atmospheric tides and periodic variations in the precipitation field

1986 ◽  
Vol 9 (3) ◽  
pp. 729-760 ◽  
Author(s):  
G. Cevolani ◽  
P. Bacci ◽  
P. Bonelli ◽  
C. Isnardi
Keyword(s):  
Atmospheric Tides ◽  
Precipitation Field

scholarly journals IMERG V06: Changes to the Morphing Algorithm

2019 ◽  
Vol 36 (12) ◽  
pp. 2471-2482 ◽  
Author(s):  
Jackson Tan ◽  
George J. Huffman ◽  
David T. Bolvin ◽  
Eric J. Nelkin
Keyword(s):  
Large Scale ◽  
Numerical Models ◽  
Precipitable Water ◽  
Passive Microwave ◽  
Precipitation Field ◽  
Motion Vectors ◽  
Surface Precipitation ◽  
General Improvement ◽  
Lagrangian Interpolation ◽  
Cloud Tops

AbstractAs the U.S. Science Team’s globally gridded precipitation product from the NASA–JAXA Global Precipitation Measurement (GPM) mission, the Integrated Multi-Satellite Retrievals for GPM (IMERG) estimates the surface precipitation rates at 0.1° every half hour using spaceborne sensors for various scientific and societal applications. One key component of IMERG is the morphing algorithm, which uses motion vectors to perform quasi-Lagrangian interpolation to fill in gaps in the passive microwave precipitation field using motion vectors. Up to IMERG V05, the motion vectors were derived from the large-scale motions of infrared observations of cloud tops. This study details the changes introduced in IMERG V06 to derive motion vectors from large-scale motions of selected atmospheric variables in numerical models, which allow IMERG estimates to be extended from the 60°N–60°S latitude band to the entire globe. Evaluation against both instantaneous passive microwave retrievals and ground measurements demonstrates the general improvement in the precipitation field of the new approach. Most of the model variables tested exhibited similar performance, but total precipitable water vapor was chosen as the source of the motion vectors for IMERG V06 due to its competitive performance and global completeness. Continuing assessments will provide further insights into possible refinements of this revised morphing scheme in future versions of IMERG.

Observation of 280 nm and 298 nm ultraviolet emissions in sodium vapor

1989 ◽  
Vol 48 (5) ◽  
pp. 421-426 ◽  
Author(s):  
T. S. Yih ◽  
H. H. Wu ◽  
H. S. Wang ◽  
Y. L. Chen
Keyword(s):  
Sodium Vapor ◽  
Ultraviolet Emissions
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