scholarly journals Characteristic time scales of UV and IR auroral emissions at Jupiter and Saturn and their possible observable effects

2019 ◽  
Author(s):  
Chihiro Tao ◽  
Sarah V. Badman ◽  
Masaki Fujimoto
Keyword(s):  
Time Scales ◽  
Characteristic Time ◽  
Auroral Emissions

scholarly journals Characteristics of Large-Scale Orographic Precipitation in a Linear Perspective

2011 ◽  
Vol 12 (1) ◽  
pp. 27-44 ◽  
Author(s):  
Michael Kunz
Keyword(s):  
Time Scales ◽  
Characteristic Time ◽  
Large Scale ◽  
Linear Perspective ◽  
Horizontal Wind ◽  
Small Scale ◽  
Orographic Precipitation ◽  
Observation Data ◽  
Horizontal Wind Speed ◽  
Precipitation Patterns

Abstract Simulations of orographic precipitation over the low mountain ranges of southwestern Germany and eastern France with two different physics-based linear precipitation models are presented. Both models are based on 3D airflow dynamics from linear theory and consider advection of condensed water and leeside drying. Sensitivity studies for idealized conditions and a real case study show that the amount and spatial distribution of orographic precipitation is strongly controlled by characteristic time scales for cloud and hydrometeor advection and background precipitation due to large-scale lifting. These parameters are estimated by adjusting the model results on a 2.5-km grid to observed precipitation patterns for a sample of 40 representative orography-dominated stratiform events (24 h) during a calibration period (1971–80). In general, the best results in terms of lowest rmse and bias are obtained for characteristic time scales of 1600 s and background precipitation of 0.4 mm h−1. Model simulations of a sample of 84 events during an application period (1981–2000) with fixed parameters demonstrate that both models are able to reproduce quantitatively precipitation patterns obtained from observations and reanalyses from a numerical model [Consortium for Small-scale Modeling (COSMO)]. Combining model results with observation data shows that heavy precipitations over mountains are restricted to situations with strong atmospheric forcings in terms of synoptic-scale lifting, horizontal wind speed, and moisture content.

scholarly journals Superconducting fluctuations and characteristic time scales in amorphous WSi

2018 ◽  
Vol 97 (17) ◽  
Author(s):  
Xiaofu Zhang ◽  
Adriana E. Lita ◽  
Mariia Sidorova ◽  
Varun B. Verma ◽  
Qiang Wang ◽  
...  
Keyword(s):  
Time Scales ◽  
Characteristic Time ◽  
Superconducting Fluctuations

scholarly journals Properties of Phase Solitons in an Optically Driven Semiconductor Ring Laser

2019 ◽  
Vol 9 (20) ◽  
pp. 4351
Author(s):  
Ghafour Hashemvand Shakarab ◽  
Reza Kheradmand ◽  
Mohammad Agha Bolorizadeh ◽  
Franco Prati
Keyword(s):  
Time Scales ◽  
Propagation Velocity ◽  
Ring Laser ◽  
Characteristic Time ◽  
Carrier Lifetime ◽  
Large Range ◽  
Semiconductor Ring Laser

A semiconductor ring laser with a long cavity supports propagating localised structures with a chiral charge, named phase solitons. In this paper we study the dependence of the velocity and of the duration of the phase solitons on the characteristic time scales of the laser, namely the photon lifetime and the carrier lifetime. We show numerically that phase solitons are stable over a large range of those parameters and verify that the propagation velocity decreases linearly with the ratio of the carrier lifetime to the photon lifetime, while the duration is proportional to the ratio of the carrier lifetime to the cavity roundtrip time.

Characteristic time scales for the adsorption process for fibrinogen on silica

Langmuir ◽  
1992 ◽  
Vol 8 (2) ◽  
pp. 514-517 ◽  
Author(s):  
P. Schaaf ◽  
P. Dejardin ◽  
A. Johner ◽  
A. Schmitt
Keyword(s):  
Time Scales ◽  
Characteristic Time ◽  
Adsorption Process

scholarly journals TESS photometry of extreme helium stars PV Tel and V821 Cen

2020 ◽  
Vol 495 (1) ◽  
pp. L135-L138 ◽  
Author(s):  
C Simon Jeffery ◽  
Geert Barentsen ◽  
Gerald Handler
Keyword(s):  
Light Curve ◽  
Time Scales ◽  
Characteristic Time ◽  
Satellite Observations ◽  
Light Curves ◽  
Single Site ◽  
Helium Stars ◽  
First Time

ABSTRACT PV Tel variables are extreme helium (EHe) stars known to be intrinsic light and velocity variable on characteristic time-scales of 0.1–25 d. With two exceptions, they are best described as irregular. Light curves have invariably been obtained from single-site terrestrial observatories. We present Transiting Exoplanet Survey Satellite observations of two bright EHe stars, Popper’s star (V821 Cen) and Thackeray’s star (PV Tel). PV Tel is variable on time-scales previously reported. V821 Cen is proven to be variable for the first time. Neither light curve shows any evidence of underlying regularity. Implications are considered.

TERRESTRIAL VEGETATION COVER ACTIVITY AS A PROBLEM OF FLUCTUATING SURFACES

2009 ◽  
Vol 23 (28n29) ◽  
pp. 5444-5452 ◽  
Author(s):  
ROSA COPPOLA ◽  
VINCENZO CUOMO ◽  
MARIAGRAZIA D'EMILIO ◽  
MARIA LANFREDI ◽  
MARGHERITA LIBERTI ◽  
...  
Keyword(s):  
Time Series ◽  
Land Cover ◽  
Time Scales ◽  
Vegetation Cover ◽  
Land Surface ◽  
Characteristic Time ◽  
Climate Models ◽  
Terrestrial Vegetation ◽  
Radiative Balance ◽  
Persistence Properties

The role of vegetation cover within the processes that link land and atmosphere is of stringent interest for the correct modeling of Climate dynamics. Temporal and spatial correlation of the terrestrial coverage varies according to Climate and acts as a major forcing on it through changes in surface energy and water balance as well as in the carbon cycle. Recent studies have enhanced the actual and potential impact of this forcing on the radiative balance thus evidencing effects that are at least comparable to that due to all the anthropogenic greenhouse gases together. At now, observational studies on land cover dynamics are strongly in progress thanks to satellite data. The availability of continuous observations of the land surface can allow us to understand the correlation structure, both in time and in space, that characterizes the land cover activity. Satellites provide time series of photosynthetic activity measures that can be regarded as a succession of observations of a two-dimensional scalar field. We exploited the paradigm of fluctuating surfaces as a mechanic analogue for our problem. To capture vegetation cover characteristic time-scales, persistence properties were evaluated by analysing annual maps of NDVI-AVHRR time series and persistence probability was estimated by using the sing-time distribution methodology. The analysis performed for ecoregions of Italian and Greek territories evidenced signatures of short range persistence with characteristic time scales that depend on land cover, climate, and anthropic activities. Our results confirm that such an approach can provide a useful parameterisation for including vegetation into climate models as a dynamical component.

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