Lagrangian Tools to Study Transport and Mixing in the Ocean

2017 ◽  
pp. 95-115 ◽  
Author(s):  
Sergey V. Prants ◽  
Michael Yu. Uleysky ◽  
Maxim V. Budyansky
Keyword(s):  
Transport And Mixing

Large Eddy Simulation of the fuel transport and mixing process in a scramjet combustor with rearwall-expansion cavity

2016 ◽  
Vol 126 ◽  
pp. 375-381 ◽  
Author(s):  
Zun Cai ◽  
Xiao Liu ◽  
Cheng Gong ◽  
Mingbo Sun ◽  
Zhenguo Wang ◽  
...  
Keyword(s):  
Large Eddy Simulation ◽  
Mixing Process ◽  
Eddy Simulation ◽  
Scramjet Combustor ◽  
Large Eddy ◽  
Transport And Mixing

scholarly journals Probability density functions of long-lived tracer observations from satellite in the subtropical barrier region: data intercomparison

2011 ◽  
Vol 11 (20) ◽  
pp. 10579-10598 ◽  
Author(s):  
E. Palazzi ◽  
F. Fierli ◽  
G. P. Stiller ◽  
J. Urban
Keyword(s):  
Michelson Interferometer ◽  
Morphological Structure ◽  
Quasi Biennial Oscillation ◽  
Temporal Sampling ◽  
Region Data ◽  
Summer Hemisphere ◽  
Consistent Picture ◽  
Transport And Mixing ◽  
The One ◽  
Satellite Instruments

Abstract. Past studies have shown that a clear relationship exists between the field of a passive tracer and the Probability Distribution Function (PDF) of tracer concentrations, which can be exploited to identify the position and variability of stratospheric barriers to isentropic mixing. In the present study, we focus on the dynamical barrier located in the subtropics. We calculate PDFs of the long-lived tracers nitrous oxide (N2O) and methane (CH4) from different satellite instruments: the Microwave Limb Sounder (MLS) on board Aura, the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on board Envisat, the Sub-Millimetre Radiometre (SMR) on board Odin and the Halogen Occultation Experiment (HALOE) on board UARS, overall covering the time period of 1992–2009. An analysis of the consistency among the different sets of data and their capability of identifying mixing regions and barrier-to-transport regions in the stratosphere and the subtropical barrier location is a prime aim of the present study. This is done looking at the morphological structure of the one- and two-dimensional PDFs of tracer concentrations measured by the different instruments. The latter differ in their spatial and temporal sampling and resolution, and there are some systematic differences in the determination of the subtropical barrier position that have been highlighted. However, the four satellite instruments offer an overall consistent picture of the subtropical barrier annual cycle. There is a strong seasonality consistently represented, characterized by the wintertime shift of the subtropical edge toward the summer hemisphere. However, the influence of the Quasi Biennial Oscillation (QBO) on isentropic transport and mixing, and by consequence, on the position of the subtropical barrier, is not equally represented in all satellite data using the methodology proposed.

scholarly journals Multi-decadal Records of Stratospheric Composition and their Relationship to Stratospheric Circulation Change

2017 ◽  
Author(s):  
Anne R. Douglass ◽  
Susan E. Strahan ◽  
Luke D. Oman ◽  
Richard S. Stolarski
Keyword(s):  
Transport Model ◽  
Atmospheric Composition ◽  
Model Driven ◽  
Earth Observing System ◽  
Circulation Change ◽  
Decadal Scale ◽  
Stratospheric Circulation ◽  
Transport And Mixing ◽  
Stratospheric Composition ◽  
Modern Era

Abstract. Constituent evolution for 1990–2015 simulated using the Global Modeling Initiative Chemistry and Transport Model driven by meteorological fields from the Modern Era Retrospective analysis for Research and Applications Version 2 (MERRA-2) is compared with three sources of observations: ground based column measurements of HNO3 and HCl from two stations in the Network for Detection of Atmospheric Composition Change (NDACCC, ~ 1990–ongoing); profiles of CH4 from the HALogen Occultation Experiment (HALOE) on the Upper Atmosphere Research Satellite (UARS, 1992–2005); profiles of N2O from the Microwave Limb Sounder on the Earth Observing System satellite Aura (2015–ongoing). The differences between observed and simulated values are shown to be time dependent, with better agreement after ~2000 compared with the prior decade. Furthermore, the differences between observed and simulated HNO3 and HCl columns are shown to be correlated with each other, suggesting that issues with the simulated transport and mixing cause the differences during the 1990s and these issues are less important during the later years. Because the simulated fields are related to mean age in the lower stratosphere, we use these comparisons to evaluate the time dependence of mean age. We use these relationships to account for dynamical variability when determining decadal scale trends in constituents and mean age. The ongoing NDACC column observations provide critical information necessary to substantiate trends in mean age obtained using fields from MERRA-2 or any other reanalysis products.

scholarly journals Hydrodynamic Processes in Massive Stars

2008 ◽  
Vol 4 (S252) ◽  
pp. 439-449 ◽  
Author(s):  
Casey A. Meakin
Keyword(s):  
Stellar Evolution ◽  
Magnetized Plasma ◽  
Mixing Properties ◽  
New Era ◽  
Linear Set ◽  
Star Evolution ◽  
Hydrodynamic Processes ◽  
Stellar Interiors ◽  
Transport And Mixing ◽  
Massive Star Evolution

AbstractThe hydrodynamic processes operating within stellar interiors are far richer than represented by the best stellar evolution model available. Although it is now widely understood, through astrophysical simulation and relevant terrestrial experiment, that many of the basic assumptions which underlie our treatments of stellar evolution are flawed, we lack a suitable, comprehensive replacement. This is due to a deficiency in our fundamental understanding of the transport and mixing properties of a turbulent, reactive, magnetized plasma; a deficiency in knowledge which stems from the richness and variety of solutions which characterize the inherently non-linear set of governing equations. The exponential increase in availability of computing resources, however, is ushering in a new era of understanding complex hydrodynamic flows; and although this field is still in its formative stages, the sophistication already achieved is leading to a dramatic paradigm shift in how we model astrophysical fluid dynamics. We highlight here some recent results from a series of multi-dimensional stellar interior calculations which are part of a program designed to improve our one-dimensional treatment of massive star evolution and stellar evolution in general.

Factors Affecting Transport and Mixing in Estuaries

2018 ◽  
pp. 543-568
Author(s):  
James L. Martin ◽  
Steven C. McCutcheon ◽  
Robert W. Schottman
Keyword(s):  
Factors Affecting ◽  
Transport And Mixing

Flow transport and mixing induced by horizontal jets impinging on a vertical wall of the multi-compartment PANDA facility

2010 ◽  
Vol 240 (8) ◽  
pp. 2054-2065 ◽  
Author(s):  
Domenico Paladino ◽  
Robert Zboray ◽  
Michele Andreani ◽  
Jörg Dreier
Keyword(s):  
Vertical Wall ◽  
Flow Transport ◽  
Transport And Mixing

scholarly journals The impact of overshooting deep convection on local transport and mixing in the tropical upper troposphere/lower stratosphere (UTLS)

2015 ◽  
Vol 15 (11) ◽  
pp. 6467-6486 ◽  
Author(s):  
W. Frey ◽  
R. Schofield ◽  
P. Hoor ◽  
D. Kunkel ◽  
F. Ravegnani ◽  
...  
Keyword(s):  
Lower Stratosphere ◽  
Deep Convection ◽  
Horizontal Resolution ◽  
Transport Processes ◽  
Convective System ◽  
Upper Troposphere ◽  
Tropical Tropopause Layer ◽  
Tropical Tropopause ◽  
Transport And Mixing ◽  
The Impact

Abstract. In this study we examine the simulated downward transport and mixing of stratospheric air into the upper tropical troposphere as observed on a research flight during the SCOUT-O3 campaign in connection with a deep convective system. We use the Advanced Research Weather and Research Forecasting (WRF-ARW) model with a horizontal resolution of 333 m to examine this downward transport. The simulation reproduces the deep convective system, its timing and overshooting altitudes reasonably well compared to radar and aircraft observations. Passive tracers initialised at pre-storm times indicate the downward transport of air from the stratosphere to the upper troposphere as well as upward transport from the boundary layer into the cloud anvils and overshooting tops. For example, a passive ozone tracer (i.e. a tracer not undergoing chemical processing) shows an enhancement in the upper troposphere of up to about 30 ppbv locally in the cloud, while the in situ measurements show an increase of 50 ppbv. However, the passive carbon monoxide tracer exhibits an increase, while the observations show a decrease of about 10 ppbv, indicative of an erroneous model representation of the transport processes in the tropical tropopause layer. Furthermore, it could point to insufficient entrainment and detrainment in the model. The simulation shows a general moistening of air in the lower stratosphere, but it also exhibits local dehydration features. Here we use the model to explain the processes causing the transport and also expose areas of inconsistencies between the model and observations.

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