東華大學圖書館 |

The Dynamic Interplay between Submesoscales and Boundary Layer Turbulence.

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	The Dynamic Interplay between Submesoscales and Boundary Layer Turbulence./
作者:	Bodner, Abigail S.
面頁冊數:	1 online resource (142 pages)
附註:	Source: Dissertations Abstracts International, Volume: 83-11, Section: B.
Contained By:	Dissertations Abstracts International83-11B.
標題:	Viscosity. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=29057169click for full text (PQDT)
ISBN:	9798426866386

The Dynamic Interplay between Submesoscales and Boundary Layer Turbulence.
Bodner, Abigail S.

The Dynamic Interplay between Submesoscales and Boundary Layer Turbulence. - 1 online resource (142 pages)

Source: Dissertations Abstracts International, Volume: 83-11, Section: B.

Thesis (Ph.D.)--Brown University, 2021.

Includes bibliographical references

The ocean mixed layer plays a key role in the climate system by transferring momentum and tracers, such as heat and carbon, from the atmosphere to the ocean interior. Variations in the mixed layer depth help determine the effectiveness of atmosphere-ocean interactions, and can be attributed to surface forcing, as well as dynamical processes such as turbulent mixing, submesoscale frontal instabilities and mixed layer eddies. Theoretical work and modeling of fronts have been useful in understanding why there are so many submesoscale fronts and filaments in the ocean, but it has been less successful in predicting the scale at which these are found in observations. Current submesoscale parameterizations, which help set mixed layer depth in global climate models, depend on a simplistic scaling of frontal width that is demonstrably wrong in several circumstances. The presence of turbulence and instabilities are likely responsible for keeping fronts at the scale observed, yet a complete understanding of how and why this happens has been a long-standing problem. Building toward a more complete understanding of the processes that set this scale, the interaction between submesoscale fronts and turbulent mixing are investigated in this thesis using several platforms. First, a theoretical approach of perturbation analysis is used to include the effects of parameterized turbulence as a first order correction to classic frontogenesis (frontal sharpening) theory. A modified solution is obtained by using potential vorticity (PV) and surface conditions, which exhibit the complex nonlinear behavior of frontal dynamics. The solution reveals that vertical processes merely delay frontal sharpening, whereas horizontal processes may completely oppose frontogenesis. This qualitative approach is next extended into a more realistic environment, by diagnosing a suite of Large Eddy Simulations (LES) spanning the submesoscale and into the boundary layer (3D) turbulence scale. A surprising result emerges, revealing the limitations of PV below the submesoscale. In models where 3D turbulence is not fully resolved, PV is strongly influenced by grid-scale processes, and becomes contaminated by the least reliable scales. Pre-filtering the velocity and buoyancy fields is found to be essential in linking larger scale PV dynamics to small scale turbulent fluxes. Furthermore, in these simulations a variety of processes--winds, waves, convection, and mixed layer instabilities-are found to compete with frontogenesis. New scaling laws are developed, under different forcing parameter ranges, by relating turbulent fluxes to frontal width by making use of the turbulent thermal wind balance. The final aspect of this thesis discusses implementing the modified frontal width scaling in submesoscale parameterizations in coarse resolution climate models for which sensitivity and changes in model bias are documented.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2023

Mode of access: World Wide Web

ISBN: 9798426866386Subjects--Topical Terms:

1050706
Viscosity.
Index Terms--Genre/Form:

542853
Electronic books.

The Dynamic Interplay between Submesoscales and Boundary Layer Turbulence.
LDR:04250nmm a2200397K 4500 001 2354138
005 20230324111208.5
006 m o d
007 cr mn ---uuuuu
008 241011s2021 xx obm 000 0 eng d
020 $a 9798426866386
035 $a (MiAaPQ)AAI29057169
035 $a (MiAaPQ)Brown_bdr_emhz8tra
035 $a AAI29057169
040 $a MiAaPQ $b eng $c MiAaPQ $d NTU
100 1 $a Bodner, Abigail S. $3 3694482
245 1 4 $a The Dynamic Interplay between Submesoscales and Boundary Layer Turbulence.
264 0 $c 2021
300 $a 1 online resource (142 pages)
336 $a text $b txt $2 rdacontent
337 $a computer $b c $2 rdamedia
338 $a online resource $b cr $2 rdacarrier
500 $a Source: Dissertations Abstracts International, Volume: 83-11, Section: B.
500 $a Advisor: Fox-Kemper, Baylor.
502 $a Thesis (Ph.D.)--Brown University, 2021.
504 $a Includes bibliographical references
520 $a The ocean mixed layer plays a key role in the climate system by transferring momentum and tracers, such as heat and carbon, from the atmosphere to the ocean interior. Variations in the mixed layer depth help determine the effectiveness of atmosphere-ocean interactions, and can be attributed to surface forcing, as well as dynamical processes such as turbulent mixing, submesoscale frontal instabilities and mixed layer eddies. Theoretical work and modeling of fronts have been useful in understanding why there are so many submesoscale fronts and filaments in the ocean, but it has been less successful in predicting the scale at which these are found in observations. Current submesoscale parameterizations, which help set mixed layer depth in global climate models, depend on a simplistic scaling of frontal width that is demonstrably wrong in several circumstances. The presence of turbulence and instabilities are likely responsible for keeping fronts at the scale observed, yet a complete understanding of how and why this happens has been a long-standing problem. Building toward a more complete understanding of the processes that set this scale, the interaction between submesoscale fronts and turbulent mixing are investigated in this thesis using several platforms. First, a theoretical approach of perturbation analysis is used to include the effects of parameterized turbulence as a first order correction to classic frontogenesis (frontal sharpening) theory. A modified solution is obtained by using potential vorticity (PV) and surface conditions, which exhibit the complex nonlinear behavior of frontal dynamics. The solution reveals that vertical processes merely delay frontal sharpening, whereas horizontal processes may completely oppose frontogenesis. This qualitative approach is next extended into a more realistic environment, by diagnosing a suite of Large Eddy Simulations (LES) spanning the submesoscale and into the boundary layer (3D) turbulence scale. A surprising result emerges, revealing the limitations of PV below the submesoscale. In models where 3D turbulence is not fully resolved, PV is strongly influenced by grid-scale processes, and becomes contaminated by the least reliable scales. Pre-filtering the velocity and buoyancy fields is found to be essential in linking larger scale PV dynamics to small scale turbulent fluxes. Furthermore, in these simulations a variety of processes--winds, waves, convection, and mixed layer instabilities-are found to compete with frontogenesis. New scaling laws are developed, under different forcing parameter ranges, by relating turbulent fluxes to frontal width by making use of the turbulent thermal wind balance. The final aspect of this thesis discusses implementing the modified frontal width scaling in submesoscale parameterizations in coarse resolution climate models for which sensitivity and changes in model bias are documented.
533 $a Electronic reproduction. $b Ann Arbor, Mich. : $c ProQuest, $d 2023
538 $a Mode of access: World Wide Web
650 4 $a Viscosity. $3 1050706
650 4 $a Turbulence models. $3 3682363
650 4 $a Wind. $3 3681788
650 4 $a Fluid dynamics. $3 545210
650 4 $a Reynolds number. $3 3681436
650 4 $a Boundary conditions. $3 3560411
650 4 $a Climate change. $2 bicssc $3 2079509
650 4 $a General circulation models. $3 3694484
650 4 $a Atmospheric sciences. $3 3168354
650 4 $a Fluid mechanics. $3 528155
650 4 $a Mathematics. $3 515831
650 4 $a Mechanics. $3 525881
650 4 $a Meteorology. $3 542822
650 4 $a Physics. $3 516296
655 7 $a Electronic books. $2 lcsh $3 542853
690 $a 0404
690 $a 0725
690 $a 0204
690 $a 0405
690 $a 0346
690 $a 0557
690 $a 0605
710 2 $a ProQuest Information and Learning Co. $3 783688
710 2 $a Brown University. $b Department of Earth, Environmental, and Planetary Sciences. $3 3694483
773 0 $t Dissertations Abstracts International $g 83-11B.
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=29057169 $z click for full text (PQDT)