@PhDThesis{Henkes:2022:ObMo,
author = "Henkes, Alice Franci{\'e}li",
title = "Evolu{\c{c}}{\~a}o de nuvens rasas {\`a} convec{\c{c}}{\~a}o
profunda na esta{\c{c}}{\~a}o seca na Amaz{\^o}nia Central:
observa{\c{c}}{\~a}o e modelagem",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2022",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2021-12-14",
keywords = "camada limite atmosf{\'e}rica, esta{\c{c}}{\~a}o seca,
transi{\c{c}}{\~a}o matutina, fluxo de calor, energia
cin{\'e}tica turbulenta, atmospheric boundary layer, dry season,
morning transition, heat flux, turbulent kinetic energy.",
abstract = "Esta pesquisa teve o objetivo de investigar a evolu{\c{c}}{\~a}o
da Camada Limite Atmosf{\'e}rica (CLA) da Amaz{\^o}nia nos
regimes convectivos com transi{\c{c}}{\~a}o de nuvens cumulus
rasas para profundas (ShDeep) e sem transi{\c{c}}{\~a}o, ou
seja, com apenas forma{\c{c}}{\~a}o de nuvens convectivas
cumulus rasas (ShCu) durante a esta{\c{c}}{\~a}o seca do projeto
Green Ocean Amazon (GoAmazon) 2014-2015. Na an{\'a}lise
observacional deste trabalho, os est{\'a}gios da CLA nas
condi{\c{c}}{\~o}es ShDeep, desde o per{\'{\i}}odo noturno
at{\'e} a fase da camada de mistura com nuvens, s{\~a}o
apresentados em compara{\c{c}}{\~a}o com o regime ShCu. As
condi{\c{c}}{\~o}es din{\^a}micas e termodin{\^a}micas da
atmosfera, perfis verticais e vari{\'a}veis pr{\'o}ximo {\`a}
superf{\'{\i}}cie foram utilizados para comparar os dois regimes
de nuvens para cada est{\'a}gio da evolu{\c{c}}{\~a}o da CLA.
As observa{\c{c}}{\~o}es mostram que a dura{\c{c}}{\~a}o do
est{\'a}gio de transi{\c{c}}{\~a}o matutina {\'e} menor nos
dias ShDeep, associado com o maior conte{\'u}do integrado da
umidade e intenso cisalhamento do vento nas primeiras horas da
manh{\~a}. Dessa forma, o in{\'{\i}}cio da CLA convectiva
(camada bem misturada) ocorre mais cedo do que nos dias ShCu.
Durante o est{\'a}gio de crescimento r{\'a}pido, os movimentos
verticais mais intensos na camada sub-nuvem favorecem o
aprofundamento CLA atrav{\'e}s do qual uma parcela de ar pode
alcan{\c{c}}ar o n{\'{\i}}vel de condensa{\c{c}}{\~a}o por
levantamento, favorecendo o desenvolvimento de nuvens convectivas.
Na segunda parte deste trabalho, dois casos de estudo foram
analisados com simula{\c{c}}{\~o}es num{\'e}ricas em alta
resolu{\c{c}}{\~a}o com o modelo Mesoescale Non-Hydrostatic
model Meso-NH. Os resultados das simula{\c{c}}{\~o}es mostraram
que o local e o momento do in{\'{\i}}cio das nuvens convectivas
foram criticamente influenciados pela distribui{\c{c}}{\~a}o
vertical da umidade na CLA. Al{\'e}m disso, o efeito brisa de rio
mostrou ser crucial para o desenvolvimento de nuvens rasas para a
regi{\~a}o analisada. Com rela{\c{c}}{\~a}o a
transi{\c{c}}{\~a}o matutina, as simula{\c{c}}{\~o}es com o
Meso-NH foram consistentes com as observa{\c{c}}{\~o}es,
mostrando um in{\'{\i}}cio da CLA convectiva mais cedo no caso
ShDeep. A simula{\c{c}}{\~a}o indica que a transi{\c{c}}{\~a}o
mais r{\'a}pida para o in{\'{\i}}cio da CLA convectiva pode ser
atribu{\'{\i}}da a produ{\c{c}}{\~a}o mec{\^a}nica e
produ{\c{c}}{\~a}o t{\'e}rmica de energia cin{\'e}tica
turbulenta (TKE), associada ao maior fluxo de calor
sens{\'{\i}}vel na superf{\'{\i}}cie no processo de
eros{\~a}o da invers{\~a}o noturna. O in{\'{\i}}cio mais cedo
da CLA convectiva, devido {\`a}s condi{\c{c}}{\~o}es ambientais
mais prop{\'{\i}}cias, mostrou ter um importante efeito no
movimento vertical, TKE e instabilidade no est{\'a}gio de
crescimento r{\'a}pido da CLA convectiva. Nessa
condi{\c{c}}{\~o}es, a fase de crescimento da CLA e a
forma{\c{c}}{\~a}o de nuvens rasas s{\~a}o fortemente modulados
pela instabilidade e pela energia total dispon{\'{\i}}vel na
CLA, enquanto que a umidade na atmosfera livre {\'e} determinante
na transi{\c{c}}{\~a}o de nuvem convectiva rasa para profunda.
ABSTRACT: This work aimed to investigate the Amazonian Atmospheric
Boundary Layer (BL) on shallow convective days (ShCu) and
shallow-to-deep convective days (ShDeep) during the dry season
using a suite of ground-based measurements from the Observation
and Modeling of the Green Ocean Amazon (GoAmazon 2014/5)
Experiment and modeling results. In the observational analysis,
the BL stages in ShDeep days, from the nighttime to the cloudy
mixing layer stage, are then described in comparison with ShCu
days. Atmospheric thermodynamics and dynamics, environmental
profiles, and near-surface variables were employed to compare
these two distinct situations for each stage of the BL evolution.
Results show that the decrease in time duration of the morning
transition on ShDeep days is associated with high humidity and
well-established vertical wind shear patterns in the early morning
hours. Therefore, the onset of full convection (e.g, well-mixed
layer) is earlier on the ShDeep conditions. During the rapid
growth stage, vertical mixing in the deeper BL will entrain moist
air into the BL through which the air parcel can reach the LCL
(thus causing the first cell of shallow cumulus to emerge) and
thus favoring deep convection. In the second part of this work,
two case studies were analyzed with A 200-m grid spacing LES run
with the Mesoescale Non-Hydrostatic model Meso-NH. The results of
the simulations showed that the location and timing of convective
cloud onset were critically influenced by the vertical
distribution of moisture in the BL. In addition, the river breeze
effect has been shown to be crucial for the development of shallow
clouds for the analyzed region. In terms of the morning BL
condition, the Meso-NH is consistent with the observations,
showing an earlier onset of convective CLA on ShDeep case. The
simulation results indicates that the sorter morning transition to
the onset of convective CLA can be attributed to mechanical
production and thermal production of turbulent kinetic energy
(TKE), associated with the higher surface sensible heat flux in
the erosion process of the nocturnal inversion. Earlier onset of
convective BL, due to more favorable environmental conditions, has
been shown to have an important effect on vertical motion, TKE,
and instability in the rapid growth stage of convective BL. Under
these conditions, the BL growth phase and shallow cloud formation
are strongly modulated by instability and the total available BL
energy, while higher humidity above the BL favors the evolution
from shallow to deep cumulus clouds.",
committee = "Randow, Celso von (presidente) and Fisch, Gilberto Fernando
(orientador) and Machado, Luiz Augusto Toledo (orientador) and
Campos Velho, Haroldo Fraga de and Acevedo, Ot{\'a}vio Costa and
Dias J{\'u}nior, Cl{\'e}o Quaresma",
englishtitle = "From shallow to deep convective cloud evolution during the dry
season in the Central Amazon",
language = "pt",
pages = "117",
ibi = "8JMKD3MGP3W34T/45QKLUS",
url = "http://urlib.net/ibi/8JMKD3MGP3W34T/45QKLUS",
targetfile = "publicacao.pdf",
urlaccessdate = "04 jun. 2024"
}