Nocturnal Boundary Layer Erosion Analysis in the Amazon Using Large-Eddy Simulation during GoAmazon Project 2014/5

Carneiro, Rayonil Gomes; Fisch, Gilberto; Neves, Theomar T. A. T.; Santos, Rosa Maria Nascimento dos; Santos, Carla; Borges, Camilla Kassar

doi:10.3390/atmos12020240

Cited by 6 publications

(10 citation statements)

References 54 publications

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“…In addition, the times when precipitation occurred were also identified in the daily visual profiles, and then the zi data during these events were disregarded. After identifying the zi values, we removed outlier values that were outside a range considered appropriate for the Amazon region (i.e., heights higher than 2.5 km during daytime) [30]. It is worth stating that the NBL heights can be overestimated, as the instrument can mistake the residual layer for the top of the ABL [14].…”

Section: Methodsmentioning

confidence: 99%

“…This calculation was performed with the data collected between 08:00 and 10:00 LT. This interval was selected because it is observed that there is an approximately linear growth during this ABL phase (see Figure 3), after the NBL is completely eroded [30]. In the next step, we performed a visual inspection of all the daily cycles of the ABL height.…”

Section: Methodsmentioning

confidence: 99%

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Long-Term Measurements of the Atmospheric Boundary Layer Height in Central Amazonia Using Remote Sensing Instruments

et al. 2023

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The height (zi) of the Atmospheric Boundary Layer (ABL) is a fundamental parameter for several areas of knowledge, especially for weather and climate forecasting, pollutant dispersion and air quality. In this work, we used data from a remote sensing instrument (ceilometer), located at the experimental site of the Amazon Tall Tower Observatory (ATTO) in the Central Amazonia rainforest, in order to obtain the height of the ABL. Data used were obtained from 2014 to 2020, with the exception of the year 2017. The results showed that the zi average varies from year to year (interannual variability) and the average of the maximum zi values (zi_max) was approximately 1400 ± 277 m, occurring at 15:00 local time. In addition, it was found that these maximum heights are higher in the dry season and during El Niño years (about 1741 ± 242 m) and they are lower during the wet period and in La Niña years (1263 ± 229 m). Taking into account all the years investigated, the month with the highest zi_max value is September (1710 ± 253 m), and the month with the lowest value is May (1108 ± 152 m). Finally, it was observed that the growth rate of the ABL during the early hours after sunrise varies from month to month (intraseasonal variability), reaching its maximum values in September and October (about 210 ± 53 m h−1 and 217 ± 59 m h−1, respectively) and minimum values in April and July (approximately 159 ± 48 m h−1 and 159 ± 50 m h−1, respectively). It is concluded that the values of zi in Central Amazonia are influenced by several seasonal factors (temperature, cloud cover, turbulent heat flux, etc.) which gives it a wide variability in terms of heights and growth rates. Additionally, a linear regression was proposed in order to model the maximum zi value as a function of its growth rate from 08:00 LT (Local Time) up to 10:00 LT. The results showed a good correlation compared with the experimental values.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Long-Term Measurements of the Atmospheric Boundary Layer Height in Central Amazonia Using Remote Sensing Instruments

et al. 2023

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“…In terms of modeling, previous studies [30,31] identified that the choice of PBL schemes is significant for PBLH simulation, especially at nighttime. Moreover, the appropriate depiction of nocturnal stable and morning transition stages is crucial to reproduce adequately the daytime PBL development [38].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of PBL Parameterization Schemes in WRF Model Predictions during the Dry Season of the Central Amazon Basin

et al. 2023

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Planetary Boundary Layer (PBL) parameterization schemes are employed to handle subgrid-scale processes on atmospheric models, playing a key role in accurately representing the atmosphere. Recent studies have shown that PBL schemes are particularly fundamental to the depiction of PBL height (PBLH), especially over the Amazon. In the present study, we investigated the performance of PBL schemes on the representation of meteorological variables, turbulent fluxes, PBL vertical structures, and PBLH over the central Amazon basin under dry conditions, taking advantage of observations from the Observations and Modeling of the Green Ocean Amazon campaign (GoAmazon2014/5) for validation and evaluation. Numerical experiments were carried out within the WRF model using eight PBL schemes for two dry periods from 2014 (typical year) and 2015 (El-Niño year), and results from the 1-km resolution domain were directly compared to hourly in situ observations. In general, all PBL schemes present good performance to reproduce meteorological variables, with nonlocal (local) PBL schemes producing better performance in the 2014 (2015) study period. All PBL schemes in general overestimate (>100%) daytime turbulent fluxes. Thermodynamic (daytime) vertical structures are better predicted than mechanical (nocturnal) ones. The local MYNN2.5 scheme showed the overall best performance for PBLH prediction, mainly at night.

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“…It is important for improving the numerical weather forecast, climate modelling, and air pollution predictions. Unfortunately, large-eddy simulation (LES) studies of the morning transition (e.g., Beare 2008;Carneiro et al 2021) revealed no signs of the presence of wave activity. Another recent comprehensive LES study by Jiang (2021) showed that KHBs in an elevated shear layer (ESL) influence the underlying atmospheric layer enhancing turbulence due to the secondary instability, increasing its depth and weakening stratification; a possible impact appears to be dependent on both ESL and lower ABL characteristics.…”

Section: Introductionmentioning

confidence: 99%

Kelvin–Helmholtz Billows in the Rising Turbulent Layer During Morning Evolution of the ABL at Dome C, Antarctica

Petenko

Casasanta

Kallistratova

et al. 2023

Boundary-Layer Meteorol

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Kelvin–Helmholtz billows (KHBs) within a rising turbulent layer during the transition period from stable to unstable stratification occurring in the morning hours in summertime at the interior of Antarctica (Dome C, Concordia station) are examined in this study. The wave pattern captured by high-resolution sodar echograms from November 2014–February 2015 exhibits regular braid-like structures, associated with Kelvin–Helmholtz shear instabilities. This phenomenon is observed in more than 70% of days in the selected period. Two main regimes of the morning evolution with KHBs are identified roughly, distinguished by the presence or absence of turbulence in the preceding night-time. The weather and turbulent conditions favouring the occurrence of these regimes are analyzed. Also, two distinct patterns of KHBs are identified: (i) quasi-periodical (with periods ≈ 8–15 min) trains containing 5–10 braids, (ii) about continuous series lasting 20–90 min containing 20–80 braids. A composite shape of KHBs is determined. The periodicity of these waves is estimated to be between 20 and 70 s, and their wavelength is estimated roughly to be 100–400 m. The vertical thickness of individual braids at the wave crests ranges between 5 and 25 m. The total depth of a rising turbulent layer containing these waves varies between 15 and 120 m, and the ratio of the wavelength to the depth of the wave layer varies from 3 to 12 with a mean value ≈ 8.2. The morphology of the turbulence structure in the ABL is studied as a function of both temperature and wind field characteristics retrieved from an instrumented 45-m tower and an ultrasonic anemometer-thermometer at 3.5 m. The observational results highlight the necessity of considering the interaction between convective and wave processes when occurring simultaneously.

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Nocturnal Boundary Layer Erosion Analysis in the Amazon Using Large-Eddy Simulation during GoAmazon Project 2014/5

Cited by 6 publications

References 54 publications

Long-Term Measurements of the Atmospheric Boundary Layer Height in Central Amazonia Using Remote Sensing Instruments

Long-Term Measurements of the Atmospheric Boundary Layer Height in Central Amazonia Using Remote Sensing Instruments

Evaluation of PBL Parameterization Schemes in WRF Model Predictions during the Dry Season of the Central Amazon Basin

Kelvin–Helmholtz Billows in the Rising Turbulent Layer During Morning Evolution of the ABL at Dome C, Antarctica

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