气候变化领域集成服务门户(CCPortal): Planetary boundary layer evolution over the Amazon rainforest in episodes of deep moist convection at the Amazon Tall Tower Observatory

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DOI	10.5194/acp-20-15-2020
	Planetary boundary layer evolution over the Amazon rainforest in episodes of deep moist convection at the Amazon Tall Tower Observatory
	Oliveira M.I.; Acevedo O.C.; Sörgel M.; Nascimento E.L.; Manzi A.O.; Oliveira P.E.S.; Brondani D.V.; Tsokankunku A.; Andreae M.O.
发表日期	2020
ISSN	1680-7316
起始页码	15
结束页码	27
卷号	20 期号:1
英文摘要	In this study, high-frequency, multilevel measurements, performed from late October to mid-November of 2015 at a 80m tall tower of the Amazon Tall Tower Observatory (ATTO) project in the central state of Amazonas, Brazil, were used to diagnose the evolution of thermodynamic and kinematic variables as well as scalar fluxes during the passage of outflows generated by deep moist convection (DMC). Outflow associated with DMC activity over or near the tall tower was identified through the analysis of storm echoes in base reflectivity data from an S-band weather radar at Manaus, combined with the detection of gust fronts and cold pools utilizing tower data. Four outflow events were selected, three of which took place during the early evening transition or nighttime hours and one during the early afternoon. Results show that the magnitude of the drop in virtual potential temperature and changes in wind velocity during outflow passages vary according to the type, organization, and life cycle of the convective storm. The nocturnal events had well-defined gust fronts with moderate decreases in virtual potential temperature and increases in wind speed. The early afternoon event lacked a sharp gust front and only a gradual drop in virtual potential temperature was observed, probably because of weak or undeveloped outflow. Sensible heat flux (H) increased at the time of the gust front arrival, which was possibly due to the sinking of colder air. This was followed by a prolonged period of negative H, associated with enhanced nocturnal negative H in the wake of the storms. In turn, increased latent heat flux (LE) was observed following the gust front, owing to drier air coming from the outflow; however, malfunctioning of the moisture sensors during rain precluded a better assessment of this variable. Substantial enhancements of turbulent kinetic energy (TKE) were observed during and after the gust front passage, with values comparable to those measured in grass fire experiments, evidencing the highly turbulent character of convective outflows. The early afternoon event displayed slight decreases in the aforementioned quantities in the passage of the outflow. Finally, a conceptual model of the time evolution of H in nocturnal convective outflows observed at the tower site is presented. © Author(s) 2020.
语种	英语
scopus关键词	atmospheric convection; boundary layer; kinetic energy; moisture transfer; rainforest; thermodynamics; turbulent flow; Amazonas [Brazil]; Brazil; Manaus
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/248073
作者单位	Universidade Federal Santa Maria, Departamento de Física, Santa Maria-RS, Brazil; Max Planck Institute for Chemistry, P.O. Box 3060, Mainz, 55020, Germany; Instituto Nacional de Pesquisas da Amazônia (INPA), Clima e Ambiente (CLIAMB), Av. André Araújo 2936, Manaus-AM, CEP 69083-000, Brazil; Scripps Institution of Oceanography, University of California San Diego, San Diego, CA, United States; Center for Analysis and Prediction of Storms, School of Meteorology, University of Oklahoma, Norman, OK, United States
推荐引用方式 GB/T 7714	Oliveira M.I.,Acevedo O.C.,Sörgel M.,et al. Planetary boundary layer evolution over the Amazon rainforest in episodes of deep moist convection at the Amazon Tall Tower Observatory[J],2020,20(1).
APA	Oliveira M.I..,Acevedo O.C..,Sörgel M..,Nascimento E.L..,Manzi A.O..,...&Andreae M.O..(2020).Planetary boundary layer evolution over the Amazon rainforest in episodes of deep moist convection at the Amazon Tall Tower Observatory.ATMOSPHERIC CHEMISTRY AND PHYSICS,20(1).
MLA	Oliveira M.I.,et al."Planetary boundary layer evolution over the Amazon rainforest in episodes of deep moist convection at the Amazon Tall Tower Observatory".ATMOSPHERIC CHEMISTRY AND PHYSICS 20.1(2020).