Observational Characteristics of Low-Level Jets in Central Western Mexico

Abstract

During field experiments using surface weather stations and a Sodar-RASS (radio acoustic sounding system) combination, low-level jets were observed in the Colima Valley of central western Mexico. These low-level jet events have not been previously observed in this part of the tropics. The present study focuses on events from one specific field period from December 2011 to April 2013 performed at a specific location. From this dataset, it was found that these phenomena typically develop at night at around 0300 local time and they reach their maximum speed 20 min after sunrise and end at 1100 local time. For the considered period, low-level jet events occurred during 88 % of nights, and most of these events were fully characterized; thus, 73 % of the nights presented with categorized lowlevel jets following the classical literature on this mesoscale phenomenon in other parts of the world. The low-level wind maxima occurred with events ranging from category sub-zero to category 3. The strongest category 3 events are around 25 m s −1 and the longest event was 57.5 h, but they are more typical of category 1. Their average speed is 11.7 m s −1 and their height distribution is bimodal, with a group of events occurring at lower levels, with an average height of 190 m; higher levels have a mean height of 480 m. The higher cases are more typical of the rainy season. During all seasons, their direction is predominantly from the north-north-west to north-north-east with some dispersion occurring during the rainy season. The region of study is typically considered to have low wind speeds in the atmospheric boundary layer, making these events super-geostrophic.

Low‐Level Jets Over the Bohai Sea and Yellow Sea: Climatology, Variability, and the Relationship With Regional Atmospheric Circulations

“…This contributes to the aridity and dryness of some coastal regions such as the Peruvian coastal desert strip (Nicholson, 2010;Warner, 2004). LLJs are also significant for human activities, such as aviation safety, offshore wind energy applications, sound propagation, fishery resources, and the transport of pollutants (Arfeuille et al, 2015;Nunalee & Basu, 2013). frequent during the warm seasons from April to October and are greatly influenced by the sloping terrain of the Rocky Mountains.…”

Observational Investigation of the Low‐Level Jets in the Metropolitan Region of São Paulo, Brazil

“…The LLJs have been observed in different parts of the world, more frequently in the Great Plains, USA (Banta et al., 2002; Berg et al., 2015; Du et al., 2014; Klein et al., 2016; Lundquist & Mirocha, 2008; Parish, 2017; Shapiro et al., 2016; Song et al., 2005; Wang et al., 2007; Whiteman et al., 1997); Andes (Garreaud & Muñoz, 2005; Jones, 2019; Marengo et al., 2004; Montini et al., 2019); China (Du et al., 2014; He et al., 2016; Li et al., 2018; Wei et al., 2013, 2014; Zhang et al., 2019); India (Ruchith & Raj, 2015; Ruchith et al., 2014); Colima Valley, Mexico (Arfeuille et al., 2015); Cabauw, Netherlands (Baas et al., 2009); Antarctica (Andreas et al., 2000; King et al., 2008); Negev, Israel (Kutsher et al., 2012); Hannover, Germany (Emeis, 2014b); Boulogne‐sur‐Mer, France (Roy et al., 2021); Amazon Rain Forest (Corrêa et al., 2021; Oliveira & Fitzjarrald, 1994), Pantanal (Martins et al., 2013) and Southern Brazil (Beu, 2019; Karam, 2002).…”

“…; Andes (Garreaud & Muñoz, 2005;Jones, 2019;Marengo et al, 2004;Montini et al, 2019); China (Du et al, 2014;He et al, 2016;Li et al, 2018;Wei et al, 2013Wei et al, , 2014Zhang et al, 2019); India (Ruchith & Raj, 2015;Ruchith et al, 2014); Colima Valley, Mexico (Arfeuille et al, 2015); Cabauw, Netherlands (Baas et al, 2009); Antarctica (Andreas et al, 2000;King et al, 2008); Negev, Israel (Kutsher et al, 2012); Hannover, Germany (Emeis, 2014b); Boulogne-sur-Mer, France (Roy et al, 2021); Amazon Rain Forest (Corrêa et al, 2021;Oliveira & Fitzjarrald, 1994), Pantanal (Martins et al, 2013) and Southern Brazil (Beu, 2019;Karam, 2002).…”

Investigação dos Jatos de Baixos Níveis na Região Metropolitana de São Paulo

“…JBNs têm sido identificados e estudados usando dados coletados com diferentes equipamentos de sensoriamento remoto, tais como: sodar (Song et al, 2005;Karipot et al, 2009;Kallistratova et al, 2009;Kallistratova e Kouznetsov, 2012;Helmis et al, 2013;Emeis, 2014b), lidar (Banta et al, 2002;Wang et al, 2007;Ruchith et al, 2014;Barlow et al, 2015;Vanderwende et al, 2015;Lampert et al, 2016;Beu, 2019), RASS (Baas et al, 2009), sodar-RASS (Arfeuille et al, 2015) e perfiladores de vento (Song et al, 2005;Du et al, 2012;Wei et al, 2013;Klein et al, 2016).…”

“…Banta et al (2002) testaram diferentes valores limiares e encontraram um valor crítico de 0,5 m s -1 . Alguns autores categorizam os JBNs em termos de intensidade considerando faixas de velocidade máxima do vento entre 5 e 20 m s -1 e limiares entre 2 e 10 m s -1 (Bonner, 1968;Whiteman et al, 1997;Song et al, 2005;Wei et al, 2013Wei et al, , 2014Arfeuille et al, 2015;Miao et al, 2018). De acordo com Kallistratova e Kouznetsov (2012) os valores limiares, e como consequência a identificação dos JBNs, são sensíveis à resolução vertical das medições de velocidade do vento.…”