Transport of Asian trace gases via eddy shedding from the Asian summer monsoon anticyclone and associated impacts on ozone heating rates

Abstract

11The highly vibrant Asian Summer Monsoon (ASM) anticyclone plays an important role in 12 efficient transport of Asian tropospheric air masses to the extratropical upper troposphere and 13 lower stratosphere (UTLS). In this paper, we demonstrate long-range transport of Asian trace 14 gases via eddy shedding events using MIPAS (Michelson Interferometer for

The stratospheric ozone rich cold intrusion during El‐Niño over the Indian region: Implication during the Indian summer monsoon

“…The stratospheric intrusion associated with RWB events can be identified from the distribution of PV at the isentropic level of 350 K (Strong and Magnusdottir, 2008; Homeyer and Bowman, 2012; Samanta et al ., 2015). In the horizontal, RWB is manifested as a rapid and large‐scale irreversible overturning of PV contours on isentropic surfaces (McIntyre and Palmer, 1985; Strong and Magnusdottir, 2008), while, in the vertical, it appears as tropopause fold (Allen et al ., 2009; Fadnavis et al ., 2018). On occasions, RWB shed eddies deep into the troposphere (Garny and Randel, 2013; Fadnavis et al ., 2018).…”

“…In the horizontal, RWB is manifested as a rapid and large‐scale irreversible overturning of PV contours on isentropic surfaces (McIntyre and Palmer, 1985; Strong and Magnusdottir, 2008), while, in the vertical, it appears as tropopause fold (Allen et al ., 2009; Fadnavis et al ., 2018). On occasions, RWB shed eddies deep into the troposphere (Garny and Randel, 2013; Fadnavis et al ., 2018). Samanta et al .…”

“…Although model simulations reproduce stratospheric ozone intrusion events, the amount of ozone intruded is underestimated by 30–40 ppb in comparison to ERA‐Interim reanalysis. The reasons for this difference may be due to the underestimation of ozone precursors in the model emission inventory, error in model transport processes and coarse model resolution (Fadnavis et al ., 2017, 2018; Roy et al ., 2017). Tropospheric ozone enhancement by 20–30% has been observed over northern mid‐latitudes during winter and spring, after the peak of an El Niño event (Zeng and Pyle, 2005; Koumoutsaris et al ., 2008; Neu et al ., 2014).…”

“…The model comprises of an atmospheric general circulation module, ECHAM5 (Roeckner et al ., 2003), a tropospheric chemistry module, MOZ (Horowitz et al ., 2003), and an aerosol module, namely the Hamburg Aerosol Model (HAM; Stier et al ., 2005). The model parameterization and other details have been previously documented (Fadnavis et al ., 2013, 2015, 2018, 2019; Roy et al ., 2017). The model simulations were performed at a spectral resolution of T42 corresponding to 2.8° × 2.8° in horizontal and 31 levels in the vertical from surface up to 10 hPa.…”

Climatological patterns of subseasonal eddy flux transfer based on the co‐spectral analysis over the Indian region and the derivation of an index of eddy transfer for operational tracking

“…Over the Indian subcontinent, there are shreds of evidence that the transient extratropical systems (mostly called western disturbances in synoptic parlance) transport mid‐latitude vortices and influence the weather by inducing the low‐pressure dynamical systems (Dimri et al ., 2016; Hunt et al ., 2018b; Sooraj et al ., 2020), modulate Tibetan Anticyclones and monsoon break type situations (Ramaswamy, 1962; Raman and Rao, 1981; Krishnan et al ., 2009; Hunt et al ., 2018a), extreme events over the northern part of the Indian subcontinent (Srivastava et al ., 2014; Joseph et al ., 2015; Vellore et al ., 2016). The Rossby wave breaking, eddy shedding and potential vorticity advection (Hsu and Plumb, 2000; Fadnavis and Chattopadhyay, 2017; Fadnavis et al ., 2018), as well as Rossby wave intrusion and their transport in the tropics, has a significant link to mid‐latitude (Kiladis and Feldstein, 1994; Knippertz, 2007; Samanta et al ., 2016). These studies indicate significant regional departures from zonally symmetric momentum and heat transport (i.e., Hadley type transport) over this region that contribute to zonal asymmetries in different seasons.…”