Search Results
justifies the use of υyQ 0 as a reasonable approximation for the moisture meridional advection υ Q ¯ y . It also gives the meridional moisture advection term the same form as the Coriolis term under the equatorial β -plane approximation, and allows Eq. (4) to preserve its symmetry about the equator in all terms. b. Reduction to a second-order ODE for υ We assume plane wave solutions proportional to exp[ i ( kx − ωt )] for u , υ , ϕ , and q , where k is the nondimensional planetary
justifies the use of υyQ 0 as a reasonable approximation for the moisture meridional advection υ Q ¯ y . It also gives the meridional moisture advection term the same form as the Coriolis term under the equatorial β -plane approximation, and allows Eq. (4) to preserve its symmetry about the equator in all terms. b. Reduction to a second-order ODE for υ We assume plane wave solutions proportional to exp[ i ( kx − ωt )] for u , υ , ϕ , and q , where k is the nondimensional planetary
, we chose MT instead of pure MRG waves ( Matsuno 1966 ) in this study. Table 1. The range of planetary zonal wavenumber, period, and equivalent depth chosen for filtering waves and their corresponding reference. Positive (negative) planetary zonal wavenumber indicates eastward (westward) propagation. MJO and MT do not follow the dispersion curve so the equivalent depths are not calculated. c. Diurnal cycle analysis To analyze the diurnal variation of precipitation, the dates are separated into
, we chose MT instead of pure MRG waves ( Matsuno 1966 ) in this study. Table 1. The range of planetary zonal wavenumber, period, and equivalent depth chosen for filtering waves and their corresponding reference. Positive (negative) planetary zonal wavenumber indicates eastward (westward) propagation. MJO and MT do not follow the dispersion curve so the equivalent depths are not calculated. c. Diurnal cycle analysis To analyze the diurnal variation of precipitation, the dates are separated into
1. Introduction The Madden–Julian oscillation (MJO) is the dominant intraseasonal variability in the tropical atmosphere. It can be described as a tropical planetary-scale circulation system coupled with a multiscale convective complex and propagating eastward slowly with a rearward tilted vertical structure and a mixed Kelvin–Rossby wave horizontal structure ( Madden and Julian 1972 ; Wheeler and Kiladis 1999 ; Wheeler et al. 2000 ; Kiladis et al. 2005 ; Wang 2012 ). The planetary
1. Introduction The Madden–Julian oscillation (MJO) is the dominant intraseasonal variability in the tropical atmosphere. It can be described as a tropical planetary-scale circulation system coupled with a multiscale convective complex and propagating eastward slowly with a rearward tilted vertical structure and a mixed Kelvin–Rossby wave horizontal structure ( Madden and Julian 1972 ; Wheeler and Kiladis 1999 ; Wheeler et al. 2000 ; Kiladis et al. 2005 ; Wang 2012 ). The planetary
, S.-K. Yang , J. J. Hnilo , M. Fiorino , and G. L. Potter , 2002 : NCEP–DOE AMIP-II Reanalysis (R-2) . Bull. Amer. Meteor. Soc. , 83 , 1631 – 1644 , https://doi.org/10.1175/BAMS-83-11-1631 . 10.1175/BAMS-83-11-1631 Kodera , K. , H. Mukougawa , and S. Itoh , 2008 : Tropospheric impact of reflected planetary waves from the stratosphere . Geophys. Res. Lett. , 35 , L16806 , https://doi.org/10.1029/2008GL034575 . 10.1029/2008GL034575 Lee , S. , T. Gong , N
, S.-K. Yang , J. J. Hnilo , M. Fiorino , and G. L. Potter , 2002 : NCEP–DOE AMIP-II Reanalysis (R-2) . Bull. Amer. Meteor. Soc. , 83 , 1631 – 1644 , https://doi.org/10.1175/BAMS-83-11-1631 . 10.1175/BAMS-83-11-1631 Kodera , K. , H. Mukougawa , and S. Itoh , 2008 : Tropospheric impact of reflected planetary waves from the stratosphere . Geophys. Res. Lett. , 35 , L16806 , https://doi.org/10.1029/2008GL034575 . 10.1029/2008GL034575 Lee , S. , T. Gong , N
characterized by a zonally planetary length scale with global wavenumber 1–2 ( Wang and Rui 1990 ; Li and Zhou 2009 ), a Kelvin wave and Rossby wave couplet pattern ( Rui and Wang 1990 ; Wang and Li 1994 ; Li and Wang 1994 ; Adames and Wallace 2014 ), and a vertically tilted structure in vertical velocity and moisture fields ( Sperber 2003 ; Hsu and Li 2012 ). Table 1. List of acronyms. Most MJO events initiate in the west Indian Ocean ( Matthews 2008 ; Zhao et al. 2013 ; Straub 2013 ), weaken over
characterized by a zonally planetary length scale with global wavenumber 1–2 ( Wang and Rui 1990 ; Li and Zhou 2009 ), a Kelvin wave and Rossby wave couplet pattern ( Rui and Wang 1990 ; Wang and Li 1994 ; Li and Wang 1994 ; Adames and Wallace 2014 ), and a vertically tilted structure in vertical velocity and moisture fields ( Sperber 2003 ; Hsu and Li 2012 ). Table 1. List of acronyms. Most MJO events initiate in the west Indian Ocean ( Matthews 2008 ; Zhao et al. 2013 ; Straub 2013 ), weaken over
baroclinic models to show extratropical responses to tropical heating as a Rossby wave train propagating out of the tropics in the upper troposphere (e.g., Hoskins and Karoly 1981 ; Jin and Hoskins 1995 ). Ferranti et al. (1990) studied tropical–extratropical interaction associated with the 30–60-day oscillation and its impact on medium- and extended-range prediction. The anomalous upper-tropospheric divergence associated with tropical heating acts as a Rossby wave source for poleward dispersing
baroclinic models to show extratropical responses to tropical heating as a Rossby wave train propagating out of the tropics in the upper troposphere (e.g., Hoskins and Karoly 1981 ; Jin and Hoskins 1995 ). Ferranti et al. (1990) studied tropical–extratropical interaction associated with the 30–60-day oscillation and its impact on medium- and extended-range prediction. The anomalous upper-tropospheric divergence associated with tropical heating acts as a Rossby wave source for poleward dispersing
1. Introduction The Madden–Julian oscillation (MJO) is the dominant planetary-scale convective structure and intraseasonal mode in the tropics ( Zhang et al. 2020 ). The MJO generally propagates eastward from the Indian Ocean to the central Pacific Ocean with a speed of ∼5 m s −1 , recurring at Earth’s equator every 30–90 days ( Xie et al. 1963 ; Madden and Julian 1971 , 1972 ; Li et al. 2018 ). The anomalous convection of the MJO as a diabatic heating source excites poleward
1. Introduction The Madden–Julian oscillation (MJO) is the dominant planetary-scale convective structure and intraseasonal mode in the tropics ( Zhang et al. 2020 ). The MJO generally propagates eastward from the Indian Ocean to the central Pacific Ocean with a speed of ∼5 m s −1 , recurring at Earth’s equator every 30–90 days ( Xie et al. 1963 ; Madden and Julian 1971 , 1972 ; Li et al. 2018 ). The anomalous convection of the MJO as a diabatic heating source excites poleward
1. Introduction The Maritime Continent (MC) plays an important role as a heat and moisture source that can impact global circulation and modulate planetary-scale variability ( Neale and Slingo 2003 ). However, despite its importance, large errors are commonly found in the MC region in global and regional climate and weather models (e.g., Gianotti et al. 2012 ; Holloway et al. 2012 ; Nguyen et al. 2015 ; Dirmeyer et al. 2012 ; and others). One likely source of these errors arises from the
1. Introduction The Maritime Continent (MC) plays an important role as a heat and moisture source that can impact global circulation and modulate planetary-scale variability ( Neale and Slingo 2003 ). However, despite its importance, large errors are commonly found in the MC region in global and regional climate and weather models (e.g., Gianotti et al. 2012 ; Holloway et al. 2012 ; Nguyen et al. 2015 ; Dirmeyer et al. 2012 ; and others). One likely source of these errors arises from the
1. Introduction The Madden–Julian oscillation (MJO; Madden and Julian 1971 , 1972 ) is a primary source of predictability of the Earth system on subseasonal (3–6 weeks) time scales ( Waliser et al. 2003 ). As the MJO moves eastward, its influences on many environmental hazards (e.g., tropical cyclones, cold surges, heat waves, lightning, and flood) and climate modes [e.g., Indian Ocean dipole (IOD), ENSO, and NAO] depend on whether its convection center is over the Indian Ocean, the Indo
1. Introduction The Madden–Julian oscillation (MJO; Madden and Julian 1971 , 1972 ) is a primary source of predictability of the Earth system on subseasonal (3–6 weeks) time scales ( Waliser et al. 2003 ). As the MJO moves eastward, its influences on many environmental hazards (e.g., tropical cyclones, cold surges, heat waves, lightning, and flood) and climate modes [e.g., Indian Ocean dipole (IOD), ENSO, and NAO] depend on whether its convection center is over the Indian Ocean, the Indo
et al. 2013 ; Narsey et al. 2020 ). Regional climate models (RCMs), which operate at higher spatial resolution, have contributed to improve our understanding and simulation of the mechanisms underlying rainfall in the Maritime Continent ( Vincent and Lane 2018 ; Ruppert and Zhang 2019 ; Li et al. 2020 ) through better representation of fine-scale processes (i.e., sea breeze, gravity waves, interaction across scales, air–ocean fine-scale interactions). However, RCMs are still prone to
et al. 2013 ; Narsey et al. 2020 ). Regional climate models (RCMs), which operate at higher spatial resolution, have contributed to improve our understanding and simulation of the mechanisms underlying rainfall in the Maritime Continent ( Vincent and Lane 2018 ; Ruppert and Zhang 2019 ; Li et al. 2020 ) through better representation of fine-scale processes (i.e., sea breeze, gravity waves, interaction across scales, air–ocean fine-scale interactions). However, RCMs are still prone to
