The Madden-Julian oscillation (MJO, Madden and Julian, 1971, 1972) is a dominant feature of intraseasonal (20-90 day) variability in the tropics. According to the classic view, the MJO begins as a positive convective anomaly in the equatorial western Indian Ocean. It then propagates eastward toward the maritime continent where convection weakens until the MJO reaches the west Pacific where the ...

[1] The Madden-Julian Oscillation (MJO) is the primary mode of large-scale intraseasonal variability in the tropics. Recent work has connected the MJO to atmospheric variability in mid-latitudes. We focus on relationships between the MJO and wintertime surface air temperatures in the Northern Hemisphere high latitudes. The MJO is diagnosed using principal EOF of 850 hPa zonal winds from the NCE...

The effect of the Madden-Julian Oscillation (MJO) on the Northern Hemisphere wintertime stratospheric polar vortex in the period preceding stratospheric sudden warmings is evaluated in operational subseasonal forecasting models. Reforecasts which simulate stronger MJO-related convection in the Tropical West Pacific also simulate enhanced heat flux in the lowermost stratosphere and a more realis...

8 [1] The Madden-Julian Oscillation (MJO), the primary 9 mode of large-scale intraseasonal variability in the tropics, 10 is known to relate to the mid-latitude atmospheric 11 variability. Using neural network techniques, a nonlinear 12 projection of the MJO onto the precipitation and 200-hPa 13 wind anomalies in the northeast Pacific during January– 14 March shows asymmetric atmospheric patter...

Prior work has suggested that Rossby wave accumulation in the lower troposphere may be an important mechanism for the development of synoptic-scale disturbances in the western north Pacific in northern summer. This work examines the intraseasonal and interannual variability of wave accumulation by computing the barotropic wave activity flux divergence at 850 hPa for different phases of the Madd...

It is well known that the envelope of the Madden–Julian oscillation (MJO) consists of smaller-scale convective systems, including mesoscale convective systems (MCS), tropical cyclones, and synoptic-scale waves called ‘‘convectively coupled equatorial waves’’ (CCW). In fact, recent results suggest that the fundamental mechanisms of the MJO involve interactions between the synoptic-scale CCW and ...

The Madden-Julian oscillation (MJO) modulates atmospheric river (AR) activity along the West Coast of North America. forecast skill ARs based solely on MJO phase is limited, motivating identification other predictive factors. Here we show that low-frequency variability Pacific/North American (PNA) pattern mostly independent MJO, and monthly PNA influences MJO-AR relationship much more robustly ...

JANUARY 2003 AMERICAN METEOROLOGICAL SOCIETY | S ince its discovery by Madden and Julian (1971, 1972) over two decades ago, the Madden–Julian oscillation (MJO) has continued to be a topic of significant interest due to its complex nature (Madden and Julian 1994) and the wide range of phenomena with which it interacts. The onset and break activity of the Asian–Australian monsoon system is strong...

The long-term goal of this project is to understand the role of the atmosphere-ocean interaction processes in the initiation, maintenance and propagation of Madden Julian Oscillation (MJO). Better grasp of the atmosphere/ocean feedbacks in the Tropics will allow formulating more accurate parameterizations of the air-sea interface in the forecasting models. It will contribute to improved predict...

The 30–60-day Madden–Julian oscillation (MJO) has been documented in previous research to impact tropical cyclone (TC) activity for various tropical cyclone basins around the globe. TheMJOmodulates largescale convective activity throughout the tropics, and concomitantly modulates other fields known to impact tropical cyclone activity such as vertical wind shear, midlevelmoisture, vertical motio...