Judul: Unravelling the Extratropical Response to MJO Under Different Phases of QBO Using Linear Baroclinic Model (LBM)
Abstrak: Interaksi antara proses Madden-Julian Oscillation (MJO) yang dipengaruhi Quasi-Biennial Oscillation (QBO) dapat mempengaruhi kondisi atmosfer ekstratropis melalui perbedaan dinamika atmosfer. Hubungan MJO-QBO menunjukkan kekuatan amplitudo MJO akan lebih lemah saat fase baratan QBO (W-QBO) dibanding fase timuran (E-QBO). Penelitian ini bertujuan menganalisis dan memahami mekanisme respon ekstratropis terhadap kejadian MJO saat E-QBO dan W-QBO yang kaitannya dengan telekoneksi ke wilayah ekstratropis menggunakan linear baroclinic model (LBM). Penentuan karakteristik MJO saat kejadian QBO menggunakan parameter outgoing longwave radiation berdasarkan fase MJO-QBO yang telah dibentuk. Analisis perambatan sinyal MJO saat QBO dilihat berdasarkan anomali ketinggian geopotensial data observasi dan hasil LBM. Perambatan MJO terhadap QBO memberikan dampak pada kekuatan aktivitas konvektif yang menghasilkan pemanasan diabatik dan dikonversi menjadi forcing untuk menjalankan model. Berdasarkan kedua fase QBO, aktivitas konveksi lebih kuat terjadi saat E-QBO sehingga pemanasan dan pembentukan awan lebih sering terjadi. E-QBO memiliki hasil telekoneksi MJO lebih kuat yang ditunjukkan dengan adanya anomali ketinggian geopotensial yang membentuk sistem tekanan tinggi dan rendah di wilayah Pasifik. Respon belahan bumi utara menunjukkan adanya gangguan saat 2 minggu setelah fase MJO pada setiap fase QBO. Hasil model dan observasi cukup berbeda sehingga perlu dinamika nonlinier untuk meningkatkan aspek respon telekoneksi terhadap wilayah ekstratropis., The interaction between Madden-Julian Oscillation (MJO) and Quasi-Biennial Oscillation (QBO) processes can have an impact on extratropical atmospheric conditions through differences in atmospheric dynamics. The MJO-QBO relationship indicates that the amplitude of the MJO will be weaker during the westward phase of the QBO (W-QBO) compared to the eastward phase (E-QBO). This study aims to analyze and understand the extratropical response mechanism to MJO events during E-QBO and W-QBO phases, which are related to teleconnections to extratropical regions using a linear baroclinic model (LBM). The MJO characteristics during QBO events were determined using the outgoing longwave radiation parameter based on the established MJO-QBO phase. The propagation analysis of MJO signals during QBO was based on geopotential height anomalies from observation data and LBM results. The propagation of MJO to QBO has an impact on the strength of convective activity, which generates diabatic heating and is converted into forcing to run the model. Based on both QBO phases, convective activity is stronger during E-QBO, so heating and cloud formation occur more frequently. E-QBO has a stronger MJO teleconnection result, indicated by geopotential height anomalies that form high and low-pressure systems in the Pacific region. The Northern Hemisphere's response shows disturbances two weeks after the MJO phase in each QBO phase. The model and observational results are quite different, indicating the need for nonlinear dynamics to improve teleconnection response aspects to extratropical regions.
Keyword: teleconnection, Madden-Julian Oscillation, Quasi-Biennial Oscillation, Linear Baroclinic Model, diabatic heating, geopotential height, extratropical response