The Madden–Julian Oscillation in ECHAM6 and the Introduction of an Objective MJO Metric

Abstract This study presents a quantitative evaluation of the simulated Madden–Julian oscillation (MJO) in an ensemble of 42 experiments performed with ECHAM6 and previous ECHAM versions. The ECHAM6 experiments differ in their parameter settings, resolution, and whether the atmosphere is coupled to an ocean or not. The analysis concentrates on a few basic features of the MJO, namely, the signatures of convection/precipitation coupled with the circulation system and the eastward propagation strength of outgoing longwave radiation (OLR) and 850- and 200-hPa zonal winds within the MJO-related frequency–wavenumber range. It also examines whether precipitation and OLR show similar signatures in the MJO as simulated by ECHAM. The experiments reveal an MJO, however, to different degrees and in different aspects, so that a sound assessment requires a multivariate approach. In particular, the convective rainfall signatures are decoupled from the dynamic signature of the MJO in the simulations herein, which eventually leads to the introduction of a new MJO diagram and metric that incorporate OLR and the zonal winds in 850 and 200 hPa. The analysis here confirms the importance of the convection scheme: only with the Nordeng modifications to the Tiedtke scheme can realistic MJO features be simulated. High-resolution coupled experiments better represent the MJO as compared to low-resolution AMIP experiments. This is shown to follow from two more general findings, namely, that 1) air–sea interaction mainly increases the convective signature and 2) increased resolution enhances eastward propagation.

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An Evaluation of Northern Australian Wet Season Rainfall Bursts in CMIP5 Models

Journal of Climate ◽

10.1175/jcli-d-17-0637.1 ◽

2018 ◽

Vol 31 (19) ◽

pp. 7789-7802 ◽

Cited By ~ 3

Author(s):

Sugata Narsey ◽

Michael J. Reeder ◽

Christian Jakob ◽

Duncan Ackerley

Keyword(s):

Outgoing Longwave Radiation ◽

Climate Models ◽

Longwave Radiation ◽

Cmip5 Models ◽

Madden Julian Oscillation ◽

Wet Season ◽

The North ◽

Coupled Climate Models ◽

The Tropics ◽

The Relationship

The simulation of northern Australian wet season rainfall bursts by coupled climate models is evaluated. Individual models produce vastly different amounts of precipitation over the north of Australia during the wet season, and this is found to be related to the number of bursts they produce. The seasonal cycle of bursts is found to be poor in most of the models evaluated. It is known that northern Australian wet season bursts are often associated with midlatitude Rossby wave packets and their surface signature as they are refracted toward the tropics. The relationship between midlatitude waves and the initiation of wet season bursts is simulated well by the models evaluated. Another well-documented influence on the initiation of northern Australian wet season bursts is the Madden–Julian oscillation (MJO). No model adequately simulated the tropical outgoing longwave radiation temporal–spatial patterns seen in the reanalysis-derived OLR. This result suggests that the connection between the MJO and the initiation of northern Australian wet season bursts in models is poor.

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PENGEMBANGAN MODEL PREDIKSI MADDEN JULIAN OSCILLATION (MJO) BERBASIS PADA HASIL ANALISIS DATA REAL TIME MULTIVARIATE MJO (RMM1 DAN RMM2) (PREDICTION MODEL DEVELOPMENT MADDEN JULIAN OSCILLATION (MJO) BASED ON THE RESULTS OF DATA ANALYSIS ...

Agromet ◽

10.29244/j.agromet.22.2.144-159 ◽

2008 ◽

Vol 22 (2) ◽

pp. 144 ◽

Cited By ~ 1

Author(s):

Lisa Evana ◽

Sobri Effendy ◽

Eddy Hermawan

Keyword(s):

Prediction Model ◽

Real Time ◽

Outgoing Longwave Radiation ◽

Time Series Data ◽

Longwave Radiation ◽

Empirical Orthogonal Functions ◽

Wave Radiation ◽

Series Data ◽

Madden Julian Oscillation ◽

Coverage Area

Background of this research is the importance of study on the Madden Julian Oscillation, the dominant oscillation in the equator area. MJO cycle showed by cloud cluster growing in the Indian Ocean then moved to the east and form a cycle with a range of 40-50 days and the coverage area from 10N-10S. Method that used to predict RMM is Box-Jenkins based on ARIMA (Autoregressive Integrated Moving Average) statistical analysis. The data used RMM daily data period 1 Maret 1979–1 Maret 2009 (30 years). RMM1 and RMM2 is an index for monitoring MJO. This is based on two empirical orthogonal functions (EOFs) from the combined average zonal 850hPa wind, 200hPa zonal wind, and satellite-observed Outgoing Longwave Radiation (OLR) data. The results in form of the Power Spectral Density (PSD) graph Real Time Multivariate MJO (RMM) and long wave radiation (OLR = Outgoing Longwave Radiation) at the position 100° BT, 120° BT, and 140°BT that show the wave pattern (spectrum pattern) and clearly shows the oscillation periods. There is a close relation between RMM1 with OLR at the position 100oBT that characterized the PSD value about 45 day. Through Box-Jenkins method, the prediction model that close to time series data of RMM1 and RMM2 is ARIMA (2,1,2), that mean the forecasts of RMM data for the future depending on one time previously and the error one time before. Prediction model for Zt = Zt = 1,681 Zt-1 – 0,722 Zt-2 - 0,02 at-1 - 0,05 at-2.. Prediction model for RMM2 is Zt = 1,714 Zt-1 – 0,764 Zt-2 - 0,109 at-1 - 0,05 at-2.. The flood case in Jakarta January-February 1996 and 2002 are one of real evidence that made the MJO prediction important. MJO with active phase dominant cover almost the entire Indonesia west area at that moment.

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The Madden–Julian Oscillation in CCSM4

Journal of Climate ◽

10.1175/jcli-d-11-00031.1 ◽

2011 ◽

Vol 24 (24) ◽

pp. 6261-6282 ◽

Cited By ~ 53

Author(s):

Aneesh C. Subramanian ◽

Markus Jochum ◽

Arthur J. Miller ◽

Raghu Murtugudde ◽

Richard B. Neale ◽

...

Keyword(s):

Large Scale ◽

Intraseasonal Variability ◽

Power Spectra ◽

Longwave Radiation ◽

Meridional Wind ◽

Dominant Mode ◽

Madden Julian Oscillation ◽

Asian Monsoon Region ◽

Climate System Model ◽

Zonal Winds

Abstract This study assesses the ability of the Community Climate System Model, version 4 (CCSM4) to represent the Madden–Julian oscillation (MJO), the dominant mode of intraseasonal variability in the tropical atmosphere. The U.S. Climate Variability and Predictability (CLIVAR) MJO Working Group’s prescribed diagnostic tests are used to evaluate the model’s mean state, variance, and wavenumber–frequency characteristics in a 20-yr simulation of the intraseasonal variability in zonal winds at 850 hPa (U850) and 200 hPa (U200), and outgoing longwave radiation (OLR). Unlike its predecessor, CCSM4 reproduces a number of aspects of MJO behavior more realistically. The CCSM4 produces coherent, broadbanded, and energetic patterns in eastward-propagating intraseasonal zonal winds and OLR in the tropical Indian and Pacific Oceans that are generally consistent with MJO characteristics. Strong peaks occur in power spectra and coherence spectra with periods between 20 and 100 days and zonal wavenumbers between 1 and 3. Model MJOs, however, tend to be more broadbanded in frequency than in observations. Broad-scale patterns, as revealed in combined EOFs of U850, U200, and OLR, are remarkably consistent with observations and indicate that large-scale convergence–convection coupling occurs in the simulated MJO. Relations between MJO in the model and its concurrence with other climate states are also explored. MJO activity (defined as the percentage of time the MJO index exceeds 1.5) is enhanced during El Niño events compared to La Niña events, both in the model and observations. MJO activity is increased during periods of anomalously strong negative meridional wind shear in the Asian monsoon region and also during strong negative Indian Ocean zonal mode states, in both the model and observations.

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Centered Composite Analysis of Variations Associated with the Madden–Julian Oscillation

Journal of Climate ◽

10.1175/jcli3703.1 ◽

2006 ◽

Vol 19 (9) ◽

pp. 1834-1849 ◽

Cited By ~ 4

Author(s):

Bryan C. Weare

Keyword(s):

Surface Pressure ◽

Lower Troposphere ◽

Longwave Radiation ◽

Specific Humidity ◽

Composite Analysis ◽

Madden Julian Oscillation ◽

Mixing Properties ◽

Zonal Winds ◽

The Indian Ocean ◽

Key Events

Abstract Centered composite analysis is described and applied to gain a better understanding of the initial phases of the Madden–Julian oscillation (MJO). Centered composite analysis identifies the dates and central locations of key events. The elements of the composite means are centered on these central locations before averages are calculated. In this way much of the spatial fuzziness, which is inherent in traditional composite analysis, is removed. The results for the MJO, based on MJO-filtered outgoing longwave radiation for the reference data and 40-yr ECMWF Re-Analysis (ERA-40) and NCEP–NCAR reanalysis products for the composites, show highly significant composites of unfiltered data for not only zero lag, but also lags back to 20 days before the target events. These composites identify propagating patterns of surface pressure, upper- and lower-troposphere zonal winds, surface temperature, and 850-hPa specific humidity associated with MJO convective events in the Indian Ocean. The propagation characteristics of important features, especially surface pressure, differ substantially for MJO convective anomalies centered over the Indian or western Pacific Oceans. This suggests that distinctly different mechanisms may be dominant in these two regions, and that many earlier analyses may be mixing properties of the two.

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Latitude–Height Structure of the Atmospheric Angular Momentum Cycle Associated with the Madden–Julian Oscillation

Monthly Weather Review ◽

10.1175/mwr3363.1 ◽

2007 ◽

Vol 135 (4) ◽

pp. 1564-1575 ◽

Cited By ~ 7

Author(s):

Joseph Egger ◽

Klaus Weickmann

Keyword(s):

Angular Momentum ◽

Principal Components ◽

Outgoing Longwave Radiation ◽

Opposite Sign ◽

Longwave Radiation ◽

Empirical Orthogonal Functions ◽

Madden Julian Oscillation ◽

Orthogonal Functions ◽

Tropical Troposphere ◽

Global Mean

Abstract The angular momentum cycle of the Madden–Julian oscillation is analyzed by regressing the zonally averaged axial angular momentum (AAM) budget including fluxes and torques against the first two principal components P1 and P2 of the empirical orthogonal functions (EOFs) of outgoing longwave radiation (OLR). The maximum of P1 coincides with an OLR minimum near 150°E and a shift from anomalously negative AAM to positive AAM in the equatorial troposphere. AAM anomalies of one sign develop first in the upper-equatorial troposphere and then move downward and poleward to the surface of the subtropics within two weeks. During the same time the opposite sign AAM anomaly develops in the upper-equatorial troposphere. The tropical troposphere is warming when P1 approaches its maximum while the stratosphere is cooling. The torques are largest in the subtropics and are linked with the downward and poleward movement of AAM anomalies. The evolution is conveniently summarized using a time–height depiction of the global mean AAM and vertical flux anomaly.

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A Comparison of OLR and Circulation-Based Indices for Tracking the MJO

Monthly Weather Review ◽

10.1175/mwr-d-13-00301.1 ◽

2014 ◽

Vol 142 (5) ◽

pp. 1697-1715 ◽

Cited By ~ 204

Author(s):

George N. Kiladis ◽

Juliana Dias ◽

Katherine H. Straub ◽

Matthew C. Wheeler ◽

Stefan N. Tulich ◽

...

Keyword(s):

Real Time ◽

Outgoing Longwave Radiation ◽

Seasonal Cycle ◽

Large Scale ◽

Longwave Radiation ◽

Tropical Convection ◽

Madden Julian Oscillation ◽

Primary Interest ◽

Large Scale Circulation ◽

Reasonable Approximation

Abstract Two univariate indices of the Madden–Julian oscillation (MJO) based on outgoing longwave radiation (OLR) are developed to track the convective component of the MJO while taking into account the seasonal cycle. These are compared with the all-season Real-time Multivariate MJO (RMM) index of Wheeler and Hendon derived from a multivariate EOF of circulation and OLR. The gross features of the OLR and circulation of composite MJOs are similar regardless of the index, although RMM is characterized by stronger circulation. Diversity in the amplitude and phase of individual MJO events between the indices is much more evident; this is demonstrated using examples from the Dynamics of the Madden–Julian Oscillation (DYNAMO) field campaign and the Year of Tropical Convection (YOTC) virtual campaign. The use of different indices can lead to quite disparate conclusions concerning MJO timing and strength, and even as to whether or not an MJO has occurred. A disadvantage of using daily OLR as an EOF basis is that it is a much noisier field than the large-scale circulation, and filtering is necessary to obtain stable results through the annual cycle. While a drawback of filtering is that it cannot be done in real time, a reasonable approximation to the original fully filtered index can be obtained by following an endpoint smoothing method. When the convective signal is of primary interest, the authors advocate the use of satellite-based metrics for retrospective analysis of the MJO for individual cases, as well as for the analysis of model skill in initiating and evolving the MJO.

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Dynamic Characteristics of the Circulation and Diurnal Spatial Cycle of Outgoing Longwave Radiation in the Different Phases of the Madden–Julian Oscillation during the Formation of the South Atlantic Convergence Zone

Atmosphere ◽

10.3390/atmos12111399 ◽

2021 ◽

Vol 12 (11) ◽

pp. 1399

Author(s):

Liviany P. Viana ◽

Jhonatan A. A. Manco ◽

Dirceu Luis Herdies

Keyword(s):

Outgoing Longwave Radiation ◽

Longwave Radiation ◽

Active Phase ◽

South Atlantic Convergence Zone ◽

South Atlantic ◽

Meteorological Variables ◽

Convergence Zone ◽

Madden Julian Oscillation ◽

The South ◽

Subtropical Highs

In this work, we verified the formation of the South Atlantic Convergence Zone (SACZ) during the active, unfavorable, and transition phases of the Madden–Julian Oscillation (MJO), as well as the diurnal spatial variability in the estimated Outgoing Longwave Radiation (OLR) data. The real-time multivariate index (RMM) and the composites of meteorological variables were used, along with the temporal average of the estimated OLR data. All the different patterns for the average period of SACZ showed classic behavior: well-organized and with meteorological variables in phases throughout the troposphere. However, some differences were evident in the organization of each phase of the MJO: at 200 hPa, the Bolivian High (BH) was more flattened during the active phase pattern than in the unfavorable and transition phases, being wider and with a wavier trough embedded in the western flow; at medium levels, the subtropical highs appeared more defined and with a very wide trough; the trough supported the frontal systems on the surface and, together with the subtropical highs, concentrated all the moisture in this layer. In the OLR dataset, the formation of the Coast Squall Line (CSL) occurred during SACZ events in the active phase and MJO transition, whereas in the unfavorable phase, this system was not observed.

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RESPON CURAH HUJAN DIURNAL TERHADAP MADDEN-JULIAN OSCILLATION AKTIF DI BENUA MARITIM BERBASIS GSMAP GAUGE-CALIBRATED V7

Jurnal Sains & Teknologi Modifikasi Cuaca ◽

10.29122/jstmc.v22i1.4525 ◽

2021 ◽

Vol 22 (1) ◽

pp. 17-24

Author(s):

Achmad Fahruddin Rais ◽

Ahmad Kosasih ◽

Soenardi ◽

Yamin Saleh Saidu ◽

Sanya Gautami ◽

...

Keyword(s):

Phase Shift ◽

Outgoing Longwave Radiation ◽

Longwave Radiation ◽

Madden Julian Oscillation ◽

Maritime Continent ◽

June July August ◽

Diurnal Rainfall ◽

The Mean ◽

June July ◽

Peak Phase

Intisari Keberadaan pergeseran puncak curah hujan diurnal (DR) terhadap Madden-Julian Oscillation (MJO) aktif di Maritime Continent (MC) masih diperdebatkan sehingga studi ini bertujuan untuk menginvestigasi perubahan tersebut. Selain itu, intensitas rata-rata dan amplitudo DR juga dikaji dalam penelitian ini berbasis GSMaP Gauge-Calibrated V7. Komposit anomali intensitas rata-rata (Ra), amplitudo (Rax) DR MJO aktif dan perbandingan fase puncak DR MJO aktif terhadap klimatologinya (Pax-Pm) pada periode Desember-Januari-Februari (DJF), Maret-April-Mei (MAM), Juni-Juli-Agustus (JJA) dan September-Oktober-November (SON) digunakan dalam tulisan ini dengan uji-z 80%. MJO aktif berbasis rekonstruksi outgoing longwave radiation (OLR) dari kedua indeks realtime multivariate MJO (RMM). Hasil memperlihatkan bahwa MJO aktif memodulasi peningkatan intensitas rata-rata dan amplitudo DR di lautan dan mempengaruhi pergeseran puncak DR menjadi lebih cepat 1 jam dari klimatologi musimannya. Abstract The occurrence of peak phase shift of diurnal rainfall (DR) to active Madden-Jullian Oscillation (MJO) has been debatable, so this study is aimed to investigate the change. Moreover, the mean and amplitude intensity of DR were also analyzed in this study based on GSMaP Gauge-Calibrated V7. The composite of the mean (Ra) and amplitude (Rax) intensity anomaly of DR, and the comparison of DR peak phase during the active MJO to its climatology (Pax-Pm) in the period December-January-February (DJF), March-April-May (MAM), June-July-August (JJA), and September-October-November (SON) were used in the study with the z-test of 80%. The active MJO was based on reconstructed outgoing longwave radiation (OLR) of two real-time multivariate MJO (RMM) indexes. The results showed that active MJO modulated the increased mean and amplitude intensity of DR over the ocean and influenced the DR peak phase shift to be faster than its seasonal climatology by one hour.

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Karakteristik Outgoing Longwave Radiation (OLR) dan Hubungannya dengan Madden Jullian Oscillation (MJO) di Kota Pontianak Menggunakan Metode Wavelet

PRISMA FISIKA ◽

10.26418/pf.v7i3.38406 ◽

2020 ◽

Vol 7 (3) ◽

pp. 282

Author(s):

Ade Tri Wahyuni ◽

Muliadi Muliadi ◽

Riza Adriat

Keyword(s):

Outgoing Longwave Radiation ◽

Longwave Radiation ◽

Madden Julian Oscillation

Outgoing Longwave Radiation (OLR) erat kaitannya dengan Madden Julian Oscilation (MJO) karena variasi OLR yang terukur dapat memperlihatkan fenomena MJO, hal tersebut berpengaruh pada variasi cuaca di daerah tropis sehingga perlu dilakukan kajian terkait karakteristik OLR di daerah tropis khususnya di Kota Pontianak dan hubungannya dengan MJO. Metode wavelet digunakan untuk mengkaji karakteristik OLR dan hubungannya dengan MJO. Hasil yang diperoleh adalah OLR di Kota Pontianak memiliki periode dominan pada kisaran 183 dan 365 hari. Kata Kunci : Madden Julian Oscillation (MJO), Outgoing Longwave Radiation (OLR), Wavelet

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IDENTIFIKASI PENGARUH MJO FASE 3 TERHADAP CURAH HUJAN DI PULAU SUMATERA DAN JAWA (STUDI KASUS 14 – 17 OKTOBER 2018)

Prosiding SNFA (Seminar Nasional Fisika dan Aplikasinya) ◽

10.20961/prosidingsnfa.v3i0.28552 ◽

2019 ◽

Vol 3 ◽

pp. 228

Author(s):

Rahpeni Fajarianti ◽

Deffi Munadiyat Putri ◽

Paulus Agus Winarso

Keyword(s):

Outgoing Longwave Radiation ◽

Longwave Radiation ◽

Heavy Rain ◽

Sea Surface ◽

Madden Julian Oscillation ◽

Phase 3 ◽

Convective Clouds ◽

Precipitation Measurement ◽

Global Precipitation Measurement ◽

Global Precipitation

Abstract:. Madden Julian Oscillation (MJO) is a wave in tropical atmosphere that moving eastward from Indian ocean to Pacific Ocean for a period 30 – 60 days. There are many research that explain when MJO is active in phases 2, 3 and 4 it affects convective activities in the Indonesian Maritime Continent. The purpose of this study is to determine the effect of MJO in phase 3 on temporal rainfall intensity in Sumatra and Java island on 14 – 17 October 2018. This study uses the descriptive analysis method using parameter such as Outgoing Longwave Radiation (OLR) and Phase MJO diagram from Bureau of Meteorology (BOM), Sea Surface Temperature (SST) and vertical velocity data from the National Oceanic and Atmospheric Administration (NOAA) and also raw data of HCAI Himawari-8 satellite to monitor cloud formation on Sumatra and Java island and Global Precipitation Measurement (GPM) data obtained from the Meteorology, Climatology and Geophysics Agency (BMKG) to determine its rainfall distribution on 14 – 17 October 2018. The active MJO in phase 3 causing an increase in convective activity on the Sumatra. The SST value of 29.50 – 300 Celcius supports the occurrence of sufficient evaporation to produce convective clouds with a vertical velocity of less than -0.12 Pa/s (strong updraft) so as to form Cumulonimbus clouds which cause heavy rain intensity which can cause floods. However, in Java Island the influence of MJO was less significant due to the influence of relatively lower sea surface temperatures in the south of Java island so that it is not strong enough to form convective clouds that produce heavy rain.Abstrak: Madden Julian Oscillation (MJO) merupakan gelombang di kawasan tropis yang menjalar dari Barat (Samudera Hindia) ke timur (Samudera Pasifik) dengan periode 30 – 60 hari. Banyak penelitian menjelaskan bahwa pada saat MJO aktif pada fase 2, 3 dan 4 berpengaruh terhadap giatnya aktivitas konvektif di Benua Maritim Indonesia. Penelitian ini bertujuan untuk mengetahui pengaruh MJO di fase 3 terhadap intensitas curah hujan secara temporal di wilayah Pulau Sumatra dan Pulau Jawa pada 14 – 17 Oktober 2018. Penelitian ini menggunakan metode analisis deskriptif dengan parameter antara lain : Outgoing Longwave Radiation (OLR) dan diagram fase MJO yang diambil dari Bureau of Meteorology (BOM), Sea Surface Temperature (SST) dan kecepatan vertikal yang diambil dari National Oceanic and Atmospheric Administration (NOAA) serta raw data HCAI satelit Himawari-8 untuk memonitoring pembentukan awan di Pulau Sumatera dan Jawa dan data Global Precipitation Measurement (GPM) yang didapatkan dari Badan Meteorologi, Klimatologi dan Geofisika (BMKG) untuk mengetahui distribusi curah hujannya pada 14 – 17 Oktober 2018. Aktifnya MJO pada fase 3 menyebabkan peningkatan aktivitas konvektif di Pulau Sumatera. Nilai SST sebesar 29.50 – 300 Celcius mendukung terjadinya penguapan yang cukup untuk menghasilkan awan konvektif dengan kecepatan vertikal kurang dari -0.12 Pa/s (updraft kuat) sehingga membentuk awan Cumulonimbus yang menyebabkan intensitas hujan lebat yang mampu menimbulkan bencana banjir. Sedangkan di Pulau Jawa pengaruh MJO kurang signifikan akibat pengaruh suhu permukaan laut di selatan Jawa yang relatif lebih rendah sehingga tidak cukup kuat untuk membentuk awan konvektif yang menghasilkan hujan lebat.

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