scholarly journals Influence of the Madden-Julian Oscillation on multiweek prediction of Australian rainfall extremes using the ACCESS-S1 prediction system

2021 ◽  
Author(s):  
Andrew G. Marshall ◽  
Harry H. Hendon ◽  
Debra Hudson
Keyword(s):  
Prediction System ◽  
Madden Julian Oscillation ◽  
Rainfall Extremes ◽  
Australian Rainfall

Impacts of the Madden–Julian Oscillation on Australian Rainfall and Circulation

2009 ◽  
Vol 22 (6) ◽  
pp. 1482-1498 ◽  
Author(s):  
Matthew C. Wheeler ◽  
Harry H. Hendon ◽  
Sam Cleland ◽  
Holger Meinke ◽  
Alexis Donald
Keyword(s):  
Austral Summer ◽  
Madden Julian Oscillation ◽  
Northern Australia ◽  
Trade Winds ◽  
Four Seasons ◽  
Rainfall Anomalies ◽  
Circulation Anomalies ◽  
The Tropics ◽  
Australian Rainfall ◽  
Rainfall Impact

Abstract Impacts of the Madden–Julian oscillation (MJO) on Australian rainfall and circulation are examined during all four seasons. The authors examine circulation anomalies and a number of different rainfall metrics, each composited contemporaneously for eight MJO phases derived from the real-time multivariate MJO index. Multiple rainfall metrics are examined to allow for greater relevance of the information for applications. The greatest rainfall impact of the MJO occurs in northern Australia in (austral) summer, although in every season rainfall impacts of various magnitude are found in most locations, associated with corresponding circulation anomalies. In northern Australia in all seasons except winter, the rainfall impact is explained by the direct influence of the MJO’s tropical convective anomalies, while in winter a weaker and more localized signal in northern Australia appears to result from the modulation of the trade winds as they impinge upon the eastern coasts, especially in the northeast. In extratropical Australia, on the other hand, the occurrence of enhanced (suppressed) rainfall appears to result from induced upward (downward) motion within remotely forced extratropical lows (highs), and from anomalous low-level northerly (southerly) winds that transport moisture from the tropics. Induction of extratropical rainfall anomalies by remotely forced lows and highs appears to operate mostly in winter, whereas anomalous meridional moisture transport appears to operate mainly in the summer, autumn, and to some extent in the spring.

scholarly journals Relative Merit of Model Improvement versus Availability of Retrospective Forecasts: The Case of Climate Forecast System MJO Prediction

2012 ◽  
Vol 27 (4) ◽  
pp. 1045-1051 ◽  
Author(s):  
Qin Zhang ◽  
Huug van den Dool
Keyword(s):  
Systematic Error ◽  
Error Correction ◽  
Initial Conditions ◽  
Climate Forecast ◽  
Prediction System ◽  
Madden Julian Oscillation ◽  
Forecast System ◽  
Climate Forecast System ◽  
Model Improvement ◽  
Ncep Climate Forecast System

Abstract Retrospective forecasts of the new NCEP Climate Forecast System (CFS) have been analyzed out to 45 days from 1999 to 2009 with four members (0000, 0600, 1200, and 1800 UTC) each day. The new version of CFS [CFS, version 2 (CFSv2)] shows significant improvement over the older CFS [CFS, version 1 (CFSv1)] in predicting the Madden–Julian oscillation (MJO), with skill reaching 2–3 weeks in comparison with the CFSv1’s skill of nearly 1 week. Diagnostics of experiments related to the MJO forecast show that the systematic error correction, possible only because of the enormous hindcast dataset and the ensemble aspects of the prediction system (4 times a day), do contribute to improved forecasts. But the main reason is the improvement in the model and initial conditions between 1995 and 2010.

Prediction of the Madden–Julian oscillation with the POAMA dynamical prediction system

2010 ◽  
Vol 36 (3-4) ◽  
pp. 649-661 ◽  
Author(s):  
Harun A. Rashid ◽  
Harry H. Hendon ◽  
Matthew C. Wheeler ◽  
Oscar Alves
Keyword(s):  
Prediction System ◽  
Madden Julian Oscillation

Surface Wind and Upper-Ocean Variability Associated with the Madden–Julian Oscillation Simulated by the Coupled Ocean–Atmosphere Mesoscale Prediction System (COAMPS)

2013 ◽  
Vol 141 (7) ◽  
pp. 2290-2307 ◽  
Author(s):  
Toshiaki Shinoda ◽  
Tommy G. Jensen ◽  
Maria Flatau ◽  
Sue Chen
Keyword(s):  
High Resolution ◽  
Indian Ocean ◽  
Surface Wind ◽  
Upper Ocean ◽  
Prediction System ◽  
Madden Julian Oscillation ◽  
Atmospheric Component ◽  
Ocean Variability ◽  
Ocean Atmosphere ◽  
Nested Grid

Abstract Simulation of surface wind and upper-ocean variability associated with the Madden–Julian oscillation (MJO) by a regional coupled model, the Coupled Ocean–Atmosphere Mesoscale Prediction System (COAMPS), is evaluated by the comparison with in situ and satellite observations. COAMPS is configured for the tropical Indian Ocean domain with the horizontal resolution of 27 km for the atmospheric component and ⅛° for the ocean component. A high-resolution nested grid (9 km) for the atmospheric component is used for the central Indian Ocean. While observational data are assimilated into the atmospheric component, no data are assimilated into the ocean component. The model was integrated during 1 March–30 April 2009 when an active episode of large-scale convection associated with the MJO passed eastward across the Indian Ocean. During this MJO event, strong surface westerly winds (~8 m s−1) were observed in the central equatorial Indian Ocean, and they generated a strong eastward jet (~1 m s−1) on the equator. COAMPS can realistically simulate these surface wind and upper-ocean variations. The sensitivity of upper-ocean variability to the atmospheric model resolution is examined by the COAMPS experiment without the high-resolution nested grid. The equatorial jet generated in this experiment is about 20% weaker than that in the first experiment, which significantly influences upper-ocean salinity and temperature. The large diurnal warming of SST during the suppressed phase of the MJO is also adequately simulated by the model. Weak winds during this period are mostly responsible for the large SST diurnal variation based on the comparison with the spatial variation of surface forcing fields.

scholarly journals How did ocean warming affect Australian rainfall extremes during the 2010/2011 La Niña event?

2015 ◽  
Vol 42 (22) ◽  
pp. 9942-9951 ◽  
Author(s):  
Caroline C. Ummenhofer ◽  
Alexander Sen Gupta ◽  
Matthew H. England ◽  
Andréa S. Taschetto ◽  
Peter R. Briggs ◽  
...  
Keyword(s):  
Ocean Warming ◽  
La Niña ◽  
La Nina ◽  
Rainfall Extremes ◽  
La Nina Event ◽  
Australian Rainfall

scholarly journals Influence of Madden-Julian Oscillation on Southeast Asia rainfall extremes: Observations and predictability

2014 ◽  
Vol 41 (12) ◽  
pp. 4406-4412 ◽  
Author(s):  
Prince Xavier ◽  
Raizan Rahmat ◽  
Wee Kiong Cheong ◽  
Emily Wallace
Keyword(s):  
Southeast Asia ◽  
Madden Julian Oscillation ◽  
Rainfall Extremes

Application of the Boundary Element Method and Modal Analysis to Tire Acoustics Problems

1993 ◽  
Vol 21 (2) ◽  
pp. 66-90 ◽  
Author(s):  
Y. Nakajima ◽  
Y. Inoue ◽  
H. Ogawa
Keyword(s):  
Finite Element ◽  
Boundary Element Method ◽  
Boundary Element ◽  
Acoustic Radiation ◽  
Traffic Noise ◽  
Noise Prediction ◽  
Prediction System ◽  
Tire Noise ◽  
Acoustic Contribution ◽  
Element Method

Abstract Road traffic noise needs to be reduced, because traffic volume is increasing every year. The noise generated from a tire is becoming one of the dominant sources in the total traffic noise because the engine noise is constantly being reduced by the vehicle manufacturers. Although the acoustic intensity measurement technology has been enhanced by the recent developments in digital measurement techniques, repetitive measurements are necessary to find effective ways for noise control. Hence, a simulation method to predict generated noise is required to replace the time-consuming experiments. The boundary element method (BEM) is applied to predict the acoustic radiation caused by the vibration of a tire sidewall and a tire noise prediction system is developed. The BEM requires the geometry and the modal characteristics of a tire which are provided by an experiment or the finite element method (FEM). Since the finite element procedure is applied to the prediction of modal characteristics in a tire noise prediction system, the acoustic pressure can be predicted without any measurements. Furthermore, the acoustic contribution analysis obtained from the post-processing of the predicted results is very helpful to know where and how the design change affects the acoustic radiation. The predictability of this system is verified by measurements and the acoustic contribution analysis is applied to tire noise control.

Short-Term Flood Prediction System

2014 ◽  
Vol 13 (1) ◽  
Author(s):  
Konrad Nering
Keyword(s):  
Flash Floods ◽  
Prediction System ◽  
Short Term ◽  
Data Set ◽  
Flood Prediction ◽  
Full Operation

AbstractThis paper describes a fully functional short-term flood prediction system. Its effect has been tested on watershed of Lubieńka river in Małopolska. To use this system it must have a data set also described in this paper. A modification of the system to adopt for predicting flash floods was described. Full operation of the system is shown on example of real flood on Lubieńka river in June 2011.

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