Maritime Continent rainfall variability during the TRMM era: The role of monsoon, topography and El Niño Modoki

2016 ◽  
Vol 75 ◽  
pp. 58-77 ◽  
Author(s):  
Abd. Rahman As-syakur ◽  
Takahiro Osawa ◽  
Fusanori Miura ◽  
I. Wayan Nuarsa ◽  
Ni Wayan Ekayanti ◽  
...  
Keyword(s):  
El Niño ◽  
El Nino ◽  
Rainfall Variability ◽  
Maritime Continent ◽  
El Niño Modoki

scholarly journals Multi-scale meteorological conceptual analysis of observed active fire hotspot activity and smoke optical depth in the Maritime Continent

2012 ◽  
Vol 12 (4) ◽  
pp. 2117-2147 ◽  
Author(s):  
J. S. Reid ◽  
P. Xian ◽  
E. J. Hyer ◽  
M. K. Flatau ◽  
E. M. Ramirez ◽  
...  
Keyword(s):  
Tropical Cyclone ◽  
Optical Depth ◽  
El Niño ◽  
El Nino ◽  
Tropical Cyclone Activity ◽  
Seasonal Migration ◽  
Cyclone Activity ◽  
Maritime Continent ◽  
El Niño Modoki ◽  
Active Fire

Abstract. Much research and speculation exists about the meteorological and climatological impacts of biomass burning in the Maritime Continent (MC) of Indonesia and Malaysia, particularly during El Nino events. However, the MC hosts some of the world's most complicated meteorology, and we wish to understand how tropical phenomena at a range of scales influence observed burning activity. Using Moderate Resolution Imaging Spectroradiometer (MODIS) derived active fire hotspot patterns coupled with aerosol data assimilation products, satellite based precipitation, and meteorological indices, the meteorological context of observed fire prevalence and smoke optical depth in the MC are examined. Relationships of burning and smoke transport to such meteorological and climatic factors as the interannual El Nino-Southern Oscillation (ENSO), El Nino Modoki, Indian Ocean Dipole (IOD), the seasonal migration of the Intertropical Convergence Zone, the 30–90 day Madden Julian Oscillation (MJO), tropical waves, tropical cyclone activity, and diurnal convection were investigated. A conceptual model of how all of the differing meteorological scales affect fire activity is presented. Each island and its internal geography have different sensitivities to these factors which are likely relatable to precipitation patterns and land use practices. At the broadest scales as previously reported, we corroborate ENSO is indeed the largest factor. However, burning is also enhanced by periods of El Nino Modoki. Conversely, IOD influences are unclear. While interannual phenomena correlate to total seasonal burning, the MJO largely controls when visible burning occurs. High frequency phenomena which are poorly constrained in models such as diurnal convection and tropical cyclone activity also have an impact which cannot be ignored. Finally, we emphasize that these phenomena not only influence burning, but also the observability of burning, further complicating our ability to assign reasonable emissions.

scholarly journals Multi-scale meteorological conceptual model of observed active fire hotspot activity and smoke optical depth in the Maritime Continent

2011 ◽  
Vol 11 (7) ◽  
pp. 21091-21170 ◽  
Author(s):  
J. S. Reid ◽  
P. Xian ◽  
E. J. Hyer ◽  
M. K. Flatau ◽  
E. M. Ramirez ◽  
...  
Keyword(s):  
Tropical Cyclone ◽  
Conceptual Model ◽  
Optical Depth ◽  
El Niño ◽  
El Nino ◽  
Tropical Cyclone Activity ◽  
Cyclone Activity ◽  
Maritime Continent ◽  
El Niño Modoki ◽  
Active Fire

Abstract. Much research and speculation exists about the meteorological and climatological impacts of biomass burning in the Maritime Continent (MC) of Indonesia and Malaysia, particularly during El Niño events. However, the MC hosts some of the world's most complicated meteorology, and we wish to understand how tropical phenomena at a range of scales influence observed burning activity. Using Moderate Resolution Imaging Spectroradiometer (MODIS) derived active fire hotspot patterns coupled with aerosol data assimilation products, satellite based precipitation, and meteorological indices, the meteorological context of observed fire prevalence and smoke optical depth in the MC are examined. Relationships of burning and smoke transport to such meteorological and climatic factors as the interannual El Niño-Southern Oscillation (ENSO), El Niño Modoki, Indian Ocean Dipole (IOP), the seasonal migration of the Intertropical Convergence Zone, the 30–90 day Madden Julian Oscillation (MJO), tropical waves, tropical cyclone activity, and diurnal convection were investigated. A conceptual model of how all of the differing meteorological scales affect fire activity is presented. Each island and its internal geography have different sensitivities to these factors which are likely relatable to precipitation patterns and land use practices. At the broadest scales as previously reported, we confirm ENSO is indeed the largest factor. However, burning is also enhanced by periods of El Niño Modoki. Conversely IOD influences are unclear. While interannual phenomena correlate to total seasonal burning, the MJO largely controls when visible burning occurs. High frequency phenomena which are poorly constrained in models such as diurnal convection and tropical cyclone activity also have an impact which cannot be ignored. Finally, we emphasize that these phenomena not only influence burning, but also the observability of burning, further complicating our ability to assign reasonable emissions.

scholarly journals How Does Shifting Pacific Ocean Warming Modulate on Tropical Cyclone Frequency over the South China Sea?

2011 ◽  
Vol 24 (17) ◽  
pp. 4695-4700 ◽  
Author(s):  
Guanghua Chen
Keyword(s):  
Pacific Ocean ◽  
Tropical Cyclone ◽  
South China Sea ◽  
South China ◽  
El Niño ◽  
El Nino ◽  
Ocean Warming ◽  
The South China Sea ◽  
Maritime Continent ◽  
El Niño Modoki

The different modulation of El Niño Modoki and canonical El Niño events on tropical cyclone (TC) frequency over the South China Sea (SCS) during boreal summer and fall for 1960–2009 is investigated. The bootstrap resampling method and two-sample permutation procedure are applied to simulate sampling distributions and conduct statistical tests, respectively. Results from the hypothesis testing indicate that the above-normal TC frequency over the SCS occurs during June–August (JJA) for the El Niño Modoki years, whereas the below-normal TC frequency is significant during September–November (SON) for the canonical El Niño years. The remarkably opposite modulations can be attributed to the different large-scale circulation anomalies, which are consistent with Matsuno–Gill-type responses to the tropical heating source/sink over the western North Pacific (WNP) and Maritime Continent for two kinds of Pacific Ocean warming events. In response to a broad-scale convection anomaly over the WNP during JJA for El Niño Modoki, a zonally elongated cyclonic anomaly dominates the WNP and SCS, leading to enhanced TC activity. In contrast, during SON for the canonical El Niño, a markedly strengthened cooling source centered in the Maritime Continent induces an anticyclonic anomaly over the SCS, resulting in suppressed TC activity.

scholarly journals Differential Influences of Teleconnections from the Indian and Pacific Oceans on Rainfall Variability in Southeast Asia

Atmosphere ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 886
Author(s):  
Abdul Azim Amirudin ◽  
Ester Salimun ◽  
Fredolin Tangang ◽  
Liew Juneng ◽  
Muhamad Zuhairi
Keyword(s):  
Indian Ocean ◽  
Southeast Asia ◽  
El Niño ◽  
El Nino ◽  
Rainfall Variability ◽  
June July August ◽  
Rainfall Patterns ◽  
Negative Impacts ◽  
The Individual ◽  
June July

This study investigates the individual and combined impacts of El Niño and the positive Indian Ocean Dipole (IOD) on the Southeast Asia (SEA) rainfall variability. Using composite and partial correlation techniques, it is shown that both inter-annual events have individually distinct impacts on the SEA rainfall anomaly distribution. The results showed that the impacts of the co-occurrence of El Niño and IOD events are significant compared to the individual effects of pure El Niño or pure IOD. During June-July-August and September-October-November, the individual impacts of the pure El Niño and IOD events are similar but less significant. Both events caused negative impacts over the southern part of SEA during June-July-August (JJA) and propagated northeastward/eastward during September-October-November (SON). Thus, there are significant negative impacts over the southern part of SEA during the co-occurrence of both events. The differential impacts on the anomalous rainfall patterns are due to the changes in the sea surface temperature (SST) surrounding the region. Additionally, the differences are also related to the anomalous regional atmospheric circulations that interact with the regional SST. The anomalous Walker circulation that connects the Indian Ocean and tropical Pacific Ocean also plays a significant role in determining the regional anomalous rainfall patterns.

scholarly journals The Response of Tropical Atmospheric Energy Budgets to ENSO*

2013 ◽  
Vol 26 (13) ◽  
pp. 4710-4724 ◽  
Author(s):  
Michael Mayer ◽  
Kevin E. Trenberth ◽  
Leopold Haimberger ◽  
John T. Fasullo
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Warm Pool ◽  
Smooth Transition ◽  
Energy Budgets ◽  
Enso Events ◽  
El Niño Modoki ◽  
Static Energy ◽  
The Tropics

Abstract The variability of zonally resolved tropical energy budgets in association with El Niño–Southern Oscillation (ENSO) is investigated. The most recent global atmospheric reanalyses from 1979 to 2011 are employed with removal of apparent discontinuities to obtain best possible temporal homogeneity. The growing length of record allows a more robust analysis of characteristic patterns of variability with cross-correlation, composite, and EOF methods. A quadrupole anomaly pattern is found in the vertically integrated energy divergence associated with ENSO, with centers over the Indian Ocean, the Indo-Pacific warm pool, the eastern equatorial Pacific, and the Atlantic. The smooth transition, particularly of the main maxima of latent and dry static energy divergence, from the western to the eastern Pacific is found to require at least two EOFs to be adequately described. The canonical El Niño pattern (EOF-1) and a transition pattern (EOF-2; referred to as El Niño Modoki by some authors) form remarkably coherent ENSO-related anomaly structures of the tropical energy budget not only over the Pacific but throughout the tropics. As latent and dry static energy divergences show strong mutual cancellation, variability of total energy divergence is smaller and more tightly coupled to local sea surface temperature (SST) anomalies and is mainly related to the ocean heat discharge and recharge during ENSO peak phases. The complexity of the structures throughout the tropics and their evolution during ENSO events along with their interactions with the annual cycle have often not been adequately accounted for; in particular, the El Niño Modoki mode is but part of the overall evolutionary patterns.

scholarly journals Role of the Indo-Pacific Interbasin Coupling in Predicting Asymmetric ENSO Transition and Duration

2012 ◽  
Vol 25 (9) ◽  
pp. 3321-3335 ◽  
Author(s):  
Masamichi Ohba ◽  
Masahiro Watanabe
Keyword(s):  
El Niño ◽  
General Circulation ◽  
El Nino ◽  
Southern Oscillation ◽  
La Niña ◽  
La Nina ◽  
The Pacific ◽  
Enso Asymmetry ◽  
Sst Anomalies

Warm and cold phases of El Niño–Southern Oscillation (ENSO) exhibit a significant asymmetry in their transition/duration such that El Niño tends to shift rapidly to La Niña after the mature phase, whereas La Niña tends to persist for up to 2 yr. The possible role of sea surface temperature (SST) anomalies in the Indian Ocean (IO) in this ENSO asymmetry is investigated using a coupled general circulation model (CGCM). Decoupled-IO experiments are conducted to assess asymmetric IO feedbacks to the ongoing ENSO evolution in the Pacific. Identical-twin forecast experiments show that a coupling of the IO extends the skillful prediction of the ENSO warm phase by about one year, which was about 8 months in the absence of the IO coupling, in which a significant drop of the prediction skill around the boreal spring (known as the spring prediction barrier) is found. The effect of IO coupling on the predictability of the Pacific SST is significantly weaker in the decay phase of La Niña. Warm IO SST anomalies associated with El Niño enhance surface easterlies over the equatorial western Pacific and hence facilitate the El Niño decay. However, this mechanism cannot be applied to cold IO SST anomalies during La Niña. The result of these CGCM experiments estimates that approximately one-half of the ENSO asymmetry arises from the phase-dependent nature of the Indo-Pacific interbasin coupling.

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