scholarly journals ANALISIS CUACA PADA SAAT PELAKSANAAN TMC PENANGGULANGAN BANJIR JAKARTA JANUARI FEBRUARI 2014

2015 ◽  
Vol 16 (1) ◽  
pp. 15
Author(s):  
Erwin Mulyana
Keyword(s):  
Southern Oscillation ◽  
Sea Surface ◽  
Madden Julian Oscillation ◽  
Weather Modification ◽  
Indian Ocean Dipole Mode ◽  
Monsoon Index ◽  
West Part ◽  
Cloud Development ◽  
Australian Summer Monsoon ◽  
Australian Summer

AbstrakPada tanggal 11 Januari sampai dengan 14 Februari 2014 telah dilaksanakan penerapan teknologi modifikasi cuaca (TMC) untuk menanggulangi banjir di wilayah Jakarta dan sekitarnya. Selama kegiatan tersebut fenomena ENSO dan IOD dalam kondisi normal. MJO menunjukkan aktifitas konvektif netral di wilayah Indonesia pada pertengahan Januari hingga pertengahan Februari 2014. Temperatur  permukaan laut di perairan Jawa bagian barat sekitar 28-290C. Kelembagan udara pada level 850 mb sekitar 70-80%. Pertumbuhan awan umumnya berada di sebelah barat daya, barat dan barat laut Jakarta. Indeks Monsoon Australia positif berpengaruh terhadap peningkatan pembentukan awan hujan di Jawa.Abstract Application of weather modification has carried out to reduce precipitation over Jakarta on 11 January to 14 February 2013. During this period, El Nino Southern Oscillation and Indian Ocean Dipole Mode were normal condition. The Madden Julian Oscillation shows that the convection over Indonesia region was netral condition. The sea surface temperature over west part of Java waters was 29-30 290C. The 850 mb average of relative humidity on mid January - mid February 2014 was 70-80%. Based on visual and weather radar observation, cloud development mainly over northwest to southwest of Jakarta. Positive Australian Summer Monsoon Index affected to increase precipitation over Java area.

scholarly journals ANALISIS CUACA SELAMA KEGIATAN TMC REDISTRIBUSI CURAH HUJAN

2013 ◽  
Vol 14 (1) ◽  
pp. 13
Author(s):  
Erwin Mulyana
Keyword(s):  
Relative Humidity ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Normal Condition ◽  
Sea Surface ◽  
Weather Modification ◽  
West Part ◽  
Cloud Development

IntisariPada tanggal 26 Januari sampai dengan 27 Februari 2013 telah dilaksanakan penerapan teknologi modifikasi cuaca (TMC) untuk redistribusi curah hujan di wilayah Jakarta dan sekitarnya. Selama kegiatan tersebut fenomena ENSO dan IOD dalam kondisi normal. MJO menunjukkan adanya peningkatan aktifitas konvektif di wilayah Indonesia pada pertengahan hingga akhir bulan Februari 2013. Temperatur  permukaan laut di perairan sekitar Jawa bagian barat sekitar 29-300C. Kelembagan udara pada level 850 mb sekitar 75-80%. Pertumbuhan awan umumnya berada di sebelah barat laut hingga barat daya Jakarta.AbstractApplication of weather modification has carried out to redistribute of precpitiaion over Jakarta and the surrounding during  26 January to 27 February 2013. During this period, ENSO and IOD was normal condition. The MJO shows that the convection enhanched over Indonesia region on mid to late February 2013. The sea surface temperature over west part of Java waters was 29-300C. The 850 mb relative humidity on February 2013 was 75-80%. Cloud development mainly over northwest to southwest of Jakarta,

scholarly journals The Onset of the Indonesian–Australian Summer Monsoon Triggered by the First-Branch Eastward-Propagating Madden–Julian Oscillation

2019 ◽  
Vol 32 (17) ◽  
pp. 5453-5470 ◽  
Author(s):  
Yongliang Duan ◽  
Hongwei Liu ◽  
Weidong Yu ◽  
Lin Liu ◽  
Guang Yang ◽  
...  
Keyword(s):  
Summer Monsoon ◽  
Heat Budget ◽  
Sea Surface ◽  
Specific Humidity ◽  
Surface Mixed Layer ◽  
Madden Julian Oscillation ◽  
Northern Australia ◽  
Surface Warming ◽  
Australian Summer Monsoon ◽  
Australian Summer

Abstract The Madden–Julian oscillation (MJO) often causes the onset of the Indonesian–Australian summer monsoon (IASM) over Indonesia and northern Australia. In the present study, a composite analysis is conducted to reveal the detailed IASM onset process and its air–sea interactions associated with the first-branch eastward-propagating MJO (FEMJO) based on 30-yr ERA-Interim data, satellite-derived sea surface temperature (SST), outgoing longwave radiation (OLR), and SODA3 ocean reanalysis. The results distinctly illustrate the phase-locked relationships among the persistent sea surface warming north of Australia, the FEMJO, and the established westerlies. It is found that the SST to the north of Australia reaches its annual maximum just before the onset of the summer monsoon. The oceanic surface mixed layer heat budget discloses that this rapid warming is primarily produced by the enhanced surface heat flux. In addition, this premonsoon sea surface warming increases the air specific humidity in the low-level troposphere and then establishes zonal moisture asymmetry relative to the FEMJO convection. This creates a more unstable atmospheric stratification southeast of the FEMJO and favors convection throughout the vicinity of northern Australia, which ultimately triggers the onset of the IASM. The results in this study thus may potentially be applicable to seasonal monsoon climate monitoring and prediction.

The Australian summer monsoon: a review

1992 ◽  
Vol 16 (3) ◽  
pp. 283-318 ◽  
Author(s):  
R. Suppiah
Keyword(s):  
Summer Monsoon ◽  
Southern Oscillation ◽  
Human Life ◽  
Research Priorities ◽  
Global Scale ◽  
Northwestern Part ◽  
Greenhouse Condition ◽  
Australian Summer Monsoon ◽  
Circulation Characteristics ◽  
Australian Summer

The Australian summer monsoon influences the climate of the Australian tropics during the period from December to March. During this period, interannual and intraseasonal variations of rainfall associated with global-scale circulation anomalies strongly effect human life and economic activities in this region. Any changes in the global-scale circulation patterns in relation to changes in the heat balance components under enhanced greenhouse condition could alter monsoonal circulation characteristics and thus could bring serious impacts to human life in the monsoon-dominated region. To provide a basis for looking at changes in monsoonal characteristics under enhanced greenhouse condition, the current understanding of the Australian summer monsoonal circulation characteristics is reviewed here. Detailed information is given on the formation and the steady development of the Pilbara heat low over the northwestern part of Australia and the importance of the location of the monsoon shear line, active and break cycles of the monsoon, influence of South China Sea cold surges on monsoon activity, 40-50 oscillation in monsoon rainfall and winds and their link to El Nino/ Southern Oscillation (ENSO) phenomenon, the influence of the ENSO phenomenon on rainfall on interannual time scales and the link between monsoonal activity and tropical cyclones. The problems related to the above mentioned topics and their research priorities are highlighted.

scholarly journals Possible Role of the Indian Ocean in the In-Phase Transition of the Indian-to-Australian Summer Monsoon

2008 ◽  
Vol 21 (21) ◽  
pp. 5727-5741 ◽  
Author(s):  
Renguang Wu
Keyword(s):  
Indian Ocean ◽  
Summer Monsoon ◽  
Southern Oscillation ◽  
Tropical Indian Ocean ◽  
Australian Summer Monsoon ◽  
The Indian Ocean ◽  
Numerical Model Experiments ◽  
Sst Anomalies ◽  
Australian Summer

Abstract Analysis of observations shows that in-phase transitions from the Indian summer monsoon (ISM) to the Australian summer monsoon (ASM) have occurred both in El Niño–Southern Oscillation (ENSO) and non-ENSO years. The present study investigates possible roles of the Indian Ocean in the in-phase ISM-to-ASM transitions. It is shown that an anomalous ISM leads to sea surface temperature (SST) anomalies in the tropical Indian Ocean through wind–evaporation effects. The resultant Indian Ocean SST anomalies induce an anomalous ASM of the same sign as the ISM through an anomalous east–west circulation over the eastern Indian Ocean and the Maritime Continent–northern Australia. The results indicate that the in-phase ISM-to-ASM transitions in non-ENSO years can be accomplished through monsoon–Indian Ocean interactions. The results of observational analysis are confirmed with numerical model experiments.

scholarly journals EVALUASI PERFORMA INDEKS MONSUN AUSMI DAN WNPMI DI WILAYAH INDONESIA

2021 ◽  
Vol 22 (2) ◽  
pp. 61-70
Author(s):  
Adi Mulsandi ◽  
Ardhasena Sopaheluwakan ◽  
Akhmad Faqih ◽  
Rahmat Hidayat ◽  
Yonny Koesmaryono
Keyword(s):  
Annual Cycle ◽  
Global Precipitation Climatology Project ◽  
Australian Monsoon ◽  
Monsoon Index ◽  
Monsoon System ◽  
Australian Summer Monsoon ◽  
Two Indices ◽  
Global Precipitation ◽  
Monsoon Indices ◽  
Australian Summer

Intisari Iklim di wilayah Indonesia sangat dipengaruhi oleh aktivitas monsun Asia-Australia. Variabilitas kedua sistem monsun tersebut dapat direpresentasikan dengan baik masing-masing oleh indeks monsun Australian Summer Monsoon Index (AUSMI) dan Western North Pacific Monsoon Index (WNPMI). Saat ini, BMKG secara operasional menggunakan indeks AUSMI dan WNPMI untuk memonitor aktivitas monsun di wilayah Indonesia sebagai bahan prakiraan musim. Meskipun banyak literatur menyatakan bahwa wilayah Indonesia merupakan bagian dari sistem monsun Asia-Australia, namun kondisi topografi lokal yang kompleks berpotensi memodifikasi sirkulasi monsun sehingga perlu dikaji performa kedua indeks tersebut sebelum digunakan secara operasional. Penelitian ini dilakukan untuk menguji performa indeks monsun AUSMI dan WNPMI dalam menggambarkan variasi antartahunan (interannual), variasi dalam musim (intraseasonal), dan siklus tahunan (annual cycle) hujan monsun Indonesia. Hasil penelitian mengungkapkan bahwa kedua indeks memiliki performa yang sangat baik hanya di wilayah dimana indeks tersebut didefinisikan namun kurang baik untuk wilayah Indonesia seperti yang ditunjukan oleh nilai koefisien korelasi yang tidak signifikan dari hasil uji statistik antara kedua indeks dengan curah hujan dari Global Precipitation Climatology Project (GPCP) pada periode 1981-2010. Selain itu, kedua indeks juga memperlihatkan karakteristik siklus tahunan yang berbeda dengan karakteristik siklus tahunan hujan wilayah Jawa sebagai wilayah kunci monsun Indonesia. Hasil ini mengindikasikan perlunya pendefinisian indeks sendiri untuk memonitor aktivitas monsun di wilayah Indonesia.    Abstract  The climate of Indonesia is strongly affected by the Asian-Australian monsoon system. The variability of the two monsoon systems can be well represented by the Western North Pacific Monsoon Index (WNPMI) and the Australian Summer Monsoon Index (AUSMI) respectively. For producing seasonal forecast, BMKG uses the WNPMI and AUSMI monsoon index to monitor monsoon activity in Indonesia. Although most literature states that the Indonesian region is part of the Asian-Australian monsoon system, the complex local topography may modify the monsoon circulation. Hence, it is necessary to assess the performance of the two indices before they are operationally used. This study was conducted to evaluate the performance of the AUSMI and WNPMI monsoon indices in describing the annual cycle, intraseasonal and interannual variability of the Indonesian monsoon rainfall. The results revealed that the two indices only performed very well in the areas where the index was defined but lack of skill for the Indonesian region because of insignificant linear correlation based on a statistical significance test between the two indices and the Global Precipitation Climatology Project (GPCP) rainfall in the 1981-2010 period. In addition, both monsoon indices and Java rainfall showed different characteristics of the annual cycle. These results indicate that it is necessary to define a specific index for monitoring monsoon activity in Indonesia.

Seasonal climate summary for the southern hemisphere (summer 2016–17): a season of extremes despite neutral ENSO, IOD

2019 ◽  
Vol 69 (1) ◽  
pp. 290
Author(s):  
Ben Hague
Keyword(s):  
Southern Hemisphere ◽  
Southern Oscillation ◽  
Heavy Rain ◽  
Southern Annular Mode ◽  
Sea Surface ◽  
Madden Julian Oscillation ◽  
Extreme Temperatures ◽  
Atmospheric Circulation Patterns ◽  
Circulation Patterns ◽  
The Indian Ocean

This is a summary of the southern hemisphere atmospheric circulation patterns and meteorological indices for summer 2016–17; an account of seasonal rainfall and temperature for the Australian region is also provided. Although indices for the El Niño–Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) represented typical neutral condition for these drivers, evidence of other climate drivers can be found in the land, ocean and atmosphere data from this time. The Southern Annular Mode appeared to have had some effect on rainfall in the east of Australia, and the Madden–Julian Oscillation active periods produced heavy rain in the tropical north. Despite neutral ENSO and IOD, extreme temperatures, in some areas highest on record, occurred in northern NSW and southern Queensland. High sea-surface temperatures caused further severe bleaching on the Great Barrier Reef.

scholarly journals Interannual Variability and Trends in Sea Surface Temperature, Lower and Middle Atmosphere Temperature at Different Latitudes for 1980–2019

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 454
Author(s):  
Andrew R. Jakovlev ◽  
Sergei P. Smyshlyaev ◽  
Vener Y. Galin
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Lower Stratosphere ◽  
Middle Atmosphere ◽  
Southern Oscillation ◽  
Lower Troposphere ◽  
Reanalysis Data ◽  
Sea Surface ◽  
The Arctic ◽  
The Impact

The influence of sea-surface temperature (SST) on the lower troposphere and lower stratosphere temperature in the tropical, middle, and polar latitudes is studied for 1980–2019 based on the MERRA2, ERA5, and Met Office reanalysis data, and numerical modeling with a chemistry-climate model (CCM) of the lower and middle atmosphere. The variability of SST is analyzed according to Met Office and ERA5 data, while the variability of atmospheric temperature is investigated according to MERRA2 and ERA5 data. Analysis of sea surface temperature trends based on reanalysis data revealed that a significant positive SST trend of about 0.1 degrees per decade is observed over the globe. In the middle latitudes of the Northern Hemisphere, the trend (about 0.2 degrees per decade) is 2 times higher than the global average, and 5 times higher than in the Southern Hemisphere (about 0.04 degrees per decade). At polar latitudes, opposite SST trends are observed in the Arctic (positive) and Antarctic (negative). The impact of the El Niño Southern Oscillation phenomenon on the temperature of the lower and middle atmosphere in the middle and polar latitudes of the Northern and Southern Hemispheres is discussed. To assess the relative influence of SST, CO2, and other greenhouse gases’ variability on the temperature of the lower troposphere and lower stratosphere, numerical calculations with a CCM were performed for several scenarios of accounting for the SST and carbon dioxide variability. The results of numerical experiments with a CCM demonstrated that the influence of SST prevails in the troposphere, while for the stratosphere, an increase in the CO2 content plays the most important role.

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