The mechanism of general flowering in Dipterocarpaceae in the Malay Peninsula

1999 ◽  
Vol 15 (4) ◽  
pp. 437-449 ◽  
Author(s):  
Masatoshi Yasuda ◽  
Jun Matsumoto ◽  
Noriyuki Osada ◽  
San'ei Ichikawa ◽  
Naoki Kachi ◽  
...  
Keyword(s):  
El Niño ◽  
Atmospheric Carbon Dioxide ◽  
El Nino ◽  
Meteorological Data ◽  
Equatorial Region ◽  
La Niña ◽  
Malay Peninsula ◽  
Night Time ◽  
La Nina ◽  
General Flowering

The mechanism of general flowering in Dipterocarpaceae in the Malay Peninsula is revealed through field survey and meteorological data analyses. The regions of general flowering coincide with those which experienced a low night-time temperature (LNT) c. 2 mo before flowering. This supports the hypothesis that low air temperature induces the development of floral buds of dipterocarps. LNT was found to be caused by radiative cooling during dry spells in winter when the northern subtropical ridge (STR) occasionally migrates southwards with a dry air mass into the equatorial region. LNT events usually occur in La Niña episodes, not in El Niño episodes as believed previously. This is because the southward migration of the STR is associated with the intensification of local meridional Hadley Circulation in the western Pacific, which is strengthened in a La Niña episode. Results suggest that El Niño-like climate change in increased atmospheric carbon dioxide concentrations may be critical for the tropical rain forest biome in south-east Asia.

Sea Surface Temperature in the Subtropical Pacific Boosted the 2015 El Niño and Hindered the 2016 La Niña

2018 ◽  
Vol 31 (2) ◽  
pp. 877-893 ◽  
Author(s):  
Jingzhi Su ◽  
Renhe Zhang ◽  
Xinyao Rong ◽  
Qingye Min ◽  
Congwen Zhu
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
El Niño ◽  
El Nino ◽  
Heat Content ◽  
Equatorial Region ◽  
La Niña ◽  
Sea Surface ◽  
La Nina ◽  
Super El Niño

After the quick decaying of the 2015 super El Niño, the predicted La Niña unexpectedly failed to materialize to the anticipated standard in 2016. Diagnostic analyses, as well as numerical experiments, showed that this ENSO evolution of the 2015 super El Niño and the hindered 2016 La Niña may be essentially caused by sea surface temperature anomalies (SSTAs) in the subtropical Pacific. The self-sustaining SSTAs in the subtropical Pacific tend to weaken the trade winds during boreal spring–summer, leading to anomalous westerlies along the equatorial region over a period of more than one season. Such long-lasting wind anomalies provide an essential requirement for ENSO formation, particularly before a positive Bjerknes feedback is thoroughly built up between the oceanic and atmospheric states. Besides the 2015 super El Niño and the hindered La Niña in 2016, there were several other El Niño and La Niña events that cannot be explained only by the oceanic heat content in the equatorial Pacific. However, the questions related to those eccentric El Niño and La Niña events can be well explained by suitable SSTAs in the subtropical Pacific. Thus, the leading SSTAs in the subtropical Pacific can be treated as an independent indicator for ENSO prediction, on the basis of the oceanic heat content inherent in the equatorial region. Because ENSO events have become more uncertain under the background of global warming and the Pacific decadal oscillation during recent decades, thorough investigation of the role of the subtropical Pacific in ENSO formation is urgently needed.

scholarly journals Different El Niño Types and Tropical Cyclone Landfall in East Asia

2012 ◽  
Vol 25 (19) ◽  
pp. 6510-6523 ◽  
Author(s):  
Wei Zhang ◽  
H.-F. Graf ◽  
Yee Leung ◽  
Michael Herzog
Keyword(s):  
Tropical Cyclone ◽  
East Asia ◽  
El Niño ◽  
El Nino ◽  
The Philippines ◽  
La Niña ◽  
Malay Peninsula ◽  
Cp El Niño ◽  
La Nina ◽  
Ep El Niño

Abstract This study examines whether there exist significant differences in tropical cyclone (TC) landfall between central Pacific (CP) El Niño, eastern Pacific (EP) El Niño, and La Niña during the peak TC season (June–October) and how and to what extent CP El Niño influences TC landfall over East Asia for the period 1961–2009. The peak TC season is subdivided into summer [June–August (JJA)] and autumn [September–October (SO)]. The results are summarized as follows: (i) during the summer of CP El Niño years, TCs are more likely to make landfall over East Asia because of a strong easterly steering flow anomaly induced by the westward shift of the subtropical high and northward-shifted TC genesis. In particular, TCs have a greater probability of making landfall over Japan and Korea during the summer of CP El Niño years. (ii) In the autumn of CP El Niño years, TC landfall in most areas of East Asia, especially Indochina, the Malay Peninsula, and the Philippines, is likely to be suppressed because the large-scale circulation resembles that of EP El Niño years. (iii) During the whole peak TC season [June–October (JJASO)] of CP El Niño years, TCs are more likely to make landfall over Japan and Korea. TC landfall in East Asia as a whole has an insignificant association with CP El Niño during the peak TC season. In addition, more (less) TCs are likely to make landfall in China, Indochina, the Malay Peninsula, and the Philippines during the peak TC season of La Niña (EP El Niño) years.

The Pacific’s Response to Surface Heating in 130 Yr of SST: La Niña–like or El Niño–like?

2010 ◽  
Vol 67 (8) ◽  
pp. 2649-2657 ◽  
Author(s):  
Ka-Kit Tung ◽  
Jiansong Zhou
Keyword(s):  
El Niño ◽  
Climate Model ◽  
El Nino ◽  
Walker Circulation ◽  
Dominant Mode ◽  
Equatorial Region ◽  
La Niña ◽  
Radiative Heating ◽  
Modified Method ◽  
La Nina

Abstract Using a modified method of multiple linear regression on instrumented sea surface temperature (SST) in the two longest historical datasets [the Extended Reconstructed SST dataset (ERSST) and the Met Office Hadley Centre Sea Ice and SST dataset (HadISST)], it is found that the response to increased greenhouse forcing is a warm SST in the mid- to eastern Pacific Ocean in the equatorial region in the annual or seasonal mean. The warming is robustly statistically significant at the 95% confidence level. Consistent with this, the smaller radiative heating from solar forcing produces a weak warming also in this region, and the spatial pattern of the response is neither La Niña–like nor El Niño–like. It is noted that previous reports of a cold-tongue (La Niña–like) response to increased greenhouse or to solar-cycle heating were likely caused by contaminations due to the dominant mode of natural response in the equatorial Pacific. The present result has implications on whether the Walker circulation is weakened or strengthened in a warmer climate and on coupled atmosphere–ocean climate model validation.

scholarly journals A Nonlinear Analysis of the ENSO Cycle and Its Interdecadal Changes*

2005 ◽  
Vol 18 (16) ◽  
pp. 3229-3239 ◽  
Author(s):  
Soon-Il An ◽  
William W. Hsieh ◽  
Fei-Fei Jin
Keyword(s):  
El Niño ◽  
El Nino ◽  
Heat Content ◽  
Principal Component ◽  
Equatorial Region ◽  
La Niña ◽  
Enso Cycle ◽  
Heat Accumulation ◽  
Neural Network Approach ◽  
La Nina

Abstract The nonlinear principal component analysis (NLPCA), via a neural network approach, was applied to thermocline anomalies in the tropical Pacific. While the tropical sea surface temperature (SST) anomalies had been nonlinearly mapped by the NLPCA mode 1 onto an open curve in the data space, the thermocline anomalies were mapped to a closed curve, suggesting that ENSO is a cyclic phenomenon. The NLPCA mode 1 of the thermocline anomalies reveals the nonlinear evolution of the ENSO cycle with much asymmetry for the different phases: The weak heat accumulation in the whole equatorial Pacific is followed by the strong El Niño, and the subsequent strong drain of equatorial heat content toward the off-equatorial region precedes a weak La Niña. This asymmetric ENSO evolution implies that the nonlinear instability enhances the growth of El Niño, but dwarfs the growth of La Niña. The nonlinear ENSO cycle was found to have changed since the late 1970s. For the pre-1980s the ENSO cycle associated with the thermocline is less asymmetrical than that during the post-1980s, indicating that the nonlinearity of the ENSO cycle has become stronger since the late 1970s.

scholarly journals Spatial analysis and model construction of NDVI Based on meteorological data

2022 ◽  
Vol 355 ◽  
pp. 03040
Author(s):  
Jifeng Wu ◽  
Yayu Cheng
Keyword(s):  
El Niño ◽  
Vegetation Change ◽  
Vegetation Index ◽  
El Nino ◽  
Meteorological Data ◽  
Southern Region ◽  
La Niña ◽  
La Nina ◽  
Geographical Regions ◽  
Precipitation And Temperature

NDVI (Normalized Vegetation Index) is an important characteristic index to study regional vegetation change, which is greatly influenced by meteorological data. Based on the analysis of the trend change and correlation between NDVI and PWV (Precipitable Water Vapor), precipitation and temperature in four geographical regions of China, this paper constructs a model between NDVI and PWV, precipitation and temperature in each geographical region according to multiple regression, and predicts NDVI through meteorological data. The results show that:(1) NDVI and meteorological factors have the same changing trend, and the maximum value appears in every region from June to September, and the value of NDVI in southern region is relatively large. (2) The correlation between rainfall and NDVI is the highest in Qinghai-Tibet region, the correlation between temperature, PWV and NDVI is the highest in northern region, the correlation between NDVI and rainfall, temperature and PWV is the lowest in southern region. (3)According to the meteorological data ,NDVI prediction can be achieved better, and the prediction effect in southern region is the best and the model accuracy is the highest. (4) NDVI is negatively related to El Niño event, positively related to La Nina event, and the stronger El Niño and La Nina events are, the higher the correlation is.

ANALISIS DAERAH RAWAN KEKERINGAN LAHAN JAGUNG BERDASARKAN IKLIM OLDEMAN DAN KETERSEDIAN AIR TANAH DI NUSA TENGGARA TIMUR SAAT PERIODE EL NINO DAN LA NINA

2019 ◽  
Vol 3 ◽  
pp. 1219
Author(s):  
Oki Adrianto ◽  
Sudirman Sudirman ◽  
Suwandi Suwandi
Keyword(s):  
El Niño ◽  
El Nino ◽  
La Niña ◽  
La Nina

Perekonomian Provinsi Nusa Tenggara Timur secara sektoral masih didominasi sektor pertanian.Tanaman jagung menjadi salah satu produksi tanaman pangan terbesar berdasarkan data dari Dinas Pertanian dan Perkebunan Provinsi Nusa Tenggara Timur tahun 2015. Peningkatan produksi pertanian dapat dilakukan melalui berbagai strategi adaptasi dan upaya penanganan bencana, salah satu upaya tersebut adalah dengan penyediaan informasi iklim terkait penentuan daerah-daerah rawan kekeringan. Tujuan dari penelitian ini adalah untuk mengetahui sebaran wilayah rawan kekeringan lahan jagung bulanan di Provinsi Nusa Tenggara Timur saat kondisi El Nino dan La Nina dengan periodeisasi bulanan januari hingga desember. Data yang digunakan dalam penelitian ini adalah data curah hujan rata rata bulanan di 19 pos hujan di Provinsi Nusa Tenggara Timur dan suhu udara rata-rata bulanan dihitung menggunakan pendekatan teori Brack dengan titik referensi Stasiun Klimatologi Lasiana Kupang. Periode dari masing-masing data yang digunakan adalah dari tahun 1991 dan 1997 digunakan sebagai tahun El Nino dan tahun 1999 dan 2010 digunakan sebagai tahun La Nina. Metode yang digunakan untuk menentukan tingkat rawan kekeringan dengan menggunakan pembobotan berdasarkan penjumlahan bobot tipe iklim Oldeman dan bobot ketersediaan air tanah. Hasil penelitian menunjukkan sebaran daerah kekeringan di Provinsi Nusa Tenggara Timurpada tahun el nino lebih luas dibandingkan tahun la nina.

A Influência dos fenômenos El Niño e La Niña sobre a dinâmica climática da região Amazônica

2018 ◽  
Vol 1 ◽  
pp. e2018014
Author(s):  
Samya de Freitas MOREIRA ◽  
Cleiciane Silva da CONCEIÇÃO ◽  
Milla Cristina Santos da CRUZ ◽  
Antônio PEREIRA JÚNIOR
Keyword(s):  
El Niño ◽  
El Nino ◽  
La Niña ◽  
La Nina

Caracterização climática da temperatura do ar em Veranópolis, Rio Grande do Sul

Agrometeoros ◽  
2020 ◽  
Vol 26 (2) ◽  
Author(s):  
Amanda Heemann Junges
Keyword(s):  
El Niño ◽  
El Nino ◽  
Rio Grande ◽  
La Niña ◽  
Rio Grande Do Sul ◽  
La Nina

Estudos locais de caraterização e variabilidade climática são fundamentais para geração de informações mais adaptadas às atividades agrícolas desenvolvidas em um município ou região. O objetivo desse trabalho foi caracterizar climaticamente e analisar a influência de eventos El Niño Oscilação Sul (ENOS) na série 1956-2015 de temperatura do ar de Veranópolis, RS. Para caracterização climática foram estabelecidas estatísticas descritivas das temperaturas do ar máximas, mínimas e médias mensais, estacional e anual na série e normal climatológica padrão 1961- 1990. Para identificação de diferenças entre estações e influência de eventos ENOS, os dados foram submetidos à análise de variância e teste de Duncan. Os resultados indicaram que a temperatura média anual é de 17,3ºC, variando entre 12,7ºC (julho) e 21,8ºC (janeiro). O clima é do tipo Cfb, de acordo com a classificação climática de Köppen e TE (temperado) na classificação climática do Estado. Temperaturas mínimas médias mensais inferiores a 10ºC ocorrem de maio a setembro, período de maior variabilidade interanual das temperaturas máximas (desvio padrão entre 1,5º e 1,8ºC), mínimas (1,6-1,8ºC) e médias mensais (1,4-1,7ºC). Anos de La Niña possuem temperaturas médias estacionais inferiores as de El Niño, embora diferenciação em relação a neutros ocorra somente para temperaturas mínimas na primavera e máximas no outono.

Rendimento de grãos de soja e de milho, no Rio Grande do Sul, não difere entre eventos El Niño Oscilação Sul

Agrometeoros ◽  
2018 ◽  
Vol 26 (1) ◽  
Author(s):  
Ronaldo Matzenauer ◽  
Bernadete Radin ◽  
Alberto Cargnelutti Filho
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Rio Grande ◽  
La Niña ◽  
Rio Grande Do Sul ◽  
La Nina ◽  
Significant Difference ◽  
Income Data ◽  
The Relationship

O objetivo deste trabalho foi avaliar a relação entre o fenômeno El Niño Oscilação Sul - ENOS e o rendimento de grãos de soja e de milho no Rio Grande do Sul e verificar a hipótese de que os eventos El Niño são favoráveis e os eventos La Niña são prejudiciais ao rendimento de grãos das culturas. Foram utilizados dados de rendimento de grãos dos anos agrícolas de 1974/75 a 2016/17, e relacionados com as ocorrências de eventos ENOS. Foram analisados os dados de rendimento observados na colheita e os dados estimados com a remoção da tendência tecnológica. Os resultados mostraram que não houve diferença significativa do rendimento médio de grãos de soja e de milho na comparação entre os eventos ENOS. Palavras-chave: El Niño, La Niña, safras agrícolas. Abstract – The objective of this work was to evaluate the relationship between the El Niño Southern Oscillation (ENSO) phenomenon with the grain yield of soybean and maize in Rio Grande do Sul state, Brazil and to verify the hypothesis that the El Niño events are favorable and the La Niña events are harmful to the culture’s grain yields. Were used data from the agricultural years of 1974/75 to 2016/17, and related to the occurrence of ENOS events. We analyzed income data observed at harvest and estimated data with technological tendency was removed. The results showed that there was no significant difference in the average yield of soybeans and corn in the comparison between events.

Atmospheric teleconnection patterns associated with severe and mild ice cover on the Great Lakes, 1963–2011

2012 ◽  
Vol 47 (3-4) ◽  
pp. 421-435 ◽  
Author(s):  
Xuezhi Bai ◽  
Jia Wang
Keyword(s):  
North America ◽  
Great Lakes ◽  
El Niño ◽  
El Nino ◽  
Ice Cover ◽  
Reanalysis Data ◽  
Teleconnection Pattern ◽  
La Niña ◽  
Atmospheric Teleconnection ◽  
La Nina

Atmospheric teleconnection circulation patterns associated with severe and mild ice cover over the Great Lakes are investigated using the composite analysis of lake ice data and National Center of Environmental Prediction (NCEP) reanalysis data for the period 1963–2011. The teleconnection pattern associated with the severe ice cover is the combination of a negative North Atlantic Oscillation (NAO) or Arctic Oscillation (AO) and negative phase of Pacific/North America (PNA) pattern, while the pattern associated with the mild ice cover is the combination of a positive PNA (or an El Niño) and a positive phase of the NAO/AO. These two extreme ice conditions are associated with the North American ridge–trough variations. The intensified ridge–trough system produces a strong northwest-to-southeast tilted ridge and trough and increases the anomalous northwesterly wind, advecting cold, dry Arctic air to the Great Lakes. The weakened ridge–trough system produces a flattened ridge and trough, and promotes a climatological westerly wind, advecting warm, dry air from western North America to the Great Lakes. Although ice cover for all the individual lakes responds roughly linearly and symmetrically to both phases of the NAO/AO, and roughly nonlinearly and asymmetrically to El Niño and La Niña events, the overall ice cover response to individual NAO/AO or Niño3.4 index is not statistically significant. The combined NAO/AO and Niño3.4 indices can be used to reliably project severe ice cover during the simultaneous –NAO/AO and La Niña events, and mild ice cover during the simultaneous +NAO/AO and El Niño events.

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