scholarly journals Pengaruh Fenomena El Nino Southern Oscillation (ENSO) Terhadap Peningkatan Ozon Troposferik di Indonesia

2018 ◽  
Vol 2 (3) ◽  
Author(s):  
Fatimah Dinan Qonitan

ABSTRAKOzon troposferik merupakan polutan sekunder yang bersifat racun bagi manusia. Beberapa penelitian menemukan terjadinya peningkatan konsentrasi ozon di troposfer selama periode El Nino pada tahun 1997/1998 dan 2006 di Indonesia. Studi ini berisi kajian dan sintesis berbagai literatur ilmiah untuk mengetahui aspek-aspek yang mempengaruhi peningkatan konsentrasi ozon troposferik di periode tersebut. Peningkatan ozon rata-rata diketahui dengan membandingkan konsentrasi latar belakang total ozon pada tahun-tahun normal dengan periode El Nino 1997/1998 dan 2006. Peningkatan ozon terutama terjadi di musim kering pada periode El Nino, ketika terjadi penurunan tingkat presipitasi yang signifikan dan kebakaran hutan besar di Indonesia. Pada El-Nino 1997/1998 terjadi anomali positif konsentrasi ozon troposferik sebesar 10-20 DU, sedangkan pada El-Nino 2006 sebesar 10-15 DU. Peristiwa kebakaran hutan ini mengemisikan prekursor pembentuk ozon (O3) dalam jumlah besar, diantaranya adalah karbon monoksida (CO) dan Nitrogen Oksida (NOx).Kata kunci: El Nino, ENSO, Indonesia, Kebakaran, Tropospheric OzoneABSTRACTTropospheric ozone is a secondary pollutant that is toxic to humans. Several studies have found an increase in ozone concentration in the troposphere during periods of 1997/1998 and 2006 El Nino in Indonesia. This study intends to review and synthesize earlier research to determine important aspects affecting increase of tropospheric ozone concentration during those period. Average tropospheric ozone increase was estimated by subtracting the background concentration of total ozone during the normal years on 1997/1998 and 2006 El Nino periods. Significant increase tropospheric ozone mostly occurred in the dry season during the El Nino periods when the precipitation decreased significantly and extensive forest fire occurred frequently in Indonesia. During the 1997/1998 El-Nino, there is positive anomaly of tropospheric ozone by 10-20 DU, and 10-15 DU in 2006 El Nino. Forest fires event emit large numbers of ozone (O3)-forming precursors, such as carbon monoxide (CO) and nitrogen oxides (NOx).Keywords: El Nino, ENSO, Forest Fire, Indonesia, Tropospheric Ozone

2018 ◽  
Vol 373 (1760) ◽  
pp. 20170409 ◽  
Author(s):  
Xiangzhong Luo ◽  
Trevor F. Keenan ◽  
Joshua B. Fisher ◽  
Juan-Carlos Jiménez-Muñoz ◽  
Jing M. Chen ◽  
...  

The El Niño-Southern Oscillation exerts a large influence on global climate regimes and on the global carbon cycle. Although El Niño is known to be associated with a reduction of the global total land carbon sink, results based on prognostic models or measurements disagree over the relative contribution of photosynthesis to the reduced sink. Here, we provide an independent remote sensing-based analysis on the impact of the 2015–2016 El Niño on global photosynthesis using six global satellite-based photosynthesis products and a global solar-induced fluorescence (SIF) dataset. An ensemble of satellite-based photosynthesis products showed a negative anomaly of −0.7 ± 1.2 PgC in 2015, but a slight positive anomaly of 0.05 ± 0.89 PgC in 2016, which when combined with observations of the growth rate of atmospheric carbon dioxide concentrations suggests that the reduction of the land residual sink was likely dominated by photosynthesis in 2015 but by respiration in 2016. The six satellite-based products unanimously identified a major photosynthesis reduction of −1.1 ± 0.52 PgC from savannahs in 2015 and 2016, followed by a highly uncertain reduction of −0.22 ± 0.98 PgC from rainforests. Vegetation in the Northern Hemisphere enhanced photosynthesis before and after the peak El Niño, especially in grasslands (0.33 ± 0.13 PgC). The patterns of satellite-based photosynthesis ensemble mean were corroborated by SIF, except in rainforests and South America, where the anomalies of satellite-based photosynthesis products also diverged the most. We found the inter-model variation of photosynthesis estimates was strongly related to the discrepancy between moisture forcings for models. These results highlight the importance of considering multiple photosynthesis proxies when assessing responses to climatic anomalies. This article is part of a discussion meeting issue ‘The impact of the 2015/2016 El Niño on the terrestrial tropical carbon cycle: patterns, mechanisms and implications'.


Agromet ◽  
2021 ◽  
Vol 35 (1) ◽  
pp. 1-10
Author(s):  
Sri Nurdiati ◽  
Ardhasena Sopaheluwakan ◽  
Pandu Septiawan

Land and forest fires in Kalimantan and Sumatra, Indonesia occurred annually at different magnitude and duration. Climate and sea interaction, like El Niño, influences the severity of dry seasons preceding the fires. However, research on the influence of El Niño intensity to fire regime in Kalimantan and Sumatra is limited. Therefore, this study aims to analyze the spatial and temporal patterns of the effects of El Niño intensity on land and forest fires in fire-prone provinces in Indonesia. Here, we applied the empirical orthogonal function analysis based on singular value decomposition to determine the dominant patterns of hotspots and rainfall data that evolve spatially and temporally. For analysis, the study required the following data: fire hotspots, dry-spell, and rainfall for period 2001-2019. This study revealed that El Niño intensity had a different impacts for each province. Generally, El Niño will influence the severity of forest fire events in Indonesia. However, we found that the impact of El Niño intensity varied for Kalimantan, South Sumatra, and Riau Province. Kalimantan was the most sensitive province to the El Niño event. The duration and number of hotspots in Kalimantan increased significantly even in moderate El Niño event. This was different for South Sumatra, where the duration and number of hotspots only increased significantly when a strong El Niño event occurred.


2021 ◽  
Vol 17 (4) ◽  
Author(s):  
Ida Bagus Mandhara Brasika ◽  
◽  
I Made Oka Guna Antara ◽  
I Wayan Gede Astawa Karang ◽  
◽  
...  

2011 ◽  
Vol 50 (4) ◽  
pp. 785-799 ◽  
Author(s):  
Amir Shabbar ◽  
Walter Skinner ◽  
Mike D. Flannigan

AbstractAn empirical scheme for predicting the meteorological conditions that lead to summer forest fire severity for Canada using the multivariate singular value decomposition (SVD) has been developed for the 1953–2007 period. The levels and sources of predictive skill have been estimated using a cross-validation design. The predictor fields are global sea surface temperatures (SST) and Palmer drought severity index. Two consecutive 3-month predictor periods are used to detect evolving conditions in the predictor fields. Correlation, mean absolute error, and percent correct verification statistics are used to assess forecast model performance. Nationally averaged skills are shown to be statistically significant, which suggests that they are suitable for application to forest fire prediction and for management purposes. These forecasts average a 0.33 correlation skill across Canada and greater than 0.6 in the forested regions from the Yukon, through northern Prairie Provinces, northern Ontario, and central Quebec into Newfoundland. SVD forecasts generally outperform persistence forecasts. The importance of the leading two SVD modes to Canadian summer forest fire severity, accounting for approximately 95% of the squared covariance, is emphasized. The first mode relates strongly to interdecadal trend in global SST. Between 1953 and 2007 the western tropical Pacific, the Indian, and the North Atlantic Oceans have tended to warm while the northeastern Pacific and the extreme Southern Hemisphere oceans have shown a cooling trend. During the same period, summer forest fire exhibited increased severity across the large boreal forest region of Canada. The SVD diagnostics also indicate that the El Niño–Southern Oscillation and the Pacific decadal oscillation play a significant role in Canadian fire severity. Warm episodes (El Niño) tend to be associated with severe fire conditions over the Yukon, parts of the northern Prairie Provinces, and central Quebec. The linearity of the SVD manifests opposite response during the cold (La Niña) events.


2009 ◽  
Vol 9 (13) ◽  
pp. 4239-4249 ◽  
Author(s):  
S. Chandra ◽  
J. R. Ziemke ◽  
B. N. Duncan ◽  
T. L. Diehl ◽  
N. J. Livesey ◽  
...  

Abstract. We have studied the effects of the 2006 El Niño on tropospheric O3 and CO at tropical and sub-tropical latitudes measured from the OMI and MLS instruments on the Aura satellite. The 2006 El Niño-induced drought caused forest fires (largely set to clear land) to burn out of control during October and November in the Indonesian region. The effects of these fires are clearly seen in the enhancement of CO concentration measured from the MLS instrument. We have used a global model of atmospheric chemistry and transport (GMI CTM) to quantify the relative importance of biomass burning and large scale transport in producing observed changes in tropospheric O3 and CO. The model results show that during October and November biomass burning and meteorological changes contributed almost equally to the observed increase in tropospheric O3 in the Indonesian region. The biomass component was 4–6 DU but it was limited to the Indonesian region where the fires were most intense. The dynamical component was 4–8 DU but it covered a much larger area in the Indian Ocean extending from South East Asia in the north to western Australia in the south. By December 2006, the effect of biomass burning was reduced to zero and the observed changes in tropospheric O3 were mostly due to dynamical effects. The model results show an increase of 2–3% in the global burden of tropospheric ozone. In comparison, the global burden of CO increased by 8–12%.


2014 ◽  
Vol 7 (1) ◽  
pp. 727-768 ◽  
Author(s):  
P. Valks ◽  
N. Hao ◽  
S. Gimeno Garcia ◽  
D. Loyola ◽  
M. Dameris ◽  
...  

Abstract. This paper presents the operational retrieval of tropical tropospheric ozone columns (TOC) from the Second Global Ozone Monitoring Experiment (GOME-2) instruments using the convective-cloud-differential (CCD) method. The retrieval is based on total ozone and cloud property data provided by the GOME Data Processor (GDP) 4.7, and uses above-cloud and clear-sky ozone column measurements to derive a monthly mean TOC between 20° N and 20° S. Validation of the GOME-2 TOC with several tropical ozonesonde sites shows good agreement, with a high correlation between the GOME-2 and sonde measurements, and small biases within ~ 3 DU. The TOC data have been used in combination with tropospheric NO2 measurements from GOME-2 to analyse the effect of the 2009–2010 El Niño–Southern Oscillation (ENSO) on the tropospheric ozone distribution in the tropics. El-Niño induced dry conditions in September–October 2009 resulted in relatively high tropospheric ozone columns over the southern Indian Ocean and northern Australia, while La Niña conditions in September–October 2010 resulted in a strong increase in tropospheric NO2 in South America, and enhanced ozone in the eastern Pacific and South America. Comparisons of the GOME-2 tropospheric ozone data with simulations of the ECHAM/MESSy Atmospheric Chemistry (EMAC) model for 2009 El Nino conditions, illustrate the usefulness of the GOME-2 TOC measurements in evaluating chemistry climate models. Evaluation of CCMs with appropriate satellite observations helps to identify strengths and weaknesses of the model systems, providing a better understanding of driving mechanisms and adequate relations and feedbacks in the Earth atmosphere, and finally leading to improved models.


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