scholarly journals Black and brown carbon over central Amazonia: long-term aerosol measurements at the ATTO site

2018 ◽  
Vol 18 (17) ◽  
pp. 12817-12843 ◽  
Author(s):  
Jorge Saturno ◽  
Bruna A. Holanda ◽  
Christopher Pöhlker ◽  
Florian Ditas ◽  
Qiaoqiao Wang ◽  
...  
Keyword(s):  
Optical Properties ◽  
El Niño ◽  
El Nino ◽  
Dry Season ◽  
Wet Season ◽  
Aerosol Optical Properties ◽  
Brown Carbon ◽  
Central Amazonia ◽  
Physical And Chemical ◽  
Aerosol Properties

Abstract. The Amazon rainforest is a sensitive ecosystem experiencing the combined pressures of progressing deforestation and climate change. Its atmospheric conditions oscillate between biogenic and biomass burning (BB) dominated states. The Amazon further represents one of the few remaining continental places where the atmosphere approaches pristine conditions during occasional wet season episodes. The Amazon Tall Tower Observatory (ATTO) has been established in central Amazonia to investigate the complex interactions between the rainforest ecosystem and the atmosphere. Physical and chemical aerosol properties have been analyzed continuously since 2012. This paper provides an in-depth analysis of the aerosol's optical properties at ATTO based on data from 2012 to 2017. The following key results have been obtained. The aerosol scattering and absorption coefficients at 637 nm, σsp,637 and σap,637, show a pronounced seasonality with lowest values in the clean wet season (mean ± SD: σsp,637=7.5±9.3 M m−1; σap,637=0.68±0.91 M m−1) and highest values in the BB-polluted dry season (σsp,637=33±25 M m−1; σap,637=4.0±2.2 M m−1). The single scattering albedo at 637 nm, ω0, is lowest during the dry season (ω0=0.87±0.03) and highest during the wet season (ω0=0.93±0.04). The retrieved BC mass absorption cross sections, αabs, are substantially higher than values widely used in the literature (i.e., 6.6 m2 g−1 at 637 nm wavelength), likely related to thick organic or inorganic coatings on the BC cores. Wet season values of αabs=11.4±1.2 m2 g−1 (637 nm) and dry season values of αabs=12.3±1.3 m2 g−1 (637 nm) were obtained. The BB aerosol during the dry season is a mixture of rather fresh smoke from local fires, somewhat aged smoke from regional fires, and strongly aged smoke from African fires. The African influence appears to be substantial, with its maximum from August to October. The interplay of African vs. South American BB emissions determines the aerosol optical properties (e.g., the fractions of black vs. brown carbon, BC vs. BrC). By analyzing the diel cycles, it was found that particles from elevated aerosol-rich layers are mixed down to the canopy level in the early morning and particle number concentrations decrease towards the end of the day. Brown carbon absorption at 370 nm, σap,BrC,370, was found to decrease earlier in the day, likely due to photo-oxidative processes. BC-to-CO enhancement ratios, ERBC, reflect the variability of burnt fuels, combustion phases, and atmospheric removal processes. A wide range of ERBC between 4 and 15 ng m−3 ppb−1 was observed with higher values during the dry season, corresponding to the lowest ω0 levels (0.86–0.93). The influence of the 2009/2010 and 2015/2016 El Niño periods and the associated increased fire activity on aerosol optical properties was analyzed by means of 9-year σsp and σap time series (combination of ATTO and ZF2 data). Significant El Niño-related enhancements were observed: in the dry season, σsp,637 increased from 24±18 to 48±33 M m−1 and σap, 637 from 3.8±2.8 to 5.3±2.5 M m−1. The absorption Ångström exponent, åabs, representing the aerosol absorption wavelength dependence, was mostly <1.0 with episodic increases upon smoke advection. A parameterization of åabs as a function of the BC-to-OA mass ratio for Amazonian aerosol ambient measurements is presented. The brown carbon (BrC) contribution to σap at 370 nm was obtained by calculating the theoretical BC åabs, resulting in BrC contributions of 17 %–29 % (25th and 75th percentiles) to σap 370 for the entire measurement period. The BrC contribution increased to 27 %–47 % during fire events under El Niño-related drought conditions from September to November 2015. The results presented here may serve as a basis to understand Amazonian atmospheric aerosols in terms of their interactions with solar radiation and the physical and chemical-aging processes that they undergo during transport. Additionally, the analyzed aerosol properties during the last two El Niño periods in 2009/2010 and 2015/2016 offer insights that could help to assess the climate change-related potential for forest-dieback feedbacks under warmer and drier conditions.

scholarly journals Field measurements of trace gases and aerosols emitted by peat fires in Central Kalimantan, Indonesia, during the 2015 El Niño

2016 ◽  
Vol 16 (18) ◽  
pp. 11711-11732 ◽  
Author(s):  
Chelsea E. Stockwell ◽  
Thilina Jayarathne ◽  
Mark A. Cochrane ◽  
Kevin C. Ryan ◽  
Erianto I. Putra ◽  
...  
Keyword(s):  
Optical Properties ◽  
El Niño ◽  
El Nino ◽  
Trace Gases ◽  
Field Measurements ◽  
Optical Data ◽  
Trace Gas ◽  
Aerosol Optical Properties ◽  
Central Kalimantan ◽  
Peat Fires

Abstract. Peat fires in Southeast Asia have become a major annual source of trace gases and particles to the regional–global atmosphere. The assessment of their influence on atmospheric chemistry, climate, air quality, and health has been uncertain partly due to a lack of field measurements of the smoke characteristics. During the strong 2015 El Niño event we deployed a mobile smoke sampling team in the Indonesian province of Central Kalimantan on the island of Borneo and made the first, or rare, field measurements of trace gases, aerosol optical properties, and aerosol mass emissions for authentic peat fires burning at various depths in different peat types. This paper reports the trace gas and aerosol measurements obtained by Fourier transform infrared spectroscopy, whole air sampling, photoacoustic extinctiometers (405 and 870 nm), and a small subset of the data from analyses of particulate filters. The trace gas measurements provide emission factors (EFs; grams of a compound per kilogram biomass burned) for up to  ∼  90 gases, including CO2, CO, CH4, non-methane hydrocarbons up to C10, 15 oxygenated organic compounds, NH3, HCN, NOx, OCS, HCl, etc. The modified combustion efficiency (MCE) of the smoke sources ranged from 0.693 to 0.835 with an average of 0.772 ± 0.053 (n  =  35), indicating essentially pure smoldering combustion, and the emissions were not initially strongly lofted. The major trace gas emissions by mass (EF as g kg−1) were carbon dioxide (1564 ± 77), carbon monoxide (291 ± 49), methane (9.51 ± 4.74), hydrogen cyanide (5.75 ± 1.60), acetic acid (3.89 ± 1.65), ammonia (2.86 ± 1.00), methanol (2.14 ± 1.22), ethane (1.52 ± 0.66), dihydrogen (1.22 ± 1.01), propylene (1.07 ± 0.53), propane (0.989 ± 0.644), ethylene (0.961 ± 0.528), benzene (0.954 ± 0.394), formaldehyde (0.867 ± 0.479), hydroxyacetone (0.860 ± 0.433), furan (0.772 ± 0.035), acetaldehyde (0.697 ± 0.460), and acetone (0.691 ± 0.356). These field data support significant revision of the EFs for CO2 (−8 %), CH4 (−55 %), NH3 (−86 %), CO (+39 %), and other gases compared with widely used recommendations for tropical peat fires based on a lab study of a single sample published in 2003. BTEX compounds (benzene, toluene, ethylbenzene, xylenes) are important air toxics and aerosol precursors and were emitted in total at 1.5 ± 0.6 g kg−1. Formaldehyde is probably the air toxic gas most likely to cause local exposures that exceed recommended levels. The field results from Kalimantan were in reasonable agreement with recent lab measurements of smoldering Kalimantan peat for “overlap species,” lending importance to the lab finding that burning peat produces large emissions of acetamide, acrolein, methylglyoxal, etc., which were not measurable in the field with the deployed equipment and implying value in continued similar efforts. The aerosol optical data measured include EFs for the scattering and absorption coefficients (EF Bscat and EF Babs, m2 kg−1 fuel burned) and the single scattering albedo (SSA) at 870 and 405 nm, as well as the absorption Ångström exponents (AAE). By coupling the absorption and co-located trace gas and filter data we estimated black carbon (BC) EFs (g kg−1) and the mass absorption coefficient (MAC, m2 g−1) for the bulk organic carbon (OC) due to brown carbon (BrC). Consistent with the minimal flaming, the emissions of BC were negligible (0.0055 ± 0.0016 g kg−1). Aerosol absorption at 405 nm was  ∼  52 times larger than at 870 nm and BrC contributed  ∼  96 % of the absorption at 405 nm. Average AAE was 4.97 ± 0.65 (range, 4.29–6.23). The average SSA at 405 nm (0.974 ± 0.016) was marginally lower than the average SSA at 870 nm (0.998 ± 0.001). These data facilitate modeling climate-relevant aerosol optical properties across much of the UV/visible spectrum and the high AAE and lower SSA at 405 nm demonstrate the dominance of absorption by the organic aerosol. Comparing the Babs at 405 nm to the simultaneously measured OC mass on filters suggests a low MAC ( ∼  0.1) for the bulk OC, as expected for the low BC/OC ratio in the aerosol. The importance of pyrolysis (at lower MCE), as opposed to glowing (at higher MCE), in producing BrC is seen in the increase of AAE with lower MCE (r2 =  0.65).

scholarly journals Field measurements of trace gases and aerosols emitted by peat fires in Central Kalimantan, Indonesia during the 2015 El Niño

2016 ◽  
Author(s):  
Chelsea E. Stockwell ◽  
Thilina Jayarathne ◽  
Mark A. Cochrane ◽  
Kevin C. Ryan ◽  
Erianto I. Putra ◽  
...  
Keyword(s):  
Optical Properties ◽  
El Niño ◽  
El Nino ◽  
Trace Gases ◽  
Field Measurements ◽  
Optical Data ◽  
Trace Gas ◽  
Aerosol Optical Properties ◽  
Central Kalimantan ◽  
Peat Fires

Abstract. Peat fires in Southeast Asia have become a major annual source of trace gases and particles to the regional-global atmosphere. The assessment of their influence on atmospheric chemistry, climate, air quality, and health has been uncertain partly due to a lack of field measurements of the smoke characteristics. During the strong 2015 El Niño event we deployed a mobile smoke sampling team in the Indonesian province of Central Kalimantan on the island of Borneo and made the first, or rare, field measurements of trace gases, aerosol optical properties, and aerosol mass emissions for authentic peat fires burning at various depths in different peat types. This paper reports the trace gas and aerosol measurements obtained by Fourier transform infrared spectroscopy, whole air sampling, photoacoustic extinctiometers (405 and 870 nm), and a small subset of the data from analyses of particulate filters. The trace gas measurements provide emission factors (EFs, g compound per kg biomass burned) for CO2, CO, CH4, non-methane hydrocarbons up to C10, 15 oxygenated organic compounds, NH3, HCN, NOx, OCS, HCl, etc.; up to ~90 gases in all. The modified combustion efficiency (MCE) of the smoke sources ranged from 0.693 to 0.835 with an average of 0.772 ± 0.053 (n = 35) indicating essentially pure smoldering combustion and the emissions were not initially strongly lofted. The major trace gas emissions by mass (EF as g/kg) were: carbon dioxide (1564 ± 77), carbon monoxide (291 ± 49), methane (9.51 ± 4.74), hydrogen cyanide (5.75 ± 1.60), acetic acid (3.89 ± 1.65), ammonia (2.86 ± 1.00), methanol (2.14 ± 1.22), ethane (1.52 ± 0.66), dihydrogen (1.22 ± 1.01), propylene (1.07 ± 0.53), propane (0.989 ± 0.644), ethylene (0.961 ± 0.528), benzene (0.954 ± 0.394), formaldehyde (0.867 ± 0.479), hydroxyacetone (0.860 ± 0.433), furan (0.772 ± 0.035), acetaldehyde (0.697 ± 0.460), and acetone (0.691 ± 0.356). These field data support significant revision of the EFs for CO2 (−8 %), CH4 (−55 %), NH3 (−86 %), CO (+39 %) and other gases compared with widely-used recommendations for tropical peat fires based on a lab study of a single sample published in 2003. BTEX compounds (benzene, toluene, ethylbenzene, xylenes) are important air toxics and aerosol precursors and were emitted in total at 1.5 ± 0.6 g/kg. Formaldehyde is probably the air toxic gas most likely to cause local exposures that exceed recommended levels. The field results from Kalimantan were in reasonable agreement with recent (2012) lab measurements of smoldering Kalimantan peat for “overlap species,” lending importance to the lab finding that burning peat produces large emissions of acetamide, acrolein, methylglyoxal, etc., which were not measureable in the field with the deployed equipment and implying value in continued similar efforts. The aerosol optical data measured include EFs for the scattering and absorption coefficients (EF Bscat and EF Babs, m2/kg fuel burned) and the single scattering albedo (SSA) at 870 and 405 nm, as well as the absorption Ångstrӧm exponents (AAE). By coupling the absorption and co-located trace gas and filter data we estimated black carbon (BC) EFs (g/kg) and the mass absorption coefficient (MAC, m2/g) for the bulk organic carbon (OC) due to brown carbon (BrC). Consistent with the minimal flaming, the emissions of BC were negligible (0.0055 ± 0.0016 g/kg). Aerosol absorption at 405 nm was ~52 times larger than at 870 nm and BrC contributed ~96 % of the absorption at 405 nm. Average AAE was 4.97 ± 0.65 (range, 4.29–6.23). The average SSA at 405 nm (0.974 ± 0.016) was marginally lower than the average SSA at 870 nm (0.998 ± 0.001). These data facilitate modeling climate-relevant aerosol optical properties across much of the UV/visible spectrum and the high AAE and lower SSA at 405 nm demonstrate the dominance of absorption by the organic aerosol. Comparing the Babs at 405 nm to the simultaneously measured OC mass on filters suggests a low MAC (~0.1) for the bulk OC, as expected for the low BC / OC ratio in the aerosol. The importance of pyrolysis (at lower MCE), as opposed to glowing (at higher MCE), in producing BrC is seen in the increase of AAE with lower MCE (r2 = 0.65).

scholarly journals Black and brown carbon over central Amazonia: Long-term aerosol measurements at the ATTO site

2017 ◽  
Author(s):  
Jorge Saturno ◽  
Bruna A. Holanda ◽  
Christopher Pöhlker ◽  
Florian Ditas ◽  
Qiaoqiao Wang ◽  
...  
Keyword(s):  
El Niño ◽  
Light Absorption ◽  
Rain Forest ◽  
El Nino ◽  
Aerosol Particles ◽  
Wavelength Dependence ◽  
Brown Carbon ◽  
Amazon Rain Forest ◽  
Central Amazonia ◽  
Measurement Period

Abstract. The Amazon rain forest is considered a very sensitive ecosystem that could be significantly affected by a changing climate. It is still one of the few places on Earth where the atmosphere in the continent approaches near-pristine conditions for some periods of the year. The Amazon Tall Tower Observatory (ATTO) has been built in central Amazonia to monitor the atmospheric and forest ecosystem conditions. The atmospheric conditions at the ATTO site oscillate between biogenic and biomass burning (BB) dominated states. By using a comprehensive ground-based aerosol measurement setup, we studied the physical and chemical properties of aerosol particles at the ATTO site. This paper presents results from 2012 to 2017, with special focus on light absorbing aerosol particles. The aerosol absorption wavelength dependence (expressed as the absorption Ångström exponent, åabs) was usually below 1.0 and increased during the presence of smoke transported from fires in the southern and eastern regions of the Amazon or advected from savanna fires in Africa. In this study, the brown carbon (BrC) contribution to light absorption at 370 nm was obtained by calculating the theoretical wavelength dependence of åabs (WDA). Our calculations resulted in BrC contributions of 17–29 % (25th and 75th percentiles) to total light absorption at 370 nm (σap 370) during the measurement period (2012–2017). The BrC contribution increased up to 27–47 % during fire events occurring under the influence of El Niño, between September and November 2015. An extended time series of ATTO and ZF2 (another Amazon rain forest sampling site) data showed enhanced light scattering and absorption coefficients during El Niño periods in 2009 and 2015. Long-range transport (LRT) aerosol particles that reached the central Amazon Basin from Africa or from southern Amazon exhibited a wide range of black carbon (BC) to carbon monoxide (CO) enhancement ratios (ERBC) (between 4 and 15 ng m−3 ppb−1) reflecting the variability of fuels, combustion phase, and removal processes in the atmosphere. Higher ERBC were measured during the dry season when we observed values up to 15 ng m−3 ppb−1, which were related to the lowest single scattering albedo (ω0) measured during the studied period, (0.86–0.93). A parameterization of åabs as a function of the BC to OA mass ratio was investigated and was found applicable to tropical forest emissions but further investigation is required, especially by segregating fuel types. Additionally, important enhancements of the BC mass absorption cross‑section (αabs) were found over the measurement period. This enhancement could be linked to heavy coating of the BC aerosol particles. In the future, the BC mixing state should be systematically investigated by using different instrumental approaches.

scholarly journals ANALYSIS OF WATER PRODUCTIVITY IN THE BANDA SEA BASED ON REMOTE SENSING SATELLITE DATA

2020 ◽  
Vol 17 (1) ◽  
pp. 25
Author(s):  
Sartono Marpaung ◽  
Risky Faristyawan ◽  
Anang Dwi Purwanto ◽  
Wikanti Asriningrum ◽  
Argo Galih Suhada ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
El Niño ◽  
El Nino ◽  
Dry Season ◽  
La Niña ◽  
Wet Season ◽  
Conservation Areas ◽  
Conservation Area ◽  
Chlorophyll A Concentration ◽  
La Nina

Abstract. This study examines the density of potential fishing zone (PFZ) points and chlorophyll-a concentration in the Banda Sea. The data used are those on chlorophyll-a from the Aqua MODIS satellite, PFZ points from ZAP and the monthly southern oscillation index. The methods used are single image edge detection, polygon center of mass, density function and a Hovmoller diagram. The result of the analysis show that productivity of chlorophyll-a in the Banda Sea is influenced by seasonal factors (dry season and wet season) and ENSO phenomena (El Niño and La Niña). High productivity of chlorophyll-a  occurs during in the dry season with the peak in August, while low productivity occurs in the wet season and the transition period, with the lowest levels in April and December. The variability in chlorophyll-a production is influenced by the global El Niño and La Niña phenomena; production increases during El Niño and decreases during La Niña. Tuna conservation areas have as lower productivity of chlorophyll-a and PFZ point density compared to the northern and southern parts of the Banda Sea. High density PFZ point regions are associated with regions that have higher productivity of chlorophyll-a, namely the southern part of the Banda Sea, while low density PFZ point areas  are associated with regions that have a low productivity of chlorophyll-a, namely tuna conservation areas. The effect of the El Niño phenomenon in increasing chlorophyll-a concentration is stronger in the southern part of study area than in the tuna conservation area. On the other hand, the effect of La Niña phenomenon in decreasing chlorophyll-a concentration is stronger in the tuna conservation area than in the southern and northern parts of the study area. 

Seasonal–Interannual Variation and Prediction of Wet and Dry Season Rainfall over the Maritime Continent: Roles of ENSO and Monsoon Circulation

2016 ◽  
Vol 29 (10) ◽  
pp. 3675-3695 ◽  
Author(s):  
Tuantuan Zhang ◽  
Song Yang ◽  
Xingwen Jiang ◽  
Ping Zhao
Keyword(s):  
El Niño ◽  
Large Scale ◽  
El Nino ◽  
Southern Oscillation ◽  
Dry Season ◽  
La Niña ◽  
Monsoon Circulation ◽  
Wet Season ◽  
Maritime Continent ◽  
La Nina

Abstract The authors analyze the seasonal–interannual variations of rainfall over the Maritime Continent (MC) and their relationships with El Niño–Southern Oscillation (ENSO) and large-scale monsoon circulation. They also investigate the predictability of MC rainfall using the hindcast of the U.S. National Centers for Environmental Prediction (NCEP) Climate Forecast System version 2 (CFSv2). The seasonal evolution of MC rainfall is characterized by a wet season from December to March and a dry season from July to October. The increased (decreased) rainfall in the wet season is related to the peak-decaying phase of La Niña (El Niño), whereas the increased (decreased) rainfall in the dry season is related to the developing phase of La Niña (El Niño), with an apparent spatial incoherency of the SST–rainfall relationship in the wet season. For extremely wet cases of the wet season, local warm SST also contributes to the above-normal rainfall over the MC except for the western area of the MC due to the effect of the strong East Asian winter monsoon. The CFSv2 shows high skill in predicting the main features of MC rainfall variations and their relationships with ENSO and anomalies of the large-scale monsoon circulation, especially for strong ENSO years. It predicts the rainfall and its related circulation patterns skillfully in advance by several months, especially for the dry season. The relatively lower skill of predicting MC rainfall for the wet season is partly due to the low prediction skill of rainfall over Sumatra, Malay, and Borneo (SMB), as well as the unrealistically predicted relationship between SMB rainfall and ENSO.

scholarly journals Variabilitas Curah Hujan Indonesia dan Hubungannya dengan ENSO/IOD: Estimasi Menggunakan Data JRA-25/JCDAS

Agromet ◽  
2018 ◽  
Vol 28 (1) ◽  
pp. 1
Author(s):  
Rahmat Hidayat ◽  
Kentaro Ando
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Rainfall Variability ◽  
Dry Season ◽  
Japan Meteorological Agency ◽  
Climate Data ◽  
Wet Season ◽  
Indonesian Rainfall ◽  
The Impact

Rainfall variability over Indonesia and its relation to El Niño – Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) events were investigated using the Japanese 25-year reanalysis/Japan Meteorological Agency (JMA) Climate Data Assimilation System (JRA-25/ JCDAS). The JRA-25 data consistently depicts seasonal variation of Indonesian rainfall with a wet season that peaks at December-January and a dry season that peaks in July-August when the convection belt moved northward. Composite analysis of rainfall, sea surface temperature and low-level wind anomalies have shown that the impact of ENSO/IOD on rainfall variations in Indonesia is clearly dominant during dry season. Drought conditions typically occur during El Niño years when SST anomalies surrounding Indonesia are cool and walker circulation is weakened, resulting in anomalous surface easterlies across Indonesia. In contrast, in the wet season, the weakening of the relationship between ENSO and Indonesian rainfall is linked to the transition between surface southeasterlies to northwesterlies. At this time persistent surface easterly anomalies across Indonesia superimposed on the climatological mean winds during a warm phase of ENSO event acts to reduce the wind speed resulting reduced the negative DJF rainfall anomalies.

scholarly journals Relations between Interannual Variability of Regional-Scale Indonesian Precipitation and Large-Scale Climate Modes during 1960–2007

2020 ◽  
Vol 33 (12) ◽  
pp. 5271-5291 ◽  
Author(s):  
Givo Alsepan ◽  
Shoshiro Minobe
Keyword(s):  
El Niño ◽  
Large Scale ◽  
El Nino ◽  
Regional Scale ◽  
Moisture Flux ◽  
Dry Season ◽  
Wet Season ◽  
Climate Modes ◽  
Eastern Indonesia ◽  
El Niño Modoki

AbstractRegional-scale precipitation responses over Indonesia to major climate modes in the tropical Indo–Pacific Oceans, namely canonical El Niño, El Niño Modoki, and the Indian Ocean dipole (IOD), and how the responses are related to large-scale moisture convergences are investigated. The precipitation responses, analyzed using a high-spatial-resolution (0.5° × 0.5°) terrestrial precipitation dataset for the period 1960–2007, exhibit differences between the dry (July–September) and wet (November–April) seasons. Canonical El Niño strongly reduces precipitation in central to eastern Indonesia from the dry season to the early wet season and northern Indonesia in the wet season. El Niño Modoki also reduces precipitation in central to eastern Indonesia during the dry season, but conversely increases precipitation in western Indonesia in the wet season. Moisture flux analysis indicates that corresponding to the dry (wet) season precipitation reduction due to the canonical El Niño and El Niño Modoki anomalous divergence occurs around the southern (northern) edge of the convergence zone when one of the two edges is located near the equator (10°S–15°N) associated with their seasonal migration. This largely explains the seasonality and regionality of precipitation responses to canonical El Niño and El Niño Modoki. IOD reduces precipitation in southwestern Indonesia in the dry season, associated with anomalous moisture flux divergence. The seasonality of precipitation response to IOD is likely to be controlled by the seasonality of local sea surface temperature anomalies in the eastern pole of the IOD.

scholarly journals The Correlation of Southern Oscillation Index (SOI) with the Rainfall at Rainy and Dry Season Peak in Kintamani-Bangli Region period 1986-2015

2019 ◽  
Vol 20 (2) ◽  
pp. 6
Author(s):  
Wayan Mita Restitiasih ◽  
I Ketut Sukarasa ◽  
I Wayan Andi Yuda
Keyword(s):  
Correlation Coefficient ◽  
El Niño ◽  
Southern Oscillation Index ◽  
El Nino ◽  
Southern Oscillation ◽  
Management Plan ◽  
Correlation Study ◽  
Dry Season ◽  
Rainfall Data ◽  
The Relationship

A correlation study of the Southern Oscillation Index (SOI) on rainfall at the peak of the wet and dry season in the Kintamani-Bangli region has been carried out by taking SOI values and rainfall data for the period 1986-2015. The rainfall data used were recorded at 2 rain posts, namely Kembangsari and Kintamani. The research aimed to determine the relationship of fluctuations in the value of SOI with the intensity of rainfall, so that it can be used as a regional management plan when El Nino occurs. The method used in this study is correlation. The results obtained from the correlation that is the relationship between SOI value and rainfall in February were quite strong in the Kembangsari post with correlation coefficient of 0.409. Whereas for the Kintamani post the correlation obtained was weak with a correlation coefficient of 0.308. Then in August a weak correlation occurred in the Kembangsari post with a correlation coefficient of 0.2398 and was quite strong in the Kintamani post with a correlation coefficient of 0.4662. So that the influence of El Nino in the Kintamani area in February was more dominant in the Kembangsari post and in August at the Kintamani post.

scholarly journals Rehearsal for Assessment of atmospheric optical Properties during biomass burning Events and Long-range transportation episodes at Metropolitan Area of São Paulo-Brazil (RAPEL)

2018 ◽  
Vol 176 ◽  
pp. 08011 ◽  
Author(s):  
Fábio J. S. Lopes ◽  
Juan Luis Guerrero-Rascado ◽  
Jose A. Benavent-Oltra ◽  
Roberto Román ◽  
Gregori A. Moreira ◽  
...  
Keyword(s):  
Optical Properties ◽  
Long Range ◽  
Metropolitan Area ◽  
Sao Paulo ◽  
Vertical Profiles ◽  
São Paulo ◽  
Inversion Algorithm ◽  
Aerosol Transport ◽  
Aerosol Optical Properties ◽  
Aerosol Properties

During the period of August-September 2016 an intensive campaign was carried out to assess aerosol properties in São Paulo-Brazil aiming to detect long-range aerosol transport events and to characterize the instrument regarding data quality. Aerosol optical properties retrieved by the GALION - LALINET SPU lidar station and collocated AERONET sunphotometer system are presented as extinction/ backscatter vertical profiles with microphysical products retrieved with GRASP inversion algorithm.

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