| Autor: |
Nur Maisarah Jantan, Maggie Chel Gee Ooi, Neil Rp Harris, Mohd Shahrul Mohd Nadzir, A'fifah Abd Razak, Andy Chan, Firoz Khan, Ahmad Norazhar Mohd Yatim, R. Macatangay, Asnor Azrin Sabuti, Mohd Fadzil Firdzaus Mohd Nor, Sherin Hassan Bran, Yahaya Hawari, Yit Arn Teh, Badrul Hisyam Zainudin, Lin Chin Yik, Muhammad Ikram A. Wahab, Yusri Yusup, Khairul Nizam Abdul Maulud, Mazrura Sahani, Noratiqah Mohd Ariff, Lip Khoon Kho, Conor G. Bolas, Mohd Talib Latif, Mohd Aftar Abu Bakar, Haris Hafizal Abd Hamid, Fatimah Ahamad, Wan Shafrina Wan Mohd Jaafar |
| Rok vydání: |
2020 |
| Předmět: |
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| DOI: |
10.21203/rs.3.rs-56420/v1 |
| Popis: |
Background: Biogenic Volatile Organic Compounds (BVOCs) such as isoprene (C5H8) are ozone (O3) precursors that can be emitted at significant concentrations from the oil palm tree (Elaeis guineensis). Reactions involving BVOCs can lead to increased levels of surface O3 which can significantly impair air quality and cause crop damage. This study focuses on the link between isoprene, surface O3 and carbon dioxide (CO2) over an oil palm plantation and the effects of meteorological factors such as temperature and irradiance on the gas concentrations. The mixing ratios of isoprene, surface O3 and CO2 were measured using a portable gas chromatograph with a photoionization detector called ‘iDirac’, an EcoTech O3 analyser, and LI-COR, respectively. Atmospheric models were used for measured selected gases estimation and validation purposes.Results: Results showed that isoprene and surface O3 had maximum daytime mixing ratios of ~25 ppb and ~57 ppb, respectively. CO2 mixing ratios were high during the night compared to the day, with a maximum night-time ratio of ~883 ppm. It is also showed that suppression of isoprene emissions from plants by high CO2 concentrations during the night was due to the reduction of dimethylallyl diphosphate (DMADP) in the leaf cells. The meteorological parameters temperature and light intensity were significantly correlated with isoprene and surface O3, with r2=0.91 and p2=0.87 and p-2 h-1 which are higher than previous studies on pristine forest. This information together with the the in-situ measurement information on isoprene emission flux is then fed into the WRF-CMAQ atmospheric chemistry model to study the effect of oil palm plantation expansion over the years (2000 – 2016) on the local atmospheric chemistry.Conclusions: The in-situ of isoprene measurement in oil palm plantation has provided the variations of atmospheric concentration at different time scale which is important in giving information of surface O3 production. The relationship between isoprene-surface O3 and CO2-isoprene were interconnected at different time and influenced by meteorological factors. The model has discovered regions that are converted into oil palm plantation has experienced rise in isoprene concentration in region that are converted into oil palm plantation, and it even can be carried downwind up to 100 km inland of the emission source. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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