Modelling hourly air temperature, relative humidity and solar irradiance over several major oil palm growing areas in Malaysia
Hourly values of air temperature, relative humidity and solar irradiance are often not available in most of the oil palm growing areas in Malaysia, thus limiting research in studying how these weather variables affect oil palm growth and yield. Therefore, a study was carried out to determine the acc...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Malaysian Palm Oil Board
2020
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| Online Access: | http://psasir.upm.edu.my/id/eprint/86788/ http://psasir.upm.edu.my/id/eprint/86788/1/Modelling%20hourly%20air%20temperature.pdf |
| _version_ | 1848860287592038400 |
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| author | Siang, Cheah See Teh, Christopher Boon Sung Ismail, Mohd Razi Yusop, Mohd Rafii |
| author_facet | Siang, Cheah See Teh, Christopher Boon Sung Ismail, Mohd Razi Yusop, Mohd Rafii |
| author_sort | Siang, Cheah See |
| building | UPM Institutional Repository |
| collection | Online Access |
| description | Hourly values of air temperature, relative humidity and solar irradiance are often not available in most of the oil palm growing areas in Malaysia, thus limiting research in studying how these weather variables affect oil palm growth and yield. Therefore, a study was carried out to determine the accuracy of some selected models to estimate hourly values of these weather variables in six major oil palm growing areas in Malaysia. Using daily maximum and minimum temperatures, hourly air temperature was estimated. Together with mean hourly dew point temperature, the estimated hourly air temperature was used to simulate hourly relative humidity which was subsequently used to estimate hourly total solar irradiance. The mean absolute error, root mean square error and Willmott’s index of agreement within a 24-hr period for air temperature ranged from 0.5°C-0.7°C, 0.6°C-1.0°C and 0.81-0.84, respectively; for relative humidity ranged from 0.8%-1.5%, 1.0%-2.0% and 0.88-0.93, respectively and for total solar irradiance ranged from 83-139 W m-2, 109-178 W m-2 and 0.66-0.75, respectively. These models thus could be used to simulate hourly air temperature, relative humidity and solar irradiance in the six major oil palm growing areas in Malaysia. |
| first_indexed | 2025-11-15T12:42:50Z |
| format | Article |
| id | upm-86788 |
| institution | Universiti Putra Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-15T12:42:50Z |
| publishDate | 2020 |
| publisher | Malaysian Palm Oil Board |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | upm-867882021-11-16T06:41:31Z http://psasir.upm.edu.my/id/eprint/86788/ Modelling hourly air temperature, relative humidity and solar irradiance over several major oil palm growing areas in Malaysia Siang, Cheah See Teh, Christopher Boon Sung Ismail, Mohd Razi Yusop, Mohd Rafii Hourly values of air temperature, relative humidity and solar irradiance are often not available in most of the oil palm growing areas in Malaysia, thus limiting research in studying how these weather variables affect oil palm growth and yield. Therefore, a study was carried out to determine the accuracy of some selected models to estimate hourly values of these weather variables in six major oil palm growing areas in Malaysia. Using daily maximum and minimum temperatures, hourly air temperature was estimated. Together with mean hourly dew point temperature, the estimated hourly air temperature was used to simulate hourly relative humidity which was subsequently used to estimate hourly total solar irradiance. The mean absolute error, root mean square error and Willmott’s index of agreement within a 24-hr period for air temperature ranged from 0.5°C-0.7°C, 0.6°C-1.0°C and 0.81-0.84, respectively; for relative humidity ranged from 0.8%-1.5%, 1.0%-2.0% and 0.88-0.93, respectively and for total solar irradiance ranged from 83-139 W m-2, 109-178 W m-2 and 0.66-0.75, respectively. These models thus could be used to simulate hourly air temperature, relative humidity and solar irradiance in the six major oil palm growing areas in Malaysia. Malaysian Palm Oil Board 2020-03 Article PeerReviewed text en http://psasir.upm.edu.my/id/eprint/86788/1/Modelling%20hourly%20air%20temperature.pdf Siang, Cheah See and Teh, Christopher Boon Sung and Ismail, Mohd Razi and Yusop, Mohd Rafii (2020) Modelling hourly air temperature, relative humidity and solar irradiance over several major oil palm growing areas in Malaysia. Journal of Oil Palm Research, 32 (1). 34 - 49. ISSN 1511-2780 http://jopr.mpob.gov.my/V2/?p=9835 10.21894/jopr.2020.0010 |
| spellingShingle | Siang, Cheah See Teh, Christopher Boon Sung Ismail, Mohd Razi Yusop, Mohd Rafii Modelling hourly air temperature, relative humidity and solar irradiance over several major oil palm growing areas in Malaysia |
| title | Modelling hourly air temperature, relative humidity and solar irradiance over several major oil palm growing areas in Malaysia |
| title_full | Modelling hourly air temperature, relative humidity and solar irradiance over several major oil palm growing areas in Malaysia |
| title_fullStr | Modelling hourly air temperature, relative humidity and solar irradiance over several major oil palm growing areas in Malaysia |
| title_full_unstemmed | Modelling hourly air temperature, relative humidity and solar irradiance over several major oil palm growing areas in Malaysia |
| title_short | Modelling hourly air temperature, relative humidity and solar irradiance over several major oil palm growing areas in Malaysia |
| title_sort | modelling hourly air temperature, relative humidity and solar irradiance over several major oil palm growing areas in malaysia |
| url | http://psasir.upm.edu.my/id/eprint/86788/ http://psasir.upm.edu.my/id/eprint/86788/ http://psasir.upm.edu.my/id/eprint/86788/ http://psasir.upm.edu.my/id/eprint/86788/1/Modelling%20hourly%20air%20temperature.pdf |