EGU21-13694, updated on 04 Mar 2021
https://doi.org/10.5194/egusphere-egu21-13694
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Quantifying Teleconnection pathways leading to Low Rainfall anomalies during Boreal Summer in Indonesian Borneo

Timothy Lam1, Marlene Kretschmer2, Samantha Adams3, Alberto Arribas3,4, Rachel Prudden3, Elena Saggioro5, Jennifer Catto4, and Rosa Barciela6
Timothy Lam et al.
  • 1University of Exeter, Centre for Doctoral Training in Environmental Intelligence, Exeter, United Kingdom of Great Britain – England, Scotland, Wales (tl493@exeter.ac.uk)
  • 2Department of Meteorology, University of Reading, Reading, UK
  • 3Informatics Lab, Met Office, Exeter, UK
  • 4College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK
  • 5Department of Mathematics and Statistics, University of Reading, Reading, UK
  • 6Met Office, Exeter, UK

Teleconnections are sources of predictability for regional weather and climate, which can be represented by causal relationships between climate features in physically separated regions. In this study, teleconnections of low rainfall anomalies in Indonesian Borneo are analysed and quantified using causal inference theory and causal networks. Causal hypotheses are first developed based on climate model experiments in literature and then justified by means of partial regression analysis between NCEP reanalysis sea surface temperatures and climate indices (drivers) and rainfall data in Indonesian Borneo from various sources (target variable). We find that, as previous studies have highlighted, El Niño Southern Oscillation (ENSO) has a profound effect on rainfall in Indonesia Borneo, with positive Niño 3.4 index serving as a direct driver of low rainfall, also partially through reduced sea surface temperatures (SSTs) over Indonesian waters. On the other hand, while Indian Ocean Dipole (IOD) influences Indonesian Borneo rainfall through SSTs over the same area as a thermodynamic effect, its remaining effect has shifted at multidecadal timescale, opening the rooms for further research. This work informs the potential of a systematic causal approach to statistical inference as a powerful tool to verify and explore atmospheric teleconnections and enables seasonal forecasting to strengthen prevention and control of drought and fire multihazards over peatlands in the study region.

Keywords: Tropical teleconnections, Causal inference, Climate variability, Drought, Indonesia

How to cite: Lam, T., Kretschmer, M., Adams, S., Arribas, A., Prudden, R., Saggioro, E., Catto, J., and Barciela, R.: Quantifying Teleconnection pathways leading to Low Rainfall anomalies during Boreal Summer in Indonesian Borneo, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13694, https://doi.org/10.5194/egusphere-egu21-13694, 2021.

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