Monsoonal precipitation over Peninsular Malaysia in the CMIP6 HighResMIP experiments: the role of model resolution

Abstract

This study investigates the ability of 20 model simulations which contributed to the CMIP6 HighResMIP to simulate precipitation in different monsoon seasons and extreme precipitation events over Peninsular Malaysia. The model experiments utilize common forcing but are run with different horizontal and vertical resolutions. The impact of resolution on the models’ abilities to simulate precipitation and associated environmental fields is assessed by comparing multi-model ensembles at different resolutions with three observed precipitation datasets and four climate reanalyses. Model simulations with relatively high horizontal and vertical resolution exhibit better performance in simulating the annual cycle of precipitation and extreme precipitation over Peninsular Malaysia and the coastal regions. Improvements associated with the increase in horizontal and vertical resolutions are also found in the statistical relationship between precipitation and monsoon intensity in different seasons. However, the increase in vertical resolution can lead to a reduction of annual mean precipitation compared to that from the models with low vertical resolutions, associated with an overestimation of moisture divergence and underestimation of lower-tropospheric vertical ascent in the different monsoon seasons. This limits any improvement in the simulation of precipitation in the high vertical resolution experiments, particularly for the Southwest monsoon season.

Rapid Extreme Tropical Precipitation and Flood Inundation Mapping Framework (RETRACE): Initial Testing for the 2021–2022 Malaysia Flood

“…Meanwhile, the precipitation analysis for the 2021-2022 Malaysia flood event is consistent with the results reported by Mayowa et al [72] and Liang et al [75], in which an extreme flood event happens in the east coast part of Peninsular Malaysia when the daily precipitation exceeds 100 mm per day. Extreme precipitation and flood events have increased significantly in terms of frequency and intensity in tropical regions.…”

Amplified Interhemispheric Rainfall Contrast in Boreal Summer Due To Reduction in Anthropogenic Emissions Under COVID‐MIP Green Economic‐Recovery Scenarios

“…The uncertainty of the above precipitation projections could arise from the model‐dependent responses of circulation to anthropogenic forcings (Chen et al., 2020). Limited horizontal resolution makes it challenging for most ScenarioMIP models to properly resolve the complex topographies over the coastal regions of continents, as well as the Maritime Continent, which also contribute to the uncertainty of projected precipitation changes over these areas (Liang et al., 2022). The preceding analyses partly explain the precipitation differences at tropics between the BCC_AGCM2.0_CUACE/Aero and the ScenarioMIP models (Figures S4a and S4b in Supporting Information S1).…”

A 30 m global flood inundation model for any climate scenario

“…These HighResMIP focuses on comparing models with relatively high spatial and temporal resolutions (≤ 0.5° horizontal resolution compared to 1-3° in the wider CMIP6 model ensemble), and is the first ensemble of GCMs with a comparable resolution to the current generation of regional models, such as the CORDEX ensemble. We expect that higher resolution climate models will generally better represent extreme precipitation than coarser ones, through better representation of regional characteristics such as topography and coastlines (e.g., Park et al, 2016;Prein et al, 2016), as well as atmospheric processes and features such as atmospheric rivers, monsoons, and tropical cyclones (e.g., Liang et al, 2022;Zhang et al, 2021). This does, GWLs in many regions.…”