Hourly temperature and precipitation time series characteristics in São Paulo with urban land use type of convection-permitting model (CPM) outputs

Chun, Kwok; Reboita, M.; Rocha, R.; Danaila, L.; Octavianti, Thanti; Risanto, Bayu; Ezber, Y.; Yetemen, O.; Tan, M.; Cheng, L.; Sens, O.; Prein, Andrea

Abstract

The influences of regional atmospheric drivers on the joint distribution of temperature and precipitation from a Convection-Permitting Model (CPM) over São Paulo are explored. Time series of temperature and precipitation are extracted from urban land data points from a 22-year Weather Research and Forecasting (WRF) model simulation between 2000 and 2021 from the South American Affinity Group (SAAG). These hourly time series are aggregated into daily, monthly, and annual time series for both maximum and mean values, and their anomalies are computed. Comparisons with ERA5 reanalysis show that the CPM simulations for São Paulo have higher local temperatures and more intermittent precipitation, with higher variance and rougher surfaces. This means that the spreads of CPM simulated distributions are larger and their tails longer resulting in more intense extreme events.
Regarding regional variability drivers, the Atlantic Meridional Mode (AMM) is useful in explaining monthly variations in precipitation, while the multivariate El Nino-Southern Oscillation index (MEI) is related to temperature and nonstationary extreme distributions for daily precipitation maxima. When analysing the joint distribution of temperatures and precipitation amounts, joint distributions differ dependent on the AMM phase. Therefore, if the AMM signal is captured accurately, it will allow the prediction of extreme temperature and precipitation events from the joint distribution.
This study provides a framework to explore multiscaling relationships by considering the distribution of convection-permitting model simulations. This framework will be useful in investigating how multiple urban land use types affect precipitation and temperature extremes. Such effects will be analysed in future sub-kilometre simulations focused on São Paulo. The findings of this study will be valuable for regional planning for sustainable development goals 11 and 13 related to climate action in cities and communities.

• Presentation Conference Type: Poster
• Conference Name: The VII Convective Permitting Climate Modelling 2023 workshop
• Start Date: Aug 29, 2023
• End Date: Aug 31, 2023
• Deposit Date: Sep 6, 2023
• Publicly Available Date: Sep 8, 2023
• Keywords: Convection-Permitting Model; Scaling; South America; SDG11; SDG13
• Public URL: https://uwe-repository.worktribe.com/output/11075862
• Publisher URL: https://cpm2023.w.uib.no/program/book-of-abstracts/