Valmassoi et al. (2020) Irrigation impact on precipitation during a heatwave event using WRF-ARW: The summer 2015 Po Valley case

Identification

• Journal: Atmospheric Research
• Year: 2020
• Date: 2020-03-19
• Authors: Arianna Valmassoi, Jimy Dudhia, Silvana Di Sabatino, Francesco Pilla
• DOI: 10.1016/j.atmosres.2020.104951

Research Groups

• School of Architecture, Planning and Environmental Policy, University College Dublin, Dublin, Ireland
• National Center for Atmospheric Research, Boulder, CO, United States
• Climate Monitoring and Diagnostics group, Hans-Ertel-Centre for Weather Research, Germany
• Meteorology Section, Institute of Geosciences, University of Bonn, Germany
• Department of Physics and Astronomy, University of Bologna, Bologna, Italy

Short Summary

This study investigates the impact of irrigation on precipitation during a heatwave in the Po Valley, Italy, using the WRF model with new irrigation parameterizations. It finds that irrigation increases overall regional precipitation by enhancing nighttime events while inhibiting afternoon convection.

Objective

• To investigate the impact of irrigation on precipitation patterns and atmospheric properties during a heatwave event in the Po Valley, Italy, using the Weather Research and Forecasting (WRF) model with newly developed irrigation parameterizations.

Study Configuration

• Spatial Scale: Northern Italy (Po Valley) at a 3 km convection-permitting resolution.
• Temporal Scale: Model simulations starting May 2015, with analysis focused on July 2015. Irrigation applied daily from May 15, 2015.

Methodology and Data

• Models used: Weather Research and Forecasting (WRF) model (ARW core) with newly developed irrigation parameterizations defined by different evaporative processes. Both convection-permitting and convection-parameterized sensitivity simulations were performed.
• Data sources: National radar composite (used for comparison and validation of model results).

Main Results

• Irrigation increases the total accumulated precipitation over the Po Valley region.
• Convection-permitting simulations show that irrigation inhibits afternoon precipitation events due to an increase in convection inhibition and a decrease in boundary layer height. This occurs despite an increase in Convective Available Potential Energy (CAPE) and a decrease in both the Lifting Condensation Level (LCL) and Level of Free Convection (LFC).
• For nighttime events, irrigation significantly increases both boundary layer moisture and CAPE, leading to an increase in precipitation.
• Irrigated model runs demonstrate better performance compared to control runs when validated against the national radar composite accumulated over two hours.
• A daily irrigation amount of 5.7 mm was applied at 5 UTC for 3 hours.

Contributions

• Application and evaluation of newly developed irrigation parameterizations within the WRF model for a specific heatwave event.
• Detailed analysis of the differential impact of irrigation on daytime versus nighttime convective precipitation, highlighting complex atmospheric responses.
• Demonstration of improved model skill in simulating precipitation patterns during a heatwave when irrigation effects are included, validated against observational radar data.
• Focus on the Po Valley, a region highly vulnerable to heatwaves and dependent on irrigation, providing regional insights into climate-irrigation interactions.

Funding

• Not explicitly mentioned in the provided text.

Citation

@article{Valmassoi2020Irrigation,
  author = {Valmassoi, Arianna and Dudhia, Jimy and Sabatino, Silvana Di and Pilla, Francesco},
  title = {Irrigation impact on precipitation during a heatwave event using WRF-ARW: The summer 2015 Po Valley case},
  journal = {Atmospheric Research},
  year = {2020},
  doi = {10.1016/j.atmosres.2020.104951},
  url = {https://doi.org/10.1016/j.atmosres.2020.104951}
}