WRF-Chem-LDA-LFR

Authors

Xin Zhang and Yunyao Li

Background

The WRF-Chem-LDA-LFR Model is open-source code in the public domain, and its use is unrestricted.

We have added the lightning assimilation to the basic WRF model.

Modifications

Note that the lightning assimilation has two parts:

1. LDA

The lightning data assimilation (LDA) technique was applied to improve the WRF meteorological simulations.

We provide two methods to create the gridded flashes data for LDA.

​ 1) The Python scripts saved in /LDA/Python

​ 2) The IDL scripts in /LDA/IDL.

For the LDA concept, please check the following papers:

[1] Li, Y., Pickering, K. E., Allen, D. J., Barth, M. C., Bela, M. M., Cummings, K. A., ... & Biggerstaff, M. I. (2017). Evaluation of deep convective transport in storms from different convective regimes during the DC3 field campaign using WRF‐Chem with lightning data assimilation. Journal of Geophysical Research: Atmospheres, 122(13), 7140-7163.

[2] Fierro, A. O., Mansell, E. R., Ziegler, C. L., & MacGorman, D. R. (2012). Application of a lightning data assimilation technique in the WRF-ARW model at cloud-resolving scales for the tornado outbreak of 24 May 2011. Monthly Weather Review, 140(8), 2609-2627.

[3] Fierro, A. O., Gao, J., Ziegler, C. L., Mansell, E. R., MacGorman, D. R., & Dembek, S. R. (2014). Evaluation of a cloud-scale lightning data assimilation technique and a 3DVAR method for the analysis and short-term forecast of the 29 June 2012 derecho event. Monthly Weather Review, 142(1), 183-202.

[4] Fierro, A. O., Clark, A. J., Mansell, E. R., MacGorman, D. R., Dembek, S. R., & Ziegler, C. L. (2015). Impact of storm-scale lightning data assimilation on WRF-ARW precipitation forecasts during the 2013 warm season over the contiguous United States. Monthly Weather Review, 143(3), 757-777.

2. LFR

The lightning flash rate (LFR) is read directly from the generated LFR files to replace the lightning parameterization.

Then, both lightning flash and lightning NO_x will be placed in the "true" grids.

For the LFR concept, please check the following papers:

[1] Kang, D., Foley, K. M., Mathur, R., Roselle, S. J., Pickering, K. E., & Allen, D. J. (2019). Simulating lightning NO production in CMAQv5. 2: performance evaluations. Geoscientific model development, 12(10), 4409-4424.

[2] Kang, D., Pickering, K. E., Allen, D. J., Foley, K. M., Wong, D. C., Mathur, R., & Roselle, S. J. (2019). Simulating lightning NO production in CMAQv5. 2: evolution of scientific updates. Geoscientific model development, 12(7), 3071-3083.

Usage

Please check the README.md under LDA and LFR directories.

Applications

• Improving the convection simulation
• Improving the lightning NO_x estimation

Publications

Feel free to use this model for your own research and add the paper information below:

• Xin Zhang et al. (2021). Influence of convection on the upper tropospheric O3 and NOx budget in China. In review.