Xin Zhang and Yunyao Li

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.

Note that the lightning assimilation has two parts:

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.

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.

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

• Improving the convection simulation
• Improving the lightning NO_x estimation

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.