HazeDayIndex

Cai et al., 2017, NCC

• 10.1038/nclimate3249

• Haze weather index (HWI)

• Because V850, $\Delta{T}$ and U500 are not independent, we normalized each time series by its respective standard deviation

  and summed the three normalized time series to construct a single index.

Zhang et el., 2018, EP

• https://doi.org/10.1016/j.envpol.2018.08.019
• Haze Day Index (HDI)

Horton et al., 2014, NCC

• DOI: 10.1038/NCLIMATE2272
• Air Stagnation Index (ASI)
• A grid cell day is considered stagnant when daily-mean near-surface (10-m) wind speeds are <3.2 m s−1 , daily-mean mid-tropospheric (500 mb) wind speeds are <13 m s−1 , and daily-mean precipitation accumulation is <1 mm.

Wang et al., 2018, BMAS

• doi:10.1175/BAMS-D-16-0301.1
• air stagnation day