Table 1 Computation details of the Haines Index (HI). ΔTA and ΔTB indicate the temperature difference of the stability and moisture term, respectively. Three variants are defined depending on elevation: Low-variant Haines Index (LHI), Mid-variant Haines Index (MHI), and High-variant Haines Index (HHI). T is the air temperature and TD is the dew-point temperature at the atmospheric pressure level indicated at the respective subscript. HI = ΔTA + ΔTB for all variants. The resulting values are classified as: 2 to 3 (very low), 4 (low), 5 (moderate), and 6 (high)
From: Implementation of a GNSS meteorological model to the estimation of the Haines Index
Variants | Stability | Moisture | ||
|---|---|---|---|---|
Condition | Term value | Condition | Term value | |
LHI | ∆TA < 4 °C | 1 | ∆TB < 6 °C | 1 |
∆TA = T950 hPa – T850 hPa | 4° C ≪ ∆TA ≪ 7 °C | 2 | 6 °C ≪ ∆TB ≪ 9 °C | 2 |
∆TB = T850 hPa – TD850 hPa | ∆TA ≫ 8 °C | 3 | ∆TB ≫ 10 °C | 3 |
MHI | ∆TA < 6 °C | 1 | ∆TB < 6 °C | 1 |
∆TA = T850 hPa – T700 hPa | 6 °C ≪ ∆TA ≪ 10 °C | 2 | 6 °C ≪ ∆TB ≪ 12 °C | 2 |
∆TB = T850 hPa – TD850 hPa | ∆TA ≫ 11 °C | 3 | ∆TB ≫ 13 °C | 3 |
HHI | ∆TA < 18 °C | 1 | ∆TB < 15 °C | 1 |
∆TA = T700 hPa – T500 hPa | 18 °C ≪ ∆TA ≪ 21 °C | 2 | 15°C ≪ ∆TB ≪ 20 °C | 2 |
∆TB = T700 hPa – TD700 hPa | ∆TA ≫ 22 °C | 3 | ∆TB ≫ 21 °C | 3 |