This is further illustrated in Figure 7(c) where the vector winds are southeasterly over the Free State region that are driven by a low pressure anomaly situated to the southeast of the subcontinent as indicated by the geopotential heights
. This is bound to advect relatively cold and relatively drier maritime winds into the region.
Caption: Figure 8: The 850 hPa geopotential height
(G850), mean sea level pressure (MSLP), 850 hPa moisture (Q850), and 850hPa temperature (T850) from CFSv2 during 15 May to 15 October 2010 at the 30 stations in Thailand.
In order to better describe the changes in the WPSH, SI is used, which has been defined by the Central Meteorological Observatory  to characterize the WPSH range and intensity, that is, the average grid points of 500 hPa geopotential height
greater than 588 gpm in the range [10[degrees]-90[degrees]N, 110[degrees]E-180[degrees]E].
The adjustment of geopotential height
differences of the United Levelling Network was performed as a constrained adjustment linked to the datum points presented in Tables 2 and 4.
Three sets of 500 hPa geopotential height
anomaly composites were constructed to further explore the increase in variability during El Nino January.
Gray lines are streamlines, (b) 500-hPa geopotential heights
(black lines), temperature (dashed red), and upper-level observations of winds (blue barbs, kt), temperature (red), dewpoint depression (green), and height (purple, dam) [source: Storm Prediction Center (SPC)].
The 500-hPa geopotential height
indicates a ridge passing through the region (Figure 7(b)).
As noted above, applying PCA for geopotential height
and temperature at 500 and 850 hPa, respectively, we extracted 5, 5, 8, and 7 components.
Dust aerosol mixing ratio at 10 m (shading; kg [kg.sup.-1]), geopotential height
at 850 hPa (contours; m), and 10-m wind (arrows) on 5 Sep 2017.
 defined the India-Burma index with the averaged geopotential height
in the area of 15[degrees]N-27.5[degrees]N and 80[degrees]E-100[degrees]E at 500 hPa and pointed out that the India-Burma trough was relatively strong in the winter half year from the 1950s to the 1970s.