Mean sea level pressure in January and July

The global mean sea level pressure is shown in Fig 1 for January and July. In the southern hemisphere the pressure field is largely consistent with the Palmen-Newton model of the general circulation. In the northern hemisphere the land-sea contrast dominates in the extreme seasons.

Fig 1. Global mean sea level pressure in January (top) and July (bottom). The letter A stands for the Aleutian Low, P for the Pacific High, I for the Icelandic Low, Z for the Azores High, S for the Siberian High, B for the Bermuda High, H is a high. (an improvement over Fig 12.1 in the book)