Ambient pressure concept of pressure becomes irrelevant, and it is undefined at a gravitational singularity. The SI unit of pressure is the pascal (Pa), which is a very small unit relative to atmospheric pressure on Earth, so kilopascals (kPa) are more commonly used in this context. The ambient atmospheric pressure at sea level is not constant: it varies with the weather, but averages around 100 kPa. In fields such as meteorology and underwater diving, it is common to see ambient pressure expressed in bar or millibar. One bar is 100 kPa or approximately ambient pressure at sea level. Ambient pressure may in
ISO 3166-2:PA ISO 3166-2:PA ISO 3166-2:PA is the entry for Panama in ISO 3166-2, part of the ISO 3166 standard published by the International Organization for Standardization (ISO), which defines codes for the names of the principal subdivisions (e.g., provinces or states) of all countries coded in ISO 3166-1. Currently for Panama, ISO 3166-2 codes are defined for 10 provinces and 3 indigenous regions. Each code consists of two parts, separated by a hyphen. The first part is , the ISO 3166-1 alpha-2 code of Panama. The second part is either of the following: The codes for the provinces are assigned in