10. WAP Climate
- The last two decades (1980-90’s) were warmer than the previous several decades (Fig 1), and the largest temperature changes occurred in winter (JJA), in contrast to relatively little change in spring (SOND) (Fig 2a).
- The later advance and earlier retreat of sea ice in the 1990’s (Fig 2b) translates into a shorter sea ice season (~2 weeks) during the 1990’s as compared with the 1980’s.
- There is significantly less variation in Faraday air temperatures during the 1990’s compared to either the 1980’s or the earlier decades (Fig 2c); this indicates an increased maritime influence in the WAP area.
- Sea ice extent in the WAP region is anti-correlated with both Faraday air temperature and the Southern Oscillation Index (Fig 3); these data support the idea that the linkage between sea ice and cyclonic activity is varying on global scales.
- The Southern Ocean as a whole shows a slightly increasing trend in sea ice extent (Fig 4), whereas in the WAP region there is a decreasing trend, particularly in summer sea ice extent, which is consistent with the increased maritime influence in the WAP area.
- During the decade of the 1990’s, sea ice extent anomalies in the WAP region have generally been lower, and their timing more seasonally erratic, than in the earlier decade (Fig 4).
- The last two winter seasons in the WAP have been distinguished by above average temperatures from January to July with corresponding low sea ice (Fig 5); in both seasons the sea ice advance was late (August).