This study projects the change in environmental fields and the typhoon IGP (genesis potential index) in the western North Pacific (0°–40°N and 100°E–180°) in the late 21st century (2080–2099) using outputs from the RCP (Representative Concentration Pathway) 4.5 and RCP8.5 experiments of CMIP5 (Phase 5 of Coupled Model Intercomparison Project), carried out using 19 climate models. These models are capable of reasonably reproducing modern typhoon-related environmental fields and are thus selected for the analysis. Compared with the reference period of 1986–2005, there appears to be an increase in SST (sea surface temperature) in the western North Pacific, a weakening of VWS (vertical wind shear), and a decrease in OLR (outgoing long wave radiation) in the key regions where there are significantly negative correlations between these factors and the frequency of the typhoon; this is beneficial for the formation and development of the typhoon. On the contrary, the low pressure system that extends from the mainland to the South China Sea is weakened, suppressing typhoon activities. In general, changes in the typhoon environmental fields in the RCP8.5 scenario are greater than in the RCP4.5 scenario. In addition, the signal-to-noise ratio is examined to measure consistency between individual models. This ratio is found to be greater than 3.0 for SST change and greater than 1.0 for sea level pressure in regions under the low pressure system; for VWS and OLR changes, a ratio of less than 0.6 denotes a degree of disagreement between the models. However, the models agree well with the OLR change in regions associated with typhoon activities. The aforementioned changes in the typhoon’s environmental fields are in line with the increase in IGP in the future.
王一格,姜大膀,华维.西北太平洋地区台风环境场的预估研究.大气科学,2020,44(3):552~564 WANG Yige, JIANG Dabang, HUA Wei. Projection of Typhoon-Related Environmental Fields in the Western North Pacific. Chinese Journal of Atmospheric Sciences (in Chinese),2020,44(3):552~564复制