Changes in Marine Fog Over the North Pacific Under Different Climates in CMIP5 Multimodel Simulations. Issue 19 (8th October 2018)

• Record Type: Journal Article
• Authors: Kawai, Hideaki; Koshiro, Tsuyoshi; Endo, Hirokazu; Arakawa, Osamu
• Is Part Of: Journal of geophysical research. Volume 123:Issue 19(2018)
• Page Start: 10, 911
• Page End: 10, 924
• Publication Date: 2018-10-08
• Subjects: marine fog -- climate change -- circulation changes -- CMIP5 -- cloud feedback; Atmospheric physics -- Periodicals; Geophysics -- Periodicals; 551.5
• DOI: 10.1029/2018JD028899
• Languages: English
• ISSNs: 2169-897X

Abstract

Abstract: In this study, the changes in the occurrence of marine fog over the summer North Pacific in warmer sea surface temperature (SST) or increased CO2 climates were investigated based on atmospheric model simulations by using the fifth phase of the Climate Model Intercomparison Project (CMIP5) multimodel data. Initially, the marine fog representation in CMIP5 multimodels was briefly evaluated globally. We found that the simulated marine fog occurrence was represented relatively well in boreal summer but poorly in other seasons. The results indicated that the changes in the North Pacific high‐pressure system accompanied by changes in horizontal wind patterns control the changes in marine fog occurrence in the North Pacific. The magnitude of contrasting pair changes in marine fog occurrence in the western and eastern North Pacific are primarily determined by the magnitude of changes in the North Pacific high‐pressure system. Global‐scale changes in the vertical profiles of the atmosphere (stability changes) can also affect the marine fog changes. These changes in marine fog over the North Pacific were consistent among most CMIP5 models. Plain Language Summary: Marine fog often occurs over the midlatitude ocean and affects maritime traffic and fishing vessels significantly. Therefore, it is extremely important to determine the changes in marine fog occurrence in a warmer climate. To the best of the authors' knowledge, this study is the first to reveal that marine fog occurrence decreases in the western North Pacific and increases in the eastern North Pacific in boreal summer when SST increases. Many models indicate similar changes, and thus these changes must be reliable. The study also explains the mechanisms driving these changes in marine fog. Key Points: Marine fog is well represented in state‐of‐the‐art climate models in boreal summer, but not in boreal winter Changes in large‐scale marine fog are mainly controlled by changes in sea level pressure patterns Changes in global‐scale atmospheric vertical profile also affect changes in marine fog under an increased CO2 climate