2016/03/02 by Dariusz B. Baranowski, Baranowski, Dariusz B.
Earth and Planetary Sciences · Environmental Science · #Geophysics and Gravity Measurements #Oceanographic and Atmospheric Processes #Climate variability and models
paper · pdf · doi:10.48550/arxiv.1603.00902
One the major factors determining the development and evolution of\natmospheric convection is the sea surface temperature and its variability.\nResults of this thesis show that state of atmospheric convection impacts the\ndiurnal distribution of thermal energy in the upper ocean. Under calm and clear\nsky conditions a shallow warm layer of several meters depth develops on the\nsurface of the ocean. This warm layer drives an anomalous flux from the ocean\nto the atmosphere. A novel Kelvin wave trajectory database based on satellite\ndata is introduced in this study. The investigation of its data shows that\nsubstantial fraction of Kelvin waves is initiated as a result of interaction\nwith another Kelvin wave. Two distinct categories are defined and analyzed: the\ntwo- and multiple Kelvin wave initiations, and a spin off initiation. Results\nshow that primary forcing of such waves are high diurnal cycle and/or increased\nwind speed and latent heat flux at the ocean surface. Variability of the ocean\nsurface and subsurface along Kelvin wave trajectories over Indian Ocean is\ninvestigated: wind speed and latent heat flux increase and a sea surface\ntemperature anomaly decreases during a wave passage. It is also shown that\nKelvin waves are longitude-diurnal cycle phase locked over the Maritime\nContinent. This cycle phase locking is such that it agrees with mean, local\ndiurnal cycle of convection in the atmosphere. The strength of the\nlongitude-diurnal cycle phase locking differs between non-blocked Kelvin waves,\nwhich make successful transition over the Maritime Continent, and blocked waves\nthat terminate within it. The distance between the islands of Sumatra and\nBorneo agrees with the distance travelled by an average Kelvin wave in one day.\nThis suggests that the Maritime Continent may act as a filter, favoring\nsuccessful propagation waves, which are in phase with the local diurnal cycle\nof convection.\n