Analysis of the Land−Atmosphere Environment of Cyclone Kelvin over Northern Australia: A Possible "Brown Ocean" Case

In 2018, Cyclone Kelvin made landfall in northwest Australia as a category 1 storm on 18 February 2018. The storm intensified inland with winds of 80 knots, and gusts as high as 100 knots. Like Tropical Storm Erin (2007) in the United States, a distinct eye feature was apparent well inland. The tendencies for Cyclone Kelvin were characteristic of a recently proposed intensification process called “the Brown Ocean effect (BOE).” In BOE storms, it is hypothesized that within certain atmospheric, soil moisture, and flux environments, tropical cyclone maintenance or intensification may occur. The literature as shown that the region of Northern Australis is favorable such processes because of its topography, soil characteristics, and the climatological regime. An analysis of the inland intensification of Cyclone Kelvin was conducted to investigate the synoptic-mesoscale meteorological environments and underlying land surface conditions associated with Cyclone Kelvin. Herein, we present results from this preliminary analysis to determine whether inland intensification was related to land surface interactions. Such analyses will also provide context for ongoing NASA-funded experiments employing coupled atmosphere-land modeling systems such as the NASA Unified WRF model and the Land Information System (LIS).