Title: Uncovering moisture transport processes in the recent paleoclimate of Earth (and Titan)
Abstract: Atmospheric transport of water vapor from the North Pacific is the primary source of moisture for western North America; wintertime precipitation accounts for upwards of 75% of the
total along the west coast of the United States, and is associated with extratropical storms and atmospheric rivers. Paleoclimate proxy records from western North America indicate a much wetter environment in Nevada and southern California at the Last Glacial Maximum (approximately 21,000 years ago). Using climate models and reanalysis data, I investigate the influence of atmospheric rivers on the climatology of North Pacific moisture transport, as well as the influence of the Last Glacial Maximum conditions on the atmospheric circulation and moisture budget of the eastern North Pacific and western North America. I will show that changes of the atmospheric river “track” into the continent, resulting from a reorganized atmospheric circulation in response to the North American ice sheets, can explain the inferred hydroclimate changes.
Similarly, I will discuss the impact of atmospheric moisture transport in the exotic hydrologic cycle of Saturn’s moon Titan. As in the terrestrial case, Titan’s surface contains records of the climate and climate evolution, and I will describe the possibility that Titan undergoes Milankovitch climate cycles, suggesting that extratropical storms also link Titan’s weather to its paleoclimate.