UW-AOS Department Seminar - October 2, 2024 - Emily Mather

Speaker: Emily Mather, AOS graduate student

TItle: Where Has All the Energy Gone? Quantifying Advective Energy Fluxes With Dense Tower Networks

Abstract: Accurate and extensive measurements of surface-atmosphere energy exchange are necessary to improve models of the earth’s climate system. The eddy covariance method (EC), used to measure the exchange of energy and gasses between the land surface and atmosphere, consistently measures an imbalance in the surface-atmosphere energy budget, with greater incoming energy fluxes than outgoing fluxes. Studies have suggested that large-scale secondary circulations (SCs) may be responsible for some of the energy transport that is not captured by EC systems. This study investigates whether, and under what conditions, advective fluxes of sensible and latent heat may be estimated from a high-density network of tower measurements such as those taken during the CHEESHEAD19 experiment. Horizontal and vertical interpolation methods were applied to measurements of temperature and humidity in order to calculate x, y, and z gradients across each EC measurement site within the CHEESEHEAD19 domain. These gradients were used to quantify horizontal and vertical advective energy fluxes. Additionally, the contribution of these advective fluxes to the surface energy balance was assessed. Inclusion of the advective fluxes did not consistently improve energy budget closure, indicating that this method fails to provide accurate estimates of advective energy transport. Results suggest, however, that a greater spatial density of measurements, and an alternative vertical velocity measurement method, may allow for improved advection estimates from similar tower networks.