GISS Lunch Seminar

Speaker: Paulina Czarnecki (Columbia University)
Topic: Data Driven Quadrature as a Fast, Flexible Gas Optics Scheme

Broadband radiation calculations are computationally expensive, and climate and weather models require fast parameterizations for computing atmospheric radiation. Though modern gas optics schemes, called correlated-k distributions, are efficient and accurate, they are finely tuned for specific applications and can be difficult to understand. In this talk, I introduce the data-driven quadrature (DDQ) scheme, which accurately calculates quantities important to characterizing Earth's energy balance, including radiative fluxes, heating rates, and radiative forcing. While originally developed in cloudless present-day conditions for longwave (thermal) radiation, DDQ extrapolates well to cloudy atmospheres. New updates expand DDQ to shortwave (sunlight) calculations, which must be robust to variations in solar zenith angle and surface reflectivity, as well as to variability in all greenhouse gases, with potential application to different climate scenarios or exoplanetary atmospheres. Data-driven quadrature offers a versatile and efficient alternative to traditional methods, and application in a single-column model demonstrates potential for operationalization as a gas optics scheme in climate and weather models.