NSF National Center for Atmospheric Research

Unifying Observations, Simulations, and Theory for Drizzle Size Distribution Tails

Abstract The onset and rate of drizzle remain open problems in atmospheric physics. This study brings together theory, simulations, and observations to analyze the emergence of power‐law tails in droplet size distributions as a signature of a dynamic steady state with coalescence...

Exploring divergent long-term stratospheric aerosol injection scenarios with the G2-SAI and ARISE-hybrid experiments

Abstract. Stratospheric aerosol injection (SAI) simulations are often short relative to climatic timescales and conducted against a background that evolves due to changes in anthropogenic greenhouse gas emissions and other forcings. This can cause challenges in assessing certain...

Forecast-based attribution of the role of stratospheric variability in weather extremes

Abstract. Variability of the stratospheric polar vortex, particularly its dramatic breakdown during sudden stratospheric warming (SSW) events, has been linked to a number of surface weather extremes. However, attributing the role of stratospheric variability in a specific observe...

Hydrologic model parameter estimation in snow-dominated headwater catchments using multiple observation datasets

Abstract. Hydrologic models are often calibrated using streamflow alone, but increasing availability of in situ and satellite-based observations provide numerous opportunities to constrain model outputs and improve process representation. However, as new observation data emerges,...

Data-driven equation discovery of a sea ice albedo parametrisation

Abstract. In many sea ice models, a single-category, zero layer thermodynamic scheme is employed, in which sea ice albedo is prescribed based on surface types depending on snow cover, surface temperature, or sea ice thickness. The Parkinson and Washington parametrisation (PW79) i...

Significance of Size‐Dependent Hygroscopicity Parameterization for Aerosol‐Cloud Interactions

Abstract Aerosol‐cloud interactions (aerosol indirect effects) are the most significant source of uncertainties in the effective radiative forcing (ERF) due to aerosols which can act as cloud condensation nuclei (CCN). Uncertainties in the indirect effect can result from systemat...

Middle atmosphere chemical and dynamical effects in the CCMI-2022 stratospheric aerosol injection scenario

Abstract. Stratospheric aerosol injection (SAI) could slow surface warming, however, potential side effects include changes in stratospheric ozone and changes in regional surface temperatures and precipitation resulting from tropical lower stratospheric warming. Previous multi-mo...

Layer‐Dependent Diurnal Moist Static Energy Biases in the Unified Forecast System During the MJO Preconditioning Stage: A DYNAMO Case Study

Abstract Accurate simulation of the Madden‐Julian Oscillation (MJO) requires realistic diurnal evolution and vertical distribution of moist static energy (MSE). While prior studies documented MSE bias in simulations, vertically dependent physical processes responsible for these b...

Sensitivity of Arctic mixed-phase cloud simulations to ice microphysical modifications in the WDM6 scheme of WRF (v4.3.1)

Abstract. Arctic mixed-phase clouds (MPCs) remain challenging to represent in atmospheric models, with bulk microphysics schemes typically biased toward either excessive glaciation or inadequate ice formation. This study evaluates the behavior of the Weather Research and Forecast...