Dynamics and Chemistry of the Summer Stratosphere Model Output

DCOTSS-Model-Output features numerical model output for the Dynamics and Chemistry of the Summer Stratosphere sub-orbital campaign. Featured in this product are trajectory calculations, convection-permitting model simulations, and chemistry model output. Air parcel trajectories are computed using the TRAJ3D trajectory model. Two types of trajectory products are created: flight trajectories and overshoot trajectories. Flight trajectories will be initialized every second along each Dynamics and Chemistry of the Summer Stratosphere (DCOTSS) flight track and run backwards for up to 10 days. Overshoot trajectories will be initialized in overshoot volumes identified from both GridRad radar and GOES satellite data every 10 minutes and run forward for up to 5 days. Convection allowing model simulations are carried out using the Weather Research and Forecasting Model coupled with Chemistry (WRF-Chem). These will aid in the evaluation of aircraft observations and evaluate the ability of numerical models to represent overshooting convection and transport. Photodissociation frequencies (J values) will also be computed using a radiative transfer model of the UV and Visible (UV/Vis) spectral regions. Data collection for this product is ongoing and currently only features the first deployment.

Each summer the North American Monsoon Anticyclone (NAMA) dominates the circulation of the North-Western Hemisphere and acts to partially confine and isolate air from the surrounding atmosphere. Strong convective storms in the NAMA regularly reach altitudes deep into the lower stratosphere, with some ascending above 20 km. These storms carry water and pollutants from the troposphere into the otherwise very dry stratosphere, where they can have a significant impact on radiative and chemical processes, potentially including destruction of stratospheric ozone. The DCOTSS field campaign is a NASA Earth Venture Suborbital research project aimed at investigating these thunderstorms. DCOTSS utilizes NASA’s ER-2 aircraft and conducted two ~8-week science deployments based out of Salina, KS spanning early to late summer.