Using NUCAPS to Observe the Thermodynamic Structure of Strong Saharan Air Layer Outbreaks about Its Source within the Deserts of Northeast Africa

The Suomi-NPP NOAA NUCAPS (Unique Combined Atmospheric Processing System) is an algorithm that combines infrared with microwave sounders for the National Weather Service (NWS) Advanced Weather Interactive Processing System (AWIPS-II) forecast workstations. NUCAPS products consist of Skew-T plots, along with planar gridded cross sections of temperature, moisture, trace gases and cloud-cleared radiances. NUCAPS has been gaining traction operationally by demonstrating skill in diagnosing 3D profiling of cold air aloft, atmospheric rivers, as well as spring-summer pre-convective environments over the Central US and Alaska. The Naval Research Laboratory (NRL) in Monterey, CA is investigating the unprecedented possibilities of exploiting NUCAPS toward improvements in diagnosing the thermodynamic structure of the Saharan Air Layer (SAL), an elevated air mass of hot, dry and often dusty conditions propagating across Africa into the data sparse Atlantic basin. The overarching objective is to assist forecasters at the NWS in San Juan, Puerto Rico toward providing effective alerts of hazardous air quality associated with the dusty SAL air mass propagating across the greater Caribbean. Other agencies standing to benefit from this effort includes the Tropical Analysis and Forecast Branch at the National Hurricane Center, the International Desk at the Weather Prediction Center, the Caribbean Institute for Meteorology and Hydrology in Barbados, and the NOAA NWS Weather Forecasting Offices (WFOs) at Key West, Miami, Melbourne, and Ruskin.

There has been much literature describing the SAL structure once it has crossed from the West African coast into the maritime Atlantic basin. By applying NUCAPS, this paper will explore both the less understood SAL characteristics about its formation within the deserts of Northeast Africa as well as the north tropical Atlantic basin further downstream. A wealth of remote sensing imagery, in-situ measurements, and model output will accompany this effort.