NASA’s CPEX-CV mission in September 2022 collected data on early hurricane formation off Africa’s northwestern coast, revealing how dust, moisture, clouds, and the ocean affect storm development. This publicly available data, including meteorological element profiles and a big dust storm, will improve future study and weather forecasting.
The eastern Atlantic experiences a rainy “disturbance” when Sahel and Sahara dust mixed with tropical clouds. These disturbances are immature hurricanes that can dissipate or evolve into strong storms as they cross the ocean.
NASA scientists spent a month on NASA’s DC-8 research plane off Africa’s northern coast in September 2022 studying these newborn storms. The squad flew 100 hours from Cabo Verde, a west African island nation. On April 1, CPEX-CV provided their statistics.
CPEX-CV operated September 1-30, 2022. Scientists collected and documented data during each trip using state-of-the-art remote-sensing lidars, radars, radiometers, and dropsondes—11-inch, lightweight tubes with a parachute that are dropped from the plane to detect wind, temperature, and humidity. The instrument teams sent data to the NASA Atmospheric Science Data Center and Global Hydrometeorology Resource Center this month.
“Combined with the global picture that satellites provide, this data offers finer details that only an airplane outfitted with instrumentation can measure,” said Will McCarty, CPEX program scientist at NASA Headquarters in Washington, DC.
These observations show how dust, moisture, clouds, and the ocean affect hurricane-forming rainy disturbances. According to Amin Nehrir, a research scientist at NASA’s Langley Research Center in Virginia, this public data will aid atmospheric scientists and weather forecasters.
“Discovery data,” Nehrir stated. It will answer unasked questions in the future.
As the plane flew, wingtip sensors recorded dust and cloud characteristics. Once the plane was above the clouds, remote sensing devices recorded Saharan dust profiles, wind speed and direction, temperature, moisture, and cloud convection and rain structures. These data give a multidimensional perspective of the air over the northeast Atlantic, revealing how those factors affect weather systems in their infancy.
The DC-8 flew across the ITCZ, where northeast and southeast trade winds meet, several times throughout the campaign. Sailors call the windless ITCZ “the calms.” Nehrir noted the ITCZ includes isolated seas.
“Looking out the window and seeing how the clouds changed as far as the eye could see from faint, puffy clouds to cloud streets to convective systems was most striking to me,” he added. “You see convective systems all at once.”
NASA’s greatest dust outburst was sampled by CPEX on September 22, 2022.
“Epic dust day,” Nehrir remarked. “These atmospheric waves that propagate off the African shore and pick up air and dust were strong.”
These “waves” interact with clouds and convection to impact tropical storm formation, which may or may not become a hurricane.
CPEX-CV followed CPEX in 2017 and CPEX – Aerosols & Winds in 2021. Previous campaign data is also published.
“Nine science projects and 10 instrument and support teams were funded under this campaign, so those investigators helped plan the mission, and now they will take that data back to their home institutions to learn,” McCarty said. “We’re racing.”