Tropical Convection through the Lens of the Incus Mission

The Investigation of Convective UpdraftS (INCUS) is the third of the NASA Earth Venture
Missions, selected in 2021 launch scheduled for August 2026. INCUS is comprised of three
SmallSat observatories, each carrying a RainCube-heritage Ka-band 7-beam scanning radar. The
satellite platforms will be 30 and 90 seconds apart, thus providing three time intervals (30, 90
and 120 seconds) over which radar observations will be made. In addition to the Ka-band radar,
the center observatory will also house a single TEMPEST-D-heritage cross-track-scanning
passive microwave radiometer. The INCUS radars will provide a novel time-differenced radar
reflectivity view of convective storms. The radiometer will provide the spatial storm context for
the radar observations, as well as observations of the convective anvils. The combination of the
radars and radiometer on INCUS will deliver unprecedented three-dimensional views of tropical
convective storms.

The science focus of INCUS is to enhance our understanding of why, when and where tropical
convective storms form, and why only some of these storms produce extreme weather.
Convective storms transport air and water from near the Earth’s surface into the middle and
upper troposphere (convective mass flux; CMF), which can be estimated from INCUS’ time
differenced radar reflectivity profiles. CMF exerts a critical influence on Earth’s weather and
climate via its impacts on: precipitation rates, upper tropospheric moistening, high cloud
radiative feedbacks, and the large-scale circulation. Potential changes to the CMF as a function
of the local environment in which it occurs may also have significant implications for severe
weather, such as flood-producing rainfall, damaging hail, and lightning. In spite of the critical
role of convective vertical transport of water and air, representation of CMF remains a major
source of error in weather and climate models, thereby limiting our ability to accurately predict
convective storms and their impacts. The tropics-wide observations from INCUS will enhance
our understanding of tropical convective storm processes and will provide guidance for
representing these processes in numerical models across scales.

INCUS will be the first systematic investigation of the rapidly evolving CMF within tropical
convective storms, the observations of which are expected to significantly enhance both our
understanding and prediction of storm structure, their dynamics and microphysical processes,
and the ways in which these evolve over storm lifetimes. This presentation will highlight the
observational capabilities and scientific approach of the INCUS mission. It will also present
early scientific analysis into the interactions among convection and its environment using largeeddy
resolving simulations of convection as well as ground and space-based observational
analysis.