The INCUS Mission: Measuring Convective Mass Flux from Space

NASA’s Investigation of Convective Updrafts (INCUS) aims to improve understanding of how, when, and why tropical convective storms form and why only some lead to extreme weather. Much of the vertical transport of water and air between Earth’s surface and the upper troposphere is facilitated by convective storms. This vertical transport of water and air, often referred to as convective mass flux (CMF), plays a critical role in Earth’s weather and climate system through its impacts on precipitation rates, detrainment and upper tropospheric moistening, high cloud feedbacks, and the large-scale circulation. Recent studies have also suggested that CMF may change with changing climates with subsequent implications for flood-producing rainfall, severe weather, and lightning. In spite of the critical role of this vertical transport of water and air within the weather and climate system, much is still not understood about the impacts of CMF on high cloud properties, precipitation rates, and the associated microphysical-dynamical feedbacks. Representation of CMF is also a major source of error in weather and climate models, thereby limiting our ability to predict the microphysical and dynamical properties of convective storms on weather through climate timescales.

INCUS seeks to: (1) identify environmental factors controlling CMF in tropical storms; (2) explore the connection between CMF and high anvil clouds; (3) link CMF to storm type and intensity; and (4) evaluate these relationships in models. The INCUS observations will enhance our understanding and prediction of convective storm processes.

The INCUS mission is the first to systematically measure rapidly changing CMF in tropical convection. It features three SmallSats in low Earth orbit, spaced 30 and 90 seconds apart, each with a Ka-band scanning radar (RainCube heritage). The middle satellite also carries a TEMPEST-D–based passive microwave radiometer. This setup captures radar observations at 30-, 90-, and 120-second intervals, enabling the use of time-differenced radar profiles to retrieve CMF. These observations will help quantify CMF intensity, vertical transport duration, and storm evolution. The radiometer provides insights into high anvil cloud properties and storm context. Together, these instruments will provide unprecedented 3D views of tropical convection.

Extensive research is being conducted in support of the INCUS mission. This includes high-resolution storm simulations, storm tracking, forward modeling, adaptive ground radar scanning, and analysis of storm environments and anvil clouds. This talk will provide an overview of the INCUS mission architecture, time-differencing retrieval approach, and early research results supporting the INCUS science goals related to this session on atmospheric convection.