Abstract
Clouds play a significant role in the Earth’s energy balance and
hydrological cycle through their effects on radiation and precipitation,
and therefore are crucial for life on Earth. Earth’s NexT‐generation ICE
mission (ENTICE) is proposed to measure diurnally resolved global
vertical profiles of cloud ice particle size, ice water content, and
in-cloud humidity and temperature using multi-frequency sub-millimeter
(sub-mm) microwave radiometers and a 94 GHz cloud radar from space. The
scientific objective of ENTICE is to identify the important processes by
which anvil clouds evolve and interact with ambient thermodynamic
conditions to advance our fundamental understanding of clouds and reduce
uncertainties in cloud climate feedback. Whether such an objective could
be achieved depends on the orbital sampling characteristics of the
mission. In this study, ENTICE sampling statistics are simulated using
five different scanning methods in a 400 km altitude precession orbit
with an inclination of 65°: nadir, forward pointing, side scanning, and
conical scanning for the radiometers, and nadir pointing for the radar.
Using the GEOS-5 Nature Run produced at 7-km and 30-min resolution,
sampling statistics with respect to cloud types and local hours with
enhancement from radar are calculated for ENTICE. The wide swath of
ENTICE radiometers by conical and side scanning methods ensures ample
high cloud samples gathered by ENTICE over its two-year mission for
different types of clouds with sufficient sampling over the diurnal
cycles. Sampling differences between radar and radiometers at nadir
demonstrate that the combination of radar and radiometers will allow for
measurements of cloud vertical profiles. Therefore, our results show
that the designed orbit sampling of ENTICE is sufficient to fulfill the
mission science goals.