ENTICE Satellite Orbital Simulator to Study Ice Clouds

Abstract

AbstractClouds play a significant role in the Earth's energy balance and hydrologic 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 combining a 94 GHz cloud radar and multi‐frequency sub‐millimeter (sub‐mm) microwave radiometers 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 a science objective could be achieved depends on the orbital sampling characteristics of the mission. In this study, ENTICE sampling statistics are simulated with more than 1 billion (109) profiles and 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. These statistics can then be used to help with future mission planning efforts. Using the GEOS‐5 model atmosphere (produced by nature‐run at 7‐km and 30‐min resolution), the simulator calculates sampling statistics related to cloud types and overpass times with enhancement from radar. The wide swath of ENTICE radiometers by conical and side scanning methods ensures ample high cloud samples (1.3 × 109 samples) gathered by ENTICE over its 2‐year mission for different types of clouds with sufficient sampling over the diurnal cycles. Sampling differences between radar and radiometers at nadir shows 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.