Utilizing ATOMIC Observations for Assessing Marine Shallow Cumuli in Single Column Models Journal Article uri icon

Overview

abstract

  • Abstract; Several different time periods of the Atlantic Tradewind Ocean‐Atmosphere Mesoscale Interaction Campaign (ATOMIC) are isolated for examining how the depiction of tradewind marine shallow cumuli in single‐column models (SCMs) is affected by choices about model physics. The periods of interest are times when the NOAA Research Vessel Ronald H. Brown and research aircraft WP‐3D Orion were collocated, enabling verification of initial conditions and large‐scale forcing (advective) tendencies constructed using gridded data from the fifth generation ECMWF atmospheric reanalysis (ERA5). To demonstrate how this new ATOMIC test case can be used to guide model development, three parameterization suites of the NOAA Unified Forecast System are evaluated within the Common Community Physics Package Single Column Model (CCPP SCM). Calculations are also performed using a large‐eddy simulation (LES) to further bridge the gap between observations and SCM output, all of which are separated into regimes of either relatively active (“cloudy”) or inactive (“clear”) marine shallow cumuli. In both regimes tested, the parameterization suites tend to: (a) generate an unrealistic skewed or bimodal distribution of cloud fraction, (b) overestimate light to moderate rain rates, (c) produce an erroneously cold and dry boundary layer, and (d) produce higher‐than‐observed cloud tops. Results show that modifying the treatment of cloud fraction as well as increasing spatial and temporal resolution help bring the SCM more in line with observations. In addition, evidence is found to suggest that some of the remaining model biases may stem from intrinsic differences in the spatio‐temporal sampling properties of the observations versus SCM output.

publication date

  • January 1, 2026

Date in CU Experts

  • January 21, 2026 11:20 AM

Full Author List

  • Hu I; Chen X; Bengtsson L; Thompson EJ; Dias J; Tulich SN

author count

  • 6

Other Profiles

International Standard Serial Number (ISSN)

  • 1942-2466

Electronic International Standard Serial Number (EISSN)

  • 1942-2466

Additional Document Info

volume

  • 18

issue

  • 1

number

  • e2024MS004814