Creating physically coherent and spatially correlated perturbations to initialize high-resolution ensembles of simulated convection
Advanced Search
Select up to three search categories and corresponding keywords using the fields to the right. Refer to the Help section for more detailed instructions.

Search our Collections & Repository

All these words:

For very narrow results

This exact word or phrase:

When looking for a specific result

Any of these words:

Best used for discovery & interchangable words

None of these words:

Recommended to be used in conjunction with other fields

Language:

Dates

Publication Date Range:

to

Document Data

Title:

Document Type:

Library

Collection:

Series:

People

Author:

Help
Clear All

Query Builder

Query box

Help
Clear All

For additional assistance using the Custom Query please check out our Help Page

i

Creating physically coherent and spatially correlated perturbations to initialize high-resolution ensembles of simulated convection

Filetype[PDF-9.44 MB]


Select the Download button to view the document
This document is over 5mb in size and cannot be previewed
Details You May Also Like

Details:

  • Journal Title:
    Quarterly Journal of the Royal Meteorological Society
  • Personal Author:
  • NOAA Program & Office:
  • Description:
    The use of ensembles for numerical weather prediction has become common during the last decade. For global models, the generation of initial-condition perturbations has a number of well-tested methodologies. In ensembles that predict convective storms explicitly (i.e., km), the generation of physically realistic perturbations is less well posed. This study introduces a technique to generate physically coherent and spatially correlated (PCSC) initial-condition perturbations that are calibrated to the environment. Ensembles of idealized CM1 simulations, initialized with either PCSC perturbations (EXP_PCSC), spatially coherent random perturbations (EXP_3KM), or Gaussian white-noise random perturbations (EXP_WHITE), are run for both a linear convective line of storms and a single “supercell” storm to demonstrate the utility of this new perturbation technique in diverse environments. PCSC perturbations are extracted from high-resolution simulations of boundary-layer turbulence and random perturbations are calibrated to be the same in magnitude as PCSC perturbations. EXP_PCSC simulations spawn turbulence fastest in this study. The simulated turbulence is more robust than in other experiments more than 1 hr into the simulation, because horizontal convective rolls enhance power at the largest scales. Random perturbations are slow to generate turbulence; this problem is exacerbated when the base model state flow is nonturbulent. Due to robust turbulence, EXP_PCSC ensemble spread increases fastest during the first simulation hour and remains largest throughout the remainder of the simulations. Although EXP_PCSC spread is the largest, the sensitivity of convection to the initial perturbations varies at different times in the storm life cycle. Storms appear more sensitive to perturbations added near the time of convective initiation.
  • Keywords:
  • Source:
    Q J R Meteorol Soc. 2022;1–21
  • DOI:
  • Document Type:
    Journal Article
  • Rights Information:
    Accepted Manuscript
  • Compliance:
    Submitted
  • Main Document Checksum:
  • Download URL:
  • File Type:

Supporting Files

  • No Additional Files

More +

You May Also Like

Checkout today's featured content at repository.library.noaa.gov

Version 3.26