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Title: Vertical structure and physical processes of the Madden-Julian Oscillation: Biases and uncertainties at short range

We present an analysis of diabatic heating and moistening processes from 12 to 36 h lead time forecasts from 12 Global Circulation Models as part of the “Vertical structure and physical processes of the Madden-Julian Oscillation (MJO)” project. A lead time of 12–36 h is chosen to constrain the large-scale dynamics and thermodynamics to be close to observations while avoiding being too close to the initial spin-up of the models as they adjust to being driven from the Years of Tropical Convection (YOTC) analysis. A comparison of the vertical velocity and rainfall with the observations and YOTC analysis suggests that the phases of convection associated with the MJO are constrained in most models at this lead time although the rainfall in the suppressed phase is typically overestimated. Although the large-scale dynamics is reasonably constrained, moistening and heating profiles have large intermodel spread. In particular, there are large spreads in convective heating and moistening at midlevels during the transition to active convection. Radiative heating and cloud parameters have the largest relative spread across models at upper levels during the active phase. A detailed analysis of time step behavior shows that some models show strong intermittency in rainfall and differences in themore » precipitation and dynamics relationship between models. In conclusion, the wealth of model outputs archived during this project is a very valuable resource for model developers beyond the study of the MJO. Additionally, the findings of this study can inform the design of process model experiments, and inform the priorities for field experiments and future observing systems.« less
Authors:
 [1] ;  [1] ;  [2] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [7] ;  [8] ;  [9] ;  [10] ;  [11] ;  [12] ;  [13] ;  [14] ;  [15]
  1. Met Office, Exeter (United Kingdom)
  2. Univ. of Reading, Reading (United Kingdom). National Centre for Atmospheric Science-Climate
  3. California Inst. of Technology (CalTech), Pasadena, CA (United States). Jet Propulsion Lab.
  4. Jet Propulsion Laboratory, California Institute of Technology, Pasadena California USA
  5. Swedish Meteorological and Hydrological Institute, Norrkoping (Sweden). Rossby Centre
  6. Environment Canada, Victoria British Columbia (Canada). Canadian Centre for Climate Modelling and Analysis
  7. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
  8. National Center for Atmospheric Research, Boulder, CO (United States)
  9. Univ. of Washington, Seattle, WA (United States). Dept. of Atmospheric Sciences,
  10. Japan Agency for Marine-Earth Science and Technology, Yokosuka (Japan). Research Institute for Global Change
  11. Univ. of California, Irvine, CA (United States). Dept. of Earth System Sciences
  12. CNRM-GAME, Meteo-France and CNRS, Toulouse (France)
  13. Meteorological Research Institute, Ibaraki (Japan). Dept. of Climate Research
  14. European Center for Medium-Range Weather Forecasts, Reading (United Kingdom)
  15. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States)
Publication Date:
OSTI Identifier:
1252214
Grant/Contract Number:
GA01101; AGS-1228302; NA12OAR4310075; NNX13AM18G; CATER 2013-3142; ATM-0425247; OCI-1053575; TG-ATM120034
Type:
Accepted Manuscript
Journal Name:
Journal of Geophysical Research: Atmospheres
Additional Journal Information:
Journal Volume: 120; Journal Issue: 10; Journal ID: ISSN 2169-897X
Publisher:
American Geophysical Union
Research Org:
Univ. of California, Irvine, CA (United States); Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); California Inst. of Technology (CalTech), Pasadena, CA (United States). Jet Propulsion Lab.
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23); National Science Foundation (NSF); NASA
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES diabatic processes; Madden-Julian Oscillation; modeling; convection; Year of Tropical convection; uncertainties