Editorial Type:
Article
Article Type:
Research Article

Effects of Spatial and Temporal Variations in PBL Depth on a GCM

Sun-Hee Shin Division of Earth Environmental System, College of Natural Science, Pusan National University, Pusan, South Korea

Search for other papers by Sun-Hee Shin in
Current site
Google Scholar
PubMed Close
and
Kyung-Ja Ha Division of Earth Environmental System, College of Natural Science, Pusan National University, Pusan, South Korea

Search for other papers by Kyung-Ja Ha in
Current site
Google Scholar
PubMed Close
Print Publication:
15 Sep 2007
DOI:
https://doi.org/10.1175/JCLI4274.1
Page(s):
4717–4732
Restricted access

Abstract

The effect of variations in planetary boundary layer (PBL) height on a GCM was investigated using the Yonsei University (YONU) AGCM. This GCM assumes a convective boundary layer constrained to the two lowest model levels. As a consequence of this fixed PBL height, the model tends to produce excessive mixing. In this study the authors focuse on the impact of spatially and temporally varying PBL height. In addition to stability-dependent eddy diffusivity, the model adopts both bulk mixing due to the surface heat flux and z-less mixing under stable conditions. The variable-depth PBL strongly suppressed excessive mixing so that the model bias was reduced over stable regions such as the Antarctic continent. On the other hand, vertical mixing over continents in the summer hemisphere was stronger than for the fixed-PBL version, resulting in greater rising motion and warming effects in the lower atmosphere. The variable-PBL height reduces excess precipitation over the western Pacific and East Asian monsoon region. Based on the improved PBL parameterization, widespread decreases in surface sensible heat flux and rising motion in the lower troposphere occurred simultaneously over the East Asian continent. This implies that the precipitation simulation is very sensitive to PBL processes.

Corresponding author address: Kyung-Ja Ha, Division of Earth Environmental System, College of Natural Science, Pusan National University, Pusan, South Korea. Email: kjha@pusan.ac.kr

Abstract

The effect of variations in planetary boundary layer (PBL) height on a GCM was investigated using the Yonsei University (YONU) AGCM. This GCM assumes a convective boundary layer constrained to the two lowest model levels. As a consequence of this fixed PBL height, the model tends to produce excessive mixing. In this study the authors focuse on the impact of spatially and temporally varying PBL height. In addition to stability-dependent eddy diffusivity, the model adopts both bulk mixing due to the surface heat flux and z-less mixing under stable conditions. The variable-depth PBL strongly suppressed excessive mixing so that the model bias was reduced over stable regions such as the Antarctic continent. On the other hand, vertical mixing over continents in the summer hemisphere was stronger than for the fixed-PBL version, resulting in greater rising motion and warming effects in the lower atmosphere. The variable-PBL height reduces excess precipitation over the western Pacific and East Asian monsoon region. Based on the improved PBL parameterization, widespread decreases in surface sensible heat flux and rising motion in the lower troposphere occurred simultaneously over the East Asian continent. This implies that the precipitation simulation is very sensitive to PBL processes.

Corresponding author address: Kyung-Ja Ha, Division of Earth Environmental System, College of Natural Science, Pusan National University, Pusan, South Korea. Email: kjha@pusan.ac.kr

Save
Cover Journal of Climate
Journal of Climate

  • Businger, J. A., J. C. Wyngaard, Y. Izumi, and E. F. Bradley, 1971: Flux-profile relationships in the atmospheric surface layer. J. Atmos. Sci., 28 , 181–189.

    • Search Google Scholar
    • Export Citation

  • Chun, H-Y., I-S. Song, J-J. Baik, and Y-J. Kim, 2004: Impact of a convectively forced gravity wave drag parameterization in NCAR CCM3. J. Climate, 17 , 3530–3547.

    • Search Google Scholar
    • Export Citation

  • Ek, M., and L. Mahrt, 1991: A user guide to OSU1DPBL version 1.0.4: A one-dimensional planetary boundary layer model with interactive soil layers and plant canopy. Department of Atmospheric Sciences, Oregon State University, Corvallis, OR, 118 pp.

  • Ghan, S. J., J. W. Lingaas, M. E. Schlesinger, R. L. Mobley, and W. L. Gates, 1982: A documentation of the OSU two-level atmospheric general circulation model. Climatic Research Institute Rep. 35, 395 pp.

  • Ha, K-J., and L. Mahrt, 2001: Simple inclusion of z-less turbulence within and above the modeled nocturnal boundary layer. Mon. Wea. Rev., 129 , 2136–2143.

    • Search Google Scholar
    • Export Citation

  • Ha, K-J., and L. Mahrt, 2003: Radiative and turbulent fluxes in the nocturnal boundary layer. Tellus, 55A , 317–327.

  • Hack, J. J., 1994: Parameterization of moist convection in the NCAR Community Climate Model (CCM2). J. Geophys. Res., 99 , 5551–5568.

    • Search Google Scholar
    • Export Citation

  • Holtslag, A. A. M., 1987: Surface fluxes and boundary-layer scaling: Models and applications. KNMI Sci. Rep. 87-2, 173 pp.

  • Holtslag, A. A. M., and B. A. Boville, 1993: Local versus nonlocal boundary layer diffusion in a global climate model. J. Climate, 6 , 1825–1842.

    • Search Google Scholar
    • Export Citation

  • Kim, J., and L. Mahrt, 1992: Simple formulation of turbulent mixing in the stable free atmosphere and nocturnal boundary layer. Tellus, 44A , 381–394.

    • Search Google Scholar
    • Export Citation

  • Medeiros, B., A. Hall, and B. Stevens, 2005: What controls the mean depth of the PBL? J. Climate, 18 , 2877–2892.

  • Moeng, C-H., P. P. Sullivan, and B. Stevens, 1999: Including radiative effects in an entrainment rate formula for buoyancy-driven PBLs. J. Atmos. Sci., 56 , 1031–1049.

    • Search Google Scholar
    • Export Citation

  • Nieuwstadt, F. T. M., 1984: The turbulent structure of the stable, nocturnal boundary layer. J. Atmos. Sci., 41 , 2202–2216.

  • Ninomiya, K., 1984: Characteristics of Baiu front as a predominant subtropical front in the summer Northern Hemisphere. J. Meteor. Soc. Japan, 62 , 880–894.

    • Search Google Scholar
    • Export Citation

  • Oh, J. H., 1989: Physically-based general circulation model parameterization of clouds and their radiative interaction. Ph.D. dissertation, Department of Atmospheric Sciences, Oregon State University, Corvallis, OR, 315 pp.

  • Oh, J. H., 1996: Radiative transfer model for climate studies: 2. Longwave radiation parameterization for a clear sky. J. Korean Meteor. Soc., 32 , 471–484.

    • Search Google Scholar
    • Export Citation

  • Oh, J. H., Y. Noh, J. J. Baik, and S. M. Lee, 1993: Implementation of cloud-topped mixed layer in a general circulation model. J. Korean Meteor. Soc., 30 , 615–630.

    • Search Google Scholar
    • Export Citation

  • Randall, D. A., J. A. Abeles, and T. G. Corsetti, 1985: Seasonal simulations of the planetary boundary layer stratocumulus clouds with a general circulation model. J. Atmos. Sci., 42 , 641–671.

    • Search Google Scholar
    • Export Citation

  • Sanjay, J., P. Mukhopadhyay, and S. S. Singh, 2002: Impact of nonlocal boundary layer diffusion scheme on forecasts over Indian region. Meteor. Atmos. Phys., 80 , 207–216.

    • Search Google Scholar
    • Export Citation

  • Schlesinger, M. E., and W. L. Gates, 1979: Numerical simulation of the January and July global climate with the OSU two-level atmospheric general circulation model. Climatic Research Institute Rep. 9, 102 pp.

  • Shin, H. J., I. U. Chung, and J. W. Kim, 2004: The annual variation and closure of the water cycle for the Asian continent. J. Climate, 17 , 4840–4855.

    • Search Google Scholar
    • Export Citation

  • Tokioka, T., K. Yamazaki, I. Yagai, and A. Kitoh, 1984: A description of the Meteorological Research Institute atmospheric general circulation model (MRI GCM-I). Meteorological Research Institute Tech. Rep. 8, 249 pp.

  • Troen, I. B., and L. Mahrt, 1986: A simple model of the atmospheric boundary layers: Sensitivity to surface evaporation. Bound.-Layer Meteor., 37 , 129–148.

    • Search Google Scholar
    • Export Citation

  • Vogelezang, D. H. P., and A. A. M. Holtslag, 1996: Evaluation and model impacts of alternative boundary-layer height formulations. Bound.-Layer Meteor., 81 , 245–269.

    • Search Google Scholar
    • Export Citation

  • Wyngaard, J. C., 1973: On surface-layer turbulence. Workshop on Micrometeorology, D. A. Haugen, Ed., Amer. Meteor. Soc., 101–149.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 605 351 23
PDF Downloads 166 31 2