Inferring Regional Scale Surface Heat Flux around FK KoFlux Site: From One Point Tower Measurement to MM5 Mesoscale Model

FK KoFlux 관측지에서의 지역 규모 열 플럭스의 추정 : 타워 관측에서 MM5 중규모 모형까지

  • Jinkyu Hong (Lab for Atmospheric Modeling Research, Yonsei University, Biometeorology Lab/Department of Atmospheric Sciences, Yonsei University) ;
  • Hee Choon Lee (Biometeorology Lab/Department of Atmospheric Sciences, Yonsei University) ;
  • Joon Kim (Lab for Atmospheric Modeling Research, Yonsei University, Biometeorology Lab/Department of Atmospheric Sciences, Yonsei University) ;
  • Baekjo Kim (Forecast Research Lab., METRI, KMA) ;
  • Chonho Cho (Forecast Research Lab., METRI, KMA) ;
  • Seongju Lee (Haenam Observatory, KMA)
  • Published : 2003.06.01

Abstract

Korean regional network of tower flux sites, KoFlux, has been initiated to better understand $CO_2$, water and energy exchange between ecosystems and the atmosphere, and to contribute to regional, continental, and global observation networks such as FLUXNET and CEOP. Due to heterogeneous surface characteristics, most of KoFlux towers are located in non-ideal sites. In order to quantify carbon and energy exchange and to scale them up from plot scales to a region scale, applications of various methods combining measurement and modeling are needed. In an attempt to infer regional-scale flux, four methods (i.e., tower flux, convective boundary layer (CBL) budget method, MM5 mesoscale model, and NCAR/NCEP reanalysis data) were employed to estimate sensible heat flux representing different surface areas. Our preliminary results showed that (1) sensible heat flux from the tower in Haenam farmland revealed heterogeneous surface characteristics of the site; (2) sensible heat flux from CBL method was sensitive to the estimation of advection; and (3) MM5 mesoscale model produced regional fluxes that were comparable to tower fluxes. In view of the spatial heterogeneity of the site and inherent differences in spatial scale between the methods, however, the spatial representativeness of tower flux need to be quantified based on footprint climatology, geographic information system, and the patch scale analysis of satellite images of the study site.

KoFlux는 생태계와 대기 사이에 교환되는 이산화탄소, 수증기 및 에너지에 대한 우리의 이해를 높이고, FLUXNET과 CEOP등의 지역, 대륙 및 전구 규모의 관측망에 기여하기 위해서 시작되었다. 그거나 한반도의 지형적 특성 때문에 KoFlux의 대부분의 플럭스 타워는 관측에 이상적이지 못한 장소에 위치하고 있다. 탄소 및 에너지 교환의 정량화를 위해서 뿐만 아니라 군락 규모에서 지역 규모로 확장하기 위해서는 관측과 모델링을 병용한 다양한 접근 방법의 적용이 필요하다. 본 연구에서는 지역 규모의 현열 플럭스를 추정하기 위해 타워 플럭스 관측, 대류 경계층(CBL) 수지 방법, MM5 중규모 모형, 그리고 NCAR/NCEP 재분석 자료의 네 가지의 방법을 사용하여 다양한 면적을 대표하는 현열 플럭스를 산출하여 비교하였다. 비록 제한된 짧은 기간의 자료를 사용하였으나, 예비 분석을 통하여 (1) 해남 농경지 플럭스 타워에서 관측된 현열 플럭스가 지표의 불균질성을 보였고, (2) CBL 수지 방법으로 얻어진 지역 규모의 현열 플럭스는 수평 이류 효과의 계산 방법에 따라 다른 결과를 보였으며, (3) MM5 중규모 모형은 타워 플럭스 관측 값과 아주 유사한 현열 값을 수치 모사하였다. 그러나 관측지의 불균질성과 두 방법이 대표하는 면적의 근본적인 차이를 고려할 때, 플럭스 발자국 분석, 지리정보 시스템 및 관측지의 위성 영상 분석에 근거한 타워 플럭스의 공간 대표성을 정량화하는 것이 시급한 것으로 나타났다.

Keywords

References

  1. Arya, S. P., 2001: Introduction to Micrometeorology, Second Edition, Academic Press, San Diego, 420p.
  2. Cleugh, H. A. and C. S. B. Grimmond, 2001: Modeling regional scale surface energy exchanges and CBL growth in a heterogeneous, urban-rural landscape, 98, 1-31.
  3. Denmead, O. T., Raupach, M. R., Dunin, F. X., Cleugh, H. A. and Leuning, R., 1996: Boundary layer budgets for regional estimates of scalar fluxes, Global Change Biol., 2, 255-264.
  4. Dudhia, J., 1989: Numerical study of convection observed during the winter monsoon experiment using a mesoscale two-dimensional model, J. Atmos. Sci., 46, 3077-3107.
  5. Finnigan, J. J., 1999: A comment on the paper by Lee(1998):“"On micrometeorological observations of surface-air exchange over tall vegetation”", Agric. For. Meterol., 97, 55-64.
  6. Garrat, J. R., 1990, The internal boundary layer-A review, Boundary-Layer Meteorology, 50, 171-203.
  7. Gryning, S. and Batchvarova, E., 1999: Regional heat flux over the NOPEX area estimated from the evolution of the mixed-layer, Agric. For. Meteorol., 98-99, 159-167.
  8. Hong, J. K. and J. Kim, 2002: On processing raw data from micrometeorological field experiments, Korean J. Agric. For. Meteorol., 4, 119-126.
  9. Hong, S.-Y. and H.-L. Pan, 1996: Nonlocal boundary layer vertical diffusion in a medium-range forecast model, Mon. Wea. Rev., 124, 2322-2339.
  10. Kain, J. S. and J. M. Fritsch, 1993: Convective parameterization for mesoscale models: The Kain-Fritsch scheme. The representation of cumulus in numerical model, in Meteorological Monographs edited by K. A. Emanuel and D. J. Raymond, Amer. Meteor. Soc., 165-170.
  11. Kim, J., W. Kim, C. Cho, B. Choi, H. Chung, B. Lee, K. Kim, K. Kim, M. Kim, B. Lee, D. Lee, G. Lee, J. Lee, J. Lim, J. Oh, E. Park, J. Shim, J. Yun and C. Rho, 2002:KOFLUX: A new tool to study the biosphere-atmosphere interactions in Asia, in Ecology of Korea edited by D. Lee, 215-229.
  12. Laubach, J. and H. Fritsch, 2002: Convective boundary layer budgets derived from aircraft data, Agric. For. Meteorol., 111, 237-263.
  13. Lee, H. C., J. K. Hong, C. H., Cho, B. C. Choi, and J. Kim, 2003:Tower$CO_2$measurements in farmland (Haenam/Korea), in this issue.
  14. Lee, X., 1998: On micrometeorological observations of surface-air exchange over tall vegetation, Agrc. For. Meteorol., 91, 39-49.
  15. Levy, P. G., A. Grell, A. Lindroth, M. Molder, P. G. Jarvis, B. Kruijt and J. B. Moncrieff, 1999: Regional-scale $CO_2$fluxes over central Sweden by a boundary layer budget method, Agric. For. Meteorol., 98-99, 169-180.
  16. Massman, W. J. and X. Lee, 2002: Eddy covariance flux corrections and uncertainties in long-term studies of carbon and energy exchanges, Agric. For. Meteorol., 113, 121-144.
  17. Munley, W. G. and L. E. Hipps, 1991: Estimation of regional evaporation for a tall grass prairie from measurements of properties of the atmospheric boundary layer, Water Resour. Res., 27, 225-230.
  18. Munley, W. G. and L. E. Hipps, 1991: Estimation of regional evaporation for a tall grass prairie from measurements of properties of the atmospheric boundary layer, Water Resour. Res., 27, 225-230.
  19. Oncley, S. P. and J. Dudhian, 1995: Evaluation of surface fluxes from MM5 using Observations, Month. Weath. Rev., 123, 3344-3357.
  20. Raupach, M. R., O. T. Denmead and F. X. Dunin, 1992: Challenges in linking atmospheric$CO_2$ concentrations to fluxes at local and regional scales, Aust. J. Bot., 40, 697-716.
  21. Raupach, M. R. and J. J. Finnigan, 1995: Scale issues in boundary-layer meteorology: surface energy balances in heterogenous terrain, Hydrol. Processes, 9, 589-612.
  22. Raupach, M. R., D. D. Baldocchi, H.-J. Bolle, L. Dumenil, W. Eugster, F. X. Meixner, J. A. Olejnik, R. A. Pielke, J. D. Tenhunen and R. Valentini, 1999: Group report: How is the atmospheric coupling of land surfaces affected by topography, complexity in landscape patterning, and the vegetation mosaic$?$, in Integrating Hydrology, Ecosystem Dynamics, and Biogechemistry in Complex Landscales edited by J. D. Tenhunen and P. Kabat, John Wiley & Sons, England, 177-196.
  23. Paw U, K. T., D. D. Baldocchi, T. P. Meyers and K. B. Wilson, 2000: Correction of eddy-covariance measurements incorporating both advective effects and density fluxes, Boundary-Layer Meteorol., 97, 487-511.
  24. Stull, R., 1988: An Introduction to Boundary Layer Meteorology, Kluwer Academic Press, The Netherlands, 666p.
  25. Wofsy, S. C., R. C. Harris and W. A. Kaplan, 1988: Carbon dioxide in the atmosphere over the Amazon basin, J. Geophy. Res., 93, 1377-1387.
  26. Wood, E. F., 1995: Heterogeneity and scaling landatmospheric water and energy fluxes in climate systems, in Space and Time Scale Variability and Interdependencies in Hydrological Processes edited by R. A. Fedders, Cambridge University Press, Great Britain.