Page 144 - 《高原气象》2026年第2期
P. 144

高     原      气     象                                 45 卷
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                    Study on the Characteristics and Influencing Factors of Sensible Heat

                        Flux and Latent Heat Flux in the Coniferous and Broad-leaved
                                    Mixed Forest of Lesser Khingan Mountains



                                                                                3
                                                                                            1
                                                                  3, 4
                             SUN Pengfei 1, 2, 3 , QU Zhe , YU Zhenghua , YUAN Chao , JIA Qingyu ,
                                                    2
                                        ZHAO Xulong , DONG Xingchen , MA Hongda   5
                                                     2
                                                                      2
                      (1. Institute of Atmospheric Environment, China Meteorological Administration, Shenyang  110166, Liaoning, China;
                                      2. Yichun Meteorological Bureau, Yichun  153000, Heilongjiang, China;
                           3. Key open Laboratory of Northeast Cold Vortex Research, CMA, Shenyang  110166, Liaoning, China;
                        4. Liaoning Meteorological Disaster Monitoring and Early Warning Centre, Shenyang  110166, Liaoning, China;
                                     5. Fenglin Meteorological Bureau, Fenglin  153036, Heilongjiang, China)
             Abstract:  Located  in  the  temperate  monsoon  climate  zone  of  northeast  China,  dominated  by  coniferous  and
             broad-leaved mixed forest the Lesser Khingan Mountains has the largest and most complete primary forest of Ko‐
             rean pine in Asia, which plays an important role in regulating the regional climate. In order to explore the sensi‐
             ble heat flux (H) and latent heat flux (LE) characteristics of the coniferous and broad-leaved mixed forest in the
             Lesser Khingan Mountains and the regulation effect of environmental, biological factors on H and LE, H and LE
             at 40 m and 50 m altitude of Wuying National Climate Observatory from 2007 to 2023 were studied by using the
             eddy correlation method, and a structural equation model was constructed to analyze the influencing factors in
             detail. The results show that: The interannual variation of H and LE in the coniferous and broad-leaved mixed
             forest in the Lesser Khingan Mountains showed a decreasing trend, but the variation trend was not completely
             consistent. The annual average of H and LE at 40 m height was 19. 84±1. 83 W·m  and 29. 39±2. 93 W·m , re‐
                                                                                    -2
                                                                                                         -2
             spectively. The annual average of H and LE at 50 m altitude was 22. 71±1. 29 W·m  and 31. 76±1. 07 W·m , re‐
                                                                                    -2
                                                                                                         -2
             spectively. The peak of H appeared in April, the secondary peak in October, and the peak of LE appeared in Ju‐
             ly, in which LE was greater than H from May to September, indicating that the energy conversion was dominat‐
             ed by latent heat exchange in May to September, and by sensible heat exchange in other months. The 30-min
             scale energy closure rate was 49%, the monthly energy closure rate ranged from 32 to 61%, in which the grow‐
             ing season and non-growing season were 53% and 38%, respectively, and the daily scale energy closure rate was
             52%. The  structural  equation  model  showed  that  the  heat  transfer  process  of  the  coniferous  and  broad-leaved
             mixed forest in the Lesser Khingan Mountains was mainly limited by energy. Net radiation had a positive effect
             on H and LE, while air temperature, vapor pressure deficit, soil volumetric water content and leaf area index
             had opposite effects on H and LE. Climate change has a complex regulatory mechanism on H and LE. The com‐
             plex interannual variation of H and LE can be partially explained by constructing structural equation models for
             different years.
             Key words: coniferous and broad-leaved mixed forest in Lesser Khingan Mountains; sensible heat flux; latent
             heat flux; energy balance; influence factor; structural equation
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