CO2 Profile at Harvard Forest HEM and LPH Towers since 2009

Carbon dioxide profile measurements are designed to supplement eddy flux measurements in calculating the carbon exchange of a forest. In the case of the Harvard Forest flux towers, the change in CO2 storage between the ground and the height of the eddy flux system during each half hour must be added to the eddy flux measured above the forest to determine the total carbon exchange. The profile measurements are also necessary in order to calculate CO2 movement by advection, or horizontal air transport. The amount of CO2 removed from a particular site by advection is the product of the total CO2 within the air a given range of height above the ground, and the average velocity of airflow parallel to the ground surface within that height range.

二氧化碳廓线测量旨在补充涡度通量测量（eddy flux measurements），用于辅助计算森林的碳交换量。针对哈佛森林通量塔（Harvard Forest flux towers）的应用场景，需将每半小时内地面至涡度通量系统高度之间的二氧化碳储量变化，叠加森林上方实测得到的涡度通量数值，方可确定总碳交换量。此外，廓线测量也是通过平流（advection，即水平空气输送）计算二氧化碳运移过程的必要前提。某一特定站点经平流移除的二氧化碳总量，等于该站点地面上方特定高度区间内空气中的总二氧化碳含量，与该高度区间内平行于地表的平均气流速率的乘积。