Retrieved Number concentration of Cloud Condensation Nuclei (RNCCN) Value-Added Product (VAP)

The objective of Retrieved Number concentration of Cloud Condensation Nuclei (RNCCN) Value-Added Product (VAP) is to provide the vertical distribution of cloud condensation nuclei (CCN) number concentrations to better represent aerosol indirect effects in climate models. The RNCCN VAP allows to collect a large number of independent samples of vertical CCN measurements at various supersaturation values from the ground. This helps to avoid the high cost of aircraft and increases the temporal distribution of retrieved CCN in the planetary boundary layer. The VAP method is based on Ghan and Collins (2004) and Ghan et al. (2006) proposed parameterizations that retrieve the vertical profiles of CCN directly from the ground level CCN, humidification factor, and in-situ lidar measurements. Further, the VAP accuracy is improved by using the quality controlled data that ensures that the boundary layer is well mixed.

云凝结核反演数浓度增值产品（Retrieved Number concentration of Cloud Condensation Nuclei Value-Added Product，简称RNCCN VAP，其中VAP为增值产品（Value-Added Product）的缩写）的研制目标，是提供云凝结核（Cloud Condensation Nuclei，CCN）数浓度的垂直分布，以便在气候模式中更准确地表征气溶胶间接效应。该RNCCN VAP可采集大量来自地面、不同过饱和度条件下的垂直方向云凝结核独立测量样本，此举既可规避航空器观测的高额成本，又可提升行星边界层内反演得到的云凝结核的时间采样密度。该增值产品的反演算法基于Ghan与Collins（2004）以及Ghan等人（2006）提出的参数化方案，可直接通过地面云凝结核观测数据、加湿因子以及原位激光雷达测量结果，反演得到云凝结核的垂直廓线。此外，通过采用经过质量控制的数据（该数据可确保边界层处于充分混合状态），进一步提升了该增值产品的反演精度。