Determination of the marine boundary layer height from the GNSS RO data by using a multivariate statistical method

The Marine Boundary Layer Height (MBLH) is in general characterized as a discontinuity interface in terms of temperature, moisture and wind field over the open ocean. Monitoring changes in the MBLH over time can provide insights into climatic change. However, there is no extensive observation system to provide the accurate MBLH measurement. Global Navigation Satellite System Radio Occultation (GNSS RO) data have several advantages, including global coverage, high vertical resolution, and the data quality relative insensitivity to factors such as weather patterns, geographical location, and diurnal variations. They can complement scarce observations over the oceans. By using data inversion techniques, various high-level profile products such as bending angle (BA), refractivity (N), temperature, and water vapor pressure can be derived from GNSS RO data. Therefore, many studies have attempted to identify MBLH using GNSS RO data. Different RO products is able to offer distinct advantages in defining MBLH. This study extends and develops a hybrid GNSS RO multi-variable algorithm, with the discontinuity in BA profile as the primary criterion, supplemented by variations in refractivity and water vapor pressure to enhance the reliability of MBLH determination.