Conference Agenda

Aerosols and clouds are important factors affecting radiative forcing and climate change, and improving the ability to observe high-precision profiles of their optical properties will reduce uncertainties in climate model simulations and forecasting systems. High spectral atmospheric detection lidar is capable of wide-area, continuous, dynamic, and full-time integrated monitoring of aerosols and clouds. Three-dimensional wind field data with high spatial and temporal resolution is an important observational basis for an in-depth understanding of the structure and evolutionary characteristics of the atmospheric boundary layer, and the heat-momentum-matter exchange and equilibrium process between the upper and lower troposphere. In order to achieve global high-precision wind field and aerosol profile observations by satellite-borne Doppler wind measurement lidar and high spectral resolution lidar, it is necessary to carry out long-term and rigorous calibration and verification.

The Chinese atmospheric environment monitoring satellite DQ-1 has been successfully launched on 16 April 2022. As an integrated detection scientific research satellite, it will serve as an important part of Chinese atmospheric environment monitoring system. The DQ-1 equips five sensors including an a Particulate Observing Scanning Polarimeter (POSP), a Directional Polarization Camera (DPC), an Environmental trace gas Monitoring Instrument (EMI) and a Wide Swath Imaging system (WSI). As the primary payload, Aerosol and Carbon Detection Lidar (ACDL) is a high spectral resolution lidar (HSRL) with two-wavelength polarization detection, that can be utilized to derive the aerosol optical properties. In this study, we develop radiation calibration and optical parameter retrieval algorithms for ACDL channels in daytime and nighttime scenarios, and carry out cloud phase classification and aerosol classification studies through layer identification and scene classification algorithms. The aerosol and cloud optical properties products of the ACDL include total depolarization ratio, backscatter coefficient, extinction coefficient, lidar ratio and color ratio. After the calibration and comparison iterations, the high-resolution standardized data products of the ACDL aerosol channel developed in this study are widely used in joint multi-sensor observations and meteorological and environmental monitoring.

The ESA’s EarthCARE satellite was launched in May 2024. The HSRL payload ATLID will provide vertical profiles of aerosols and thin clouds. It will operate at a wavelength of 355 nm and have a high-spectral resolution receiver and depolarization channel. In this study, after temporal and spatial matching and quality control of the ACDL and ATLID on-orbit observation data products, synchronized observations are carried out for the scenarios of dust, cirrus clouds and polar stratospheric clouds. Through the establishment of a worldwide comparison and validation process for satellite-ground and satellite-satellite observations, the two lidars are jointly compared on optical parameters such as attenuation backscatter coefficient and depolarization ratio. The observation capability and data accuracy of the spaceborne high spectral resolution lidar are verified, and iterative optimization directions are provided for the calibration program and data processing algorithms.

Aeolus was the first satellite mission to acquire profiles of Earth’s wind on a global scale. It was launched on 22 August 2018 and finished its nominal lifetime on 30 April 2023 before an assisted re-entry on 28 July 2023. The Aeolus satellite’s only payload is a direct detection DWL ALADIN. During its lifetime, it has measured the global wind profiles and aerosol profiles simultaneously and continuously for more than 4 years. In order to guarantee the data quality and improve the inversion algorithm, the reprocessing of the Aeolus data products to improve data quality will continue in the next 5 years during phase F. This research utilizes the China Coherent Doppler Lidar Network (CDLnet) to assess the reprocessed data from Aeolus, and evaluating and analyzing the data quality.

In this study, we performed a detailed analysis of the ionospheric zonal currents from equator to middle latitudes during the recent intense geomagnetic storm on 10-12 May 2024. Magnetic measurements from two ground stations in the America sector, as well as that from the Swarm satellites have been used. Extreme intensified eastward and westward EEJ values, reaching 300 mA/m and -400 mA/m have been observed during the storm main and recovery phases, respectively. Such intense EEJ values have never been observed during the past 11-year flying period of Swarm mission. In addition, the storm responses of zonal currents at low and middle latitudes have been analyzed, by using the vertical magnetic field component from Swarm. These zonal currents showed quite prominent dependences on magnetic local time. In the noon sector, eastward currents were dominated under both quiet and storm conditions, with slightly intensification during storm. Conversely, the zonal currents in the dawn and dusk sectors displayed abrupt current reversals within 30 minutes after the sudden storm commencement, characterized by sustained eastward (dawn) and westward (dusk) perturbations persisting for the rest one and a half days. Most interestingly, two eastward zonal current jets were found located at ±25º magnetic latitudes at the dusk sector, emerged with westward zonal currents at other low and middle latitudes. To our knowledge, this is the first time to report such narrow current jets at middle latitudes during storms.