Optimization of Aerosol Model Selection for TROPOMI/S5P

To retrieve aerosol properties from satellite measurements, micro-physical aerosol models have to be assumed. Due to the spatial and temporal inhomogeneity of aerosols, choosing an appropriate aerosol model is an important task. In this paper, we use a Bayesian algorithm that takes into account model uncertainties to retrieve the aerosol optical depth and layer height from synthetic and real TROPOMI O2A band measurements. The results show that in case of insufficient information for an appropriate micro-physical model selection, the Bayesian algorithm improves the accuracy of the solution.

Dynamic control of spin-wave propagation

In this work we present a method to dynamically control the propagation of spin-wave packets. By altering an external magnetic field the refraction of the spin wave at a temporal inhomogeneity is enabled. Since the inhomogeneity is spatially invariant, the spin-wave impulse remains conserved while the frequency is shifted. We demonstrate the stopping and rebound of a traveling Backward-Volume type spin-wave packet.

Cyclone activities as inferred from the Twentieth Century Reanalysis version 3 (20CRv3) for 1836-2015

<p>Preliminary results obtained from tracking cyclones in the ensemble-average and individual members of the NOAA-CIRES-DOE Twentieth Century Reanalysis version 3 (20CRv3) ensemble for the period 1836-2015 will be presented. Comparison with tracking in the 20CRv2c ensemble-average series will also be shown.</p><p>The results indicate that the 20CRv3 is an improvement in representing cyclone climate and variability compared to previous versions (20CRv2c or 20CRv2). However, as in previous versions, the 20CRv3 ensemble-average fields are too smooth to use for tracking cyclones and studying cyclone climate, especially for the period before 1960 for the NH and for the entire reanalysis period for the SH, and that there are still temporal inhomogeneity issues in the 20CRv3, especially in the SH and in the early period for the NH, due to the increases over time of observations available for assimilation. The improvements arise from the use of a higher model resolution and the assimilation of more observations. They include that the 20CRv3 ensemble shows cyclones of higher intensities and a higher number of deep cyclones (center pressure ≤ 960 hPa) in the Northern Hemisphere than the 20CRv2c counterpart. Historical trends of cyclone activity and their uncertainties will be discussed based on the results of tracking the individual members of the 20CRv3 ensemble, with the temporal inhomogeneity issues being taken into account.  </p>

Retrieval Models of Water Vapor and Wet Tropospheric Path Delay for the HY-2A Calibration Microwave Radiometer

This paper focuses on the development and validation of retrieval models of water vapor (WV) and wet tropospheric path delay (PD) for the calibration microwave radiometer (CMR) on board the first ocean dynamic environment satellite of China—Haiyang-2A (HY-2A). The reference data are those of Jason-1 microwave radiometer (JMR) and Jason-2 advanced microwave radiometer (AMR). The crossover points of the HY-2A and Jason-1/2 satellite tracks are extracted, and the data pairs at these points are divided into fitting and validation datasets. The retrieval models of WV and PD are built for the CMR using the fitting dataset and genetic algorithm, and validated using the validation dataset. The validation shows that the results of the retrieval models are consistent with the JMR and AMR data, and the root-mean-square differences of WV and PD are 1.86 kg m−2 and 11.4 mm, respectively. Finally, the retrieved results from the CMR brightness temperature along-track data using the retrieval models and the AMR along-track data are gridded by the inverse distance weighted method. Their monthly-mean spatial distributions are compared in order to investigate the applicability of the retrieval models globally, namely, beyond locations of the data pairs in the validation dataset. The comparison shows that the retrieval models are applicable in most open ocean areas, and that the latitude and temporal inhomogeneity of the crossover point distribution in the fitting dataset does not lead to obvious latitude and temporal inhomogeneity in the gridded data.