Enrichment of desert soil elements in Takla Makan dust aerosol

During a Hungarian expedition in 1994 to and regions of north-western China, atmospheric aerosol samples were collected in the Takla Makan Desert and on some sites in mountains surrounding the Tarim Basin, PIXE data obtained for the composition and enrichment factors of the regional aerosol clearly reflected that a heavy accumulation of salts has been formed in the closed inland basin, When compared to the regional soil composition data published by other authors, it turned out that S and Cl, showing high enrichment relative to average crust composition, are of soil origin. (C) 2002 Elsevier Science B.V. All rights reserved

Toward the Full Quantum Dynamical Description of Photon Induced Processes in D-2(+)

The dissociative ionization (multiphoton regime) of the D-2(+) ion by ultrashort laser pulses has been studied theoretically using ab initio calculations. The combined ionization and dissociation spectrum was explored for fixed molecular axis orientations. In accordance with previous investigations, the dominant features in the obtained joint energy spectrum were multiphoton peaks. In addition to this, in the present work, photoelectron angular distributions were analyzed as well. By performing a partial wave analysis for each multiphoton peak, we have identified the number of absorbed photons. Moreover, we also found that the angular distribution can significantly change inside a multiphoton peak as a function of electron and nuclear kinetic energy

The role of jet adjustment processes in subtropical dust storms

Meso-α/β/γ scale atmospheric processes of jet dynamics responsible for generating Harmattan, Saudi Arabian, and Bodélé Depression dust storms are analyzed with observations and high-resolution modeling. The analysis of the role of jet adjustment processes in each dust storm shows similarities as follows: (1) the presence of a well-organized baroclinic synoptic scale system, (2) cross mountain flows that produced a leeside inversion layer prior to the large-scale dust storm, (3) the presence of thermal wind imbalance in the exit region of the midtropospheric jet streak in the lee of the respective mountains shortly after the time of the inversion formation, (4) dust storm formation accompanied by large magnitude ageostrophic isallobaric low-level winds as part of the meso-β scale adjustment process, (5) substantial low-level turbulence kinetic energy (TKE), and (6) emission and uplift of mineral dust in the lee of nearby mountains. The thermally forced meso-γ scale adjustment processes, which occurred in the canyons/small valleys, may have been the cause of numerous observed dust streaks leading to the entry of the dust into the atmosphere due to the presence of significant vertical motion and TKE generation. This study points to the importance of meso-β to meso-γ scale adjustment processes at low atmospheric levels due to an imbalance within the exit region of an upper level jet streak for the formation of severe dust storms. The low level TKE, which is one of the prerequisites to deflate the dust from the surface, cannot be detected with the low resolution data sets; so our results show that a high spatial resolution is required for better representing TKE as a proxy for dust emission. ©2017. American Geophysical Union