Results 41 to 50 of about 711,225 (168)

A High-Precision Prediction Method of Atmospheric Absorption Attenuation on Over-the-Horizon Propagation Trajectories

Atmosphere
Abnormal refraction phenomena such as atmospheric ducts due to temperature inversions or rapid decreases in humidity often happen in the lower troposphere over the sea and coastal area, which can make low-elevation signals in the duct layer propagate ...
Qinglin Zhu, Hao An, Fang Sun, Jie Han, Xiang Dong, Shoubao Zhang, Changsheng Lu, Ying Ci, Bin Xu   +8 more
doaj   +1 more source

Analysis of the accuracy of using ERA5 reanalysis data for diagnosis of evaporation ducts in the East China Sea

Frontiers in Marine Science, 2023
Evaporation ducts are a phenomenon that occurs with extremely high frequency at the boundary between the atmosphere and the ocean. Because they directly affect the propagation of electromagnetic waves, it is necessary to study their various ...
Zhijin Qiu, Zhijin Qiu, Cheng Zhang, Cheng Zhang, Bo Wang, Tong Hu, Jing Zou, Zhiqian Li, Shizhe Chen, Sheng Wu   +9 more
doaj   +1 more source

The projected occurrence changes of the lower atmospheric ducts accompanied with sea fog under different CMIP6 scenarios across the Hangzhou Bay

Frontiers in Marine Science
In this study, diagnostic schemes for sea fog and lower atmospheric ducts were established based on the WRF model. Using these schemes, four groups of ten-year continuous simulations were conducted for the Hangzhou Bay area, covering the historical ...
Yuhe Pu, Jing Zou, Bo Wang, Xiaofeng Zhao, Bin Wang, Hang Wang, Zhijin Qiu, Xiaolei Liu, Hanyue Wang   +8 more
doaj   +1 more source

Initial MST radar observations of upper tropospheric-lower stratospheric duct-like structures over Jicamarca, Peru [PDF]

Atmospheric Chemistry and Physics, 2012
Persistent wind jet structures along zonal and meridional fields, believed to be caused by stationary gravity waves, were detected in February 1999 in mesosphere-stratosphere-troposphere (MST) radar wind measurements of the troposphere and lower ...
Z. Li, S. Naqvi, A. J. Gerrard, J. L. Chau, Y. Bhattacharya   +4 more
doaj   +1 more source

Corona discharge actuator as an active sound absorber under normal and oblique incidence

Acta Acustica, 2022
In the majority of active sound absorbing systems, a conventional electrodynamic loudspeaker is used as a controlled source. However, particular situations may require an actuator that is more resistant to harsh environments, adjustable in shape, and ...
Sergeev Stanislav, Humbert Thomas, Lissek Hervé, Aurégan Yves   +3 more
doaj   +1 more source

Mesoscale Modeling of Boundary Layer Refractivity and Atmospheric Ducting

Journal of Applied Meteorology and Climatology, 2010
Abstract In this study four mesoscale forecasting systems were used to investigate the four-dimensional structure of atmospheric refractivity and ducting layers that occur within evolving synoptic conditions over the eastern seaboard of the United States.
Tracy Haack, Changgui Wang, Sally Garrett, Anna Glazer, Jocelyn Mailhot, Robert Marshall   +5 more
openaire   +1 more source

Acoustic optimisation and prediction of sound propagation in turbofan engine ducts

, 2010
The research presented in this thesis explores the prediction of noise propagation andradiation in turbofan engine intakes and bypass ducts, and the optimisation of noise attenuationby using acoustic liners.
Achunche, Iansteel Mukum
core   +1 more source

An investigation of long-distance propagation of gravity waves under CAWSES India Phase II Programme [PDF]

Annales Geophysicae, 2015
Coordinated measurements of airglow features from the mesosphere–lower thermosphere (MLT) region were performed at Allahabad (25.5° N, 81.9° E) and Gadanki (13.5° N, 79.2° E), India to study the propagation of gravity waves in 13–27° N latitude range ...
N. Parihar, A. Taori
doaj   +1 more source

Four-dimensional variational data assimilation for inverse modelling of atmospheric methane emissions: method and comparison with synthesis inversion [PDF]

, 2008
A four-dimensional variational (4D-Var) data assimilation system for inverse modelling of atmospheric methane emissions is presented. The system is based on the TM5 atmospheric transport model.
Bergamaschi, P., M. C. Krol, P. Bergamaschi, J. F. Meirink, Krol, M.C., Dep Natuurkunde, Meirink, J., Marine and Atmospheric Research, Meirink, J.F., Krol, M. C., Meirink, J. F.   +10 more
core   +3 more sources

Hybrid GRU–Random Forest Model for Accurate Atmospheric Duct Detection with Incomplete Sounding Data

Remote Sensing
Atmospheric data forecasting traditionally relies on physical models, which simulate atmospheric motion and change by solving atmospheric dynamics, thermodynamics, and radiative transfer processes.
Yi Yan, Linjing Guo, Jiangting Li, Zhouxiang Yu, Shuji Sun, Tong Xu, Haisheng Zhao, Lixin Guo   +7 more
doaj   +1 more source