Statistical estimations of atmospheric duct over the South China Sea and the tropical eastern Indian Ocean

Zhao, Xiaofeng; Wang, Dongxiao; Huang, Shuibo; Huang, Ke; Chen, Ju

doi:10.1007/s11434-013-5942-8

Cited by 31 publications

(30 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…GPS sounding data from the SCSIO open cruises were used to study the characteristics of atmospheric ducts over the SCS. The results showed that the occurrence probabilities of evaporation ducts, surface-based ducts, and elevated ducts were 75.3%, 5%, and 43.7%, respectively, and the mean evaporation duct height was 15.3 m (Zhao et al 2013).…”

Section: Sc I E Nti F Ic Applic Atio N Smentioning

confidence: 99%

Toward a Mesoscale Hydrological and Marine Meteorological Observation Network in the South China Sea

Yang

Wang

Huang

et al. 2015

Bulletin of the American Meteorological Society

Self Cite

View full text Add to dashboard Cite

Air–sea interaction in the South China Sea (SCS) has direct impacts on the weather and climate of its surrounding areas at various spatiotemporal scales. In situ observation plays a vital role in exploring the dynamic characteristics of the regional circulation and air–sea interaction. Remote sensing and regional modeling are expected to provide high-resolution data for studies of air–sea coupling; however, careful validation and calibration using in situ observations is necessary to ensure the quality of these data. Through a decade of effort, a marine observation network in the SCS has begun to be established, yielding a regional observatory for the air–sea synoptic system. Earlier observations in the SCS were scarce and narrowly focused. Since 2004, an annual series of scientific open cruises during late summer in the SCS has been organized by the South China Sea Institute of Oceanology (SCSIO), carefully designed based on the dynamic characteristics of the oceanic circulation and air–sea interaction in the SCS region. Since 2006, the cruise carried a radiometer and radiosondes on board, marking a new era of marine meteorological observation in the SCS. Fixed stations have been established for long-term and sustained records. Observations obtained through the network have been used to study regional ocean circulation and processes in the marine atmospheric boundary layer. In the future, a great number of multi-institutional, collaborative scientific cruises and observations at fixed stations will be carried out to establish a mesoscale hydrological and marine meteorological observation network in the SCS.

show abstract

Section: Sc I E Nti F Ic Applic Atio N Smentioning

confidence: 99%

Toward a Mesoscale Hydrological and Marine Meteorological Observation Network in the South China Sea

Yang

Wang

Huang

et al. 2015

Bulletin of the American Meteorological Society

Self Cite

View full text Add to dashboard Cite

show abstract

“…Based on highresolution Global Position Systerm (GPS) radiosonde data, they found that summer monsoons exerted important infl uence on lower-atmospheric ducts over the SCS. Zhao et al (2013) estimated the characteristics of ducts in the tropics in spring. Despite improvements in duct climatology, the duct characteristics for the SCS are still not well documented.…”

Section: Introductionmentioning

confidence: 99%

Observed characteristics of atmospheric ducts over the South China Sea in autumn

Cheng

Zhou

Wang

et al. 2015

Chin. J. Ocean. Limnol.

Self Cite

View full text Add to dashboard Cite

The observed characteristics of lower atmospheric ducts over the South China Sea (SCS) were analyzed based on Global Position Systerm (GPS) radiosonde data collected four times daily during autumn open cruises from 2006 to 2012. Duct occurrence, thickness, and strength over the SCS were about 40%, 150-m thick, and 8 M units, respectively, which were larger than during the summer monsoon period. Most ducts occurred at heights <1 500 m and these ducts easily trap electromagnetic wave clusters with wavelengths <2 m. Diurnal variation of the SCS ducts appeared evident. They occurred more often at midnight at higher altitudes (about 1 100 m), with a thickest layer of about 145 m and less frequently during the evening at lower altitudes (about 800 m), with a thinnest layer of about 125 m. Moreover, ducts during the daytime at a mean height of about 900 m, with the greatest strength of about 10 M units. Furthermore, all duct variables observed over the SCS in autumn decreased from north to south. These fi ndings are useful not only in the design of radar and communication systems, but also for evaluating possible effects of anomalous propagation on meteorological radar and military applications.

show abstract

“…This clutter can be described as a function of propagation loss from the radar to the range cell, which in turn depends on the refractivity profile in the troposphere (Kraut et al 2004). Compared with conventional in situ refractivity measurements, such as radiosondes, rocketsondes, and microwave refractometers (Babin and Rowland 1992;von Engeln and Teixeira 2004;Mentes and Kaymaz 2007;Ali et al 2012;Zhao et al 2013), RFC has the advantages of employing the radar itself as the remote sensing device and can provide temporal and spatial tracking of the refractive information in a dynamically changing environment (Wang et al 2009). …”

Section: Introductionmentioning

confidence: 99%

“…In general, the statistics of these errors are unknown. To characterize the profile more accurately, the adjoint method has been demonstrated to be a good choice (Zhao and Huang 2012). In Zhao and Huang (2012), numerical simulations of an evaporation duct case were considered, and the clutter observations were assumed to be no noise pollution.…”

Section: Introductionmentioning

confidence: 99%

“…To characterize the profile more accurately, the adjoint method has been demonstrated to be a good choice (Zhao and Huang 2012). In Zhao and Huang (2012), numerical simulations of an evaporation duct case were considered, and the clutter observations were assumed to be no noise pollution. In practical operations, however, the available measurements are often contaminated by much more noise, which will enhance the ill-posedness of RFC inversions.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Atmospheric Duct Estimation Using Radar Sea Clutter Returns by the Adjoint Method with Regularization Technique

Zhao

Huang

2014

Journal of Atmospheric and Oceanic Technology

Self Cite

View full text Add to dashboard Cite

This paper focuses on retrieving the atmospheric duct structure from radar sea clutter returns by the adjoint approach with the regularization technique. The adjoint is derived from the split-step Fourier parabolic equation method, and the regularization term is constructed by the background refractivity field. To ensure successful implementations of the regularization, the L-curve criterion is used to find the optimal regularization parameter. The feasibility of the proposed method is validated by the numerical simulations of different noise-level clutter returns, as well as a real clutter profile measured by the S-Band Space Range Radar located in Wallops Island. In the process of inversions, the refractivity profile is first obtained by genetic algorithm, and then it is used as the background field for the adjoint method. The retrieved results indicate that, with an appropriate regularization parameter, the structure of the background refractivity profile can be improved by the proposed method.

show abstract

Statistical estimations of atmospheric duct over the South China Sea and the tropical eastern Indian Ocean

Cited by 31 publications

References 13 publications

Toward a Mesoscale Hydrological and Marine Meteorological Observation Network in the South China Sea

Toward a Mesoscale Hydrological and Marine Meteorological Observation Network in the South China Sea

Observed characteristics of atmospheric ducts over the South China Sea in autumn

Atmospheric Duct Estimation Using Radar Sea Clutter Returns by the Adjoint Method with Regularization Technique

Contact Info

Product

Resources

About