Geoscience Reference
In-Depth Information
transportation to the ground, and demonstrated that tropopause altitude determined by
wind profiling radar with high time resolution can be used to infer the possibility of ozone
intrusions, as well as to represent tropopause motions in association with stratosphere-
troposphere transport. Using the EAR and radiosondes, Fujiwara et al. (2003) showed the
turbulence generation around the tropical tropopause caused by the Kelvin wave breaking.
Using results of RIM measurement by the MU radar and water vapor measurement by the
Raman lidar (Behrendt, et al., 2004), Luce et al. (2010c) demonstrated that vertical gradient of
humidity causes enhancement of backscattered intensity of radar echo by generating
refractive index irregularities at the Bragg scale. Further coordinated observations would
lead to clarify the radio scattering and propagation mechanisms in the clear air.
4. Conclusion
In the Chapter, new observations by wind profiling radars in the last decade were reviewed.
In section 2, the signal processing and measurement results of radar interferometry
techniques (CRI and RIM) were described. Resolution enhancements attained by CRI and
RIM will be useful not only for scientific researches aiming at clarifying atmospheric
processes but also practical radar utilization through improvement in data quality (i.e.,
clutter mitigation) and early detection of turbulence associated with storm or wind shear.
Further assessments aiming at quantifying their usefulness under various weather
conditions are desirable.
In section 3, it was demonstrated that multi-instrument measurement using wind profiling
radar and millimeter-wave radar/lidar is useful to clarify phenomena related to cloud
processes. In order to clarify interactions among dynamics, cloud physics, and radiation,
simultaneous remote sensing and in-situ measurements are highly desirable. In-situ
measurements of cloud particles, temperature, humidity, and radiation using balloons
and/or aircrafts will contribute to quantify phenomena measured by wind profiling radar,
millimeter-wave radar, and lidar. Numerical simulation is also important to assess the
interactions. The author hopes that efforts to realize further coordinated studies are
executed continuously.
5. Acknowledgment
This work was supported by the research grant for Exploratory Research on Sustainable
Humanosphere Science from Research Institute for Sustainable Humanosphere (RISH),
Kyoto University.
6. References
Behrendt, A., Nakamura, T. & Tsuda, T. (2004). Combined Temperature Lidar for
Measurements in the Troposphere, Stratosphere, and Mesosphere,
Applied Optics
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Vol. 43, No.14, pp.2930-2939, doi:10.1364/AO.43.002930.
Bertin, F., Campistron, B., Caccia, J.L. & Wilson, R. (2001). Mixing Processes in a Tropopause
Folding Observed by a Network of ST Radar and Lidar, Annales Geophysicae,
Vol.19, No.8, pp.953-963, doi:10.5194/angeo-19-953-2001.
