Dynamical and Microphysical Retrievals from Doppler Radar Observations of a Deep Convective Cloud

2000 ◽  
Vol 57 (2) ◽  
pp. 262-283 ◽  
Author(s):  
Bing Wu ◽  
Johannes Verlinde ◽  
Juanzhen Sun
Keyword(s):  
Doppler Radar ◽  
Convective Cloud ◽  
Radar Observations ◽  
Deep Convective Cloud

Buoyancy waves in the troposphere: Doppler radar observations and a theoretical model

1979 ◽  
Vol 6 (6) ◽  
pp. 429-432 ◽  
Author(s):  
T. E. VanZandt ◽  
J. L. Green ◽  
W. L. Clark ◽  
J. R. Grant
Keyword(s):  
Theoretical Model ◽  
Doppler Radar ◽  
Radar Observations ◽  
Buoyancy Waves

scholarly journals HF Doppler radar observations of low-latitude spread F

Radio Science ◽  
2009 ◽  
Vol 44 (3) ◽  
pp. n/a-n/a ◽  
Author(s):  
C. R. Reddi ◽  
M. S. S. R. K. N. Sarma ◽  
K. Niranjan
Keyword(s):  
Doppler Radar ◽  
Low Latitude ◽  
Radar Observations ◽  
Spread F

Sensitivity of microwave brightness temperatures to hydrometeors in a tropical deep convective cloud system at 89-190 GHz

Radio Science ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. n/a-n/a ◽  
Author(s):  
Gang Hong ◽  
Georg Heygster ◽  
Jungang Miao ◽  
Klaus Kunzi
Keyword(s):  
Convective Cloud ◽  
Cloud System ◽  
Brightness Temperatures ◽  
Deep Convective Cloud

scholarly journals Radiometric Performance Evaluation of FY-4A/AGRI Based on Aqua/MODIS

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1859
Author(s):  
Bo Zhong ◽  
Yingbo Ma ◽  
Aixia Yang ◽  
Junjun Wu
Keyword(s):  
Near Infrared ◽  
Spectral Response ◽  
Convective Cloud ◽  
Radiation Level ◽  
High Attenuation ◽  
Total Attenuation ◽  
Attenuation Rate ◽  
Calibration Facility ◽  
Deep Convective Cloud ◽  
Directional Reflectance

Fengyun-4A (FY-4A) is the first satellite of the Chinese second-generation geostationary orbit meteorological satellites (FY-4). The Advanced Geostationary Radiation Imager (AGRI), onboard FY-4A does not load with high-precision calibration facility in visible and near infrared (VNIR) channel. As a consequence, it is necessary to comprehensively evaluate its radiometric performance and quantitatively describe the attenuation while using its VNIR data. In this paper, the radiometric performance at VNIR channels of FY-4A/AGRI is evaluated based on Aqua/MODIS data using the deep convective cloud (DCC) target. In order to reduce the influence of view angle and spectral response difference, the bi-directional reflectance distribution function (BRDF) correction and spectral matching have been performed. The evaluation result shows the radiometric performance of FY-4A/AGRI: (1) is less stable and with obvious fluctuations; (2) has a lower radiation level because of 24.99% lower compared with Aqua/MODIS; 3) has a high attenuation with 9.11% total attenuation over 2 years and 4.0% average annual attenuation rate. After the evaluation, relative radiometric normalization between AGRI and MODIS in VNIR channel is performed and the procedure is proved effective. This paper proposed a more reliable reference for the quantitative applications of FY-4A data.

scholarly journals How do changes in warm-phase microphysics affect deep convective clouds?

2017 ◽  
Vol 17 (15) ◽  
pp. 9585-9598 ◽  
Author(s):  
Qian Chen ◽  
Ilan Koren ◽  
Orit Altaratz ◽  
Reuven H. Heiblum ◽  
Guy Dagan ◽  
...  
Keyword(s):  
Rain Rate ◽  
Convective Cloud ◽  
Cloud Fraction ◽  
Marshall Islands ◽  
Cloud System ◽  
Main Question ◽  
Convective Clouds ◽  
Deep Convective Clouds ◽  
Aerosol Effects ◽  
Deep Convective Cloud

Abstract. Understanding aerosol effects on deep convective clouds and the derived effects on the radiation budget and rain patterns can largely contribute to estimations of climate uncertainties. The challenge is difficult in part because key microphysical processes in the mixed and cold phases are still not well understood. For deep convective clouds with a warm base, understanding aerosol effects on the warm processes is extremely important as they set the initial and boundary conditions for the cold processes. Therefore, the focus of this study is the warm phase, which can be better resolved. The main question is: How do aerosol-derived changes in the warm phase affect the properties of deep convective cloud systems? To explore this question, we used a weather research and forecasting (WRF) model with spectral bin microphysics to simulate a deep convective cloud system over the Marshall Islands during the Kwajalein Experiment (KWAJEX). The model results were validated against observations, showing similarities in the vertical profile of radar reflectivity and the surface rain rate. Simulations with larger aerosol loading resulted in a larger total cloud mass, a larger cloud fraction in the upper levels, and a larger frequency of strong updrafts and rain rates. Enlarged mass both below and above the zero temperature level (ZTL) contributed to the increase in cloud total mass (water and ice) in the polluted runs. Increased condensation efficiency of cloud droplets governed the gain in mass below the ZTL, while both enhanced condensational and depositional growth led to increased mass above it. The enhanced mass loading above the ZTL acted to reduce the cloud buoyancy, while the thermal buoyancy (driven by the enhanced latent heat release) increased in the polluted runs. The overall effect showed an increased upward transport (across the ZTL) of liquid water driven by both larger updrafts and larger droplet mobility. These aerosol effects were reflected in the larger ratio between the masses located above and below the ZTL in the polluted runs. When comparing the net mass flux crossing the ZTL in the clean and polluted runs, the difference was small. However, when comparing the upward and downward fluxes separately, the increase in aerosol concentration was seen to dramatically increase the fluxes in both directions, indicating the aerosol amplification effect of the convection and the affected cloud system properties, such as cloud fraction and rain rate.

scholarly journals The characterization of deep convective cloud albedo as a calibration target using MODIS reflectances

2010 ◽  
Author(s):  
David R. Doelling ◽  
Gang Hong ◽  
Dan Morstad ◽  
Rajendra Bhatt ◽  
Arun Gopalan ◽  
...  
Keyword(s):  
Convective Cloud ◽  
Calibration Target ◽  
Cloud Albedo ◽  
Deep Convective Cloud

High-Temporal Resolution Polarimetric X-Band Doppler Radar Observations of the 20 May 2013 Moore, Oklahoma, Tornado

2015 ◽  
Vol 143 (7) ◽  
pp. 2711-2735 ◽  
Author(s):  
James M. Kurdzo ◽  
David J. Bodine ◽  
Boon Leng Cheong ◽  
Robert D. Palmer
Keyword(s):  
Temporal Resolution ◽  
Doppler Radar ◽  
Medical Center ◽  
Small Scale ◽  
High Temporal Resolution ◽  
Radar Observations ◽  
University Of Oklahoma ◽  
X Band ◽  
Damage Indicators ◽  
Gust Front

Abstract On 20 May 2013, the cities of Newcastle, Oklahoma City, and Moore, Oklahoma, were impacted by a long-track violent tornado that was rated as an EF5 on the enhanced Fujita scale by the National Weather Service. Despite a relatively sustained long track, damage surveys revealed a number of small-scale damage indicators that hinted at storm-scale processes that occurred over short time periods. The University of Oklahoma (OU) Advanced Radar Research Center’s PX-1000 transportable, polarimetric, X-band weather radar was operating in a single-elevation PPI scanning strategy at the OU Westheimer airport throughout the duration of the tornado, collecting high spatial and temporal resolution polarimetric data every 20 s at ranges as close as 10 km and heights below 500 m AGL. This dataset contains the only known polarimetric radar observations of the Moore tornado at such high temporal resolution, providing the opportunity to analyze and study finescale phenomena occurring on rapid time scales. Analysis is presented of a series of debris ejections and rear-flank gust front surges that both preceded and followed a loop of the tornado as it weakened over the Moore Medical Center before rapidly accelerating and restrengthening to the east. The gust front structure, debris characteristics, and differential reflectivity arc breakdown are explored as evidence for a “failed occlusion” hypothesis. Observations are supported by rigorous hand analysis of critical storm attributes, including tornado track relative to the damage survey, sudden track shifts, and a directional debris ejection analysis. A conceptual description and illustration of the suspected failed occlusion process is provided, and its implications are discussed.

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