. | . |
How different parts of mixed convective-stratiform clouds respond to cloud seeding by Staff Writers Beijing, China (SPX) Jul 26, 2022
Cloud seeding is a method of placing condensation nuclei into clouds that induce rain or snowfall. Seeding is a complex process, and its effectiveness depends on the target cloud type. To better understand the mechanisms behind seeding, in a recent study, scientists showed how a connected mixture of both convective and stratiform clouds responds to cloud seeding. Using data from Ka-band cloud profiling radar (KPR) measurements onboard aircraft, along with the remote sensing observations from SNPP and Himawari-8 satellites, members of the Hubei Weather Modification innovation team (HBWM), under the guidance of Prof. Chuanfeng ZHAO from Beijing Normal University (Currently at Peking University), published their findings in Advances in Atmospheric Sciences. "A mixed convective-stratiform cloud is one type of precipitating cloud with complex structure, composed of both cumulus clouds and stratiform clouds." said the study's first author, Dejun LI, Chief Expert on Weather Modification in Hubei Province. LI elaborated that the successful launch of NPP in 2011, Himawari-8 in 2014, and the new high-resolution instrument components of KPR developed by satellite scientists at the University of Wyoming in 2014, all make observing the fine structure of cloud properties possible. This study measures the properties of mixed convective-stratiform clouds using KPR onboard aircraft in China for the first time. Based on the KPR measurements before and after seeding, along with multi-source data including satellite observations, researchers now have the ability to analyze the characteristics of icing seeding tracks within the stratiform region and cloud seeding mechanisms in the convective region. This wealth of data gives important clues that help determine the differences in the cloud's macro- and micro-physical properties. "Few researchers have carried out studies regarding the characteristics and mechanisms of cloud responses to seeding at different parts of clouds." said Dr. LI. "This is mainly due to the scarcity of observation instruments for cloud macro- and micro- physical properties, the insufficiency of confidence from single source of cloud observations, and so on." According to corresponding author Prof. ZHAO, the distinct seeding responses of stratiform and convective regions within a stratocumulus cloud are quite different. In the convective region, the cloud top is higher, which is associated with more released heat and stronger convection due to water-ice conversion. This results in both a greater number of and larger precipitation particles. Within the stratiform region, the radar echo becomes weaker near cloud tops, indicating that liquid droplets are converting to ice crystals faster than in the convective region, causing icing seeding tracks to occur. "Now that we have discovered how these mechanisms between the convective and stratiform regions respond to cloud seeding, future studies should further investigate application into mesoscale weather model simulations." adds Prof. ZHAO.
Research Report:Macro- and Micro-physical Characteristics of Different Parts of Mixed Convective-stratiform Clouds and Differences in Their Responses to Seeding
Predicting equatorial plasma bubbles with SWARM London, UK (SPX) Jul 17, 2022 Changes in atmospheric density after sunset can cause hot pockets of gas called 'plasma bubbles' to form over the Earth's equator, resulting in communication disruptions between satellites and the Earth. New AI models are now helping scientists to predict plasma bubble events and create a forecast. The work was presented this week at the National Astronomy Meeting (NAM 2022) by Sachin Reddy, a PhD student at University College London. Shortly after sunset, pockets of super-heated gas called ... read more
|
|
The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us. |