• Skip to primary navigation
  • Skip to main content
SRI InternationalSRI mobile logo

SRI International

SRI International - American Nonprofit Research Institute

  • About
    • Blog
    • Press room
  • Expertise
    • Advanced imaging systems
    • Artificial intelligence
    • Biomedical R&D services
    • Biomedical sciences
    • Computer vision
    • Cyber & formal methods
    • Education and learning
    • Innovation strategy and policy
    • National security
    • Ocean & space
    • Quantum
    • QED-C
    • Robotics, sensors & devices
    • Speech & natural language
    • Video test & measurement
  • Ventures
  • NSIC
  • Careers
  • Contact
  • 日本支社
Show Search
Hide Search
Information & computer science publications January 1, 2015 Article

Effects of Tidal Forcing, Conductivity Gradient, and Active Seeding on the Climatology of Equatorial Spread F over Kwajalein

SRI International January 1, 2015

Citation

Copy to clipboard


Tsunoda, R. T., Nguyen, T., T. , & Le, M. H. (2015). Effects of tidal forcing, conductivity gradient, and active seeding on the climatology of equatorial spread F over Kwajalein. Journal of Geophysical Research-Space Physics, 120(1), 632-653.

Abstract

Plasma structure in nighttime equatorial F layer, referred to as equatorial spread F (ESF), displays climatology whose seasonal variation depends on longitude. At longitudes where ESF favors equinoxes, times when maxima occur can be predicted in terms of the day of year, when E region sunset is simultaneous in conjugate hemispheres (i.e., “sunset nodes”). Aside from occurrences around equinoxes, there are only three longitudes where ESF also occurs during a solstice; one is the central Pacific region. Here ESF activity is strong during the June solstice, when solar activity is high. To understand this puzzling behavior, ESF climatology over the Kwajalein Atoll was compared with properties of the postsunset rise (PSSR) of the F layer and seeding activity in the troposphere. The key findings are as follows: (1) Maxima in PSSR velocity (VPSSR) are better aligned with equinoxes than with sunset nodes; hence, seasonal pattern of VPSSR, not only sunset nodes, should be included in interpretation of ESF climatology. (2) The source of VPSSR during solstice appears to differ from that during equinoxes. (3) Equinoctial maxima in VPSSR could be related to a semiannual variation in equatorial electrojet strength and its contribution to polarization of the Fregion dynamo current. (4) Enhanced VPSSR during the June solstice is interpreted in terms of tidal forcing with a wave number of 2. (5) Displacements of maxima in ESF climatology from maxima inVPSSR are shown to be consistent with deep convective activity.

↓ View online

Share this

Facebooktwitterlinkedinmail

Information & computer science publications, Publication Article

How can we help?

Once you hit send…

We’ll match your inquiry to the person who can best help you.

Expect a response within 48 hours.

Career call to action image

Make your own mark.

Search jobs
Our work

Case studies

Publications

Timeline of innovation

Areas of expertise

Blog

Institute

Leadership

Press room

Media inquiries

Compliance

Privacy policy

Careers

Job listings

Contact

SRI Ventures

Our locations

Headquarters

333 Ravenswood Ave
Menlo Park, CA 94025 USA

+1 (650) 859-2000

Subscribe to our newsletter

日本支社

SRI International

  • Contact us
  • Privacy Policy
  • Cookies
  • DMCA
  • Copyright © 2022 SRI International