The Center for Atmospheric Sciences | » Jacob L. Gunnarson

    • B.S., Physics, The College of William & Mary, 2017

    • Minor, Marine Science, The College of William and Mary, 2017

    • Email

      jlgunnarson@email.wm.edu

  • Project Links

  • News

  • Jacob L. Gunnarson

    I am currently a staff researcher working on planetary atmospheres.

    During my undergraduate studies at William & Mary, I ran operations of the physics department’s telescope.  For my honors physics thesis, I worked with Ryan McCabe and Dr. Sayanagi at Hampton University to measure Venus’ zonal winds using images from Venus Express.  After graduation, I began a “gap year” at Hampton working for Dr. Sayanagi.

    The primary focus of my research is the atmospheric dynamics of gas giant planets.  Using data from the Cassini spacecraft’s ISS and VIMS instruments, I have examined the global wind profiles and dynamics of waves and vortices in Saturn’s atmosphere.  My first project analyzed Cassini images to derive the properties of “ribbon waves” in Saturn’s 42°N atmospheric jet.  We determined that the visual appearance, wavelength, and propagation of the ribbon waves were indicative of Rossby waves.  This research was published in Geophysical Research Letters.  The video below shows a movie I made from Cassini ISS Narrow Angle Camera images which shows the motion of the ribbon waves over two Saturn rotations.

    Currently, I am working on the dynamics of the large anticyclonic vortex spawned by Saturn’s Great Storm of 2010-2011.  This vortex has an exceptionally high vorticity and exhibited rapid changes in aspect ratio and orientation after its formation.

    I am involved in processing data from several spacecraft and instruments.  In addition to Cassini ISS and VIMS, I have processed images from Voyager ISS and New Horizons MVIC and LEISA.  I also process images taken with ground based instruments, from Hampton’s 8-inch Celestrons to the Apache Point 3.5-m telescope.

    These mosaics from Cassini/VIMS show Saturn’s optically thick clouds backlit by 5 μm light from the planet’s warm interior. The mosaics show the evolution of Saturn’s mid-latitudes before (1st panel), during (2nd panel), and after (3nd-6th panels) the great storm of 2010-2011. Subsidence of material upwelled from by storm caused the clouds to clear south of 40N.

    I also help manage Hampton’s project to detect asteroid impact flashes on Jupiter.  Using small telescopes and high frame rate cameras, we hope to capture the signal of an asteroid impact.  We have captured and analyzed over 45 hours of video as part of the DeTecT project.

    Jupiter, as seen by our 9.25-inch telescope on the night of May 24/25.

     

     

     

    Project: Analysis of Venusian Zonal Winds Using Venus Express Data

    View Project Page

    We measure the zonal mean wind structure of Venus between 2006 and 2013 in the ultraviolet images captured by the Venus Monitoring Camera (VMC) onboard the ESA Venus Express (VEx) spacecraft which observed Venus’s southern hemisphere. Our wind measurements employ a digital two-dimensional Correlation Imaging Velocimetry (CIV) method to track cloud motions. Our current focus is on understanding […]

    Project: Analysis of planetary waves in Saturn’s 42°N atmospheric jet

    View Project Page

    During their 1980 and 1981 flybys of Saturn, the Voyager spacecraft imaged a dark, sinuous line encircling the planet. This feature, dubbed the ribbon wave after its visual appearance, was embedded in an atmospheric jet stream at 42°N latitude. The Cassini spacecraft also discovered waves in the 42°N jet during its 2004–2017 Saturn mission. Using […]