This project is to utilize a combination of new and existing space- and ground-based data to characterize the mechanisms and pathways by which large-scale atmospheric wave drivers are able to modify the low-latitude ionospheric dynamo and subsequent motion and density of the whole ionosphere. The region of wave-ionosphere interaction and vertical coupling will be observed directly using the highly precise Arecibo incoherent scatter radar (ISR) in Puerto Rico, while COSMIC satellite measurements of ionospheric electron density, TIMED satellite wind measurements, and ground-based GPS measurements of total electron content will be used to identify the global structure of planetary-scale waves that underlie the observations. An initial focus of the analysis will use existing data from these platforms acquired during a major stratospheric warming event and strong ionospheric wave activity, and new ISR data will be acquired from Arecibo Observatory as part of the project. This work will support the education and research training of a postdoctoral researcher and a graduate student as well as involve research participation by undergraduates. This collaborative effort is a partnership between two universities, the National Center for Atmospheric Research, and Arecibo Observatory.
Summary of outcomes related to intellectual merit At altitudes over 100 km above the Earth’s surface, sunlight breaks apart atoms and molecules in the atmosphere, creating charged particles. This layer of charged particles is called the ionosphere. Global-scale observations of the ionosphere that have been made over the last decade have shown wave-like structures in this layer. It is a generally accepted scientific theory that these wave-like structures are associated with wave patterns in the winds in the atmosphere. However, the waves that correspond most closely to the wave-like patterns in the ionosphere only exist at much lower altitudes, so something else must be varying their signal to the altitudes where the wave-like patterns in the ionosphere are observed. This work aimed to find what was communicating these patterns to the ionosphere. To do this, we used observations from a network of powerful radars known as incoherent scatter radars, which were taken at the same time as measurements of the ionosphere taken by a constellation of satellites known as COSMIC. For our first of such coordinated observations came from January 2010. During this time period, we were able to see the waves in the atmosphere at around 100 km above the Earth’s surface at the same time as seeing the wave-like pattern in the ionosphere at around 300 km above the Earth’s surface. We showed that the effect of the wave in the atmosphere was being carried to those higher altitudes, at least in part by an intermediary – a second wave that appears at around 90 km above the Earth’s surface and can travel to much higher altitudes. These results were summarized in two peer-reviewed publications, both of which were published in 2012. For our second set of coordinated observations, we solicited a new set of observations through what is known as an URSI World Day Campaign. This involved submitting a written proposal to the URSI World Day committee and presenting the scientific case for these observations in-person at the CEDAR workshop. This proposal was accepted and we coordinated with the groups who operate each of the power incoherent scatter radars to carry out this observational campaign in August 2011. This campaign went very well and the results were summarized in a peer-reviewed publication, which is under review at the time of writing this summary. Summary of outcomes related to broader impacts Funds for this project supported the (then) postdoc Guiping Liu. Under the mentorship of her advisor Thomas Immel, Guiping received training in conducting independent research, writing papers and presenting her results, Guiping met with Thomas weekly and he provided guidance. During the course of this project, Guiping Liu was promoted from a postdoc to a staff position (Assistant Research), whcih marks a succesful conclusion of her postdoc training. Funds were also used to support an undergraduate physics student at UC Berkeley, Ramin Khajeh, during the summer of 2013. Ramin learnt how to display scientific data using IDL and create visualization tools that will be useful in his future research. As part of the USRI World Day campaign for 2011 described above, we worked with a network of US-lead radars located throughout the Americas, and one radar in Kharkov, Ukraine. The observations from the radar in the Ukraine were central to understanding how the atmosphere and ionosphere respond around the world. Through this work, we also started the first collaboration between our research group and the researchers in Kharkov, Ukraine.
