New Publication: Earth Networks Meteorology Team Analyzes Lightning in Central & Southern South America
We’re proud to say that our Earth Networks meteorology and lightning science teams are on the cutting edge of weather and climate research. Earlier this month, three of our scientists published “Analyzing Lightning Characteristics in Central and Southern South America” in Electric Power Systems Research. The report will be printed physically in Volume 213 (December 2022) of the journal.
The paper leveraged Earth Networks’ Total Lightning Network (ENTLN) to study trends in cloud-to-ground and in-cloud lightning distribution in one of the world’s key climate regions. If you want to get right into the meat of the matter, you can visit ScienceDirect to read the full report now for free:
We sat down with three of the paper’s five authors to get a high-level of understanding of what this exciting new paper is all about, how they carried out the work, and what they learned.
Q&A with the Team:
1. How would you describe your latest publication to a layperson? What makes Analyzing Lightning Characteristics… relevant and interesting?
Dr. Elizabeth DiGangi
Lightning Scientist & Principal Author:
This paper is essentially summarizing how lightning behaves in central and southern South America, south of the Amazon. Argentina in particular sees a lot of severe weather, similar to the plains of the United States, and we know from a lot of past research that lightning behavior can inform us about the storms that produce that lightning.
Dr. Jeff Lapierre
Principal Lightning Scientist:
South America is one of the three primary lightning “chimneys” in the world. Therefore, it is important understand the lightning climatology that makes it unique. This study took three years of ENTLN data and analyzed the various characteristics of lightning (e.g., flash density, type, polarity, amplitude, etc.) to understand how they might reveal relevant meteorology in that area.
With studying global lightning and its characteristics, you can learn a lot about the climatology of the storm seasons around the world. The area studied had never had much comprehensive work done relating to lightning climatology, and with AEM’s unique global lightning detection network, in-depth analysis could be done. Understanding lightning climatology is important in understanding climate and climate change implications.
2. What was the genesis of this project/paper? What question/challenge/observation brought the team together?
This study started as a conference proceeding for GROUND 2018, a South American conference that runs every other year (in tandem with SIPDA). Since the ENTLN recently expanded into Argentina, there was some motivation on our part to highlight those improvements. In that initial study, we only used data from a few months, since that is what existed at the time after the expansion of the network.
After the conference, one of the organizers asked if we would be interested in extending our study and submit that to a special issue journal. We gladly accepted! This was long after the conference, and so we had more data to include in the study. We completed that analysis and proceeded to work through the peer-review process. During that process, the reviewers identified several areas that could be expanded further. The team worked together to make those changes so that the reviewers were satisfied and finally accepted the paper!
3. Where did the data you analyzed for this paper come from? Who did you partner with to gather or analyze it?
All the data in this paper came from Earth Networks, which is one of the cool things about the paper – we didn’t need any external data to find interesting features to talk about. The EN R&D team at the time (myself, Jeff LaPierre, and Michael Stock) partnered with Mark Hoekzema of MetOps and our colleague Bruno Cunha, another lightning researcher who works for the Brazilian company Simtech, to do the analysis.
4. What did you, as meteorologists and weather experts, learn during the research, writing, and publication process that’s going to impact your practice moving forward?
There is a lot of excellent lightning climatology information in this paper. As meteorologists, we can take this data and translate it into valuable seasonal forecasts and climatology comparisons when doing forecasts during the convective seasons. Also, it is very apparent that with the robust, accurate lightning detection network, new and exciting information can be gleaned with this type of research for virtually every geography.
Using a multi-year dataset of lightning data capable of characterizing both the type (either intra-cloud [IC] or cloud-to-ground [CG]) as well as polarity of lightning, we were able to identify regions with interesting characteristics and provide possible meteorological explanations for their occurrence. This will provide insight to people who live in those regions on how to react to local storms to better protect against their negative effects.
Past studies have shown that South America is a hotspot for high altitude lightning such as Sprites. Our results provide a possible explanation for why, since Sprites are often associated with positive CG flashes, which we find are unusually abundant in Northern Argentina.
Another important result that impacted my understanding of lightning related to the smooth peak current transition from land to ocean. These observations imply that the surface conditions (that is, land versus water) may not be the primary contributing factor as to why oceanic lightning has larger peak currents. The impact of the ocean (salinity, aerosol content, etc.) on storm dynamics and microphysics may in fact be the primary factor.
5. What new questions do you have after completing this project? What do you feel are the next steps for you and your colleagues?
Although it was really fascinating in its own right to perform this analysis with a single dataset, I’d love to see how the conclusions we drew hold up when compared side-by-side with other lightning and weather data. One dataset only tells one side of the story, after all.
To that end, our next step with this area of study is honestly going to be enabling more research by scientists not affiliated with the company who can draw from many data sources to do multifaceted research on South American thunderstorms. We provide data freely to public sector research scientists who are doing pure research with it, so we hope that someone will come asking to pursue this research with us as collaborators.
I feel that doing similar research in other parts of the globe that have important convective seasons as it relates to agriculture, human water resources and water management would benefit from understanding the climatology of the convective nature of storms and how this might help different regions and cultures understand the implications of any climate change related to the convective seasonal rains.
There is more work that could be done to better understand why Northern Argentina experiences such a high percentage of positive CG lightning. Comparing with other datasets, such as radar or satellite, could help better understand what makes this region so unique. Since the ENTLN recently underwent a complete redesign, which improved its performance, it would be interesting to perform this study again. However, this will need to wait a couple of years so that we have enough data to compare to the three-year dataset used here.
Get the Full Paper from the EN Team
To read the full text of “Analyzing Lightning Characteristics in Central & Southern South America” and get the full story behind intra-cloud and cloud-to-ground lightning trends in one of the world’s lightning chimneys, be sure to visit ScienceDirect.
If you have any questions about the paper or would like to correspond with the lightning team about their work’s implications on your own research or business, please contact Dr. Elizabeth DiGangi, corresponding author.