Where Tropical Cyclones are born and where they go to die
(Well that was a dark title)
Since we’re still playing with the IBTrACS dataset, I decided to take a look at where Tropical Cyclones are born (cyclogenesis) and where they die (dissipation).
I am by no means taking credit for these plots as these are simply adaptations of Figure 1 of Cinco et al’s 2016 paper.
Take note for these plots I have only taken into consideration track points post 1977. Satellite tracking of Tropical Cyclone only started in the 1970s , and it is possible that data pre-1970s may be biased towards physical observation points (see Chang and Guo 2007 for a discussion). I have only included data in the Western Pacific Ocean Basin from 1977 and beyond because in the IBTrACS dataset, tracks prior to 1977 do not have wind speed data.
Anyway, for the plots.
It can be seen that most Tropical Cyclones form towards the east of the Philippines. They then dissipate at two distinct locations, towards the continent to the west (Thailand, Vietnam, Cambodia, Laos), and back to the Pacific Ocean in the northeast.
There’s this funny story, I met a Vietnamese gentleman in a workshop in Taiwan back in 2015. When he learned that I was from the Philippines, he said, “oh, Philippines! Thank you, for protecting us from typhoons.”
I never thought of it that way. That while we look to our mountains as barriers against Tropical Cyclones, they similarly consider the whole Philippines as their first line of defense.
As a post script, I am thoroughly enjoying making these plots by using a combination of GeoPandas for pre-processing and then QGIS for plotting. At least I’m having fun laying the foundation for my PhD dissertation.
Cheers to all.
Addendum. A reader (hi sir Euge!) pointed out the deficiency in the dataset, particularly towards the 100E and 180E lines. This is because I only included the Tropical Cyclones tracked in the Western Pacific Ocean Tropical Cyclone Basin (IV in image below).
The different basins are simply delineations where Tropical Cyclones typically form and cluster. Different basins have different main monitoring agencies. See the Wiki for a more thorough explanation: https://en.wikipedia.org/wiki/Tropical_cyclone_basins
Other tracks can be found in the IBTrACS website. But as my computer can only handle so much, and since the focus of my studies is the North Western Pacific, I only used the data for that basin.
Data sources:
- World shapefile from Natural Earth
- Track data from IBTrACS
References
- Cinco, T. A., de Guzman, R. G., Ortiz, A. M. D., Delfino, R. J. P., Lasco, R. D., Hilario, F. D., … Ares, E. D. (2016). Observed trends and impacts of tropical cyclones in the Philippines: OBSERVED TRENDS AND IMPACTS OF TROPICAL CYCLONES IN THE PHILIPPINES. International Journal of Climatology, 36(14), 4638–4650. https://doi.org/10.1002/joc.4659
- Chang, E. K. M., and Y. Guo (2007), Is the number of North Atlantic tropical cyclones significantly underestimated prior to the availability of satellite observations? Geophys. Res. Lett., 34, L14801, doi:10.1029/2007GL030169.
- David, C.C., Racoma, B.B., Gonzales, J., and Clutario, M. (2013). A Manifestation of Climate Change? A Look at Typhoon Yolanda in Relation to the Historical Tropical Cyclone Archive. Science Diliman, Vol 25 (2): 79–86.
For official Tropical Cyclone forecasts:
- PAGASA Monthly Tropical Cyclone Forecast https://www1.pagasa.dost.gov.ph/index.php/27-climatology-and-agrometeorology/502-monthly-tropical-cyclone-forecast
