Article
Version 1
Preserved in Portico This version is not peer-reviewed
Unreported Characteristics of the North American Monsoon
Version 1
: Received: 8 November 2023 / Approved: 8 November 2023 / Online: 8 November 2023 (07:53:21 CET)
How to cite: Reichenbacher, F. W.; Peachey, W. D. Unreported Characteristics of the North American Monsoon. Preprints 2023, 2023110520. https://doi.org/10.20944/preprints202311.0520.v1 Reichenbacher, F. W.; Peachey, W. D. Unreported Characteristics of the North American Monsoon. Preprints 2023, 2023110520. https://doi.org/10.20944/preprints202311.0520.v1
Abstract
The North American Monsoon (NAM) in southern Arizona continues to be a topic of interest to ecologists, climatologists, and citizens as well as the triggers and characteristics of plant growth and reproduction in relation to the onset of the monsoon. In researching the onset of the North American Monsoon (NAM) in south-central Arizona relative to the phenology of Saguaro cactus (Carnegiea gigantea) and other Sonoran Desert species we identified interesting and previously unreported features in the NAM rainfall data. We present preliminary descriptive analyses of (1) monsoon onset as measured by the first day after June 1 with precipitation ≥10 mm (1990-2022), (2) first day of year warming of Sea Surface temperatures (SST) in the Gulf of California to ≥29º C measured across five open-sea blocks (mean 9452 km2), and (3) El Niño Southern Oscillation (ENSO) anomaly with a threshold of +/- 0.5º C for the Oceanic Niño Index (ONI) in the Niño 3.4 region (5ºN-5ºS, 120º-170ºW). Three patterns emerge from our analyses: (1) The day of the year of monsoon onset occurs approximately 12 days earlier in the year from 1990-2022 in south-central Arizona. (2) There appears to be a signal in the rainfall onset data very roughly approximating cycles of ENSO Oceanic Niño Index (ONI) anomalies in Niño region 3.4. (3) Gulf of California sea surface temperature (SST) and monsoon onset data support an expected link between the timing of SST warming and monsoon rainfall onset.
Keywords
monsoon; North American Monsoon; precipitation; Sonoran Desert; Gulf of California; phenology; climate change; climatology; El Niño; ENSOsea surface temperature; Sonora; Arizona
Subject
Environmental and Earth Sciences, Atmospheric Science and Meteorology
Copyright: This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Comments (0)
We encourage comments and feedback from a broad range of readers. See criteria for comments and our Diversity statement.
Leave a public commentSend a private comment to the author(s)
* All users must log in before leaving a comment