Climate and weather drivers in southern California Santa Ana Wind and non-Santa Wind fires

Jon E. Keeley; Michael Flannigan; Tim J. Brown; Tom Rolinski; Daniel Cayan; Alexandra D. Syphard; Janin Guzman-Morales; Alexander Gershunov

doi:10.1071/WF23190

RESEARCH ARTICLE (Open Access)

Climate and weather drivers in southern California Santa Ana Wind and non-Santa Wind fires

Jon E. Keeley ^A ^B ^* , Michael Flannigan ^C , Tim J. Brown ^D , Tom Rolinski ^E , Daniel Cayan ^F , Alexandra D. Syphard ^G , Janin Guzman-Morales ^H and Alexander Gershunov ^F

+ Author Affiliations

- Author Affiliations

^A U.S. Geological Survey, Western Ecological Research Center, Sequoia-Kings Canyon Field Station, Three Rivers, CA 93271, USA.

^B Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095, USA.

^C Thompson Rivers University, Natural Resource Science, BC V2C 0C8, Canada.

^D Western Regional Climate Center, Reno, NV 89512, USA.

^E Southern California Edison, Los Angeles, CA, USA.

^F Climate, Atmospheric Science and Physical Oceanography Division, Scripps Institution of Oceanography, University of California, San Diego, CA 92093, USA.

^G Conservation Biology Institute, 136 SW Washington Avenue, Corvalis, OR 97333, USA.

^H Department of Geography, University of California, Santa Barbara, CA 93106, USA.

^* Correspondence to: jon_keeley@usgs.gov

International Journal of Wildland Fire 33, WF23190 https://doi.org/10.1071/WF23190

Submitted: 5 December 2023 Accepted: 10 July 2024 Published: 15 August 2024

© 2024 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of IAWF. This is an open access article distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND)

Abstract

Background

Autumn and winter Santa Ana Winds (SAW) are responsible for the largest and most destructive wildfires in southern California.

Aims

(1) To contrast fires ignited on SAW days vs non-SAW days, (2) evaluate the predictive ability of the Canadian Fire Weather Index (CFWI) for these two fire types, and (3) determine climate and weather factors responsible for the largest wildfires.

Methods

CAL FIRE (California Department of Forestry and Fire Protection) FRAP (Fire and Resource Assessment Program) fire data were coupled with hourly climate data from four stations, and with regional indices of SAW wind speed, and with seasonal drought data from the Palmer Drought Severity Index.

Key results

Fires on non-SAW days were more numerous and burned more area, and were substantial from May to October. CFWI indices were tied to fire occurrence and size for both non-SAW and SAW days, and in the days following ignition. Multiple regression models for months with the greatest area burned explained up to a quarter of variation in area burned.

Conclusions

The drivers of fire size differ between non-SAW and SAW fires. The best predictor of fire size for non-SAW fires was drought during the prior 5 years, followed by a current year vapour pressure deficit. For SAW fires, wind speed followed by drought were most important.

Keywords: aiutumn fires, Canadian Fire Weather Index, drought, summer fires, vapour pressure deficit, VPD, wind speed.

References

Abatzoglou JT, Kolden CA (2011) Relative importance of weather and climate on wildfire growth in interior Alaska. International Journal of Wildland Fire 20, 479-486.
| Crossref | Google Scholar |

Abatzoglou JT, Kolden CA (2013) Relationships between climate and macroscale area burned in the western United States. International Journal of Wildland Fire 22, 1003-1020.
| Crossref | Google Scholar |

Abatzoglou JT, Williams AP (2016) Impact of anthropogenic climate change on wildfire across western US forests. Proceedings of the National Academy of Sciences 113, 11770-11775.
| Crossref | Google Scholar | PubMed |

Abatzoglou JT, Juang CS, Williams AP, Kolden CA, Westerling AL (2021) Increasing synchronous fire danger in forests of the western United States. Geophysical Research Letters 48, e2020GL091377.
| Crossref | Google Scholar |

Abatzoglou JT, Kolden CA, Williams AP, Sadegh M, Balch JK, Hall A (2023) Downslope wind-driven fires in the western United States. Earth’s Future 5, e2022EF003471.
| Crossref | Google Scholar |

Balch JK, Abatzoglou JT, Joseph MB, Koontz MJ, Mahood AL, McGlinchy J, Cattau ME, Williams AP (2022) Warming weakens the night-time barrier to global fire. Nature 602, 442-448.
| Crossref | Google Scholar | PubMed |

Barbero R, Abatzoglou Jt, Steel EA, Larkin NK (2014) Modeling very large-fire occurrences over the continental United States from weather and climate forcing. Environmental Research Letters 9, 124009.
| Crossref | Google Scholar |

Bradstock RA (2010) A biogeographic model of fire regimes in Australia: current and future implications. Global Ecology and Biogeography 19, 145-158.
| Crossref | Google Scholar |

Brey SJ, Barnes EA, Pierce JR, Swann AL, Fischer EV (2020) Past variance and future projections of the environmental conditions driving western US summertime wildfire burn area. Earth’s Future 9, e2020EF001645.
| Crossref | Google Scholar | PubMed |

Cayan DR, DeHaan LL, Gershuvov A, Guzman-Morales J, Keeley JE, Mumford J, Syphard AD (2022) Autumn precipitation: the competition with Santa Winds in determining fire outcomes in southern California. International Journal of Wildland Fire 31, 1056-1067.
| Crossref | Google Scholar |

Dai A (2011) Characteristics and trends in various forms of the Palmer Derought Severity index during 1900-2008. Journal of Geophysical Research 116, D12115.
| Crossref | Google Scholar |

Dimitrakopoulos AP, Bemmerzouk AM, Mitsopoulos ID (2011) Evaluation of the Canadian fire weather index system in an eastern Mediterranean environment. Meteorological Applications 18, 83-93.
| Crossref | Google Scholar |

Faivre N, Jin Y, Goulden ML, Randerson JT (2014) Controls on the spatial pattern of wildfire ignitions in Southern California. International Journal of Wildland Fire 23, 799-811.
| Crossref | Google Scholar |

Flannigan MD, Krawchuk MA, de Groot WJ, Wotton BM, Gowman LM (2009) Implications of changing climate for global wildland fire. International Journal of Wildland Fire 18(5), 483-507.
| Crossref | Google Scholar |

Gershunov A, Guzman Morales J, Hatchett B, Guirguis K, Aguilera R, Shulgina T, Abatzoglou JT, Cayan D, Pierce D, Williams P, Small I, Clemesha R, Schwarz L, Benmarhnia T, Tardy A (2021) Hot and cold flavors of southern California’s Santa Ana winds: their causes, trends, and links with wildfire. Climate Dynamics 57, 2233-2248.
| Crossref | Google Scholar | PubMed |

Goss M, Swain DL, Abatzoglou JT, Sarhadi A, Kolden CA, Williams AP, Diffenbaugh NS (2020) Climate change is increasing the likelihood of extreme autumn wildfire conditions across California. Environmental Research Letters 15, 094016.
| Crossref | Google Scholar |

Guirguis KA, Gershunov A, Hatchett B, Shulgina T, DeFlorio MJ, Subramanian AC, Guzman Morales J, Aguilera R, Clemesha R, Corringham TW, Delle Monache L, Reynolds D, Tardy A, Small I, Ralph RM (2023) Winter wet–dry weather patterns driving atmospheric rivers and Santa Ana winds provide evidence for increasing wildfire hazard in California. Climate Dynamics 60, 1729-1749.
| Crossref | Google Scholar |

Guzman‐Morales J, Gershunov A, Theiss J, Li H, Cayan D (2016) Santa Ana Winds of Southern California: Their climatology, extremes, and behavior spanning six and a half decades. Geophysical Research Letters 43, 2827-2834.
| Crossref | Google Scholar |

Guzman‐Morales J, Gershunov A (2019) Climate change suppresses Santa Ana winds of Southern California and sharpens their seasonality. Geophysical Research Letters 46, 2772-2780.
| Crossref | Google Scholar |

Hardy CC, Hardy CE (2007) Fire danger rating in the United States of America: an evolution since 1916. International Journal of Wildland Fire 16, 217-231.
| Crossref | Google Scholar |

Jin Y, Randerson JT, Faivre N, Capps S, Hall A, Goulden ML (2014) Contrasting controls on wildland fires in Southern California during periods with and without Santa Ana winds. Journal of Geophysical Research: Biogeosciences 119, 432-450.
| Crossref | Google Scholar |

Jin Y, Goulden ML, Faivre N, Veraverbeke S, Sun F, Hall A, Hand MS, Hook S, Randerson JT (2015) Identification of two distinct fire regimes in Southern California: implications for economic impact and future change. Environmental Research Letters 10, 094005.
| Crossref | Google Scholar |

Jolly WM, Cochrane MA, Freeborn PH, Holden ZA, Brown TJ, Williamson GJ, Bowman DM (2015) Climate-induced variations in global wildfire danger from 1979 to 2013. Nature communications 6, 7537.
| Crossref | Google Scholar | PubMed |

Keeley JE (2004) Impact of antecedent climate on fire regimes in coastal California. International Journal of Wildland Fire 13, 173-182.
| Crossref | Google Scholar |

Keeley JE, Syphard AD (2017) Different historical fire-climate relationships in California. International Journal of Wildland Fire 26, 253-268.
| Crossref | Google Scholar |

Keeley JE, Safford H, Fotheringham CJ, Franklin J, Moritz M (2009) The 2007 southern California wildfires: lessons in complexity. Journal of Forestry 107, 287-296.
| Crossref | Google Scholar |

Keeley JE, Guzman-Morales J, Gershunov A, Syphard AD, Cayan D, Pierce DW, Flannigan M, Brown TJ (2021) Ignitions explain more than temperature or precipitation in driving Santa Ana wind fires. Science Advances 7, eabh2262.
| Crossref | Google Scholar | PubMed |

Kolden CA, Abatzoglou JT (2018) Spatial Distribution of Wildfires Ignited under Katabatic versus Non-Katabatic Winds in Mediterranean Southern California USA. Fire 1, 19.
| Crossref | Google Scholar |

Liang S, Hurteau MD (2023) Novel climate–fire–vegetation interactions and their influence on forest ecosystems in the western USA. Functional Ecology 37, 2126-2142.
| Crossref | Google Scholar |

Linley GD, Jolly CJ, Doherty TS, Geary WL, Armenteras D, Belcher CM, et al. (2022) What do you mean,‘megafire’? Global Ecology and Biogeography 31, 1906-1922.
| Crossref | Google Scholar |

Lu W, Charney JJ, Zhong S, Bian X, Liu S (2011) A North American regional reanalysis climatology of the Haines Index. International Journal of Wildland Fire 20, 91-103.
| Crossref | Google Scholar |

MacDonald GT, Wall T, Enquist CAF, LeRoy SR, et al. (2023) Drivers of California’s changing wildfires: a state-of-the-knowledge synthesis. International Journal of Wildland Fire 32, 1039-1058.
| Crossref | Google Scholar |

Madadgar S, Sadegh M, Chiang F, Ragno E, AghaKouchak A (2020) Quantifying increased fire risk in California in response to different levels of warming and drying. Stochastic Environmental Research and Risk Assessment 34, 2023-2031.
| Crossref | Google Scholar |

Mees R, Chase R (1991) Relating burning index to wildfire workload over broad geographic areas. International Journal of Wildland Fire 1, 235-238.
| Crossref | Google Scholar |

Moritz MA, Moody TJ, Krawchuk MA, Hughes M, Hall A (2010) Spatial variation in extreme winds predicts large wildfire locations in chaparral ecosystems. Geophysical Research Letters 37(4), L04801.
| Crossref | Google Scholar |

Mueller SE, Thode AE, Margolis EQ, Yocom LL, Young JD, Iniguez JM (2020) Climate relationships with increasing wildfire in the southwestern US from 1984 to 2015. Forest Ecology and Management 460, 17861.
| Crossref | Google Scholar |

Nauslar NJ, Abatzoglou JT, Marsh PT (2018) The 2017 North Bay and Southern California fires: a case study. Fire 1, 18.
| Crossref | Google Scholar |

Peterson SH, Moritz MA, Morais ME, Dennison PE, Carlson JM (2011) Modelling long-term fire regimes of southern California shrublands. International Journal of Wildland Fire 20, 1-16.
| Crossref | Google Scholar |

Pierce DW, Kalansky JF, Cayan D (2018) ‘Climate, drought, and sea level rise scenarios for California’s fourth climate change assessment.’ (California’s Fourth Climate Change Assessment, California Energy Commission and California Natural Resources Agency) Available at http://www.climateassessment.ca.gov/techreports/docs/20180827-Projections_CCCA4-CEC- 2018-006.pdf

Potter B (2018a) The Haines Index–it’s time to revise it or replace it. International Journal of Wildland Fire 27, 437-440.
| Crossref | Google Scholar |

Potter BE (2018b) Quantitative evaluation of the Haines Index’s ability to predict fire growth events. Atmosphere 9, 177.
| Crossref | Google Scholar |

Potter BE (2023) Examining the influence of mid-tropospheric conditions and surface wind changes on extremely large fires and fire growth days. International Journal of Wildland Fire 32, 777-795.
| Crossref | Google Scholar |

Rolinski T, Capps SB, Zhuang W (2019) Santa Ana winds: a descriptive climatology. Weather and Forecasting 34, 257-275.
| Crossref | Google Scholar |

Schoenberg FP, Chang CH, Keeley JE, Pompa J, Woods J, Xu H (2007) A critical assessment of the burning index in Los Angeles County, California. International Journal of Wildland Fire 16, 473-483.
| Crossref | Google Scholar |

Stavros EN, Abatzoglou J, Larkin NK, McKenzie D, Steel EA (2014) Climate and very large wildland fires in the contiguous western USA. International Journal of Wildland Fire 23, 899-914.
| Crossref | Google Scholar |

Stocks BJ, Lawson BD, Alexander ME, Wagner CV, McAlpine RS, Lynham TJ, Dube DE (1989) D.E., 1989. The Canadian forest fire danger rating system: an overview. Forestry Chronicle 65, 450-457.
| Crossref | Google Scholar |

Syphard AD, Keeley JE (2015) Location, timing and extent of wildfire vary by cause of ignition. International Journal of Wildland Fire 24, 37-47.
| Crossref | Google Scholar |

Syphard AD, Keeley JE, Pfaff AH, Ferschweiler K (2017) Human presence diminishes the importance of climate in driving fire activity across the United States. Proceedings of the National Academy of Sciences 114, 13750-13755.
| Crossref | Google Scholar | PubMed |

Syphard AD, Rustigian-Romsos H, Keeley JE (2021) Multiple-scale relationships between vegetation, the wildland-urban interface, and structure loss to wildfire in California. Fire 4, 12.
| Crossref | Google Scholar |

Tedim F, Leone V, Amraoui M, Bouillon C, Coughlan MR, Delogu GM, Fernandes PM, Ferreira C, McCaffrey S, McGee TK, Parente J (2018) Defining extreme wildfire events: difficulties, challenges, and impacts. Fire 1, 9.
| Crossref | Google Scholar |

Tian X, McRae DJ, Jin J, Shu L, Zhao F, Wang M (2011) Wildfires and the Canadian Forest Fire Weather Index system for the Daxing’anling region of China. International Journal of Wildland Fire 20, 963-973.
| Crossref | Google Scholar |

Van Wagner CE (1987) Development and structure of the Canadian forest fire weather index system, Vol. 35. Forestry Technical Report. viii + 37 pp, ref. 63. (Canadian Forestry Service)

Viegas DX, Bovio G, Gerreira A, Nosenzo A, Sol B (1999) Comparative study of various methods of fire danger evaluation in southern Europe. International Journal of Wildland Fire 9, 235-246.
| Crossref | Google Scholar |

Waddington JM, Thompson DK, Wotton M, Quinton WL, Flannigan MD (2012) Examining the utility of the Canadian Forest Fire Weather Index System in boreal peatlands. Canadian Journal of Forest Research 42, 47-58.
| Crossref | Google Scholar |

Wang X, Wotton M, Cantin A, Parisien M-A, Anderson K, Moore B, Flannigan MD (2017) cffdrs: An R package for the Canadian Forest Fire Danger Rating System. Ecological Processes 6, 5.
| Crossref | Google Scholar |

Williams AP, Seager R, Abatzoglou JT, Cook BI, Smerdon JE, Cook ER (2015) Contribution of anthropogenic warming to California drought during 2012–2014. Geophysical Research Letters 42, 6819-6828.
| Crossref | Google Scholar |

Williams AP, Abatzoglou JT, Gershunov A, Guzman‐Morales J, Bishop DA, Balch JK, Lettenmaier DP (2019) Observed impacts of anthropogenic climate change on wildfire in California. Earth’s Future 7, 892-910.
| Crossref | Google Scholar |

Winkler JA, Potter BE, Wilhelm DF, Shadbolt RP, Piromsopa K, Bian X (2007) Climatological and statistical characteristics of the Haines Index for North America. International Journal of Wildland Fire 16, 139-152.
| Crossref | Google Scholar |