May 26, 2023

Smoke from early fire season impacts irradiance across North America

Fire season for North America started early this year after record high temperatures dominated the Pacific North West in early May. Temperatures were recorded as high as 31°C at 60° latitudes, close to 35°C in British Columbia and over 32°C in Alberta.

A map showing the temperature anomalies for Alberta
Temperature anomalies for Alberta for May 1-15, 2023 | Source: NOAA

The province of Alberta saw close to 100 wildfires raging from the beginning of the month with serious consequences and evacuations for over 30,000 residents and several still burning out of control.

A widlfire status dashboard showing the active fires in Alberta
Active fires in Alberta, 25th May 2023 | Source: Alberta Wildfire Status Dashboard

Smoke impacts irradiance

Smoke produced by the fires has covered most of western Canada and is being pushed east by the prevailing winds. Aerosols present in smoke can be of concern for health and visibility for residents in the region but also affect solar generation: thick clouds of aerosols from burning biomass are spreading all the way to US's Midwest states, and are clearly visible in ECMWF's CAMS data. Solar asset operators throughout the impacted regions can expect reduced efficiency from both the irradiance impacts and increased panel soiling.

A GIF showing the movement of aerosols in North America in May 2023
Source: CAMS

Irradiance and cloud combine to limit irradiance

Solcast ingests aerosols data for its radiation modelling and the effect on solar generation from the fire's smoke is clearly visible in data accessed via the Solcast API Toolkit. The below comparison shows the irradiance impact in Alberta, differentiating aerosol losses and cloud losses. This comparison uses the average clearsky May 2022 data as a non-aerosol impacted baseline, and aerosol impacted clearsky data from May 2023, plus Solcast actuals for May 22 and May 23, 2023. Despite dissipating aerosols on the 23rd, peak irradiance was suppressed on both days by cloud and smoke.

A time series graph showing the irradiance impact from aerosol and cloud in Alberta
Source: Solcast Analysis
Smoke from early fire season impacts irradiance across North America

Harry Jack

Data Scientist

Author

Harry is Solcast's Lead Modeller and forecast systems engineer, leading our modelling team and responsible for data quality and data value across Solcast. Harry holds a BEng (Hons I) in Chemical Engineering from the University of Sydney, and a Grad. Dip. in Meteorology from the Australian Bureau of Meteorology (BoM). He has worked as an operational Meteorologist and as a forecast systems scientist at the BoM.