Societal impacts of extreme weather and climate events in Nome, Alaska
Stage 1: Catalog societal impacts of extreme weather and climate events in Nome
Because the population and infrastructure densities are far less than in the rest of the US, Alaska’s extreme events do not make the “billion-dollar disaster.” However, when normalized by the size of the local, regional, or even state economy, the impacts of these events on a per-capita basis can be greater in Alaska than elsewhere in the US. Human and social impacts can be especially severe in vulnerable, isolated communities of the state. While substantial social and economic impacts have occurred, there is no existing compilation or catalog of societal impacts of extreme events in Alaska.
This study used a novel interdisciplinary approach that integrated archival analysis, observational data, and climate model downscaling to synthesize information on historical and projected impacts of extreme weather events in Nome, Alaska. Over 300 impacts (1990–2018) were identified based on analyses of the Nome Nugget newspaper articles and Storm Data entries. Historical impacts centered on transportation, community activities, and utilities.
Analysis of observed and ERA5 reanalysis data found that impacts were frequently associated with high wind, extreme low temperatures, heavy snowfall events, and winter days above freezing. Downscaled output (2020–2100) from two climate models suggests that there will be changes in the frequency and timing of these extreme weather events.
Stage 2: Link sea ice and socio-economic impacts in Nome
ACCAP research examined the relationship between sea ice concentrations and community impacts of eight coastal storms that damaged roads, utilities, and other infrastructure near the hub community of Nome, Alaska from 1990 to 2021. Findings indicate that Nome is likely to see increasing economic impacts from coastal storms as sea ice declines.
The study focused on autumn, the season when the Bering Strait region typically experiences the most coastal storms. Sea ice historically protected communities during this time of year. Now the region often remains ice-free until November or even December, allowing larger waves and bigger swells to form during storms. The increased wave action causes erosion and destruction along shorelines that are no longer protected by ice.
To understand past storms that impacted Nome, the project used data from the local newspaper and NOAA StormData to create a database of impactful extreme events. Reported impacts ranged from water and power disruptions; damage to the Port of Nome, city dock, and community buildings; and damage to the Nome-Council Road that links Nome to smaller communities and is used by seasonal residents for subsistence hunting, fishing, and gathering.
For example, the widely reported “Bering Sea Superstorm” that occurred on November 8–10, 2011 caused about $24 million in damage to the Nome-Council road, $580 thousand in damage to Nome’s embankments and jetty, and other impacts such as power outages and canceled flights. The storm occurred when there was no sea ice in the Bering Sea.
The study also examined the satellite record for changes in sea ice since 1979 in order to better understand the relationship between extreme event impacts and sea ice concentrations during each event. ACCAP’s analysis shows that sea ice at Nome occurs about 30.5 fewer days a year now compared to the late 1970s. Between 2001 and 2022, Nome was 39% less likely to have sea ice on November 23, than on that date during the previous two decades. By December 7, Nome was 14% less likely to have sea ice. This is a remarkable change considering that Nome was consistently ice covered between November 23 and December 7 from 1979-2000. Sea ice concentrations vary from year to year, with more variability in the spring compared to the autumn.
All of the impactful extreme events identified in this study took place when the sea ice concentrations were at or below the 1979–2000 median for the day. As the autumn ice-free season is projected to continue to grow longer, coastal storms are more likely to impact Nome’s coastline, infrastructure, and economy. It is particularly important to point out that the shift toward less sea ice in November may have the greatest impact since this is the stormiest month of the year in the Bering Sea.