Marine Heatwave Index in the Barents Sea from Reanalysis

'''DEFINITION'''

Temperature deviation from the 30-year (1991-2020) daily climatological mean temperature for the Barents Sea region (68°N - 80°N, 18°E - 55°E), relative to the difference between the daily climatological average and the 90th percentile above the climatological mean. Thus, when the index is above 1 the area is in a state of a marine heatwave, and when the index is below -1 the area is in a state of a marine cold spell, following the definition by Hobday et al. (2016). For further details, see Lien et al. (2024).""

'''CONTEXT''' Anomalously warm oceanic events, often termed marine heatwaves, can potentially impact the ecosystem in the affected region. The marine heatwave concept and terminology was systemized by Hobday et al. (2016), and a generally adopted definition of a marine heatwave is a period of more than five days where the temperature within a region exceeds the 90th percentile of the seasonally varying climatological average temperature for that region. The Barents Sea region has warmed considerably during the most recent climatological average period (1991-2020) due to a combination of climate warming and positive phase of regional climate variability (e.g., Lind et al., 2018 ; Skagseth et al., 2020 ; Smedsrud et al., 2022), with profound consequences for marine life where boreal species are moving northward at the expense of arctic species (e.g., Fossheim et al., 2015; Oziel et al., 2020; Husson et al., 2022).

'''KEY FINDINGS'''

There is a clear tendency of reduced frequency and intensity of marine cold spells, and a tendency towards increased frequency and intensity of marine heat waves in the Barents Sea.

'''DOI (product):''' https://doi.org/10.48670/mds-00346