Figure 12: Daily latent heat flux
as a function of atmospheric stability (ζ=\(\frac{z}{L_{\text{Ob}}}\) where z is the measured height andLOb refers to the Obukhov length) for the
ice-free periods (15 May to 31 December) from 2018 to 2021.
Figure 13 presents the 2018, 2020 and 2021 cumulative heat storage
ΔHS calculated over the 70-m water column. Heat
storage started in spring and ended in early September (a 3.5-month
period), with maximum values of 2000 MJ m−2 for 2018
and 2021 and 1700 MJ m−2 for 2020. Heat release
followed and lasted about 4 months until ice-on. The heat release rate
was lower from September to mid-November compared to mid-November to the
end of December: 13 MJ m−2 day−1compared to 21.7 MJ m−2 day−1 for
2018. Overall, heat storage exhibited larger day-to-day fluctuations
than heat release.