Winter coccolithophore blooms in the Black Sea: Interannual variability and driving factors

Seasonal Stages of Chlorophyll‐a Vertical Distribution and Its Relation to the Light Conditions in the Black Sea From Bio‐Argo Measurements

“…Particularly, in August 2015, several strong wind events led to the rise of satellite‐derived Chla to 5.00 mg m −3 (see blue rectangle in Figure 2d) (Kubryakov, Zatsepin, et al., 2019), which is an extremely high value for the central Black Sea. Such short‐term extreme atmospheric events are also one of the triggers for the start of the phytoplankton bloom in autumn (Mikaelyan, Shapiro, et al., 2017; Kubryakova et al., 2021).…”

“…In early November, the MLD reaches 25 m and its density reaches values close to the density of the upper nitrocline layers. Periodic storms cause additional erosion of the thermocline and entrainment of new nutrients into the EL, which triggers the late autumn phytoplankton bloom (Kubryakova et al., 2021; Mikaelyan, Shapiro, et al., 2017; Türkoğlu & Koray, 2002).…”

Quasi-tropical cyclone caused anomalous autumn coccolithophore bloom in the Black Sea

“…Vertical mixing and upwelling caused by the action of tropical cyclones uplift nutrients to the euphotic layer and induce intense, sporadic phytoplankton blooms in the world ocean (for example, Babin et al, 2004;Chacko, 2017;Han et al, 2012;Kubryakov et al, 2019c;Lin et al, 2003;Miller et al, 2006;Morozov et al, 2015;Tsuchiya et al, 2013). An important tracer of such changes is the chlorophyll a concentration (Chl), which can be determined from satellite measurements.…”

“…Usually, the cell concentration (N ) during summer blooms in the Black Sea is ∼ 2-6 × 10 6 cells per liter (Mikaelyan et al, 2005(Mikaelyan et al, , 2011(Mikaelyan et al, , 2015Pautova et al, 2007), but in certain years, it can reach very high values, where N = 10-30 × 10 6 cells per liter (Korchemkina et al, 2014;Mihnea, 1997;Yasakova and Stanichny, 2012). Weaker blooms are detected in the winter period (Hay et al, 1990;Kubryakov et al, 2019cKubryakov et al, , 2021Mikaelyan et al, 2020;Sorokin, 1983;Stelmakh et al, 2009;Stelmakh, 2013;Sukhanova, 1995;Türkoglu, 2010;Yasakova et al, 2017). Recent biogeochemical Argo (BGC-ARGO; Kubryakov et al, 2019c) and satellite studies (Kubryakova et al, 2021) showed that winter blooms usually start in December, with a peak in January, and are observed almost every year.…”

“…Weaker blooms are detected in the winter period (Hay et al, 1990;Kubryakov et al, 2019cKubryakov et al, , 2021Mikaelyan et al, 2020;Sorokin, 1983;Stelmakh et al, 2009;Stelmakh, 2013;Sukhanova, 1995;Türkoglu, 2010;Yasakova et al, 2017). Recent biogeochemical Argo (BGC-ARGO; Kubryakov et al, 2019c) and satellite studies (Kubryakova et al, 2021) showed that winter blooms usually start in December, with a peak in January, and are observed almost every year. N is usually lower in winter than in summer (N = 0.5-2 × 10 6 cells per liter; Kubryakov et al, 2019c;Stelmakh et al, 2009;Stelmakh, 2013).…”