Shorter blooms expected with longer warm periods under climate change: an example from a shallow meso-eutrophic Mediterranean lake

AbstractSatellite data from the Climate Change Initiative (CCI) lakes project were used to examine the influence of climate on chlorophyll-a (Chl-a). Nonparametric multiplicative regression and machine learning were used to explain Chl-a concentration trend and dynamics. The main parameters of importance were seasonality, interannual variation, lake level, water temperature, the North Atlantic Oscillation, and antecedent rainfall. No evidence was found for an earlier onset of the summer phytoplankton bloom related to the earlier onset of warmer temperatures. Instead, a curvilinear relationship between Chl-a and the temperature length of season above 20°C (LOS) was found with longer periods of warmer temperature leading to blooms of shorter duration. We suggest that a longer period of warmer temperatures in the summer may result in earlier uptake of nutrients or increased calcite precipitation resulting in a shortening of the duration of phytoplankton blooms. The current scenario of increasing LOS of temperature with climate change may lead to an alteration of phytoplankton phenological cycles resulting in blooms of shorter duration in lakes where nutrients become limiting. Satellite-derived information on lake temperature and Chl-a concentration proved essential in detecting trends at appropriate resolution over time.

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Detecting Climate Driven Changes in Chlorophyll-a in Deep Subalpine Lakes Using Long Term Satellite Data

Water ◽

10.3390/w13060866 ◽

2021 ◽

Vol 13 (6) ◽

pp. 866

Author(s):

Gary Free ◽

Mariano Bresciani ◽

Monica Pinardi ◽

Nicola Ghirardi ◽

Giulia Luciani ◽

...

Keyword(s):

Climate Change ◽

Chlorophyll A ◽

Nutrient Dynamics ◽

Cascading Effects ◽

The North ◽

Subalpine Lakes ◽

Winter Temperatures ◽

Decadal Climate ◽

The North Atlantic Oscillation ◽

Traditional Pattern

Climate change has increased the temperature and altered the mixing regime of high-value lakes in the subalpine region of Northern Italy. Remote sensing of chlorophyll-a can help provide a time series to allow an assessment of the ecological implications of this. Non-parametric multiplicative regression (NPMR) was used to visualize and understand the changes that have occurred between 2003–2018 in Lakes Garda, Como, Iseo, and Maggiore. In all four deep subalpine lakes, there has been a disruption from a traditional pattern of a significant spring chlorophyll-a peak followed by a clear water phase and summer/autumn peaks. This was replaced after 2010–2012, with lower spring peaks and a tendency for annual maxima to occur in summer. There was a tendency for this switch to be interspersed by a two-year period of low chlorophyll-a. Variables that were significant in NPMR included time, air temperature, total phosphorus, winter temperature, and winter values for the North Atlantic Oscillation. The change from spring to summer chlorophyll-a maxima, relatively sudden in an ecological context, could be interpreted as a regime shift. The cause was probably cascading effects from increased winter temperatures, reduced winter mixing, and altered nutrient dynamics. Future trends will depend on climate change and inter-decadal climate drivers.

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Assessing Phytoplankton Bloom Phenology in Upwelling-Influenced Regions Using Ocean Color Remote Sensing

Remote Sensing ◽

10.3390/rs13040675 ◽

2021 ◽

Vol 13 (4) ◽

pp. 675

Author(s):

Afonso Ferreira ◽

Vanda Brotas ◽

Carla Palma ◽

Carlos Borges ◽

Ana C. Brito

Keyword(s):

Climate Change ◽

Remote Sensing ◽

Phytoplankton Bloom ◽

Ocean Color ◽

Coastal Region ◽

Coastal Areas ◽

Ocean Color Remote Sensing ◽

Chl A ◽

Peak Biomass ◽

Phytoplankton Communities

Phytoplankton bloom phenology studies are fundamental for the understanding of marine ecosystems. Mismatches between fish spawning and plankton peak biomass will become more frequent with climate change, highlighting the need for thorough phenology studies in coastal areas. This study was the first to assess phytoplankton bloom phenology in the Western Iberian Coast (WIC), a complex coastal region in SW Europe, using a multisensor long-term ocean color remote sensing dataset with daily resolution. Using surface chlorophyll a (chl-a) and biogeophysical datasets, five phenoregions (i.e., areas with coherent phenology patterns) were defined. Oceanic phytoplankton communities were seen to form long, low-biomass spring blooms, mainly influenced by atmospheric phenomena and water column conditions. Blooms in northern waters are more akin to the classical spring bloom, while blooms in southern waters typically initiate in late autumn and terminate in late spring. Coastal phytoplankton are characterized by short, high-biomass, highly heterogeneous blooms, as nutrients, sea surface height, and horizontal water transport are essential in shaping phenology. Wind-driven upwelling and riverine input were major factors influencing bloom phenology in the coastal areas. This work is expected to contribute to the management of the WIC and other upwelling systems, particularly under the threat of climate change.

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Spatial and temporal variability of the phytoplankton community structure in the North Water Polynya, investigated using pigment biomarkers

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f04-152 ◽

2004 ◽

Vol 61 (11) ◽

pp. 2038-2052 ◽

Cited By ~ 36

Author(s):

Francesca Vidussi ◽

Suzanne Roy ◽

Connie Lovejoy ◽

Marie Gammelgaard ◽

Helge Abildhauge Thomsen ◽

...

Keyword(s):

Community Structure ◽

Phytoplankton Community ◽

Phytoplankton Bloom ◽

Circulation Pattern ◽

Spatial And Temporal Variability ◽

Phytoplankton Community Structure ◽

Southeastern Part ◽

Chl A ◽

The North ◽

North Water

Phytoplankton taxonomic pigments were measured by high-performance liquid chromatography (HPLC) during a 3-month survey (AprilJune 1998) in the North Water (NOW) Polynya (Canadian Arctic) to investigate changes in phytoplankton biomass and composition and the physicalchemical factors that influence these changes. A phytoplankton bloom with high chlorophyll a (Chl a) concentrations (up to 17.45 mg·m3 at 15 m) occurred in mid-May along the Greenland coast in the southeastern part of the NOW Polynya. The initiation of the phytoplankton bloom was linked to shallow mixed-layer depths. The contribution of the different phytoplankton groups to Chl a inferred using a factorization program (CHEMTAX) indicated that the bloom was diatom-dominated (maximum 94% diatoms). The phytoplankton community structure was influenced by the water mass characteristics and the surface circulation pattern. Autotrophic flagellates dominated in April and May along the Canadian coast, where cold Arctic waters with relatively deep mixed layers were found. In contrast, diatoms dominated in May along the Greenland coast in warmer water masses of Atlantic origin and during June in the whole polynya, except in the southernmost part.

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Climate change and outbreaks of amphibian chytridiomycosis in a montane area of Central Spain; is there a link?

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2006.3713 ◽

2006 ◽

Vol 274 (1607) ◽

pp. 253-260 ◽

Cited By ~ 161

Author(s):

Jaime Bosch ◽

Luís M Carrascal ◽

Luis Durán ◽

Susan Walker ◽

Matthew C Fisher

Keyword(s):

Climate Change ◽

General Circulation ◽

Batrachochytrium Dendrobatidis ◽

Global Scale ◽

Amphibian Species ◽

The North ◽

Natural Park ◽

Circulation Patterns ◽

The North Atlantic Oscillation

Amphibian species are declining at an alarming rate on a global scale in large part owing to an infectious disease caused by the chytridiomycete fungus, Batrachochytrium dendrobatidis . This disease of amphibians has recently emerged within Europe, but knowledge of its effects on amphibian assemblages remains poor. Importantly, little is known about the environmental envelope that is associated with chytridiomycosis in Europe and the potential for climate change to drive future disease dynamics. Here, we use long-term observations on amphibian population dynamics in the Peñalara Natural Park, Spain, to investigate the link between climate change and chytridiomycosis. Our analysis shows a significant association between change in local climatic variables and the occurrence of chytridiomycosis within this region. Specifically, we show that rising temperature is linked to the occurrence of chytrid-related disease, consistent with the chytrid-thermal-optimum hypothesis. We show that these local variables are driven by general circulation patterns, principally the North Atlantic Oscillation. Given that B. dendrobatidis is known to be broadly distributed across Europe, there is now an urgent need to assess the generality of our finding and determine whether climate-driven epidemics may be expected to impact on amphibian species across the wider region.

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A Reply to John L. Brooke’s “Malthus and the North Atlantic Oscillation”

Journal of Interdisciplinary History ◽

10.1162/jinh_c_00906 ◽

2016 ◽

Vol 46 (4) ◽

pp. 579-584

Author(s):

Kyle Harper

Keyword(s):

Climate Change ◽

North Atlantic Oscillation ◽

North Atlantic ◽

Human Response ◽

The North ◽

Positive Mode ◽

Big Picture ◽

The North Atlantic ◽

The North Atlantic Oscillation

In this continuation of his exchange with Brooke about Brooke’s big-picture model of climate change and human response, Harper argues for careful articulation of what kind of Malthusianism Brooke claims, or does not claim, for or against his model. Harper also challenges Brooke’s description of the paleoclimate known as the Roman Climate Optimum as a period dominated by a persistently positive mode of the North Atlantic Oscillation.

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Extreme weather affects Peregrine Falcon (Falco peregrinus tundrius) breeding success in South Greenland

Ornis Hungarica ◽

10.1515/orhu-2018-0014 ◽

2018 ◽

Vol 26 (2) ◽

pp. 38-50 ◽

Cited By ~ 1

Author(s):

Linnéa Carlzon ◽

Amanda Karlsson ◽

Knud Falk ◽

Antonia Liess ◽

Søren Møller

Keyword(s):

Climate Change ◽

Breeding Success ◽

Nest Success ◽

Extreme Weather ◽

The Arctic ◽

Extreme Weather Events ◽

Breeding Cycle ◽

Peregrine Falcon ◽

The North ◽

The North Atlantic Oscillation

Abstract In order to better understand the potential effects of climate change on the Peregrine Falcon, we investigated the relationship between extreme weather events and Peregrines’ breeding success in South Greenland. We defined three variables – number of days with extremely low temperatures, extreme precipitation, consecutive rainy days – and an additive variable, total days with extreme weather, and tested their relationship with Peregrines’ breeding success (measured as young per site and nest success) over a 33 year study period. Breeding success was negatively influenced by the number of days with extreme weather and extremely low temperature. The strongest relationship found was total days with extreme weather in the entire breeding season, which explained 22% and 27% of the variation in nest success and young per site, respectively. The number of days with extreme weather in our study related to fluctuations in the North Atlantic Oscillation (NAO). Thus, with a strengthening of the NAO, linked to climate change, more extreme weather may occur in the Arctic and induce increased variation in Peregrines’ breeding success. Our data did not allow us to pinpoint when in the breeding cycle inclement weather was particularly harmful, and we recommend finer-scale research (e.g. automated nest cameras) to better monitor the species-specific effects of rapidly changing climate.

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Dissolved greenhouse gases (nitrous oxide and methane) associated with the natural iron-fertilized Kerguelen region (KEOPS 2 cruise) in the Southern Ocean

Biogeosciences Discussions ◽

10.5194/bgd-11-12531-2014 ◽

2014 ◽

Vol 11 (8) ◽

pp. 12531-12569 ◽

Cited By ~ 3

Author(s):

L. Farías ◽

L. Florez-Leiva ◽

V. Besoain ◽

C. Fernández

Keyword(s):

Nitrous Oxide ◽

Southern Ocean ◽

Greenhouse Gases ◽

Phytoplankton Bloom ◽

Polar Front ◽

Austral Spring ◽

Chl A ◽

The North ◽

Natural Iron ◽

Nutrient Fertilization

Abstract. The concentrations of greenhouse gases (GHGs) like nitrous oxide (N2O) and methane (CH4) were measured in the Kerguelen Plateau Region (KPR), an area with annual microalgal bloom caused by natural Fe fertilization, which may stimulate microbes involved in GHG cycling. This study was carried out during the KEOPS 2 cruise during the austral spring of 2011. Two transects were sampled along and across the KRP, the north–south (N–S) transect (46–51° S, 72° E meridian) and the west–east (W–E) transect (66–75° E, 48.3° S latitude), both associated with the presence of a plateau, polar fronts and other mesoscale features. The W–E transect had N2O levels ranging from equilibrium (105%) to light supersaturation (120%) with respect to the atmosphere. CH4 levels fluctuated dramatically, with intense supersaturations (120–970%) in areas close to the coastal waters of Kerguelen Island and in the polar front (PF). There, Fe and nutrient fertilization seem to promote high total chlorophyll a (TChl a) levels. The distribution of both gases was more homogenous in the N–S transect, but CH4 peaked at southeastern stations of the KPR (A3 stations), where phytoplankton bloom was observed. Both gases responded significantly to the patchy distribution of particulate matter as Chl a, stimulated by Fe supply by complex mesoscale circulation. While CH4 appears to be produced mainly at the pycnoclines, N2O seems to be consumed superficially. Air–sea fluxes for N2O (from −10.5 to 8.65, mean 1.71 μmol m−2d−1), and for CH4 (from 0.32 to 38.1, mean 10.07 μmol m−2d−1) reflected sink and source behavior for N2O and source behavior for CH4, with considerable variability associated with a highly fluctuating wind regime and, in the case of CH4, due to its high superficial levels that had not been reported before in the Southern Ocean and may be caused by an intense microbial CH4 cycling.

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A regional evaluation of the influence of climate change on long term trends in chlorophyll-a in large Italian lakes from satellite data

10.5194/esd-2020-56 ◽

2020 ◽

Author(s):

Gary Free ◽

Mariano Bresciani ◽

Monica Pinardi ◽

Nicola Ghirardi ◽

Giulia Luciani ◽

...

Keyword(s):

Climate Change ◽

Chlorophyll A ◽

Nutrient Dynamics ◽

Cascading Effects ◽

The North ◽

Lake Garda ◽

Winter Temperatures ◽

Decadal Climate ◽

The North Atlantic Oscillation ◽

Traditional Pattern

Abstract. Climate change has increased the temperature and altered the mixing regime of high-value lakes in the sub-alpine region of Northern Italy. Remote sensing of chlorophyll-a can help provide a time-series to allow an assessment of the ecological implications of this. Non-parametric multiplicative regression (NPMR) was used to visualize and understand the changes that have occurred between 2003–2018 in lakes Garda, Como, Iseo and Maggiore. In all four deep sub-alpine lakes there has been a disruption from a traditional pattern of a significant spring chlorophyll-a peak followed by a clear water phase and summer/autumn peaks. This was replaced after 2010–2012, with lower spring peaks and a tendency for annual maxima to occur in summer. There was a tendency for this switch to be interspersed by a two-year period of low chlorophyll-a, which seemed to extend until 2018 for Lake Garda. Variables that were significant in NPMR included time, air temperature, wind speed, cloud cover, winter temperature and winter values for the North Atlantic Oscillation and Eastern Atlantic pattern. The change from spring to summer chlorophyll-a maxima, relatively sudden in an ecological context, could be interpreted as a regime shift. The cause is probably cascading effects from increased winter temperatures, reduced winter mixing and altered nutrient dynamics. Future trends will depend on climate change and inter-decadal climate drivers.

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A hazard model of sub-freezing temperatures in the United Kingdom using vine copulas

Natural Hazards and Earth System Science ◽

10.5194/nhess-19-489-2019 ◽

2019 ◽

Vol 19 (3) ◽

pp. 489-506

Author(s):

Symeon Koumoutsaris

Keyword(s):

Climate Change ◽

United Kingdom ◽

North Atlantic Oscillation ◽

North Atlantic ◽

Cold Weather ◽

The North ◽

The United Kingdom ◽

Extreme Cold ◽

The North Atlantic ◽

The North Atlantic Oscillation

Abstract. Extreme cold weather events, such as the winter of 1962/63, the third coldest winter ever recorded in the Central England Temperature record, or more recently the winter of 2010/11, have significant consequences for the society and economy. This paper assesses the probability of such extreme cold weather across the United Kingdom (UK), as part of a probabilistic catastrophe model for insured losses caused by the bursting of pipes. A statistical model is developed in order to model the extremes of the Air Freezing Index (AFI), which is a common measure of the magnitude and duration of freezing temperatures. A novel approach in the modelling of the spatial dependence of the hazard has been followed which takes advantage of the vine copula methodology. The method allows complex dependencies to be modelled, especially between the tails of the AFI distributions, which is important to assess the extreme behaviour of such events. The influence of the North Atlantic Oscillation and of anthropogenic climate change on the frequency of UK cold winters has also been taken into account. According to the model, the occurrence of extreme cold events, such as the 1962/63 winter, has decreased approximately 2 times during the course of the 20th century as a result of anthropogenic climate change. Furthermore, the model predicts that such an event is expected to become more uncommon, about 2 times less frequent, by the year 2030. Extreme cold spells in the UK have been found to be heavily modulated by the North Atlantic Oscillation (NAO) as well. A cold event is estimated to be ≈3–4 times more likely to occur during its negative phase than its positive phase. However, considerable uncertainty exists in these results, owing mainly to the short record length and the large interannual variability of the AFI.

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