Variability and trends of ocean acidification in the Southern California Current System: A time series from Santa Monica Bay

Leinweber, A.; Gruber, Nicolas

doi:10.1002/jgrc.20259

Cited by 41 publications

(49 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3). These relationships between the three variables are typical of the manifestations of CaCO 3 corrosivity in coastal settings Harris et al, 2013b;Cai et al, 2011;Leinweber and Gruber, 2013;Mathis et al, 2014c). The relationships between arag , pH T and pCO 2 changed at salinities less than 24 in this setting (Fig.…”

Section: Trends In Pws Carbonate Datamentioning

confidence: 54%

“…Corrosive levels for both phases of CaCO 3 are naturally found in the ocean at depths below the level of continental shelves (Millero, 2007). However, ocean acidification as a direct response to rising atmospheric CO 2 is causing these levels to shoal above the depth of the shelf break (∼ 200 m) and inundate shallow water in some coastal locations (Bryne et al, 2010;Bates et al, 2009;Feely et al, 2008Feely et al, , 2010Leinweber and Gruber, 2013;Mathis et al, 2011aMathis et al, , b, 2014b making these areas vulnerable to environmental changes with an associated disruption in ecosystem services Barton et al, 2012;Feely et al, 2012;Mathis et al, 2014a). In many of these locations, natural variability in the carbonate system and/or coastal eutrophication can combine synergistically with OA to drive manifestations of severe CaCO 3 corrosivity (Harris et al, 2013a;Cai et al, 2011;Mathis et al, 2011b).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Calcium carbonate corrosivity in an Alaskan inland sea

2014

View full text Add to dashboard Cite

Abstract. Ocean acidification is the hydrogen ion increase caused by the oceanic uptake of anthropogenic CO 2 , and is a focal point in marine biogeochemistry, in part, because this chemical reaction reduces calcium carbonate (CaCO 3 ) saturation states ( ) to levels that are corrosive (i.e., ≤ 1) to shell-forming marine organisms. However, other processes can drive CaCO 3 corrosivity; specifically, the addition of tidewater glacial melt. Carbonate system data collected in May and September from 2009 through 2012 in Prince William Sound (PWS), a semienclosed inland sea located on the south-central coast of Alaska and ringed with fjords containing tidewater glaciers, reveal the unique impact of glacial melt on CaCO 3 corrosivity. Initial limited sampling was expanded in September 2011 to span large portions of the western and central sound, and included two fjords proximal to tidewater glaciers: Icy Bay and Columbia Bay. The observed conditions in these fjords affected CaCO 3 corrosivity in the upper water column (< 50 m) in PWS in two ways: (1) as spring-time formation sites of mode water with near-corrosive levels seen below the mixed layer over a portion of the sound, and (2) as point sources for surface plumes of glacial melt with corrosive levels ( for aragonite and calcite down to 0.60 and 1.02, respectively) and carbon dioxide partial pressures (pCO 2 ) well below atmospheric levels. CaCO 3 corrosivity in glacial melt plumes is poorly reflected by pCO 2 or pH T , indicating that either one of these carbonate parameters alone would fail to track in PWS. The unique and pCO 2 conditions in the glacial melt plumes enhances atmospheric CO 2 uptake, which, if not offset by mixing or primary productivity, would rapidly exacerbate CaCO 3 corrosivity in a positive feedback. The cumulative effects of glacial melt and air-sea gas exchange are likely responsible for the seasonal reduction of in PWS, making PWS highly sensitive to increasing atmospheric CO 2 and amplified CaCO 3 corrosivity.

show abstract

Section: Trends In Pws Carbonate Datamentioning

confidence: 54%

Section: Introductionmentioning

confidence: 99%

Calcium carbonate corrosivity in an Alaskan inland sea

2014

View full text Add to dashboard Cite

show abstract

“…Here, monthly mean climatologies for all hydrographic and chemical parameters were determined for all data spanning the 1996-2016 period. These climatologies were then compared to actual data to determine anomalies (i.e., difference between data value and monthly climatology) over the span of the time-series (e.g., Bates et al, 2012;Leinweber and Gruber, 2013;Bates et al, 2014). This approach accounts for variability in data frequency and helps remove seasonal sampling biases.…”

Section: Long-term Trend Analysismentioning

confidence: 99%

“…As the lengthiest coastal ocean time-series, Harrington Sound is difficult to compare to other shorter time-series, especially given the absence of contemporaneous observations in subtropical/tropical marine environments, in particular. In temperate environmental, seawater CO 2 -carbonate chemistry trends are mixed, with no surface trends detectable in Santa Monica Bay, for example (Leinweber and Gruber, 2013). In contrast, pH and CaCO 3 saturation states have declined at higher rates than the open ocean in the North Sea (Thomas et al, 2007;Clargo et al, 2015) and Washington state, USA (Wootton et al, 2008) in response to a combination of ocean uptake of anthropogenic CO 2 (e.g., ocean acidification) and marine ecosystem and land-ocean flux changes.…”

Section: Comparison Of Onshore and Offshore Trends In Seawater Co 2 -mentioning

confidence: 99%

Twenty Years of Marine Carbon Cycle Observations at Devils Hole Bermuda Provide Insights into Seasonal Hypoxia, Coral Reef Calcification, and Ocean Acidification

Bates

2017

Front. Mar. Sci.

View full text Add to dashboard Cite

Open-ocean observations have revealed gradual changes in seawater carbon dioxide (CO 2 ) chemistry resulting from uptake of atmospheric CO 2 and ocean acidification (OA), but, with few long-term records (>5 years) of the coastal ocean that can reveal the pace and direction of environmental change. In this paper, observations collected from 1996 to 2016 at Harrington Sound, Bermuda, constitute one of the longest time-series of coastal ocean inorganic carbon chemistry. Uniquely, such changes can be placed into the context of contemporaneous offshore changes observed at the nearby Bermuda Atlantic Time-series Study (BATS) site. Onshore, surface dissolved inorganic carbon (DIC) and partial pressure of CO 2 (pCO 2 ; >10% change per decade) have increased and OA indicators such as pH and calcium carbonate (CaCO 3 ) saturation state ( ) decreased from 1996 to 2016 at a rate of two to three times that observed offshore at BATS. Such changes, combined with reduction of total alkalinity over time, reveal a complex interplay of biogeochemical processes influencing Bermuda reef metabolism, including net ecosystem production (NEP = gross primary production-autotrophic and heterotrophic respiration) and net ecosystem calcification (NEC = gross calcification-gross CaCO 3 dissolution). These long-term data show a seasonal shift between wintertime net heterotrophy and summertime net autotrophy for the entire Bermuda reef system. Over annual time-scales, the Bermuda reef system does not appear to be in trophic balance, but rather slightly net heterotrophic. In addition, the reef system is net accretive (i.e., gross calcification > gross CaCO 3 dissolution), but there were occasional periods when the entire reef system appears to transiently shift to net dissolution. A previous 5-year study of the Bermuda reef suggested that net calcification and net heterotrophy have both increased. Over the past 20 years, rates of net calcification and net heterotrophy determined for the Bermuda reef system have increased by ∼30%, most likely due to increased coral nutrition occurring in concert with increased offshore productivity in the surrounding subtropical North Atlantic Ocean. Importantly, this long-term study reveals that other environmental factors (such as coral feeding) can mitigate against the effects of ocean acidification on coral reef calcification, at least over the past couple of decades.

show abstract

“…Spatial variability is also highest in summer, most likely driven by an interplay of high productivity and upwelling (Alin et al, 2012). At the Santa Monica Bay Observatory (SMBO at 33 • 55.9 N and 118 • 42.9 W), surface pH and arag display a large seasonal variability, ranging by ±0.08 (1 STD) and ±0.4 units, respectively (Leinweber and Gruber, 2013).…”

Section: Hauri Et Al: Variability and Long-term Trends Of Ocean Amentioning

confidence: 99%

Spatiotemporal variability and long-term trends of ocean acidification in the California Current System

et al. 2013

Self Cite

View full text Add to dashboard Cite

Abstract. Due to seasonal upwelling, the upper ocean waters of the California Current System (CCS) have a naturally low pH and aragonite saturation state ( arag ), making this region particularly prone to the effects of ocean acidification. Here, we use the Regional Oceanic Modeling System (ROMS) to conduct preindustrial and transient simulations of ocean biogeochemistry in the CCS. The transient simulations were forced with increasing atmospheric pCO 2 and increasing oceanic dissolved inorganic carbon concentrations at the lateral boundaries, as projected by the NCAR CSM 1.4 model for the IPCC SRES A2 scenario. Our results show a large seasonal variability in pH (range of ∼ 0.14) and arag (∼ 0.2) for the nearshore areas (50 km from shore). This variability is created by the interplay of physical and biogeochemical processes. Despite this large variability, we find that present-day pH and arag have already moved outside of their simulated preindustrial variability envelopes (defined by ±1 temporal standard deviation) due to the rapidly increasing concentrations of atmospheric CO 2 . The nearshore surface pH of the northern and central CCS are simulated to move outside of their present-day variability envelopes by the mid-2040s and late 2030s, respectively. This transition may occur even earlier for nearshore surface arag , which is projected to depart from its present-day variability envelope by the early-to mid-2030s. The aragonite saturation horizon of the central CCS is projected to shoal into the upper 75 m within the next 25 yr, causing near-permanent undersaturation in subsurface waters. Due to the model's overestimation of arag , this transition may occur even earlier than simulated by the model. Overall, our study shows that the CCS joins the Arctic and Southern oceans as one of only a few known ocean regions presently approaching the dual threshold of widespread and near-permanent undersaturation with respect to aragonite and a departure from its variability envelope. In these regions, organisms may be forced to rapidly adjust to conditions that are both inherently chemically challenging and also substantially different from past conditions.

show abstract

Variability and trends of ocean acidification in the Southern California Current System: A time series from Santa Monica Bay

Cited by 41 publications

References 30 publications

Calcium carbonate corrosivity in an Alaskan inland sea

Calcium carbonate corrosivity in an Alaskan inland sea

Twenty Years of Marine Carbon Cycle Observations at Devils Hole Bermuda Provide Insights into Seasonal Hypoxia, Coral Reef Calcification, and Ocean Acidification

Spatiotemporal variability and long-term trends of ocean acidification in the California Current System

Contact Info

Product

Resources

About