Causes and impacts of the 2014 warm anomaly in the NE Pacific

We develop a statistical model to predict June-July-August (JJA) daily maximum 8-h average (MDA8) ozone concentrations in the eastern United States based on large-scale climate patterns during the previous spring. We find that anomalously high JJA ozone in the East is correlated with these springtime patterns: warm tropical Atlantic and cold northeast Pacific sea surface temperatures (SSTs), as well as positive sea level pressure (SLP) anomalies over Hawaii and negative SLP anomalies over the Atlantic and North America. We then develop a linear regression model to predict JJA MDA8 ozone from 1980 to 2013, using the identified SST and SLP patterns from the previous spring. The model explains ∼45% of the variability in JJA MDA8 ozone concentrations and ∼30% variability in the number of JJA ozone episodes (>70 ppbv) when averaged over the eastern United States. This seasonal predictability results from large-scale ocean-atmosphere interactions. Warm tropical Atlantic SSTs can trigger diabatic heating in the atmosphere and influence the extratropical climate through stationary wave propagation, leading to greater subsidence, less precipitation, and higher temperatures in the East, which increases surface ozone concentrations there. Cooler SSTs in the northeast Pacific are also associated with more summertime heatwaves and high ozone in the East. On average, models participating in the Atmospheric Model Intercomparison Project fail to capture the influence of this ocean-atmosphere interaction on temperatures in the eastern United States, implying that such models would have difficulty simulating the interannual variability of surface ozone in this region.ozone | seasonal forecast | teleconnection | sea surface temperature

Section: Physical Mechanism For the Sst/slp Relationships With Us Mdasupporting

confidence: 77%

Section: Physical Mechanism For the Sst/slp Relationships With Us Mdamentioning

confidence: 99%

See 1 more Smart Citation

Seasonal prediction of US summertime ozone using statistical analysis of large scale climate patterns

Shen

Mickley

2017

“…Recent studies link the increasing variance of the NPO-the atmospheric driver of the NPGO-to greenhouse forcing (29). Consistent with this view, in the winter of 2013-2014, the NPO activity reached a record high, causing the warmest SSTa anomalies ever recorded in the northeast Pacific (30). These SSTa anomalies exhibit the same spatial pattern as the NPGO (31), suggesting that extremes in physical conditions linked to salmon survival rates may become more frequent in future decades.…”

Section: Discussionsupporting

confidence: 48%

Changing central Pacific El Niños reduce stability of North American salmon survival rates

Kilduff

Lorenzo

Botsford

et al. 2015

118

126

Pacific salmon are a dominant component of the northeast Pacific ecosystem. Their status is of concern because salmon abundance is highly variable-including protected stocks, a recently closed fishery, and actively managed fisheries that provide substantial ecosystem services. Variable ocean conditions, such as the Pacific Decadal Oscillation (PDO), have influenced these fisheries, while diminished diversity of freshwater habitats have increased variability via the portfolio effect. We address the question of how recent changes in ocean conditions will affect populations of two salmon species. Since the 1980s, El Niño Southern Oscillation (ENSO) events have been more frequently associated with central tropical Pacific warming (CPW) rather than the canonical eastern Pacific warming ENSO (EPW). CPW is linked to the North Pacific Gyre Oscillation (NPGO), whereas EPW is linked to the PDO, different indicators of northeast Pacific Ocean ecosystem productivity. Here we show that both coho and Chinook salmon survival rates along western North America indicate that the NPGO, rather than the PDO, explains salmon survival since the 1980s. The observed increase in NPGO variance in recent decades was accompanied by an increase in coherence of local survival rates of these two species, increasing salmon variability via the portfolio effect. Such increases in coherence among salmon stocks are usually attributed to controllable freshwater influences such as hatcheries and habitat degradation, but the unknown mechanism underlying the ocean climate effect identified here is not directly subject to management actions.salmon | synchrony | persistence |

“…To protect public health, DA in shellfish has been monitored along the US West Coast since 1991 (19). These records are now long enough to investigate DA regulation at the temporal-spatial scales associated with NE Pacific climate events that have occurred in recent decades, such as El Niño events, PDO transitions, and the 2013-2015 NE Pacific Warm Anomaly (20,21).…”

mentioning

confidence: 99%

Climatic regulation of the neurotoxin domoic acid

McKibben

Peterson

Wood

et al. 2017

131

Domoic acid is a potent neurotoxin produced by certain marine microalgae that can accumulate in the foodweb, posing a health threat to human seafood consumers and wildlife in coastal regions worldwide. Evidence of climatic regulation of domoic acid in shellfish over the past 20 y in the Northern California Current regime is shown. The timing of elevated domoic acid is strongly related to warm phases of the Pacific Decadal Oscillation and the Oceanic Niño Index, an indicator of El Niño events. Ocean conditions in the northeast Pacific that are associated with warm phases of these indices, including changes in prevailing currents and advection of anomalously warm water masses onto the continental shelf, are hypothesized to contribute to increases in this toxin. We present an applied domoic acid risk assessment model for the US West Coast based on combined climatic and local variables. Evidence of regional-to basin-scale controls on domoic acid has not previously been presented. Our findings have implications in coastal zones worldwide that are affected by this toxin and are particularly relevant given the increased frequency of anomalously warm ocean conditions.T he Pacific Decadal Oscillation (PDO) and El Niño Southern Oscillation (ENSO) are recurring patterns of climate variability centered over the northeastern (NE) and equatorial Pacific, respectively, that fluctuate at scales of years (ENSO) to decades (PDO) (1, 2). Distinct, yet also related, these patterns can amplify or dampen each other through atmospheric teleconnection (1, 3). In the NE Pacific, they induce similar spatial patterns of sea surface temperature anomalies during positive (warm) and negative (cool) phases (4). Low-frequency physical variability attributed to the PDO and ENSO modulates large shifts in NE Pacific water temperature, ocean currents, and foodweb dynamics that can persist for months to years (2,5,6). Shifts in NE Pacific plankton communities occur as well (7-12); however, climate impacts on phytoplankton ecology in this region are relatively underexplored, largely due to a lack of phytoplankton data at sufficient scales.Decadal, regional-scale monitoring of domoic acid (DA) in shellfish can be used to investigate climate-scale impacts on phytoplankton ecology. The neurotoxin DA is produced by some species of the diatom genus Pseudo-nitzschia. It enters secondary trophic levels when suspension feeders such as shellfish and anchovies ingest toxic Pseudo-nitzschia cells. Consumption of these organisms by humans can lead to a serious neurological disorder named Domoic Acid Poisoning (DAP), also termed Amnesic Shellfish Poisoning. DAP symptoms range from gastrointestinal disturbance to seizures, memory loss, or, rarely, death (13,14).DA was first identified as a public health threat in 1987 (15). Toxin-producing Pseudo-nitzschia spp. and DA have since been identified worldwide with the greatest prevalence in, and most deleterious impacts on, productive eastern boundary upwelling systems (16). Laboratory experiments have found multiple ...