Transcriptomic plasticity and symbiont shuffling underpin Pocillopora acclimatization across heat-stress regimes in the Pacific Ocean

The characterization of adaptation and acclimation capacities of coral holobionts is crucial for anticipating the impact of global climate change on coral reefs. Understanding the extent to which the coral host and its photosymbionts contribute to adaptive and/or plastic responses in the coral metaorganism is equally important. In this study, we highlight new and complex links between coral genomes, transcriptomes, and environmental features in Pocilloporid corals at basin-wide scale. We analyzed metagenomic and metatranscriptomic sequence data from Pocillopora colonies sampled from 11 islands across the Pacific Ocean in order to investigate patterns of gene expression in both the host and photosymbiont across an environmental gradient. Single nucleotide polymorphism (SNP) analysis partitioned coral hosts and algal photosymbionts into five genetic lineages each. We observed strong host-symbiont fidelity across environments except at islands where recent and/or historical heat stress may have induced a symbiont shift towards more heat-tolerant lineages in some colonies. Host gene expression profiles were strongly segregated by genetic lineage and environment, and were significantly correlated with several historical sea surface temperature (SST) traits. Symbiont expression profiles were less dependent on environmental context than the host and were primarily driven by algal genotype. Overall, our results suggest a three-tiered strategy underpinning thermal acclimatization in Pocillopora holobionts with 1) host-photosymbiont fidelity, 2) host transcriptomic plasticity, and 3) photosymbiont shuffling playing progressive roles in response to elevated SSTs. Our data provide a reference for the biological state of coral holobionts across the Indo-Pacific and demonstrate the power of disentangling environmental and genetic effects to provide new insights into corals′ capacities for acclimatization and adaptation under environmental change.

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Long-range transport of black carbon to the Pacific Ocean and its dependence on aging timescale

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-15-16945-2015 ◽

2015 ◽

Vol 15 (12) ◽

pp. 16945-16983 ◽

Cited By ~ 1

Author(s):

J. Zhang ◽

J. Liu ◽

S. Tao ◽

G. A. Ban-Weiss

Keyword(s):

Pacific Ocean ◽

Black Carbon ◽

Source Region ◽

Climate Impacts ◽

Average Lifetime ◽

Deposition Rates ◽

Source Regions ◽

The Pacific ◽

The Pacific Ocean ◽

The Impact

Abstract. Improving the ability of global models to predict concentrations of black carbon (BC) over the Pacific Ocean is essential to evaluate the impact of BC on marine climate. In this study, we tag BC tracers from 13 source regions around the globe in a global chemical transport model MOZART-4. Numerous sensitivity simulations are carried out varying the aging timescale of BC emitted from each source region. The aging timescale for each source region is optimized by minimizing errors in vertical profiles of BC mass mixing ratios between simulations and HIAPER Pole-to-Pole Observations (HIPPO). For most HIPPO deployments, in the Northern Hemisphere, optimized aging timescales are less than half a day for BC emitted from tropical and mid-latitude source regions, and about 1 week for BC emitted from high latitude regions in all seasons except summer. We find that East Asian emissions contribute most to the BC loading over the North Pacific, while South American, African and Australian emissions dominate BC loadings over the South Pacific. Dominant source regions contributing to BC loadings in other parts of the globe are also assessed. The lifetime of BC originating from East Asia (i.e., the world's largest BC emitter) is found to be only 2.2 days, much shorter than the global average lifetime of 4.9 days, making East Asia's contribution to global burden only 36 % of BC from the second largest emitter, Africa. Thus, evaluating only relative emission rates without accounting for differences in aging timescales and deposition rates is not predictive of the contribution of a given source region to climate impacts. Our simulations indicate that lifetime of BC increases nearly linearly with aging timescale for all source regions. When aging rate is fast, the lifetime of BC is largely determined by factors that control local deposition rates (e.g. precipitation). The sensitivity of lifetime to aging timescale depends strongly on the initial hygroscopicity of freshly emitted BC. Our findings suggest that the aging timescale of BC varies significantly by region and season, and can strongly influence the contribution of source regions to BC burdens around the globe. Improving parameterizations of the aging process for BC is important for enhancing the predictive skill of air quality and climate models. Future observations that investigate the evolution of hygroscopicity of BC as it ages from different source regions to the remote atmosphere are urgently needed.

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The impact of Eastern-Pacific versus Central-Pacific El Niños on the North Equatorial Countercurrent in the Pacific Ocean

Journal of Geophysical Research Atmospheres ◽

10.1029/2012jc008362 ◽

2012 ◽

Vol 117 (C11) ◽

pp. n/a-n/a ◽

Cited By ~ 15

Author(s):

Yi-Chia Hsin ◽

Bo Qiu

Keyword(s):

Pacific Ocean ◽

Eastern Pacific ◽

Central Pacific ◽

The North ◽

The Pacific ◽

The Pacific Ocean ◽

The Impact

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Impact of Data Assimilation on ECCO2 Equatorial Undercurrent and North Equatorial Countercurrent in the Pacific Ocean

Journal of Atmospheric and Oceanic Technology ◽

10.1175/jtech-d-14-00025.1 ◽

2015 ◽

Vol 32 (1) ◽

pp. 131-143 ◽

Cited By ~ 3

Author(s):

David Halpern ◽

Dimitris Menemenlis ◽

Xiaochun Wang

Keyword(s):

Pacific Ocean ◽

Data Assimilation ◽

Velocity Measurements ◽

Equatorial Undercurrent ◽

Substantial Impact ◽

The Pacific ◽

The Pacific Ocean ◽

The Difference ◽

The Impact

AbstractThe impact of data assimilation on the transports of eastward-flowing Equatorial Undercurrent (EUC) and North Equatorial Countercurrent (NECC) in the Pacific Ocean from 145°E to 95°W during 2004–05 and 2009–11 was assessed. Two Estimating the Circulation and Climate of the Ocean, Phase II (ECCO2), solutions were analyzed: one with data assimilation and one without. Assimilated data included satellite observations of sea surface temperature and ocean surface topography, in which the sampling patterns were approximately uniform over the 5 years, and in situ measurements of subsurface salinity and temperature profiles, in which the sampling patterns varied considerably in space and time throughout the 5 years. Velocity measurements were not assimilated. The impact of data assimilation was considered significant when the difference between the transports computed with and without data assimilation was greater than 5.5 × 106 m3 s−1 (or 5.5 Sv; 1 Sv ≡ 106 m3 s−1) for the EUC and greater than 5.0 Sv for the NECC. In addition, the difference of annual-mean transports computed from 3-day-averaged data was statistically significant at the 95% level. The impact of data assimilation ranged from no impact to very substantial impact when data assimilation increased the EUC transport and decreased the NECC transport. The study’s EUC results had some correspondence with other studies and no simple agreement or disagreement pattern emerged among all studies of the impact of data assimilation. No comparable study of the impact of data assimilation on the NECC has been made.

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Strengthening the Early Detection and Tracking of Tropical Cyclones near Indonesian Waters

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/925/1/012010 ◽

2021 ◽

Vol 925 (1) ◽

pp. 012010

Author(s):

E E S Makmur ◽

W Fitria ◽

A S Praja ◽

S P Rahayu ◽

B E Pratama ◽

...

Keyword(s):

Pacific Ocean ◽

Tropical Cyclone ◽

Early Detection ◽

Tropical Cyclones ◽

Warning System ◽

The Philippines ◽

Australian Monsoon ◽

The Pacific ◽

The Pacific Ocean ◽

The Impact

Abstract In early April 2021, the territory of Indonesia, around the province of East Nusa Tenggara in particular, was severely damaged due to being hit by tropical cyclone Seroja. The impact of tropical cyclone Seroja does not only occur in Nusa Tenggara but also in Australia. In fact, the impact that hit Australia exceeded the damage that occurred in East Nusa Tenggara. The impacts caused by tropical cyclone Seroja in East Nusa Tenggara included 181 deaths and 74,222 houses damaged. Tropical cyclones are extreme weather anomalies that hit many countries, especially in the middle latitudes associated with vast oceans, such as the area around the South China Sea, the Pacific Ocean and the Atlantic Ocean, such as the Philippines, Japan, America, Australia, Europe, etc. Early detection systems for the genesis of tropical cyclones are still being developed by international collaborations such as The Research Moored Array for African-Asian-Australian Monsoon Analysis and Prediction (RAMA) in the Indian Ocean, Tropical Atmosphere Ocean (TAO) in the Pacific Ocean, and Prediction and Research Moored, Array in the Tropical Atlantic (PIRATA). To find out the early sign of a tropical cyclone, it is characterized by sea surface temperatures > 26.5 C, the growth of very broad and thick convective clouds, and rotating wind speeds of > 63 km/hour. For this reason, continuous observations are needed in the area where the tropical cyclone first developed. Observation equipment required includes satellite observations, buoys, and weather radar. Unfortunately, in the territory of Indonesia, especially in the Indian and Pacific oceans around Indonesia, this equipment is not equipped with such equipment due to very expensive funding factors and vandalism constraints. For this reason, in the future, national and international cooperation will be needed to start building an early warning system for the emergence of tropical cyclones among research centers globally.

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On the Impact of Salinity Barrier Layer on the Pacific Ocean Mean State and ENSO

SOLA ◽

10.2151/sola.2011-025 ◽

2011 ◽

Vol 7 ◽

pp. 97-100 ◽

Cited By ~ 12

Author(s):

Christophe Maes ◽

Sophie Belamari

Keyword(s):

Pacific Ocean ◽

Barrier Layer ◽

The Pacific ◽

The Pacific Ocean ◽

The Impact ◽

Mean State

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The growing exposure of Pacific coral reefs to compound extremes caused by marine heatwaves coalescing with low saturation state extremes

10.5194/egusphere-egu21-15096 ◽

2021 ◽

Author(s):

Luke Gregor ◽

Nicolas Gruber

Keyword(s):

Pacific Ocean ◽

Coral Reefs ◽

Extreme Events ◽

Anthropogenic Heat ◽

Average Intensity ◽

Saturation State ◽

The Pacific ◽

Compound Events ◽

The Pacific Ocean ◽

The Impact

The ocean has played a key role in mitigating the impact of climate change by taking up excess anthropogenic heat and CO2 leading to warming and increased ocean acidity, which goes in hand with a reduction of the saturation state of seawater with regard to the mineral carbonate aragonite, i.e., &#937;AR. While the threats posed by these long-term changes to marine organisms and ecosystems are well recognized, only more recently has the community realized that these threats might be much more imminent owing to extreme events. This is the result of these extremes exposing vulnerable ecosystems already today to conditions that lie in the far future when considering only the changes in the mean conditions. Of particular concern are so-called compound events, i.e., conditions when both temperatures are extremely hot and the saturation states extremely low, as this compounding might be particularly threatening for marine ecosystems, especially for warm water coral reefs.Here we use satellite records of sea surface temperature (SST) and satellite &#937;AR to map globally the occurrence of marine heat waves (MHW) and low saturation state extreme events and their compounding for the period 1985 and 2018. We use SSTs from the OSTIA product, while we take &#937;AR from the newly developed OceanSODA-ETHZ (monthly 1&#176;x1&#176;) observation-based product that extrapolates ship observations with satellite data. Our study focuses on the Pacific Ocean between 25&#176;S and 25&#176;N, a region with more than 1000 identified coral reefs. We define extremes using the approach of Hobday et al. (2018) with a fixed baseline determined from the entire record (1985-2018) and where extremes are below/above the 10th/90th percentiles for &#937;/SST respectively.The majority of the compound extreme events (too hot and too low saturation state) occur in the western tropical Pacific, with 757 of the 1206 reefs in the Pacific experiencing at least three months of compound extreme events over the entire period. The average duration of these compound extremes was 3.6 months, and the average area was 247 600 km2 (roughly the size of the United Kingdom). The compound events had an average intensity of &#8211;0.13 for &#937;AR&#160;and 0.71&#176;C, where the intensity is the anomaly from the climatology. The largest and longest lasting extreme event started in 2016 and lasted nearly three years, coinciding with the El Ni&#241;o event over the same period, covering an area equivalent to Australia. These findings suggest that more than 60% of coral reefs in the Pacific Ocean are located in regions where heating events may have been compounded by decreased potential for calcification. Given the continuing increase in atmospheric CO2, the severity of this type of compound events is bound to increase in the future.&#160;

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