scholarly journals Observations of Aerosol‐Cloud Interactions During the North Atlantic Aerosol and Marine Ecosystem Study

2020 ◽  
Vol 47 (3) ◽  
Author(s):  
Kenneth Sinclair ◽  
Bastiaan Diedenhoven ◽  
Brian Cairns ◽  
Mikhail Alexandrov ◽  
Richard Moore ◽  
...  
Keyword(s):  
North Atlantic ◽  
Marine Ecosystem ◽  
Aerosol Cloud ◽  
The North ◽  
The North Atlantic ◽  
Aerosol Cloud Interactions

scholarly journals External forcing mechanisms controlling the North Atlantic coastal upwelling regime during the mid-Holocene

Geology ◽  
2020 ◽  
Author(s):  
Armand Hernández ◽  
Mário Cachão ◽  
Pedro Sousa ◽  
Ricardo M. Trigo ◽  
Jürg Luterbacher ◽  
...  
Keyword(s):  
North Atlantic ◽  
Coastal Upwelling ◽  
Marine Ecosystem ◽  
External Forcing ◽  
The North ◽  
New Findings ◽  
The North Atlantic ◽  
Eastern North Atlantic ◽  
Forcing Mechanisms ◽  
The Impact

Nearshore upwelling along the eastern North Atlantic margin regulates regional marine ecosystem productivity and thus impacts blue economies. While most global circulation models show an increase in the intensity and duration of seasonal upwelling at high latitudes under future human-induced warmer conditions, projections for the North Atlantic are still ambiguous. Due to the low temporal resolution of coastal upwelling records, little is known about the impact of natural forcing mechanisms on upwelling variability. Here, we present a microfossil-based proxy record and modeling simulations for the warmest period of the Holocene (ca. 9–5 ka) to estimate the contribution of the natural variability in North Atlantic upwelling via atmospheric and oceanic dynamics. We found that more frequent high-pressure conditions in the eastern North Atlantic associated with solar activity and orbital parameters triggered upwelling variations at multidecadal and millennial time scales, respectively. Our new findings offer insights into the role of external forcing mechanisms in upwelling changes before the Anthropocene, which must be considered when producing future projections of midlatitude upwelling activity.

scholarly journals The North Atlantic Aerosol and Marine Ecosystem Study (NAAMES): Science Motive and Mission Overview

2019 ◽  
Vol 6 ◽  
Author(s):  
Michael J. Behrenfeld ◽  
Richard H. Moore ◽  
Chris A. Hostetler ◽  
Jason Graff ◽  
Peter Gaube ◽  
...  
Keyword(s):  
North Atlantic ◽  
Marine Ecosystem ◽  
The North ◽  
The North Atlantic

scholarly journals Aerosols, clouds, and precipitation in the North Atlantic trades observed during the Barbados aerosol cloud experiment – Part 1: Distributions and variability

2016 ◽  
Vol 16 (13) ◽  
pp. 8643-8666 ◽  
Author(s):  
Eunsil Jung ◽  
Bruce A. Albrecht ◽  
Graham Feingold ◽  
Haflidi H. Jonsson ◽  
Patrick Chuang ◽  
...  
Keyword(s):  
Boundary Layer ◽  
North Atlantic ◽  
Cloud Base ◽  
Cumulus Clouds ◽  
Air Masses ◽  
Shallow Marine ◽  
Cloud Radar ◽  
Aerosol Cloud ◽  
The North ◽  
The North Atlantic

Abstract. Shallow marine cumulus clouds are by far the most frequently observed cloud type over the Earth's oceans; but they are poorly understood and have not been investigated as extensively as stratocumulus clouds. This study describes and discusses the properties and variations of aerosol, cloud, and precipitation associated with shallow marine cumulus clouds observed in the North Atlantic trades during a field campaign (Barbados Aerosol Cloud Experiment- BACEX, March–April 2010), which took place off Barbados where African dust periodically affects the region. The principal observing platform was the Center for Interdisciplinary Remotely Piloted Aircraft Studies (CIRPAS) Twin Otter (TO) research aircraft, which was equipped with standard meteorological instruments, a zenith pointing cloud radar and probes that measured aerosol, cloud, and precipitation characteristics.The temporal variation and vertical distribution of aerosols observed from the 15 flights, which included the most intense African dust event during all of 2010 in Barbados, showed a wide range of aerosol conditions. During dusty periods, aerosol concentrations increased substantially in the size range between 0.5 and 10 µm (diameter), particles that are large enough to be effective giant cloud condensation nuclei (CCN). The 10-day back trajectories showed three distinct air masses with distinct vertical structures associated with air masses originating in the Atlantic (typical maritime air mass with relatively low aerosol concentrations in the marine boundary layer), Africa (Saharan air layer), and mid-latitudes (continental pollution plumes). Despite the large differences in the total mass loading and the origin of the aerosols, the overall shapes of the aerosol particle size distributions were consistent, with the exception of the transition period.The TO was able to sample many clouds at various phases of growth. Maximum cloud depth observed was less than ∼ 3 km, while most clouds were less than 1 km deep. Clouds tend to precipitate when the cloud is thicker than 500–600 m. Distributions of cloud field characteristics (depth, radar reflectivity, Doppler velocity, precipitation) were well identified in the reflectivity–velocity diagram from the cloud radar observations. Two types of precipitation features were observed for shallow marine cumulus clouds that may impact boundary layer differently: first, a classic cloud-base precipitation where precipitation shafts were observed to emanate from the cloud base; second, cloud-top precipitation where precipitation shafts emanated mainly near the cloud tops, sometimes accompanied by precipitation near the cloud base. The second type of precipitation was more frequently observed during the experiment. Only 42–44 % of the clouds sampled were non-precipitating throughout the entire cloud layer and the rest of the clouds showed precipitation somewhere in the cloud, predominantly closer to the cloud top.

scholarly journals Tracking the movements of North Atlantic seabirds: steps towards a better understanding of population dynamics and marine ecosystem conservation

2021 ◽  
Vol 676 ◽  
pp. 97-116 ◽  
Author(s):  
H Strøm ◽  
S Descamps ◽  
M Ekker ◽  
P Fauchald ◽  
B Moe
Keyword(s):  
Population Dynamics ◽  
North Atlantic ◽  
Marine Ecosystem ◽  
Future Research ◽  
Original Research ◽  
Seabird Species ◽  
The North ◽  
Winter Distribution ◽  
Migration Strategies ◽  
The North Atlantic

Many seabird species undergo extensive seasonal migrations, often across large marine ecosystems or between marine areas under different national jurisdictions. With the advances of electronic tracking, especially of the application of Global Location Sensors (GLS or geolocators), it is now possible to study the seasonal movements of seabirds and link breeding populations to non-breeding habitats. To take full advantage of this development for better management and conservation, and to broaden the scope of scientific questions that can be assessed, there is a need for large-scale and multi-species programmes. The SEATRACK project with partners from 10 countries is ongoing and aims to identify the year-round distribution and movements of seabirds breeding in colonies across the northern part of the North Atlantic. By 2020, 14534 loggers were deployed on 11 species, and data from 5440 retrieved loggers have been analyzed and compiled. This Theme Section assembles original research articles based on data collected as part of the SEATRACK project from 2014 to 2019. A series of 11 papers advances the knowledge within 4 research themes: (1) variation in migration strategies among individuals, populations and species; (2) linking migration strategies and winter distribution to seabird demography and population dynamics; (3) linking migration and winter distribution to contaminants in seabirds and (4) the use of GLS data in marine spatial planning. We review existing literature within SEATRACK’s 4 themes with a focus on the temperate and arctic zones of the North Atlantic to provide a framework within which to discuss the 11 contributions and provide recommendations for future research.

scholarly journals Capelin (Mallotus villosus) distribution and climate: a sea “canary” for marine ecosystem change

2005 ◽  
Vol 62 (7) ◽  
pp. 1524-1530 ◽  
Author(s):  
G.A. Rose
Keyword(s):  
Temperature Change ◽  
North Atlantic ◽  
Marine Ecosystem ◽  
Predatory Fish ◽  
Ecosystem Change ◽  
Monitoring Methods ◽  
Mallotus Villosus ◽  
The North ◽  
Capelin Mallotus Villosus ◽  
The North Atlantic

Abstract Capelin (Mallotus villosus) is a classic “r” adapted pelagic species that inhabits the northern boreal oceans at the margins of cold Arctic waters. The species originated in the North Pacific and colonized the North Atlantic at least once during interglacial periods of the past few million years. Capelin became the main forage species for many larger predatory fish, and also for seabirds and marine mammals. The colonizing abilities of capelin have been noted in historical anecdotes, typically in concert with climate variations. In this paper, all known shifts in distribution are catalogued. Shifts have taken place at the larval and adult stages, and some result in new spawning locations, others do not. Displacement distance relates to temperature change: log10(distancekm) = 0.28 × temperature change + 2.16 (p < 0.05, r2 = 0.91). The persistence of the shifts relates to the displacement distance: log10(persistencey) = 2.62 × log10(distancekm) − 6.56 (p < 0.05, r2 = 0.83). The quick and consistent response of capelin to temperature change, its importance to the North Atlantic foodweb, and established monitoring methods suggest this species as a sea “canary” for northern boreal marine ecosystem responses to climate variability and change.

scholarly journals Aerosols, Clouds, and Precipitation in the North-Atlantic Trades Observed During the Barbados Aerosol Cloud Experiment. Part I: Distributions and Variability

2016 ◽  
Author(s):  
Eunsil Jung ◽  
Bruce A. Albrecht ◽  
Graham Feingold ◽  
Haflidi H. Jonsson ◽  
Patrick Chuang ◽  
...  
Keyword(s):  
Boundary Layer ◽  
North Atlantic ◽  
Cloud Base ◽  
Cumulus Clouds ◽  
Air Masses ◽  
Shallow Marine ◽  
Cloud Radar ◽  
Aerosol Cloud ◽  
The North ◽  
The North Atlantic

Abstract. Shallow marine cumulus clouds are by far the most frequently observed cloud type over the Earth's oceans; but they are poorly understood and have not been investigated as extensively as stratocumulus clouds. This study describes and discusses the properties and variations of aerosol, cloud, and precipitation associated with shallow marine cumulus clouds observed in the North-Atlantic trades during a field campaign (Barbados Aerosol Cloud Experiment- BACEX, March–April, 2010), which took place off of Barbados where African dust periodically affects the region. The principal observing platform was the Center for Interdisciplinary Remotely Piloted Aircraft Studies (CIRPAS) Twin Otter (TO) research aircraft, which was equipped with standard meteorological instruments, a zenith pointing cloud radar and probes that measured aerosol, cloud, and precipitation characteristics. The temporal variation and vertical distribution of aerosols observed from the 15 flights, which included the most intense African dust event during all of 2010 at Barbados, showed a wide range of aerosol conditions. During dusty periods, aerosol concentrations increased substantially in the size range between 0.5 μm and 10 μm (diameter), particles that large enough to be effective giant cloud condensation nuclei (CCN). The 10-day back trajectories showed three distinct air masses with distinct vertical structures associated with air masses originating in the Atlantic (typical maritime air mass with relatively low aerosol concentrations in the marine boundary layer), Africa (Saharan Air Layer), and mid-latitudes (continental pollution plumes). Despite the large differences in the total mass loading and the origin of the aerosols, the overall shapes of the aerosol particle size distributions were consistent, with the exception of the transition period. The TO was able to sample many clouds at various phases of growth. Maximum cloud depth observed was less than ~ 3 km, while most clouds were less than 1 km deep. Clouds tend to precipitate when the cloud is thicker than 500–600 m. Distributions of cloud field characteristics (depth, radar reflectivity, Doppler velocity, precipitation) were well identified in the reflectivity-velocity diagram from the cloud radar observations. Two types of precipitation features were observed for shallow marine cumulus clouds that may impact boundary layer differently: first, a classic cloud-base precipitation where precipitation shafts were observed to emanate from the cloud base; second, cloud-top precipitation where precipitation shafts emanated mainly near the cloud tops, sometimes accompanied by precipitation near the cloud base. The second type of precipitation was more frequently observed during the experiment. Only 42–44 % of the clouds sampled were non-precipitating throughout the entire cloud layer and the rest of clouds showed precipitation somewhere in the cloud, predominantly closer to the cloud top.

scholarly journals Predictability of Seawater DMS During the North Atlantic Aerosol and Marine Ecosystem Study (NAAMES)

2021 ◽  
Vol 7 ◽  
Author(s):  
Thomas G. Bell ◽  
Jack G. Porter ◽  
Wei-Lei Wang ◽  
Michael J. Lawler ◽  
Emmanuel Boss ◽  
...  
Keyword(s):  
Neural Network ◽  
North Atlantic ◽  
Spatial Scales ◽  
Mixed Layer Depth ◽  
Marine Ecosystem ◽  
Seawater Temperature ◽  
Physical Factors ◽  
Substantial Impact ◽  
The North ◽  
The North Atlantic

This work presents an overview of a unique set of surface ocean dimethylsulfide (DMS) measurements from four shipboard field campaigns conducted during the North Atlantic Aerosol and Marine Ecosystem Study (NAAMES) project. Variations in surface seawater DMS are discussed in relation to biological and physical observations. Results are considered at a range of timescales (seasons to days) and spatial scales (regional to sub-mesoscale). Elevated DMS concentrations are generally associated with greater biological productivity, although chlorophyll a (Chl) only explains a small fraction of the DMS variability (15%). Physical factors that determine the location of oceanic temperature fronts and depth of vertical mixing have an important influence on seawater DMS concentrations during all seasons. The interplay of biomass and physics influences DMS concentrations at regional/seasonal scales and at smaller spatial and shorter temporal scales. Seawater DMS measurements are compared with the global seawater DMS climatology and predictions made using a recently published algorithm and by a neural network model. The climatology is successful at capturing the seasonal progression in average seawater DMS, but does not reproduce the shorter spatial/temporal scale variability. The input terms common to the algorithm and neural network approaches are biological (Chl) and physical (mixed layer depth, photosynthetically active radiation, seawater temperature). Both models predict the seasonal North Atlantic average seawater DMS trends better than the climatology. However, DMS concentrations tend to be under-predicted and the episodic occurrence of higher DMS concentrations is poorly predicted. The choice of climatological seawater DMS product makes a substantial impact on the estimated DMS flux into the North Atlantic atmosphere. These results suggest that additional input terms are needed to improve the predictive capability of current state-of-the-art approaches to estimating seawater DMS.

scholarly journals Predictability of seawater DMS during the North Atlantic Aerosol and Marine Ecosystem Study (NAAMES)

2021 ◽  
Author(s):  
Thomas Bell ◽  
Jack Porter ◽  
Wei-Lei Wang ◽  
Michael Lawler ◽  
Faith Hoyle ◽  
...  
Keyword(s):  
Neural Network ◽  
North Atlantic ◽  
Mixed Layer Depth ◽  
Marine Ecosystem ◽  
Seawater Temperature ◽  
Substantial Impact ◽  
The North ◽  
Current State ◽  
The North Atlantic ◽  
Network Approaches

&lt;p&gt;Surface ocean dimethylsulfide (DMS) was measured during four shipboard field campaigns conducted during the North Atlantic Aerosol and Marine Ecosystem Study (NAAMES). &amp;#160;Variations in surface seawater DMS are discussed in relation to biological and physical observations. The interplay of biomass and physics influences DMS concentrations at regional/seasonal scales and at smaller spatial and shorter temporal scales. Observations are compared with the best-available climatological predictions of seawater DMS, including output from an empirical algorithm and a neural network model. The input terms common to the algorithm and neural network approaches are biological (chlorophyll) and physical (mixed layer depth, photosynthetically active radiation, seawater temperature). DMS concentrations tend to be under-predicted and the episodic occurrence of higher DMS concentrations is poorly predicted. The choice of climatological seawater DMS product makes a substantial impact on the estimated DMS flux into the North Atlantic atmosphere. These results suggest that additional input terms are needed to improve the predictive capability of current state-of-the-art approaches to estimating seawater DMS.&lt;/p&gt;

The Northern Fulmar (Fulmarus glacialis) in Arctic Canada: ecology, threats, and what it tells us about marine environmental conditions

2006 ◽  
Vol 14 (3) ◽  
pp. 187-216 ◽  
Author(s):  
Mark L Mallory
Keyword(s):  
Climate Change ◽  
North Atlantic ◽  
Oil Spills ◽  
North Atlantic Ocean ◽  
Marine Ecosystem ◽  
The Arctic ◽  
Northern Fulmar ◽  
Fulmarus Glacialis ◽  
The North ◽  
The North Atlantic

The northern fulmar Fulmarus glacialis is a ubiquitous seabird found across the North Atlantic Ocean and into the Canadian Arctic. However, we know little of its ecology in the Arctic, which is unfortunate, because it possesses many traits that make it an excellent biomonitor of the condition of Arctic marine environments. Presently, Arctic fulmars face threats from harvest, bycatch in fisheries, and fouling in oil spills while the birds are in their winter range (the North Atlantic). However, during breeding, migration, and overwintering, they may also experience stress from ecotourism, contaminants, particulate garbage, and climate change. In this paper I review the effects of all of these threats on fulmars and I describe how the ecology of these birds makes them particularly suitable for tracking contaminants, garbage, and the effects of climate change in the Arctic marine ecosystem. I also highlight our key existing knowledge gaps on this species and how additional research will strengthen the utility of fulmars as biomonitors. Key words: northern fulmar, Fulmarus glacialis, Arctic, contaminants, climate change, pollution.

Sign in / Sign up

Export Citation Format

Share Document