scholarly journals Supplementary material to "Environmental Effects on Aerosol-Cloud Interaction in non-precipitating MBL Clouds over the Eastern North Atlantic"

2021 ◽  
Author(s):  
Xiaojian Zheng ◽  
Baike Xi ◽  
Xiquan Dong ◽  
Peng Wu
Keyword(s):  
North Atlantic ◽  
Environmental Effects ◽  
Aerosol Cloud ◽  
Supplementary Material ◽  
Eastern North Atlantic

scholarly journals Environmental Effects on Aerosol-Cloud Interaction in non-precipitating MBL Clouds over the Eastern North Atlantic

2021 ◽  
Author(s):  
Xiaojian Zheng ◽  
Baike Xi ◽  
Xiquan Dong ◽  
Peng Wu
Keyword(s):  
Boundary Layer ◽  
Water Vapor ◽  
North Atlantic ◽  
Environmental Effects ◽  
Cloud Droplet ◽  
Strong Impact ◽  
Aerosol Cloud ◽  
Eastern North Atlantic ◽  
Condensational Growth ◽  
Relative Change

Abstract. Over the eastern north Atlantic (ENA) ocean, a total of 20 non-precipitating single-layer marine boundary layer (MBL) stratus and stratocumulus cloud cases are selected in order to investigate the impacts of the environmental variables on the aerosol-cloud interaction (ACIr) using the ground-based measurements from the Department of Energy Atmospheric Radiation Measurement (ARM) facility at the ENA site during the period 2016–2018. The ACIr represents the relative change of cloud-droplet effective radius re with respect to the relative change of cloud condensation nuclei (CCN) number concentration at 0.2 % supersaturation (NCCN,0.2 %) in the water vapor stratified environment. The ACIr values vary from −0.004 to 0.207 with increasing precipitable water vapor (PWV) conditions, indicating that re is more sensitive to the CCN loading under sufficient water vapor supply, owing to the combined effect of enhanced condensational growth and coalescence processes associated with higher NC and PWV. The environmental effects on ACIr are examined by stratifying the data into different lower tropospheric stability (LTS) and vertical component of turbulence kinetic energy (TKEw) regimes. The higher LTS normally associates with a more adiabatic cloud layer and a lower boundary layer and thus results in higher CCN to cloud droplet conversion and ACIr. The ACIr values under a range of PWV double from low TKEw to high TKEw regime, indicating a strong impact of turbulence on the ACIr. The stronger boundary layer turbulence represented by higher TKEw strengthens the connection and interaction between cloud microphysical properties and the underneath CCN and moisture sources. With sufficient water vapor and low CCN loading, the active coalescence process broadens the cloud droplet size distribution spectra, and consequently results in an enlargement of re. The enhanced NC conversion and condensational growth induced by more intrusions of CCN effectively decrease re, which jointly presents as the increased ACIr. The TKEw median value of 0.08 m2 s−2 suggests a feasible way in distinguishing the turbulence-enhanced aerosol-cloud interaction in non-precipitating MBL clouds.

scholarly journals Environmental effects on aerosol–cloud interaction in non-precipitating marine boundary layer (MBL) clouds over the eastern North Atlantic

2022 ◽  
Vol 22 (1) ◽  
pp. 335-354
Author(s):  
Xiaojian Zheng ◽  
Baike Xi ◽  
Xiquan Dong ◽  
Peng Wu ◽  
Timothy Logan ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Water Vapor ◽  
North Atlantic ◽  
Environmental Effects ◽  
Marine Boundary Layer ◽  
Cloud Droplet ◽  
Aerosol Cloud ◽  
Eastern North Atlantic ◽  
Condensational Growth ◽  
Relative Change

Abstract. Over the eastern North Atlantic (ENA) ocean, a total of 20 non-precipitating single-layer marine boundary layer (MBL) stratus and stratocumulus cloud cases are selected to investigate the impacts of the environmental variables on the aerosol–cloud interaction (ACIr) using the ground-based measurements from the Department of Energy Atmospheric Radiation Measurement (ARM) facility at the ENA site during 2016–2018. The ACIr represents the relative change in cloud droplet effective radius re with respect to the relative change in cloud condensation nuclei (CCN) number concentration at 0.2 % supersaturation (NCCN,0.2 %) in the stratified water vapor environment. The ACIr values vary from −0.01 to 0.22 with increasing sub-cloud boundary layer precipitable water vapor (PWVBL) conditions, indicating that re is more sensitive to the CCN loading under sufficient water vapor supply, owing to the combined effect of enhanced condensational growth and coalescence processes associated with higher Nc and PWVBL. The principal component analysis shows that the most pronounced pattern during the selected cases is the co-variations in the MBL conditions characterized by the vertical component of turbulence kinetic energy (TKEw), the decoupling index (Di), and PWVBL. The environmental effects on ACIr emerge after the data are stratified into different TKEw regimes. The ACIr values, under both lower and higher PWVBL conditions, more than double from the low-TKEw to high-TKEw regime. This can be explained by the fact that stronger boundary layer turbulence maintains a well-mixed MBL, strengthening the connection between cloud microphysical properties and the below-cloud CCN and moisture sources. With sufficient water vapor and low CCN loading, the active coalescence process broadens the cloud droplet size spectra and consequently results in an enlargement of re. The enhanced activation of CCN and the cloud droplet condensational growth induced by the higher below-cloud CCN loading can effectively decrease re, which jointly presents as the increased ACIr. This study examines the importance of environmental effects on the ACIr assessments and provides observational constraints to future model evaluations of aerosol–cloud interactions.

scholarly journals Supplementary material to "Factors controlling the depth habitat of planktonic foraminifera in the subtropical eastern North Atlantic"

2016 ◽  
Author(s):  
Andreia Rebotim ◽  
Antje H. L. Voelker ◽  
Lukas Jonkers ◽  
Joanna J. Waniek ◽  
Helge Meggers ◽  
...  
Keyword(s):  
North Atlantic ◽  
Planktonic Foraminifera ◽  
Supplementary Material ◽  
Eastern North Atlantic

scholarly journals Supplementary material to "Aircraft measurements of aerosol and trace gas chemistry in the Eastern North Atlantic"

2020 ◽  
Author(s):  
Maria A. Zawadowicz ◽  
Kaitlyn Suski ◽  
Jiumeng Liu ◽  
Mikhail Pekour ◽  
Jerome Fast ◽  
...  
Keyword(s):  
North Atlantic ◽  
Trace Gas ◽  
Aircraft Measurements ◽  
Gas Chemistry ◽  
Supplementary Material ◽  
Eastern North Atlantic

Temperature, Salinity and Plankton in the Eastern North Atlantic and Coastal Waters of Britain, 1957.: I. The Characterisation and Distribution of Surface Waters

1963 ◽  
Vol 20 (3) ◽  
pp. 789-826 ◽  
Author(s):  
B. McK. Bary
Keyword(s):  
North Sea ◽  
North Atlantic ◽  
Coastal Waters ◽  
Water Bodies ◽  
English Channel ◽  
Oceanic Water ◽  
Climatic Fluctuations ◽  
The North ◽  
The North Sea ◽  
Eastern North Atlantic

Monthly temperature-salinity diagrams for 1957 have demonstrated that three surface oceanic "water bodies" were consistently present in the eastern North Atlantic; two are regarded as modified North Atlantic Central water which give rise to the third by mixing. As well in the oceanic areas, large and small, high or low salinity patches of water were common. Effects of seasonal climatic fluctuations differed in the several oceanic water bodies. In coastal waters, differences in properties and in seasonal and annual cycles of the properties distinguish the waters from the North Sea, English Channel and the western entrance to the Channel.The geographic distributions of the oceanic waters are consistent with "northern" and "southern" water bodies mixing to form a "transitional" water. Within this distribution there are short-term changes in boundaries and long-term (seasonal) changes in size of the water bodies.Water in the western approaches to the English Channel appeared to be influenced chiefly by the mixed, oceanic transitional water; oceanic influences in the North Sea appear to have been from northern and transitional waters.

A longitudinal study of humpback whales in Irish waters

2015 ◽  
Vol 96 (4) ◽  
pp. 877-883 ◽  
Author(s):  
Conor Ryan ◽  
Pádraig Whooley ◽  
Simon D. Berrow ◽  
Colin Barnes ◽  
Nick Massett ◽  
...  
Keyword(s):  
Longitudinal Study ◽  
North Atlantic ◽  
Spatial Scales ◽  
Humpback Whales ◽  
Migratory Species ◽  
The Public ◽  
Photo Identification ◽  
The North ◽  
Breeding Grounds ◽  
Eastern North Atlantic

Knowledge on the ecology of humpback whales in the eastern North Atlantic is lacking by comparison with most other ocean basins. Humpback whales were historically over-exploited in the region and are still found in low relative abundances. This, coupled with their large range makes them difficult to study. With the aim of informing more effective conservation measures in Ireland, the Irish Whale and Dolphin Group began recording sightings and images suitable for photo-identification of humpback whales from Irish waters in 1999. Validated records submitted by members of the public and data from dedicated surveys were analysed to form a longitudinal study of individually recognizable humpback whales. The distribution, relative abundance and seasonality of humpback whale sighting records are presented, revealing discrete important areas for humpback whales in Irish coastal waters. An annual easterly movement of humpback whales along the southern coast of Ireland is documented, mirroring that of their preferred prey: herring and sprat. Photo-identification images were compared with others collected throughout the North Atlantic (N = 8016), resulting in matches of two individuals between Ireland and Iceland, Norway and the Netherlands but no matches to known breeding grounds (Cape Verde and West Indies). This study demonstrates that combining public records with dedicated survey data is an effective approach to studying low-density, threatened migratory species over temporal and spatial scales that are relevant to conservation and management.

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