Drivers of Cloud Condensation Nuclei in the Eastern North Atlantic DOI Open Access
Virendra P. Ghate,

Thomas E. Surleta,

Leehi Magaritz‐Ronen

et al.

Authorea (Authorea), Journal Year: 2023, Volume and Issue: unknown

Published: Oct. 26, 2023

Seven years of data collected at the Atmospheric Radiation Measurement (ARM)’s Eastern North Atlantic (ENA) site are analyzed to understand controls Cloud Condensation Nuclei (CCN) concentrations in region. Day-night differences aerosol as segregated by wind direction demonstrated observations be impacted local emissions when (wdir) is between 90° and 310° (measured clockwise from where air coming from). Data during marine conditions (wdir<90° or wdir>310°) showed CCN higher summer months compared winter months. budget analysis revealed advection precipitation scavenging being primarily responsible for modulating on monthly timescales, with rain rates driving term. High (greater than 75th percentile) low (lower 25th events were identified each month characterize sub-monthly variability concentrations. Low had deeper clouds, stronger rates, lower free-tropospheric mass ENA high events. Analysis satellite air-parcels 48 hours prior their arrival parcels encounter cloudiness, cloud top heights The results presented herein provide key constraints model evaluation studies climatological conducted site.

Language: Английский

Aerosol‐Correlated Cloud Activation for Clean Conditions in the Tropical Atlantic Boundary Layer During LASIC DOI Creative Commons
Jeramy L. Dedrick, Lynn M. Russell, Arthur J. Sedlacek

et al.

Geophysical Research Letters, Journal Year: 2024, Volume and Issue: 51(3)

Published: Feb. 3, 2024

Abstract Aerosol measurements during the DOE ARM Layered Atlantic Smoke Interactions with Clouds (LASIC) campaign were used to quantify differences between clean and smoky cloud condensation nuclei (CCN) budgets. Accumulation‐mode particles accounted for ∼70% of CCN at supersaturations <0.3% in conditions. Aitken‐mode contributed <20% sea‐spray‐mode <10% <0.3%, but >0.3% Aitken contributions increased 30%–40% CCN. For conditions, Hoppel minimum diameter was correlated accumulation‐mode number concentration, indicating aerosol‐correlated activation controlling lower cutoff which serve as increase correlation is masked by lower‐hygroscopicity smoke. These results provide first multi‐month situ quantitative constraints on role aerosol size distributions tropical boundary layer.

Language: Английский

Citations

6
Ice nucleating particle sources and transports between the Central and Southern Arctic regions during winter cold air outbreaks DOI Creative Commons
Paul J. DeMott, Benjamin E. Swanson, Jessie M. Creamean

et al.

Elementa Science of the Anthropocene, Journal Year: 2025, Volume and Issue: 13(1)

Published: Jan. 1, 2025

Ice nucleating particles (INPs) initiate ice formation, affecting the liquid versus distribution and radiative properties of clouds. INPs have been measured around Arctic, but few INP concentration measurements reported for air during movement south out central Arctic pack regions cold outbreaks (CAOs). We analyzed cases transports connecting Central location Multidisciplinary Drifting Observatory Study Climate (MOSAiC) expedition to near sea edge in Svalbard across ice-free ocean Cold-air Outbreaks Marine Boundary Layer Experiment (COMBLE) site at Andenes, Norway, 2019–2020 winter. Aerosol surface area CAOs indicate a switch from primarily accumulation mode MOSAiC toward marine coarse (from spray emissions) COMBLE. concentrations were independent aerosol or volume over At Svalbard, related best supermicron volume. COMBLE site, with total In 5 6 case studies analyzed, increased association transition dominance aerosols. The had unique −18°C higher nucleation active densities (e.g., per area) compared those previously other open dominated by While sources this appear be oceanic emissions shallower oceans under turbid water conditions, attribution solely aerosols mixing down free tropospheric CAO clouds remains as future topic. These provide basis parameterization numerical modeling cloud systems.

Language: Английский

Citations

0
Aerosol size distribution properties associated with cold-air outbreaks in the Norwegian Arctic DOI Creative Commons
A. Williams, Jeramy L. Dedrick, Lynn M. Russell

et al.

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(20), P. 11791 - 11805

Published: Oct. 23, 2024

Abstract. The aerosol particles serving as cloud condensation and ice nuclei contribute to key processes associated with cold-air outbreak (CAO) events but are poorly constrained in climate models due sparse observations. Here we retrieve number size distribution modes from measurements at Andenes, Norway, during the Cold-Air Outbreaks Marine Boundary Layer Experiment (COMBLE) Zeppelin Observatory, approximately 1000 km upwind Andenes Svalbard. During CAO sea-spray-mode concentration is correlated strong over-ocean winds a mean of 8±4 cm−3 that 71 % higher than non-CAO conditions. Additionally, Hoppel minimum diameter 6 nm smaller conditions, though estimated supersaturation lower, likely activated in-cloud 109±61 no statistically significant difference 99±66 cm−3. For trajectories between Observatory upwind-to-downwind change largest for accumulation mode decrease 93±95 cm−3, attributable primarily precipitation scavenging. These characteristic properties distributions provide guidance evaluating aerosol–cloud interaction models.

Language: Английский

Citations

3
Parameterizations for sea spray aerosol production flux DOI

Aijing Song,

Jianlong Li, Narcisse T. Tsona

et al.

Applied Geochemistry, Journal Year: 2023, Volume and Issue: 157, P. 105776 - 105776

Published: Aug. 24, 2023

Language: Английский

Citations

8
Biomass-burning smoke's properties and its interactions with marine stratocumulus clouds in WRF-CAM5 and southeastern Atlantic field campaigns DOI Creative Commons
Calvin Howes, Pablo E. Saide, Hugh Coe

et al.

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(21), P. 13911 - 13940

Published: Nov. 8, 2023

Abstract. A large part of the uncertainty in climate projections comes from uncertain aerosol properties and aerosol–cloud interactions as well difficulty remotely sensing them. The southeastern Atlantic functions a natural laboratory to study biomass-burning smoke constrain this uncertainty. We address these gaps by comparing Weather Research Forecasting with Chemistry Community Atmosphere Model (WRF-CAM5) multi-campaign observations ORACLES (ObseRvations Aerosols above CLouds their intEractionS), CLARIFY (CLoud–Aerosol–Radiation Interaction Forcing), LASIC (Layered Smoke Interactions Clouds) August 2017 evaluate range model's chemical properties, size distributions, processes, transport, interactions. Overall, while WRF-CAM5 is able represent some key discrepancies highlight need for further analysis. Observations composition show an overall decrease mean diameter ages over 4–12 d, model lacks trend. mass ratio organic (OA) black carbon (BC), OA:BC, OA monoxide (CO) mixing ratio, OA:CO, suggests that missing processes selectively remove particle phase, such photolysis heterogeneous chemistry. (factor ∼2.5) enhancement sulfate free troposphere (FT) boundary layer (BL) not present model, pointing importance properly representing secondary formation marine dimethyl sulfide gaseous SO2 emissions. shows persistent overprediction aerosols (MBL), especially clean conditions, which multiple pieces evidence link weaker removal modeled MBL than reality. This includes several features, observed shifts towards smaller diameters, inaccurate concentration ratios carbon, underprediction heavy rain events, little biases entrainment. average below-cloud activation fraction (NCLD/NAER) remains relatively constant between field campaigns (∼0.65), it decreases substantially (∼0.78) (∼0.5), could be due misrepresentation conditions. also overshoots upper limit on liquid cloud droplet around NCLD= 400–500 cm−3 overpredicts spread NCLD. related often drastically overestimating strength vertical turbulence up factor 10. expect results motivate similar evaluations other modeling systems promote development reduce critical uncertainties simulations.

Language: Английский

Citations

3
Assessing Radiative Impacts of African Smoke Aerosols over the Southeastern Atlantic Ocean DOI Open Access
Timothy Logan, Xiquan Dong, Baike Xi

et al.

Authorea (Authorea), Journal Year: 2023, Volume and Issue: unknown

Published: June 23, 2023

Biomass burning smoke aerosols exhibit complex impacts on the temperature profile of atmosphere and cloud development. Central Africa is a region where are constantly being transported westward over remote southeastern Atlantic Ocean. A dedicated measurement platform located Ascension Island, maintained by U. S. Department Energy, observed several plumes biomass during 2016 2017 austral burn season months. It was found that displayed different radiative properties while readily activating as condensation nuclei. An anomalously strong African Easterly Jet responsible for facilitating extreme fire conditions in 2016. During season, an weaker jet led to more mixing mineral dust marine which were efficient at cooling than

Language: Английский

Citations

1
Assessing Radiative Impacts of African Smoke Aerosols Over the Southeastern Atlantic Ocean DOI Creative Commons
Timothy Logan, Xiquan Dong, Baike Xi

et al.

Earth and Space Science, Journal Year: 2024, Volume and Issue: 11(4)

Published: April 1, 2024

Abstract Biomass burning smoke aerosols are efficient at attenuating incoming solar radiation. The Layered Atlantic Smoke Interactions with Clouds campaign was conducted from June 2016 to October 2017. U. S. Department of Energy mobile Atmospheric Radiation Measurement site located on Ascension Island (AMF‐ASI) identified several instances plume intrusions. Increases in surface and column measurements aerosol loading were directly related increases fine mode fraction, number concentrations ( N a ), cloud condensation nuclei CCN ). During periods weak lower tropospheric stability, particles more likely be advected downward either by boundary layer turbulence or top entrainment under non‐overcast sky conditions. Backward trajectory analysis illustrated that reaching the AMF‐ASI mode, less aged, strongly absorbing, had shorter trajectories while longer denoted mixtures weakly absorbing coarse marine aerosols. most polluted cases August 2017 revealed notable contrast radiative forcing per unit optical depth efficiency (Δ F eff ) atmosphere (TOA) near‐surface (BOA). (strongly) exhibited weaker (stronger) Δ TOA BOA suggesting warming (cooling) effect within layer. featured strongest cooling due mixing fresh during transport.

Language: Английский

Citations

0
Drivers of Cloud Condensation Nuclei in the Eastern North Atlantic DOI Open Access
Virendra P. Ghate,

Thomas E. Surleta,

Leehi Magaritz‐Ronen

et al.

Authorea (Authorea), Journal Year: 2023, Volume and Issue: unknown

Published: Oct. 26, 2023

Seven years of data collected at the Atmospheric Radiation Measurement (ARM)’s Eastern North Atlantic (ENA) site are analyzed to understand controls Cloud Condensation Nuclei (CCN) concentrations in region. Day-night differences aerosol as segregated by wind direction demonstrated observations be impacted local emissions when (wdir) is between 90° and 310° (measured clockwise from where air coming from). Data during marine conditions (wdir<90° or wdir>310°) showed CCN higher summer months compared winter months. budget analysis revealed advection precipitation scavenging being primarily responsible for modulating on monthly timescales, with rain rates driving term. High (greater than 75th percentile) low (lower 25th events were identified each month characterize sub-monthly variability concentrations. Low had deeper clouds, stronger rates, lower free-tropospheric mass ENA high events. Analysis satellite air-parcels 48 hours prior their arrival parcels encounter cloudiness, cloud top heights The results presented herein provide key constraints model evaluation studies climatological conducted site.

Language: Английский

Citations

0