Kathryn A. Moore

Low, mixed-phase clouds are common in polar regions and have a large impact on the surface radiative balance. One proposed method to mitigate warming during polar night is to add ice nucleating particles (INPs) to these clouds. The concept for this approach, known as mixed-phase cloud thinning (MCT), is that if liquid droplets are converted to ice particles, clouds might become optically thinner and could disappear faster, causing net cooling at both the surface and the top of the atmosphere (TOA) by decreasing downward longwave radiation to the surface and increasing longwave radiation escaping to space. However, this approach is still theoretical because modeled polar mixed-phase cloud processes are often not well-constrained.

Sea spray aerosol (SSA) represents one of the most abundant natural aerosol types, contributing significantly to global aerosol mass and aerosol optical depth, as well as to both the magnitude of and the uncertainty in aerosol radiative forcing. In addition to its direct effects, SSA can also serve as ice-nucleating particles (INPs), which are required for the initiation of cloud glaciation at temperatures warmer than ca. −36 °C. This study presents initial results from the CHaracterizing Atmosphere-Ocean parameters in SOARS (CHAOS) mesocosm campaign, which was conducted in the new Scripps Ocean-Atmosphere Research Simulator (SOARS) wind–wave channel. SOARS allows for isolation of individual factors, such as wave height, wind speed, water temperature, or biological state, and can carefully vary them in a controlled manner. Here, we focus on the influence of wind speed on the emission of SSA and INPs. In agreement with recent Southern Ocean measurements, online INP concentrations during CHAOS showed an increasing relationship with wind speed, whereas offline CHAOS INP concentrations did not, which may be related to sampling inlet differences. Changes in the INP activated fraction, dominant INP particle morphology, and INP composition were seen to vary with wind. Seawater ice-nucleating entity concentrations during CHAOS were stable over time, indicating that changes in atmospheric INPs were driven by wind speed and wave-breaking mechanics rather than variations in seawater chemistry or biology. While specific emission mechanisms remain elusive, these observations may help explain some of the variability in INP concentration and composition that has been seen in ambient measurements.

Sea spray aerosol (SSA) represent one of the most abundant natural aerosol types, contributing significantly to global aerosol mass and aerosol optical depth, as well as to both the magnitude and uncertainty of aerosol radiative forcing. In addition to their direct effects, SSA can also serve as ice nucleating particles (INPs), which are required for the initiation of cloud glaciation at temperatures warmer than ∼-36 °C. This study presents initial results from the CHaracterizing Atmosphere-Ocean parameters in SOARS (CHAOS) mesocosm campaign, which was conducted in the new Scripps Ocean-Atmosphere Research Simulator (SOARS) wind-wave channel at the Scripps Institution of Oceanography. SOARS allows for isolation of individual factors, such as wave height, wind speed, water temperature, or biological state, and can carefully vary them in a controlled manner. Here, we focus on the influence of wind speed on the emission of SSA and INPs. Unlike recent measurements from the Southern Ocean, real-time and offline INP observations during CHAOS exhibited opposite relationships with wind speed, which may be related to sampling inlet differences. Changes in the INP activated fraction, dominant INP particle morphology, and INP composition were seen to vary with wind. Seawater ice nucleating entity concentrations during CHAOS were stable over time, indicating changes in atmospheric INPs were driven by wind speed and wave-breaking mechanics rather than variations in seawater chemistry or biology. While specific emission mechanisms remain elusive, these observations may help explain some of the variability in INP concentration and composition that have been seen in ambient measurements.

Sea spray aerosol (SSA) represent one of the most abundant natural aerosol types, contributing significantly to global aerosol mass and aerosol optical depth, as well as to both the magnitude and uncertainty of aerosol radiative forcing. In addition to their direct effects, SSA can also serve as ice nucleating particles (INPs), which are required for the initiation of cloud glaciation at temperatures warmer than ∼-36 °C. This study presents initial results from the CHaracterizing Atmosphere-Ocean parameters in SOARS (CHAOS) mesocosm campaign, which was conducted in the new Scripps Ocean-Atmosphere Research Simulator (SOARS) wind-wave channel at the Scripps Institution of Oceanography. SOARS allows for isolation of individual factors, such as wave height, wind speed, water temperature, or biological state, and can carefully vary them in a controlled manner. Here, we focus on the influence of wind speed on the emission of SSA and INPs. Unlike recent measurements from the Southern Ocean, real-time and offline INP observations during CHAOS exhibited opposite relationships with wind speed, which may be related to sampling inlet differences. Changes in the INP activated fraction, dominant INP particle morphology, and INP composition were seen to vary with wind. Seawater ice nucleating entity concentrations during CHAOS were stable over time, indicating changes in atmospheric INPs were driven by wind speed and wave-breaking mechanics rather than variations in seawater chemistry or biology. While specific emission mechanisms remain elusive, these observations may help explain some of the variability in INP concentration and composition that have been seen in ambient measurements.

Sea spray aerosol (SSA) represent one of the most abundant natural aerosol types, contributing significantly to global aerosol mass and aerosol optical depth, as well as to both the magnitude and uncertainty of aerosol radiative forcing. In addition to their direct effects, SSA can also serve as ice nucleating particles (INPs), which are required for the initiation of cloud glaciation at temperatures warmer than ∼-36 °C. This study presents initial results from the CHaracterizing Atmosphere-Ocean parameters in SOARS (CHAOS) mesocosm campaign, which was conducted in the new Scripps Ocean-Atmosphere Research Simulator (SOARS) wind-wave channel at the Scripps Institution of Oceanography. SOARS allows for isolation of individual factors, such as wave height, wind speed, water temperature, or biological state, and can carefully vary them in a controlled manner. Here, we focus on the influence of wind speed on the emission of SSA and INPs. Unlike recent measurements from the Southern Ocean, real-time and offline INP observations during CHAOS exhibited opposite relationships with wind speed, which may be related to sampling inlet differences. Changes in the INP activated fraction, dominant INP particle morphology, and INP composition were seen to vary with wind. Seawater ice nucleating entity concentrations during CHAOS were stable over time, indicating changes in atmospheric INPs were driven by wind speed and wave-breaking mechanics rather than variations in seawater chemistry or biology. While specific emission mechanisms remain elusive, these observations may help explain some of the variability in INP concentration and composition that have been seen in ambient measurements.

Background: Glyoxal has been implicated as a significant contributor to the formation of secondary organic aerosols, which play a key role in our ability to estimate the impact of aerosols on climate. Elevated concentrations of glyoxal over remote ocean waters suggests that there is an additional source, distinct from urban and forest environments, which has yet to be identified. Herein, we demonstrate that the ocean can serve as an appreciable source of glyoxal in the atmosphere due to microbiological activity. Methods and Results: Based on mass spectrometric analyses of nascent sea spray aerosols and the sea surface microlayer (SSML) of naturally occurring algal blooms, we provide evidence that during the algae death phase phospholipids become enriched in the SSML and undergo autoxidation thereby generating glyoxal as a degradation product. Conclusions: We propose that the death phase of an algal bloom could serve as an important and currently missing source of glyoxal in the atmosphere.

Sea spray aerosol (SSA) represent one of the most abundant natural aerosol types, contributing significantly to global aerosol mass and aerosol optical depth, as well as to both the magnitude and uncertainty of aerosol radiative forcing. In addition to their direct effects, SSA can also serve as ice nucleating particles (INPs), which are required for the initiation of cloud glaciation at temperatures warmer than ∼-36 °C. This study presents initial results from the CHaracterizing Atmosphere-Ocean parameters in SOARS (CHAOS) mesocosm campaign, which was conducted in the new Scripps Ocean-Atmosphere Research Simulator (SOARS) wind-wave channel at the Scripps Institution of Oceanography. SOARS allows for isolation of individual factors, such as wave height, wind speed, water temperature, or biological state, and can carefully vary them in a controlled manner. Here, we focus on the influence of wind speed on the emission of SSA and INPs. Unlike recent measurements from the Southern Ocean, real-time and offline INP observations during CHAOS exhibited opposite relationships with wind speed, which may be related to sampling inlet differences. Changes in the INP activated fraction, dominant INP particle morphology, and INP composition were seen to vary with wind. Seawater ice nucleating entity concentrations during CHAOS were stable over time, indicating changes in atmospheric INPs were driven by wind speed and wave-breaking mechanics rather than variations in seawater chemistry or biology. While specific emission mechanisms remain elusive, these observations may help explain some of the variability in INP concentration and composition that have been seen in ambient measurements.

Sea spray aerosol (SSA) represent one of the most abundant natural aerosol types, contributing significantly to global aerosol mass and aerosol optical depth, as well as to both the magnitude and uncertainty of aerosol radiative forcing. In addition to their direct effects, SSA can also serve as ice nucleating particles (INPs), which are required for the initiation of cloud glaciation at temperatures warmer than ∼-36 °C. This study presents initial results from the CHaracterizing Atmosphere-Ocean parameters in SOARS (CHAOS) mesocosm campaign, which was conducted in the new Scripps Ocean-Atmosphere Research Simulator (SOARS) wind-wave channel at the Scripps Institution of Oceanography. SOARS allows for isolation of individual factors, such as wave height, wind speed, water temperature, or biological state, and can carefully vary them in a controlled manner. Here, we focus on the influence of wind speed on the emission of SSA and INPs. Unlike recent measurements from the Southern Ocean, real-time and offline INP observations during CHAOS exhibited opposite relationships with wind speed, which may be related to sampling inlet differences. Changes in the INP activated fraction, dominant INP particle morphology, and INP composition were seen to vary with wind. Seawater ice nucleating entity concentrations during CHAOS were stable over time, indicating changes in atmospheric INPs were driven by wind speed and wave-breaking mechanics rather than variations in seawater chemistry or biology. While specific emission mechanisms remain elusive, these observations may help explain some of the variability in INP concentration and composition that have been seen in ambient measurements.

Sea spray aerosol (SSA) represent one of the most abundant natural aerosol types, contributing significantly to global aerosol mass and aerosol optical depth, as well as to both the magnitude and uncertainty of aerosol radiative forcing. In addition to their direct effects, SSA can also serve as ice nucleating particles (INPs), which are required for the initiation of cloud glaciation at temperatures warmer than ∼-36 °C. This study presents initial results from the CHaracterizing Atmosphere-Ocean parameters in SOARS (CHAOS) mesocosm campaign, which was conducted in the new Scripps Ocean-Atmosphere Research Simulator (SOARS) wind-wave channel at the Scripps Institution of Oceanography. SOARS allows for isolation of individual factors, such as wave height, wind speed, water temperature, or biological state, and can carefully vary them in a controlled manner. Here, we focus on the influence of wind speed on the emission of SSA and INPs. Unlike recent measurements from the Southern Ocean, real-time and offline INP observations during CHAOS exhibited opposite relationships with wind speed, which may be related to sampling inlet differences. Changes in the INP activated fraction, dominant INP particle morphology, and INP composition were seen to vary with wind. Seawater ice nucleating entity concentrations during CHAOS were stable over time, indicating changes in atmospheric INPs were driven by wind speed and wave-breaking mechanics rather than variations in seawater chemistry or biology. While specific emission mechanisms remain elusive, these observations may help explain some of the variability in INP concentration and composition that have been seen in ambient measurements.

Sea spray aerosol (SSA) represent one of the most abundant natural aerosol types, contributing significantly to global aerosol mass and aerosol optical depth, as well as to both the magnitude and uncertainty of aerosol radiative forcing. In addition to their direct effects, SSA can also serve as ice nucleating particles (INPs), which are required for the initiation of cloud glaciation at temperatures warmer than ∼-36 °C. This study presents initial results from the CHaracterizing Atmosphere-Ocean parameters in SOARS (CHAOS) mesocosm campaign, which was conducted in the new Scripps Ocean-Atmosphere Research Simulator (SOARS) wind-wave channel at the Scripps Institution of Oceanography. SOARS allows for isolation of individual factors, such as wave height, wind speed, water temperature, or biological state, and can carefully vary them in a controlled manner. Here, we focus on the influence of wind speed on the emission of SSA and INPs. Unlike recent measurements from the Southern Ocean, real-time and offline INP observations during CHAOS exhibited opposite relationships with wind speed, which may be related to sampling inlet differences. Changes in the INP activated fraction, dominant INP particle morphology, and INP composition were seen to vary with wind. Seawater ice nucleating entity concentrations during CHAOS were stable over time, indicating changes in atmospheric INPs were driven by wind speed and wave-breaking mechanics rather than variations in seawater chemistry or biology. While specific emission mechanisms remain elusive, these observations may help explain some of the variability in INP concentration and composition that have been seen in ambient measurements.