Data from: Wind-driven emission of marine ice nucleating particles in the Scripps Ocean-Atmosphere Research Simulator (SOARS)
Data files
Jan 27, 2025 version files 3.36 MB
-
CHAOS_AFM_archive.txt
21.68 KB
-
CHAOS_bio_archive.txt
1.66 KB
-
CHAOS_CFDC_archive.txt
173.96 KB
-
CHAOS_CFDC_OPC_archive.txt
1.77 MB
-
CHAOS_channel_archive.txt
956.96 KB
-
CHAOS_fan_archive.txt
8.50 KB
-
CHAOS_IS_SSA_archive.txt
60.60 KB
-
CHAOS_IS_SW_archive.txt
12.54 KB
-
CHAOS_SEMS_APS_archive.txt
275.19 KB
-
CHAOS_SMPS_APS_archive.txt
65.10 KB
-
README.md
15.04 KB
Abstract
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. 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 observations during CHAOS showed an increasing relationship with wind speed, whereas offline CHAOS INP measurements 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 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.
README: Data from: Wind-driven Emission of Marine Ice Nucleating Particles in the Scripps Ocean-Atmosphere Research Simulator (SOARS)
https://doi.org/10.5061/dryad.1jwstqk4z
Overview of the campaign
The measurements archived here were collected using the Scripps Ocean-Atmosphere Research Simulator (SOARS) wind-wave channel at the Scripps Institution of Oceanography during the CHaracterizing Atmosphere-Ocean parameters in SOARS (CHAOS) study. The SOARS facility allows for the production of sea spray aerosol (SSA) in a controlled environment where individual biogeochemical parameters (wind speed, water biology and chemistry, air and water temperature) can be varied. The ability to control wind speed, in particular, is an advancement over previous wave channel experiments and increases the atmospheric relevance of the measurements. Results from CHAOS represent the first measurements obtained in the SOARS channel during July-August 2022, and focused on the impact of wind speed on SSA production.
Datasets
Processed data collected from a suite of instruments, along with metadata relevant to the CHAOS campaign as a whole, are archived here in separate .txt files (comma-delimited). The variables, units, and other details about each file are given below. All times are given in the local Pacific Daylight Time (PDT). Missing values for wind speeds in each file indicate measurements collected in the first ~15 minutes of each sampling period, prior to particle concentrations in SOARS reaching an approximate steady-state. Descriptions of each instrument, their measurement principles, and an overview of the data processing steps are outlined in the Methods section (2) of the corresponding manuscript.
Metadata for the CHAOS campaign
A list of the experimental periods from CHAOS that were used in this manuscript are given in the file: CHAOS_fan_archive.txt. A description of each variable in the file is given below:
Start_Time (MM/DD/YY HH:mm:SS): Start time of the experimental period
End_Time (MM/DD/YY HH:mm:SS): End time of the experimental period
Main_Fan_rpm (rpm): Speed of the main blower fans in SOARS
Makeup_Fan_rpm (rpm): Speed of the makeup blower fans in SOARS
Filter_On (unitless): 0=SOARS headspace filters are not being used, 1=SOARS headspace filters are being used to remove particles from the air stream
Waves_On (unitless): 0=waves are not turned on, 1=waves are turned on
Wave_Amplitude (unitless): Scaling factor for SOARS wave packet amplitude
Category (unitless): "Filter"=headspace filters are being used, "Waves"= waves are turned on, "Decay"=waves were previously on but have been stopped, "Wind"=main fans are turned on but waves are off.
Supplementary Meteorological and Oceanographic Measurements
SOARS Channel Continuous Measurements
Basic meteorological and oceanographic parameters measured continuously within the SOARS channel are listed in CHAOS_channel_archive.txt and further described in the manuscript Sec. 2.1. A description of each variable in the file is given below, and any missing values are indicated by NaN.
Time (MM/DD/YY HH:mm:SS): Time of the measurement
HeadSpaceAirTempCTR (degrees Celsius): Air temperature in the center of the SOARS channel
ChannelWaterTempCTR (degrees Celsius): Water temperature in the center of the SOARS channel
PracticalSalinity (PSU): Salinity in the SOARS channel
EastFanRPM (rpm): Speed of the East main blower fan in SOARS
WestFanRPM (rpm): Speed of the West main blower fan in SOARS
Seawater Biology and Chemistry
A selection of the biological and chemical measurements made on seawater collected from SOARS are given in CHAOS_bio_archive.txt and further described in the manuscript Sec. 2.1. A description of each variable in the file is given below, and any missing values are indicated by NaN.
Time (MM/DD/YY): Date of the measurement
TOC_uM (micro mole per liter): Total organic carbon concentration
Chla_ugL (microgram per liter): Chlorophyll a concentration
NO3_uM (micro mole per liter): Nitrate concentration
PO4_uM (micro mole per liter): Phosphate concentration
Sil_uM (micro mole per liter): Silicates concentration
NO2_uM (micro mole per liter): Nitrite concentration
NH4_uM (micro mole per liter): Ammonium concentration
Online Ice Nucleating Particle Measurements
Atmospheric ice nucleating particle (INP) concentrations measured with the Continuous Flow Diffusion Chamber (CFDC) are archived in CHAOS_CFDC_archive.txt and further described in the manuscript Sec. 2.2.1. A description of each variable in the file is given below, and any missing values are indicated by NaN.
Start_Time (MM/DD/YY HH:mm:SS.sss): Start time of the sample period
Stop_Time (MM/DD/YY HH:mm:SS.sss): End time of the sample period
INPs_SL (number per standard liter): Number of ice nucleating particles per standard liter of air (100 kPa, 0 degrees C)
Upper_CI_width (number per standard liter): 90% upper confidence interval width for number of ice nucleating particles per standard liter of air (100 kPa, 0 degrees C)
Lower_CI_width (number per standard liter): 90% lower confidence interval width for number of ice nucleating particles per standard liter of air (100 kPa, 0 degrees C)
Sample_Flow_slpm (standard liters per minute): Mean sample period air flow rate in the CFDC chamber (100 kPa, 0 degrees C)
SSw (percent): Mean sample period supersaturation with respect to water in the CFDC
Temp_C (degrees Celsius): Mean sample period temperature of the CFDC aerosol lamina
Pressure (mb): Mean sample period pressure inside the CFDC chamber
WS_U10 (meters per second): Wind speed in the SOARS channel, extrapolated to 10m
Offline Ice Nucleating Particle Measurements
Sea Spray Aerosol IS Measurements
Atmospheric INP concentrations from filter samples measured with the CSU Ice Spectrometer (IS) are given in CHAOS_IS_SSA_archive.txt and further described in the manuscript Sec. 2.2.2 and 2.2.3. A description of each variable in the file is given below, and any missing values are indicated by NaN. If blank-correction of the untreated (base) filter samples yielded INP concentrations below zero, those measurements have been removed. However, heat and peroxide treated (manuscript Sec. 2.2.3) filter samples with negative blank-corrected concentrations were retained to assist in calculation of INP composition. To allow for plotting on logarithmic axes, which is typical for this type of data, negative heat-treated concentrations were replaced by 0.00005 and negative peroxide treated concentrations with 0.000025 in the data file. The associated confidence interval widths are given as "NaN" and the samples are marked with the flag "BDL=1".
SampleName (unitless): Sample ID
Date (MM/DD/YY): Date of the measurement
WS_U10 (meters per second): Wind speed in the SOARS channel, extrapolated to 10m
Total_V_SL (standard liters): Total volume of air passed through filter (100 kPa, 0 degrees C)
Treatment (unitless): "Base"= untreated sample, "Heat"= heat treated sample (95 degrees C for 20 minutes), "Peroxide"=peroxide treated sample (10% H2O2 at 95 degrees C for 20 minutes under UV-B, then H2O2 decomposed with catalase)
Temp_C (degrees Celsius): Measurement temperature of IS
INPs_SL (number per standard liter): Number of ice nucleating particles per standard liter of air (100 kPa, 0 degrees C)
Lower_CI_width (number per standard liter): 95% lower confidence interval width for number of ice nucleating particles per standard liter of air (100 kPa, 0 degrees C)
Upper_CI_width (number per standard liter): 95% upper confidence interval width for number of ice nucleating particles per standard liter of air (100 kPa, 0 degrees C)
CI_overlap_zero (unitless): 0=measurement confidence interval does not overlap with zero, 1=measurement confidence interval does overlap with zero
BDL (unitless): 0=blank-corrected INP concentration is greater than 0, 1=blank-corrected INP concentration is less than 0. The BDL and CI_overlap_zero flags are mutually exclusive.
Seawater IS Measurements
Seawater ice nucleating entity (INE) concentrations measured with the CSU IS are given in CHAOS_IS_SW_archive.txt and further described in the manuscript Sec. 2.2.2. A description of each variable in the file is given below, and any missing values are indicated by NaN. If blank-correction of the samples yielded INP concentrations below zero, those measurements have been removed. Temperature spectra of seawater samples have been adjusted by +2 degrees Celsius to account for freezing point depression due to salinity.
SampleName (unitless): Sample ID
Date (MM/DD/YY): Date of the measurement
Treatment (unitless): "Base"= untreated sample, "Heat"= heat treated sample (95 degrees C for 20 minutes), "Peroxide"=peroxide treated sample (10% H2O2 at 95 degrees C for 20 minutes under UV-B, then H2O2 decomposed with catalase)
Temp_C (degrees Celsius): Measurement temperature of IS
INPs_mL (number per milliliter): Number of ice nucleating particles per milliliter of seawater
Lower_CI_width (number per milliliter): 95% lower confidence interval width for number of ice nucleating particles per milliliter of seawater
Upper_CI_width (number per milliliter): 95% upper confidence interval width for number of ice nucleating particles per milliliter of seawater
CI_overlap_zero (unitless): 0=measurement confidence interval does not overlap with zero, 1=measurement confidence interval does overlap with zero
Single Particle Atomic Force Microscopy of INPs
Ice nucleating particles collected in the CFDC were deposited onto silicon substrates and later analyzed by atomic force microscopy (AFM) to assess their physicochemical properties. The AFM data is archived in CHAOS_AFM_archive.txt and further described in the manuscript Sec. 2.2.4. A description of each variable in the file is given below, and any missing values are indicated by NaN.
Image_name (unitless): Image file name
Particle_Number (unitless): Particle sample ID in the image
Morphology_Desc (unitless): Description of the particle morphology
Morphology_Cat (unitless): Classification of the particle morphology into one of six categories: "rounded", "core-shell", "prism-like", "rod", "aggregate" or "irregular"
Vol_Eq_Diam_nm (nanometers): Volume equivalent diameter
OVF (unitless): Organic volume fraction
Org_Coat_Thickness (nanometers): Thickness of organic coating, if applicable
AR (unitless): Aspect ratio
Probe_Location (unitless): Where the AFM probe was placed to make the measurement. Options are: "center", "edge", "shell", or "shell inclusion".
VRD_RH20 (nanometers): Viscoelastic response distance at 20% RH
VRD_Std_RH20 (nanometers): Standard deviation of viscoelastic response distance at 20% RH
Phase_RH20 (unitless): Particle phase at 20% RH. Options are "solid", "semisolid", or "liquid".
VRD_RH60 (nanometers): Viscoelastic response distance at 60% RH
VRD_Std_RH60 (nanometers): Standard deviation of viscoelastic response distance at 60% RH
Phase_RH60 (unitless): Particle phase at 60% RH. Options are "solid", "semisolid", or "liquid".
WS_U10 (meters per second): Wind speed in the SOARS channel, extrapolated to 10m
Aerosol Particle Distributions
SMPS + APS Distributions
Aerosol concentrations and number size distributions were measured by multiple instruments, as described in the manuscript Sec. 2.3. Combined data from a TSI Scanning Mobility Particle Sizer (SMPS) and a TSI Aerodynamic Particle Sizer (APS) are given in CHAOS_SMPS_APS_archive.txt. A description of each variable in the file is given below, and any missing values are indicated by NaN.
Date (MM/DD/YYYY): Date of the measurement
WS_U10 (meters per second): Wind speed in the SOARS channel, extrapolated to 10m
N (number per cubic centimeter): Total aerosol number concentration across all sizes
n500 (number per cubic centimeter): Total aerosol number concentration for particles larger than 500 nm dry diameter
SA (micrometers squared per cubic centimeter): Total aerosol surface area concentration across all sizes
V (micrometers cubed per cubic centimeter): Total aerosol volume concentration across all sizes
N_xxx_um (number per cubic centimeter): Aerosol number concentration in a measurement bin, normalized by the difference of the log of the bin width (dN/dlogDp). The xxx in the variable name gives the geometric mean diameter of the bin in micrometers.
SEMS + APS Distributions
Combined data from a BMI Scanning Electrical Mobility Spectrometer (SEMS) and another TSI Aerodynamic Particle Sizer (APS) are given in CHAOS_SEMS_APS_archive.txt. A description of each variable in the file is given below, and any missing values are indicated by NaN.
Time (MM/DD/YY HH:mm:SS): Start time of the sample period (5 minutes)
WS_U10 (meters per second): Wind speed in the SOARS channel, extrapolated to 10m
N (number per cubic centimeter): Total aerosol number concentration across all sizes
n500 (number per cubic centimeter): Total aerosol number concentration for particles larger than 500 nm dry diameter
SA (micrometers squared per cubic centimeter): Total aerosol surface area concentration across all sizes
V (micrometers cubed per cubic centimeter): Total aerosol volume concentration across all sizes
N_xxx_um (number per cubic centimeter): Aerosol number concentration in a measurement bin, normalized by the difference of the log of the bin width (dN/dlogDp). The xxx in the variable name gives the geometric mean diameter of the bin in micrometers.
CDFC OPC Distributions
Aerosol data from the CFDC Optical Particle Counter (OPC) is archived in CHAOS_CFDC_OPC_archive.txt. A description of each variable in the file is given below, and any missing values are indicated by NaN. OPC integrated quantities (N, n500, SA, V) have been corrected based on simultaneous SEMS+APS data, as described in Sec. 2.3 of the manuscript.
Start_Time (MM/DD/YY HH:mm:SS.sss): Start time of the sample period
Stop_Time (MM/DD/YY HH:mm:SS.sss): End time of the sample period
WS_U10 (meters per second): Wind speed in the SOARS channel, extrapolated to 10m
OPC_N (number per cubic centimeter): Total aerosol number concentration across all sizes
OPC_n500 (number per cubic centimeter): Total aerosol number concentration for particles larger than 500 nm dry diameter
OPC_SA (micrometers squared per cubic centimeter): Total aerosol surface area concentration across all sizes
OPC_V (micrometers cubed per cubic centimeter): Total aerosol volume concentration across all sizes
N_xxx_um: (number per cubic centimeter): Aerosol number concentration in a measurement bin, normalized by the difference of the log of the bin width (dN/dlogDp). The xxx in the variable name gives the geometric mean diameter of the bin in micrometers.