Aerosol, Radiation, Meteorological, and Satellite Measurements 2019-2022, part of
the collection "Meteorological and Aerosol Measurements near the Salton Sea,
California".

Cite as:
Kuwano, Alexandra; Evan, Amato T.; Frouin, Robert; Barbero, Tyler (2024). Aerosol,
Radiation, Meteorological, and Satellite Measurements 2019-2022. In Meteorological and
Aerosol Measurements near the Salton Sea, California. UC San Diego Library Digital
Collections. https://doi.org/10.6075/J00Z73G8

Corresponding author:
Amato Evan, aevan@ucsd.edu

Primary associated publication:
Kuwano, A. M., Evan, A., Walkowiak, B., and Frouin, R. (2024). Quantifying the
dust direct radiative effect in the Southwestern United States: findings from
multiyear measurements, Atmos. Chem. Phys. Discuss. [preprint],
https://doi.org/10.5194/acp-2024-1, in review.

Methods:

Aerosol, radiometric, meteorological, and satellite measurements are collected from
various instrumentation at at a sub-sea level field site located near the western
shoreline of the Salton Sea, California (33.169011 N, -115.855960 E and -32 m AMSL)
from November 2019 through December 2022 during clear-sky, daytime, and both dusty
and non-dusty conditions. Specific details for each product are as follows:

Aerosol products are obtained from a CIMEL sun photometer from the NASA Aerosol
Robotic Network (AERONET). Here level 1.5 AERONET data processed by the version 3
AERONET algorithm is obtained. Also included are dusty observations that were
erroneously classified as being cloudy as described and investigated in
Evan et al. (2022), 'On the Misclassification of Dust as Cloud at an AERONET Site
in the Sonoran Desert'
(https://journals.ametsoc.org/view/journals/atot/39/2/JTECH-D-21-0114.1.xml?tab_body=supplementary-materials).
All level 1.5 AERONET data have been filtered for clouds via the AERONET algorithm.
These data are collected at a 5-15 minute temporal resolution.

Surface radiometric products are obtained from two Kipp and Zonen pyranometers and
pyrgeometers mounted at this field site, and the full, all-sky dataset can be obtained
from the "Measurements from Radiometers" data set in this collection (https://doi.org/10.6075/J04Q7V6M).
All data prior to 4/1/2020 were originally logged at 1 second intervals and later
converted to 1 minute averages. Currently all data are averaged over 1 minute temporal
intervals and, in this dataset, are temporally collocated to the AERONET data (i.e.
are within 1 minute of each AERONET retrieval). The radiometers are positioned such
that one pyranometer and pyrgeometer are upward and downward facing to collect net shortwave (SW)
and longwave (LW) flux. The upward facing instruments are outfitted with Kipp and Zonen CV2
unit covers while the downward facing radiometers are outfitted with Kipp and Zonen
glare screens, which have an angle of 5 degrees that shield direct sunlight during
sunrise/sunset. The pyranometers and pyrgeometers are situated side by side. The
pyranometer models and serial numbers are CM21 051475 and 051563, while the pyrgeometer
models and serial numbers are CGR4 0060013 and CG4 050764. Radiometric data are
logged via the Kipp and Zonen LOGBOX SE and the Kipp and Zonen LOGBOX SE-software
software. The CGR4 and CG4 pyrgeometers are always oriented upward and downward
facing, respectively. Before and after September 2021 the CM21 051475 pyranometer
was downward and upward facing, respectively. Before and after September 2021 the
CM21 051563 pyranometer was upward and downward facing, respectively. Further details
on the calibration and application of this data are featured in Kuwano et al. (2024).

Satellite measurements are obtained from the Clouds and Earth's Radiant Energy System
(CERES) Single Scanner Footprint (SSF) level 2 data product obtained from the NASA
Aqua, Terra, National Oceanic and Atmospheric (NOAA) Suomi National Polar-orbiting
Partnership (NPP) and NOAA-20 sun-synchronous satellites. Data from this website
can be obtained from https://ceres.larc.nasa.gov/data/ or https://subset.larc.nasa.gov/ceres/,
referenced via Wielicki, et al. (1996), 'Clouds and the Earth's Radiant Energy System (CERES):
An Earth observing system experiment'. These data are obtained instantaneously (i.e.
along-track of the satellite movement) and further averaged over 1-minute intervals.
These data are also filtered for day-time and cloud-free conditions. Cloud-free
conditions are determined from the clear-sky fraction from the CERES data product
(>=95%). Satellite measurements are obtained with a field-of-view (FOV) footprint
center within 25 km of the field site and within 30 minutes of the closest AERONET
retrieval. Further details are described in Kuwano et al. (2024).

Meteorological products include particulate matter with diameters under 10 microns (PM10),
accessed from the California Air Resources Board at https://www.arb.ca.gov/aqmis2/aqdselect.php
for the Naval Test Base, Niland English Road, Salton City, and Sonny Bono stations. These data 
are obtained on an hourly temporal resolution. Here, these data are temporally collocated to 
AERONET retrievals by repeating the PM10 value within the same hour of the AERONET measurements.
Here the PM10 data are not averaged or altered.

Also included are two masks, identifying which AERONET measurements are classified
as being dusty or cloudy. Briefly, potential dust times were selected via analysis
of ceilometer backscatter profiles where there was a strong (>3 a.u.) and persistent
(>30 minutes) profile extending from the surface to 500-3000 m. From these times,
dust is further identified when AERONET fine-mode-fraction < 0.5 or, when not available,
AERONET angstrom exponent 440-870nm <= 0.25, and PM10 from at least one station
is >= 50 ug m^-3. The cloud mask is an extra cloud identifier for this dataset and
a cloud is assumed if the cloud base height, as determined by the ceilometer
software's cloud detection algorithm, is <= 2 km AGL and within a 30 minute window
of an AERONET measurement. Ceilometer data are obtained from the Vaisala ceilometer
mounted at the field site, of which the full ceilometer dataset can be obtained
in this collection. Further details of these methods are presented in
 Kuwano et al. (2024).

Description of contents:

Aerosol, radiometric, meteorological, and satellite measurements are combined into
a single .csv file with columns corresponding to a variable with the details for
each variable listed below with the product type (as ordered from left to right):

'date_time_aeronet'                 [AERONET date-time in "dd-MM-yyyy HH:mm:ss Z" format in UTC]
'aerosol_optical_depth_500'         [AERONET aerosol optical depth at 500nm, unitless]
'total_precipitable_water_aeronet'  [AERONET total precipitable water, in cm]
'solar_zenith_aeronet'              [AERONET solar zenith angle, in degrees]
'fine_mode_fraction'                [AERONET fine-mode-fraction, unitless]
'AE_440_870'                        [AERONET angstrom exponent from 440-870 nm, unitless]

'date_time'                     [Radiometer date-time in "dd-MM-yyyy HH:mm:ss Z" format in UTC]
'surface_SW_upward'             [Surface SW upward flux at ~1 m above ground level (AGL), in W m^-2]
'surface_SW_downward'           [Surface SW downward flux at ~1 m AGL, in W m^-2]
'surface_LW_upward'             [Surface LW upward flux at ~1 m AGL, in W m^-2]
'surface_LW_downward'           [Surface LW downward flux at ~1 m AGL, in W m^-2]

'date_time_ceres'                   [CERES date-time in "dd-MM-yyyy HH:mm:ss Z" format in UTC]
'latitude'                          [CERES FOV latitude, in degrees N]
'longitude'                         [CERES FOV longitude, in degrees E]
'aerosol_optical_depth_550'         [MODIS deep blue land aerosol optical depth at 550 nm, unitless]
'total_precipitable_water_ceres'    [GEOS-5 total precipitable water vapor, in cm]
'solar_zenith_ceres'                [CERES solar zenith angle, in degrees]
'ceres_albedo'                      [CERES surface broadband SW albedo, unitless]
'surface_emissivity'                [CERES surface broadband LW emissivity, unitless]
'toa_SW_upward'                     [CERES top of the atmosphere (TOA) SW upward flux, in W m^-2]
'toa_SW_downward'                   [CERES TOA SW downward flux, in W m^-2]
'toa_LW_upward'                     [CERES TOA LW upward flux, in W m^-2]
'clearsky_fraction'                 [CERES clear-sky fraction, in percentage]
'satellite'                         [Satellite name from which the CERES data was obtained, "Aqua" = NASA Aqua,
                                          "Terra" = NASA Terra, "sNPP" = NOAA Suomi NPP, and "NOAA20" = NOAA-20]

'date_time_pm10'            [PM-10 date-time in "dd-MM-yyyy HH:mm:ss Z" format in UTC]
'PM10_Naval_Test_Base'      [PM-10 concentrations from the Naval Test Base station, in ug m^-3]
'PM10_Niland_English_Road'  [PM-10 concentrations from the Niland English Road station, in ug m^-3]
'PM10_Salton_City'          [PM-10 concentrations from the Salton City station, in ug m^-3]
'PM10_Sonny_Bono'           [PM-10 concentrations from the Sonny Bono station, in ug m^-3]

'dust_mask'       [Dust mask identified via inspection of ceilometer and AERONET data, "1" = dusty, "0" = non-dusty]
'cloud_mask'      [Cloud mask identified via ceilometer data, "1" = cloudy, "0" = non-cloudy]

All missing values are coded as "NaN = Not a number".

Source data:

The CERES satellite data were accessed at https://subset.larc.nasa.gov/ceres/. Once logged in, one can access the CERES SSF level 2 data onboard each satellite by choosing the data products CER_SSF_Aqua-FM3-MODIS_Edition4A (Aqua), CER_SSF_Terra-FM1-MODIS_Edition4A (Terra), CER_SSF_NPP-FM5-VIIRS_Edition2A (Suomi NPP), and CER_SSF_NOAA20-FM6-VIIRS_Edition1B (NOAA-20) for data within -116.0852 to -115.5867 E and 32.9041 to 33.4037 N. For each data product, the parameter group(s) that were selected are as follows:

• Default
	o All variables (Suomi NPP and NOAA-20)
	o Time of observation, lat, lon (Aqua and Terra)
• Time and Position (Suomi NPP and NOAA-20)
	o Julian observation time
• Viewing Angles
	o Solar zenith angle
• TOA and Surface Fluxes
	o Broadband surface albedo, longwave surface emissivity, TOA incoming solar radiation, TOA longwave flux, TOA shortwave flux
• Full Footprint Area
	o Precipitable water
• Cloudy Footprint Area
	o Layers coverages (Suomi NPP and NOAA-20)
	o Clear/layer/overlap percent coverages (Aqua and Terra)
• MODIS Land Aerosols (Aqua and Terra)
	o PSF wtd MOD04 deep blue aerosol optical depth land (550 nm)
• Imager Land Aerosols (Suomi NPP and NOAA-20)
	o Imager deep blue land 055um correct aerosol optical depth

The aerosol data were accessed at https://aeronet.gsfc.nasa.gov/new_web/aerosols.html. 
The data can be found by selecting the level 1.5 and the site name (Salton_Sea): 
https://aeronet.gsfc.nasa.gov/cgi-bin/data_display_aod_v3?site=Salton_Sea&nachal=2&level=2&place_code=10.