We will have combined airborne and field sampling at PACE overpass time over two sampling periods October 2024 and May 2025, spanning a wide range of aerosol and ocean states for Monterey Bay, California. Likely potential aerosol conditions include, but not limited to, maritime aerosol, wildfire smoke, long range Asian dust transport, and clear air (Zhao et al., 2013, Lewis et al., 2010, Mardi et al., 2018, Allan et al., 2004, VanCuren 2003). Expected maritime conditions include, but are not limited to, low productivity cold waters, algal blooms, riverine outflow, and turbid waters. The study site has dramatic conditions exacerbated by the changing climate and a recent history of significant fire seasons (Filoncyk et al., 2022), extreme precipitation conditions, namely drought, atmospheric rivers and subsequent changes in riverine outflow, and other climate change impacts such as harmful algal blooms and far-reaching riverine plumes. We achieve PACE validation with hyperspectral (e.g., HyperPro II water optical profiling and 4STAR-B atmospheric transmittance) and aligned contemporary radiometric measurements (C-AIR water-leaving radiance from aircraft and C-OPS water optical profiling). The latter contemporary ocean color detectors have much higher dynamic range than OCI. This unique combination of airborne and surface and profiling instrumentation and water sampling can provide high-accuracy validation of the PACE mission sensors in a globally-representative range of oceanic conditions. The repeated airborne observations can provide the calibration and validation over larger areas and time by collecting measurements over a larger spatial domain during a satellite overpass and different seasons, overcoming the problem of limited spatial coverage presented by using solely ship stations and moored buoy systems.

Multiple units of in-house built SMART-s (Spectral Measurements for Atmospheric Radiative Transfer-spectrometer, 330870 nm at ~0.8 nm resolution), as a part of NASA/Pandora network with extended spectral range, will be deployed to support PACE validation over oceanic waters (Eureka Oil Platform, CA; ~8 miles off the coast of Long Beach, CA) and seasonal transported Asian dust, southeastern biomass-burning smoke, and locally generated industrial air pollutants such as trace gases, precursors, and aerosols (Taiwan) sites. Specifically, we propose to accomplish the following two tasks:1. To evaluate OCI's atmospheric-corrected water-leaving radiance/reflectance: Since the scans of SMART-s are very flexible and programmable, we will initially adopt the AERONET-OC operational criteria (e.g., IOCCG, 2019; Zibordi et al., 2021) for data continuity and consistency checks; then, after accumulating enough lessons learned from SeaPRISM, the advantage of SMART-s spectrometry will help improving the spatial-spectral-temporal sampling efficiency and effectiveness for PACE/OCI intercomparison (validation) and application. These water-leaving radiance/reflectance will be integrated with OCI's spectral response functions to meet their spectral range (i.e., 17 bands in 350710 nm at 15 nm bandwidth; 665/678 nm at 10 nm bandwidth) and uncertainty requirements.2. To validate PACEs aerosol and cloud products: We will utilize well-calibrated SMART-s' direct-Sun and sky measurements with SMART-s published methods (Jeong et al., 2018, 2020, and 2022) to retrieve columnar properties of aerosols (e.g., spectral AOD, single-scattering albedo, and ngstrm exponent, fine-mode fraction of complex index of refraction) and abundance of trace gases (O3, NO2, H2Ovapor). By leveraging the assets of the upcoming 7-SEAS (Seven SouthEast Asian Studies, 20242026, Taiwan in collaborating NASA AERONET/ MPLNET) international field campaigns, SMART-s measurements can be maximized for improving scientific understanding and validating PACE/OCI products.

Aerosol measurements began at the NOAA Earth System Research Laboratory (ESRL) Global Monitoring Division (GMD) baseline observatories in the mid-1970's with the purpose of detecting a response, or lack of response, of atmospheric aerosols to changing conditions on a global scale. In 1992 ESRL/GMD expanded its aerosol research program to include regional aerosol monitoring stations due to anthropogenic aerosols creating a significant perturbation in the Earth's radiative balance on regional scales. The goals of this regional-scale monitoring program are to characterize means, variability, and trends of climate-forcing properties of different types of aerosols, and the factors that control them. In situ measurements of aerosol optical properties (including light absorption, total scattering, hemispheric backscattering, and total aerosol number concentration) are made at monitoring sites at hourly time resolution. The basic aerosol measurement system consists of a nephelometer (measures aerosol light scattering), absorption photometer (measures light absorption), and a condensation nuclei counter (measures particle number concentration). Data from the aerosol monitoring stations are updated several times a day. Following collection of the raw data at the station, the data are inspected through automatic and manual contamination screenings to eliminate contamination from local pollution sources. Automatic screenings use measured wind speed, direction, and/or total particle number concentration to flag contaminated data. Manual screening is more subjective, relying on the station scientist to evaluate the data in the context of automated contamination flags and their knowledge of the site. Data applications indicate the importance of continuing to provide long-term aerosol in-situ measurements for use in analysis of trends and climatologies, evaluation of model simulations of aerosol climatologies, and behavior and validation of remote sensing retrievals of aerosol optical properties. GMD's measurements also provide ground-truth for satellite measurements and global models, as well as key aerosol parameters for global-scale models. Through the Big Earth Data Initiative (BEDI), ESRL/GMD has taken their data collection and converted files into NetCDF-4, a self-describing format.

Aerosol measurements began at the NOAA Earth System Research Laboratory (ESRL) Global Monitoring Division (GMD) baseline observatories in the mid-1970's with the purpose of detecting a response, or lack of response, of atmospheric aerosols to changing conditions on a global scale. In 1992 ESRL/GMD expanded its aerosol research program to include regional aerosol monitoring stations due to anthropogenic aerosols creating a significant perturbation in the Earth's radiative balance on regional scales. The goals of this regional-scale monitoring program are to characterize means, variability, and trends of climate-forcing properties of different types of aerosols, and the factors that control them. In situ measurements of aerosol optical properties (including light absorption, total scattering, hemispheric backscattering, and total aerosol number concentration) are made at monitoring sites at hourly time resolution. The basic aerosol measurement system consists of a nephelometer (measures aerosol light scattering), absorption photometer (measures light absorption), and a condensation nuclei counter (measures particle number concentration). Data from the aerosol monitoring stations are updated several times a day. Following collection of the raw data at the station, the data are inspected through automatic and manual contamination screenings to eliminate contamination from local pollution sources. Automatic screenings use measured wind speed, direction, and/or total particle number concentration to flag contaminated data. Manual screening is more subjective, relying on the station scientist to evaluate the data in the context of automated contamination flags and their knowledge of the site. Data applications indicate the importance of continuing to provide long-term aerosol in-situ measurements for use in analysis of trends and climatologies, evaluation of model simulations of aerosol climatologies, and behavior and validation of remote sensing retrievals of aerosol optical properties. GMD's measurements also provide ground-truth for satellite measurements and global models, as well as key aerosol parameters for global-scale models. Through the Big Earth Data Initiative (BEDI), ESRL/GMD has taken their data collection and converted files into NetCDF-4, a self-describing format.

The Suomi National Polar-orbiting Partnership (SNPP) Visible Infrared Imaging Radiometer Suite (VIIRS) NASA standard Level-2 (L2) dark target (DT) aerosol product provides satellite-derived measurements of Aerosol Optical Thickness (AOT) and their properties over land and ocean, and spectral AOT and their size parameters over oceans every 6 minutes, globally. The VIIRS incarnation of the DT aerosol product is based on the same DT algorithm that was developed and used to derive products from the Terra and Aqua mission’s MODIS instruments. Two separate and distinct DT algorithms exist. One helps retrieve aerosol information over ocean (dark in visible and longer wavelengths), while the second aids retrievals over vegetated/dark-soiled land (dark in the visible).This orbit-level product (Short-name: AERDT_L2_VIIRS_SNPP_NRT) has an at-nadir resolution of 6 km x 6 km, and progressively increases away from nadir given the sensor's scanning geometry and Earth's curvature. Viewed differently, this product's resolution accommodates 8 x 8 native VIIRS moderate-resolution (M-band) pixels that nominally have ~750 m horizontal pixel size. Hence, the Level-2 Dark Target Aerosol Optical Thickness data product incorporates 64 (750 m) pixels over a 6-minute acquisition. Version 2.0 constitutes the latest collection of the L2 Dark Target Aerosol product and contains improvements over its previous collection (v1.1).

Multiple units of in-house built SMART-s (Spectral Measurements for Atmospheric Radiative Transfer-spectrometer, 330870 nm at ~0.8 nm resolution), as a part of NASA/Pandora network with extended spectral range, will be deployed to support PACE validation over oceanic waters (Eureka Oil Platform, CA; ~8 miles off the coast of Long Beach, CA) and seasonal transported Asian dust, southeastern biomass-burning smoke, and locally generated industrial air pollutants such as trace gases, precursors, and aerosols (Taiwan) sites. Specifically, we propose to accomplish the following two tasks:1. To evaluate OCI's atmospheric-corrected water-leaving radiance/reflectance: Since the scans of SMART-s are very flexible and programmable, we will initially adopt the AERONET-OC operational criteria (e.g., IOCCG, 2019; Zibordi et al., 2021) for data continuity and consistency checks; then, after accumulating enough lessons learned from SeaPRISM, the advantage of SMART-s spectrometry will help improving the spatial-spectral-temporal sampling efficiency and effectiveness for PACE/OCI intercomparison (validation) and application. These water-leaving radiance/reflectance will be integrated with OCI's spectral response functions to meet their spectral range (i.e., 17 bands in 350710 nm at 15 nm bandwidth; 665/678 nm at 10 nm bandwidth) and uncertainty requirements.2. To validate PACEs aerosol and cloud products: We will utilize well-calibrated SMART-s' direct-Sun and sky measurements with SMART-s published methods (Jeong et al., 2018, 2020, and 2022) to retrieve columnar properties of aerosols (e.g., spectral AOD, single-scattering albedo, and ngstrm exponent, fine-mode fraction of complex index of refraction) and abundance of trace gases (O3, NO2, H2Ovapor). By leveraging the assets of the upcoming 7-SEAS (Seven SouthEast Asian Studies, 20242026, Taiwan in collaborating NASA AERONET/ MPLNET) international field campaigns, SMART-s measurements can be maximized for improving scientific understanding and validating PACE/OCI products.

The Suomi National Polar-orbiting Partnership (SNPP) Visible Infrared Imaging Radiometer Suite (VIIRS) NASA standard Level-2 (L2) dark target (DT) aerosol product provides satellite-derived measurements of Aerosol Optical Thickness (AOT) and their properties over land and ocean, and spectral AOT and their size parameters over oceans every 6 minutes, globally. The VIIRS incarnation of the DT aerosol product is based on the same DT algorithm that was developed and used to derive products from the Terra and Aqua mission’s MODIS instruments. Two separate and distinct DT algorithms exist. One helps retrieve aerosol information over ocean (dark in visible and longer wavelengths), while the second aids retrievals over vegetated/dark-soiled land (dark in the visible).

Three Modified Yankee Multi-Filtered Rotating Shadow Band Spectrometers (M-MFRSR) will be deployed at three locations to measure UV aerosol absorption properties at 340nm and 380 nm. Aerosol parameters to be derived are single scattering albedo (SSA) and Aerosol Absorption Optical Depth (AAOD). Instruments will be deployed at operational Aerosol RObotic NETwork (AERONET) sites. AERONET derived information on aerosol optical depth (AOD), surface albedo, and particle size distribution (PSD) will be used as input to the inversion of M-MFRSR total (direct plus diffuse), diffuse, and direct (total â€" diffuse) multi-spectral planar irradiance measurements.

Measurements taken during the Aerosol Characterization Experiment (ACE) off the coast of Asia in the East China Sea, Sea of Japan, and Pacific Ocean.

The VIIRS/SNPP Dark Target Aerosol L2 6-Min Swath 6 km product provides satellite-derived measurements of Aerosol Optical Thickness (AOT) and their properties over land and ocean, and spectral AOT and their size parameters over oceans every 6 minutes, globally. The Suomi National Polar-orbiting Partnership (SNPP) Visible Infrared Imaging Radiometer Suite (VIIRS) incarnation of the dark target (DT) aerosol product is based on the same DT algorithm that was developed and used to derive products from the Terra and Aqua mission’s MODIS instruments. Two separate and distinct DT algorithms exist. One helps retrieve aerosol information over ocean (dark in visible and longer wavelengths), while the second aids retrievals over vegetated/dark-soiled land (dark in the visible). This orbit-level product (Short-name: AERDT_L2_VIIRS_SNPP) has an at-nadir resolution of 6 km x 6 km, and progressively increases away from nadir given the sensor's scanning geometry and Earth's curvature. Viewed differently, this product's resolution accommodates 8 x 8 native VIIRS moderate-resolution (M-band) pixels that nominally have ~750 m horizontal pixel size. Hence, the Level-2 Dark Target Aerosol Optical Thickness data product incorporates 64 (750 m) pixels over a 6-minute acquisition. Version 2.0 constitutes the latest collection of the L2 Dark Target Aerosol product and contains improvements over its previous collection (v1.1). For more information consult LAADS product description page at: https://ladsweb.modaps.eosdis.nasa.gov/missions-and-measurements/products/AERDT_L2_VIIRS_SNPP Or, Dark Target aerosol team Page at: https://darktarget.gsfc.nasa.gov/