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.

This dataset provides extensive calibration and in-flight performance data for two Ultra-High Sensitivity Aerosol Spectrometers (UHSAS) used for particle size distribution and volatility measurements during the NASA Atmospheric Tomography Mission (ATom) airborne campaign. UHSAS-1 was equipped with a compact thermodenuder operating at 300 degrees C and UHSAS-2 was operated without a thermodenuder to determine the number and volume fraction of volatile particles. Laboratory studies utilized aerosols from limonene ozonolysis (limon), atomization of ammonium sulfate (AS), and atomization of 2-diethylhexyl (dioctyl) sebacate (DOS). Data include: UHSAS detection efficiency, sizing calibration, performance at a range of pressures and at a range of thermodenuder temperatures, comparison of UHSAS-2 and condensation particle counter (CPC) particle number concentrations, comparisons of UHSAS-1 and UHSAS-2 for dry particle number concentration, surface area and volume collected onboard of a NASA DC-8 aircraft during August 2016, and dry aerosol size distributions for thermodenuded and non-thermodenuded instrument collected in February 2017.

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.

As part of the NASA's Making Earth System Data Records for Use in Research Environments (MEaSUREs) program, this projects describes a multi-decadal Fundamental Climate Data Record (FCDR) of calibrated radiances as well as an Earth System Data Record (ESDR) of aerosol properties over the continents derived from a 40-year record of satellite near-UV observations by three sensors. The TOMS Nimbus 7 version 2 Level-2 orbital data product consists of cloud fraction, cloud optical depth, normalized radiance, reflectivity, residue, and UV aerosol index at approximately 50x50 km resolution (at nadir). This product also contains ancillary variables for ocean corrected surface albedo and terrain pressure.Total Ozone Mapping Spectrometer (TOMS) instruments have been successfully flown in orbit aboard the Nimbus-7(Nov. 1978 - May 1993), Meteor-3 (Aug. 1991 - Dec. 1994), Earth Probe (June 1996 - December 2005), and ADEOS (Sep. 1996 - June 1997) satellites.These Level-2 data are stored in the Hierarchical Data Format 5 (HDF5) and are available from the Goddard Earth Sciences (GES) Data and Information Services Center (DISC).

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).

The TROPESS Chemical Reanalysis Surface Aerosol NH4 Monthly 3-dimensional Product contains vertical concentrations of ammonium aerosols. The data are part of the Tropospheric Chemical Reanalysis v2 (TCR-2) for the period 2005-2021. TCR-2 uses JPL's Multi-mOdel Multi-cOnstituent Chemical (MOMO-Chem) data assimilation framework that simultaneously optimizes both concentrations and emissions of multiple species from multiple satellite sensors.The data files are written in the netCDF version 4 file format, and each file contains a year of data at monthly resolution, and a spatial resolution of 1.125 x 1.125 degrees at 27 pressure levels between 1000 and 60 hPa. The principal investigator for the TCR-2 data is Miyazaki, Kazuyuki.

This dataset contains comprehensive measurements of aerosol microphysical, chemical, and optical properties derived for both dry and ambient conditions from in situ measurements made during the four ATom campaigns. The dataset includes composition-resolved size distributions the integrated mass of sulfate, organics, nitrate, sea salt, dust, black carbon, and other compounds in coarse and fine fractions; extinction and absorption coefficients from each species at both dry and ambient conditions; asymmetry parameters; Angstrom exponents; and fitted lognormal functions to describe the size distribution. Optical parameters are calculated for 10 wavelengths from the near UV to the near IR, and size distributions range from 3 nm to 50 um in diameter. One file contains these data at 1-minute time intervals. Another file contains a subset of these data averaged into 1-km vertical bins for each vertical profile the aircraft made, as well as composition-resolved integrated aerosol optical depth derived from each profile. The concentration of cloud condensation nuclei is calculated for 5 supersaturations.

The TROPESS Chemical Reanalysis Surface Aerosol NH4 2-Hourly 2-dimensional Product contains surface concentrations of ammonium aerosols. The data are part of the Tropospheric Chemical Reanalysis v2 (TCR-2) for the period 2005-2021. TCR-2 uses JPL's Multi-mOdel Multi-cOnstituent Chemical (MOMO-Chem) data assimilation framework that simultaneously optimizes both concentrations and emissions of multiple species from multiple satellite sensors.The data files are written in the netCDF version 4 file format, and each file contains a year of data at 2-hourly resolution, and a spatial resolution of 1.125 x 1.125 degrees. The principal investigator for the TCR-2 data is Miyazaki, Kazuyuki.