PEM-Tropics-B_MetNav_AircraftInSitu_P3B_Data is the in-situ meteorology and navigation data collected onboard the P-3B aircraft during the Pacific Exploratory Mission (PEM) Tropics B suborbital campaign. Data from the Turbulent Air Motion Measurement System (TAMMS) is featured in this collection. Data collection for this product is complete.

From 1983-2001, NASA conducted a collection of field campaigns as part of the Global Tropospheric Experiment (GTE). Among those was PEM, which intended to improve the scientific understanding of human influence on tropospheric chemistry. Part of the PEM field campaigns were focused on the tropical Pacific region (PEM-Tropics) which was recognized as a “very large chemical vessel.” The overarching science objective was to assess the anthropogenic impact on tropospheric oxidizing power. A secondary objective was to investigate the impact of atmospheric sulfur chemistry, including oxidation of marine biogenic emission of dimethyl sulfide (DMS) on aerosol loading and radiative effect, which is of critical importance in the assessment of global climate change. The PEM-Tropics mission was conducted in two phases to contrast the influence of biomass burning in the dry season and the “relatively clean” wet season. The first, PEM-Tropics A, was carried out during the end of the dry season (August-September 1996), and the second, PEM-Topics B, was conducted during the wet season (March-April 1999).
To accomplish its objectives, PEM-Tropics enlisted the NASA DC-8 and P-3B aircrafts to carry out longitudinal and latitudinal surveys at various altitudes as well as vertical profile sampling across the Pacific basin. Both aircrafts were equipped with in-situ instruments measuring hydroperoxyl radicals (HOx), ozone (O3), photochemical precursors (including, reactive nitrogen species and non-methane hydrocarbon species), and intermediate products (e.g., hydrogen peroxide (H2O2), formaldehyde (CH2O), and acetic acid (CH3OOH). The P3-B in-situ instrument payload also included a direct measurement of hydroxyl (OH) for both missions, while the OH and hydroperoxyl radical (HO2) measurements were added to DC-8 aircraft for PEM-Tropics B. Taking advantage of its excellent low altitude capability, the P-3B was instrumented with a comprehensive sulfur measurement package and conducted pseudo-Lagragian sampling for evaluating DMS oxidation chemistry, including measurements of DMS, sulfur dioxide (SO2), sulfuric acid (H2SO4), and methylsulfonic acid (MSA) as well as the first airborne measurement of dimethyl sulfoxide (DMSO) during PEM-Tropics B. More importantly, it was the first time that DMS (the source), OH and O3 (primary oxidants), and products (DMSO, MSA, H2SO4, SO2) were measured simultaneously aboard an aircraft in the tropical pacific. These observations, specifically DMSO, presented a substantial challenge to the DMS oxidation kinetics to this day. The DC-8 aircraft was equipped with the Differential Absoprtion Lidar (DIAL) during PEM-Tropics A, and the differential absorption lidars DIAL and LASE during PEM-Tropics B. These lidars provided real-time information for fine tuning the flight tracks to capture sampling opportunities. The lidar data products themselves provide valuable information of vertical profiles of ozone as well as aerosol and water vapor in tropical Pacific Furthermore, both aircrafts were fitted with instruments for aerosol composition and microphysical property measurements. Detailed description related to the motivation, implementation, and instrument payloads are available in the PEM-Tropics A overview paper and the PEM-Tropics B overview paper. Most of the publications based on PEM-Tropics A and B observations are available in the Journal of Geophysical Research special issues: Pacific Exploratory Mission-Tropics A and NASA Global Tropospheric Experiment Pacific Exploratory Mission in the Tropics Phase B: Measurement and Analyses (PEM-Tropics B), while other publications

NARSTO_EPA_SS_PITTSBURGH_PM_COMPOSITION_DATA is the North American Research Strategy for Tropospheric Ozone (NARSTO) Environmental Protection Agency (EPA) Supersite (SS) Pittsburgh Particulate Matter (PM) Composition Data. It was obtained between June 30 and September 1, 2001 during the Pittsburgh Air Quality Study (PAQS). The data set provides PM Composition Data of the following types:1) PM2.5 nitrate and PM2.5 sulfate.2) Semi-Continuous Organic and Elemental Carbon Measurements.3) Air concentrations of water soluble PM2.5 aerosol species and water soluble gases, as measured with the CMU steam sampler - IC combination.4) Manual filter-based PM2.5 element measurements from microwave decomposition of filters followed by Inductively Coupled Plasma Mass Spectrometer analysis.5) Manual filter-based PM10 element measurements from microwave decomposition of filters and Inductively Coupled Plasma Mass Spectrometer analysis.6) Manual filter-based PM2.5 inorganic composition with analysis performed using ion chromatography.7) Manual filter-based PM2.5 organic and elemental carbon measurements with analysis performed using a Thermal Optical Transmission carbon analyzer.8) Measurements of PM composition size distributions using a MOUDI cascade impactor.9) PM2.5 organic and elemental carbon concentrations from an activated carbon denuder/quartz filter/charcoal impregnated fiber filter backup combination. Quartz filters analyzed using a Thermal/Optical transmittance carbon analyzer.10) Fog chemistry dataPAQS, along with the Pittsburgh Supersite Program, was a comprehensive, multi-disciplinary investigation to characterize the ambient PM in the Pittsburgh region, to improve understanding the links between ambient PM and public health, and to develop new instrumentation for PM measurements. The Pittsburgh Supersite was designed to achieve several objectives: to determine the physical and chemical characteristics of PM in the Pittsburgh region; to develop and evaluate the next generation of atmospheric aerosol monitoring techniques; to update emission profiles for important regional sources; to quantify the impact of the various sources on the local PM concentrations; and to predict changes in the PM characteristics due to proposed changes in emissions. The last objective was based on concurrent modeling studies and was designed to support the development of regulations. These objectives were addressed through four components of the research: (1) ambient monitoring at a central site and a set of satellite sites in the region; (2) an instrument development and evaluation study; (3) a data analysis and synthesis component; and (4) a comprehensive modeling component.

The central supersite was located on a grassy hill in a large urban park adjacent to the Carnegie Mellon University campus, approximately 6km east of downtown Pittsburgh. It was separated from the city in the predominant upwind direction (south and west) by roughly 1km of parkland. It was at least several hundred meters from any other major source of air pollution: the site was positioned approximately 50m past the end of a dead end street, and several hundred meters from the nearest heavily traveled street. Five additional sites were operated as Satellite sites to character the spatial variation of the PM. The measurement campaign lasted for 14 months (July 2001-September 2002). Intensive monitoring was performed during two periods, from 1 July to 3 August 2001 (ESP01) and 1 January to 15 January, 2002 (ESP02). Baseline monitoring was conducted for the rest of the study. Baseline measurements included daily filter samples for fine particle mass and composition (OC/EC, major ions, elemental composition). The U.S. EPA PM Supersites Program was an ambient air monitoring research program designed to provide information of value to the atmospheric sciences, and human health and exposure research communities. Eight geographically diverse projects were chosen to specifically address t

This dataset provides the first year of hourly ocean bottom pressure measurements at the North Pole from the Arctic Bottom Pressure Recorder - Follow On (ABPR-FO) deployed in August 2022. Based around a Paroscientific Digiquartz pressure sensor, the ABPR-FO is designed and powered to collect and transmit data for 5 years. The 5-year record will be collected, quality-controlled and updated at PO.DAAC on a yearly basis. The full time series is provided as a single netCDF file, and reports both bottom pressure (reported as liquid water equivalent thickness) and temperature. This dataset aims to serve as in situ validation for GRACE-FO data products in the central Arctic. This project is funded by NASA’s GRACE and GRACE-FO Science Team and supported by PONANT Science.

DSCOVR_EPIC_L2_MAIAC_02 is the DSCOVR EPIC L2 Multi-Angle Implementation of Atmospheric Correction (MAIAC) Version 02 data product. Data collection for this product is ongoing.
Level 2 Multi-Angle Implementation of Atmospheric Correction (MAIAC) provides an interdisciplinary suite of products for the Deep Space Climate Observatory (DSCOVR) Earth Polychromatic Imaging Camera (EPIC). The current version 2 reports the following products:
a) Atmosphere: cloud mask, global aerosol optical depth at 443nm and 551nm, fine mode fraction (over ocean) and spectral aerosol absorption for detected biomass burning or mineral dust aerosols. The absorption information includes single scattering albedo at 443nm, imaginary refractive index at 680nm, and Absorption Angstrom Exponent (AAE) characterizing spectral increase of imaginary refractive index at Vis-UV wavelengths. The absorption information is provided for two effective aerosol layer heights of 1km and 4km generally representing boundary layer and transport mode.
b) Land: atmospherically corrected spectral bidirectional reflectance factors (BRF) along with Lambertian surface reflectance, and bidirectional reflectance distribution function (BRDF) for the backscattering view geometries of EPIC. The BRDF is represented by 3 parameters of the Ross-Thick Li-Sparse model.
c) Ocean: Water leaving reflectance (non-dimensional) at Ultraviolet-Visible (UV-Vis) bands.

The parameters are distributed at 10 km rotated sinusoidal grid and 1 to 2-hour temporal frequency. MAIAC version 02 also provides gap-filled global composite products for Normalized Difference Vegetation Index (NDVI) over land, and water leaving reflectance in 5 UV-Vis bands over global ocean. The composite products represent a weighted running average where the weight of the latest observation is maximized towards the local noon and low aerosol conditions.

This data set is produced by the Center for Space Research (CSR) GRACE-FO (Gravity Recovery and Climate Experiment Follow-On) program and derives the ocean bottom pressure (OBP) anomaly given as equivalent water thickness. These monthly grids are derived from GRACE-FO time-variable gravity observations during the specified timespan, and relative to the specified time-mean reference period. This quantity represents sea floor pressure changes due to the integral effect of ocean and atmosphere processes, including global mean ocean bottom pressure changes (mean ocean mass and mean atmosphere mass over the global oceans). A glacial isostatic adjustment (GIA) correction has been applied, and standard corrections for geocenter (degree-1), C20 (degree-20) and C30 (degree-30) are incorporated. Post-processing filters have been applied to reduce correlated errors. Data grids are provided in ASCII/netCDF/GeoTIFF formats.



GRACE-FO was launched on 22 May 2018, and extends the original GRACE mission (2002 – 2017) and expands its legacy of scientific achievements in tracking earth surface mass changes. Version 04 (v04) of the ocean bottom pressure data uses updated and consistent C20 and Geocenter corrections (i.e., Technical Notes TN-14 and TN-13), as well as an ellipsoidal correction to account for the non-spherical shape of the Earth when mapping gravity anomalies to surface mass change. Additionally, this release 06.3 is an updated version of the Level 3 products in coordination with the release of the analogous Level 2 products used to generate them. It differs from RL06.1 only in the Level-1B accelerometer transplant data that is used for the GF2 (GRACE-FO 2) satellite; see respective L-2 data descriptions. RL06.3 uses the ACX2-L1B data products. All GRACE-FO RL06.3 Level-3 fields are fully compatible with the GRACE RL06 data.

ARCTAS_Aerosol_AircraftInSitu_P3B_Data is the in-situ aerosol data collected by the P-3B aircraft during the Arctic Research of the Composition of the Troposphere from Aircraft & Satellites (ARCTAS) mission. Data was collected by the Particle Soot Absorption Photometer (PSAP), Aerodynamic Particle Sizer (APS), Condensation Particle Counter (CPC), Single Particle Soot Photometer (SP2), Differential Mobility Analyzer (DMA), Long Differential Mobility Analyzer (LDMA), Tandem Differential Mobility Analyzer (TDMA), Optical Particle Counter (OPC), and the Aerosol Mass Spectrometer (AMS). Data collection for this product is complete.

The Arctic is a critical region in understanding climate change. The responses of the Arctic to environmental perturbations such as warming, pollution, and emissions from forest fires in boreal Eurasia and North America include key processes such as the melting of ice sheets and permafrost, a decrease in snow albedo, and the deposition of halogen radical chemistry from sea salt aerosols to ice. ARCTAS was a field campaign that explored environmental processes related to the high degree of climate sensitivity in the Arctic. ARCTAS was part of NASA’s contribution to the International Global Atmospheric Chemistry (IGAC) Polar Study using Aircraft, Remote Sensing, Surface Measurements, and Models of Climate, Chemistry, Aerosols, and Transport (POLARCAT) Experiment for the International Polar Year 2007-2008.

ARCTAS had four primary objectives. The first was to understand long-range transport of pollution to the Arctic. Pollution brought to the Arctic from northern mid-latitude continents has environmental consequences, such as modifying regional and global climate and affecting the ozone budget. Prior to ARCTAS, these pathways remained largely uncertain. The second objective was to understand the atmospheric composition and climate implications of boreal forest fires; the smoke emissions from which act as an atmospheric perturbation to the Arctic by impacting the radiation budget and cloud processes and contributing to the production of tropospheric ozone. The third objective was to understand aerosol radiative forcing from climate perturbations, as the Arctic is an important place for understanding radiative forcing due to the rapid pace of climate change in the region and its unique radiative environment. The fourth objective of ARCTAS was to understand chemical processes with a focus on ozone, aerosols, mercury, and halogens. Additionally, ARCTAS sought to develop capabilities for incorporating data from aircraft and satellites related to pollution and related environmental perturbations in the Arctic into earth science models, expanding the potential for those models to predict future environmental change.

ARCTAS consisted of two, three-week aircraft deployments conducted in April and July 2008. The spring deployment sought to explore arctic haze, stratosphere-troposphere exchange, and sunrise photochemistry. April was chosen for the deployment phase due to historically being the peak in the seasonal accumulation of pollution from northern mid-latitude continents in the Arctic. The summer deployment sought to understand boreal forest fires at their most active seasonal phase in addition to stratosphere-troposphere exchange and summertime photochemistry.

During ARCTAS, three NASA aircrafts, the DC-8, P-3B, and BE-200, conducted measurements and were equipped with suites of in-situ and remote sensing instrumentation. Airborne data was used in conjunction with satellite observations from AURA, AQUA, CloudSat, PARASOL, CALIPSO, and MISR.

The ASDC houses ARCTAS aircraft data, along with data related to MISR, a satellite instrument aboard the Terra satellite which provides measurements that provide information about the Earth’s environment and climate.

ABLE-2A_Aerosol_AircraftInSitu_Electra_Data is the in-situ aerosol data collected onboard the NASA Electra aircraft during the Amazon Boundary Layer Experiment - 2A (ABLE-2A) suborbital campaign. Data collection for this product is complete.

From 1983-2001, NASA conducted a collection of field campaigns as part of the Global Tropospheric Experiment (GTE). Among those were the Amazon Boundary Layer Experiment (ABLE 2) campaigns. ABLE 2 was divided into two sub-campaigns, ABLE 2A (dry season) and ABLE 2B (wet season). ABLE 2A took place from July-August 1985, while ABLE 2B took place from April-May 1987. The goal of ABLE 2 was to better understand the role of tropics in global atmospheric chemistry and investigate processes which might lead to the enhanced concentrations of carbon monoxide (CO) in the tropical upper troposphere. ABLE 2 was a partnership with NASA and the Brazilian agency, Instituto Nacional de Pesquisas Espaciais (INPE), along with the Instituto Nacional de Pesquisas da Amazonia (INPA) providing facilities and logistical information.

To accomplish its objectives, the ABLE 2 science team deployed the NASA Lockheed Electra aircraft, balloons, and free-flying sondes. Flights took place over the Amazon region in Brazil for both sub-campaigns. ABLE 2A consisted of 15 flights while ABLE 2B consisted of 21 flights with the fully equipped Electra. For most ABLE 2A flights, the data collected included in-situ measurements of CO2, CO, MHC, NO (nitric oxide), N2O, O3, DMS (dimethyl sulfide), aerosol composition, and meteorological parameters. ABLE 2B had the Electra instrumented with remote and in-situ techniques for measuring the atmospheric distribution of a variety of carbon, nitrogen, and sulfur gases; aerosol size and composition; and to measure ozone. The typical approach to flights involved high-altitude passes over research areas using the downward facing UV Differential Absorption Lidar (DIAL). The ABLE 2 campaign represents a modest advance in understanding the influence of the tropical rain forest ecosystem on the chemistry of the troposphere. Detailed descriptions related to the motivation, implementation, and instrument payloads are available in the ABLE 2A overview paper and the ABLE 2B overview paper. A collection of the publications based on ABLE 2A and 2B observation are available in the Journal of Geophysical Research special issues: Global Tropospheric Experiment/Chemical Instrumentation Test and Evaluation Results (GTE/ABLE 2A) and The Amazon Boundary Layer Experiment 2B.

This project contributes to the validation of global surface radiation products and diffuse attenuation coefficients (Kd) generated by the PACE mission, essential for quantifying net primary production. The radiation products include instantaneous, daily mean, spectral, band-integrated, planar, and scalar fluxes, in particular daily mean photosynthetically available radiation (PAR). In-situ observations are gathered through a network of automatic stations measuring hyperspectral downward planar irradiance (Ed(0+)) at selected AERONET-OC sites, and BGC-Argo profilers equipped with hyperspectral Ed sensors.

The AMSR-E/AMSR2 Unified L3 Global Daily Ascending/Descending .25x.25 deg Ocean Grids data set is a gridded product that reports daily estimates of water vapor, cloud liquid water content, and surface wind speed over the ocean, derived from resampled Near Real-Time (NRT) Level-1R data provided by Japan Aerospace Exploration Agency (JAXA).

Sea surface temperatures from the NOAA 1/4° Daily Optimum Interpolation Sea Surface Temperature (OISST) product are also included.

!!!Temporary notice posted Sept. 27th, 2024!!! These data are in the process of being ingested and not all files are available yet. The data were made public early to allow assessment by early science users. Accordingly, not all data set resources may be available yet. Please check over the next 2-3 weeks for finalization of this data set and PO.DAAC's release announcement.



This dataset includes satellite-based observations of geolocated surface wind vectors, precipitable water vapor, and integrated cloud liquid water, as well as the microwave brightness temperatures used to derive them. Theses measurements make up the environmental data record (EDR) from the COWVR (Compact Ocean Wind Vector Radiometer) sensor aboard the international space station (ISS), beginning in January 2022 with forward-streaming to PO.DAAC. Data over the satellite swath are available in HDF5 format with roughly one file per hour (the ISS orbit period is ~90 minutes), and coverage shown in the thumbnail is for a full day. The file metadata formats may be different than what an average user is familiar with – please see the User Guide to learn more. Version 10.0 is the first public release, and is named as such to be consistent with the internal version numbering of the project team prior to release.



The COWVR sensor is a fully polarimetric, conically imaging microwave radiometer for measuring ocean surface wind vectors. It operates nominally on-orbit aboard the ISS and data are non-sun-synchronous. It was deployed as part of the Space Test Program - Houston 8 (STP-H8) technology demonstration mission. A successful COWVR mission will demonstrate a lower-cost sensor architecture (e.g. in comparison to WindSat) for providing imaging passive microwave data, including ocean surface vector wind products for the Department of Defense (DoD). COWVR was provided by the Jet Propulsion Laboratory and flown by the United States Space Force, Space Systems Command, Development Corps for Innovation and Prototyping.