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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Long‐Term Large‐Scale Atmospheric Forcing Data From Three‐Dimensional Constrained Variational Analysis for the ARM SGP Site

Here, this study presents a long‐term three‐dimensional large‐scale forcing data set (VARANAL3D) derived from the three‐dimensional constrained variational analysis (3DCVA) method at the Atmospheric Radiation Measurement (ARM) program Southern Great Plains (SGP) site from 2004 to 2018. Building on the same input data sets as the conventional continuous forcing data set (VARANAL), VARANAL3D maintains overall consistency in domain‐averaged fields while introducing spatial variability, offering critical insights into the influence of mesoscale synoptic systems on cloud‐related processes. Evaluations are conducted across four cloud and precipitation regimes: Clear‐sky, Shallow‐clouds, Afternoon‐precipitation, and Nocturnal‐precipitation, presenting high consistency of the domain‐mean forcing data sets while emphasizing the role of subdomain forcing variability particularly in precipitating regimes. Single column model (SCM) simulations demonstrate that subdomain VARANAL3D forcing improves cloud and precipitation representation, with the ensemble outperforming domain‐mean forcing in three cloudy and precipitating regimes. Overall, these results highlight VARANAL3D's value for investigating the impacts of spatial variability of large‐scale forcing on atmospheric processes. The VARANAL3D data set provides new opportunities for evaluating model physics, advancing the development of scale‐aware parameterizations and deepening our understanding of cloud and precipitation dynamics.

Environmental sciences↗
DOE OSTI2021

Examining the Ice Nucleating Particles from Southern Great Plains Part II (ExINP-SGP). Field Campaign Report

Knowledge of airborne particulate matter (PM), especially the particles that have supermicron diameters, is key for understanding ice-nucleating particles (INPs). Supported by the Atmospheric Radiation Measurement (ARM) user facility, recent INP measurements at the Southern Great Plains observatory (SGP; 36'' 36' 18→ N, 97° 29' 6'' W) during multiple campaigns, such as SINCE-2014 (DeMott et al. 2015), Examining the Ice-Nucleating Particles from SGP (ExINP-2019; Hiranuma and Vepuri 2020), and Aerosol-Ice Formation Closure Pilot Study (AEROICESTUDY; Knopf et al. 2021a), strongly suggested the contribution of supermicron aerosol particles to observed INP abundance at SGP. However, verification of this hypothesis was hampered since additional offline laboratory analyses require sufficient amounts of collected airborne PM, which was lacking. Therefore, the principal investigators (PIs) conducted a field campaign, named ExINP-SGP II, to collect airborne PM at SGP for complementary laboratory characterization of the particles’ physicochemical properties (including ice nucleation properties). We used a passive particle sampler, which is a 4’ x 4’ x 2” (L x W x D) aluminum pan inside the 12”-high wooden windshield wall at the rooftop deck of the ARM Aerosol Observing System (AOS) trailer to collect dry PM deposits from January to April 2021. Figure 1 shows images of our experimental setup at the site. Additionally, we also collected surface soil near the ARM AOS trailer on 20 November 2020 (Figure 1b) to examine the ground soil dust particles (< 63 µm sieved) for their propensities to initiate immersion freezing compared to collected ambient PM. Surface soil and airborne samples were stored in the chemically inert container separately and kept in a dry, cool place until analyzed.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

Tropopause Characteristics Based on Long-Term ARM Radiosonde Data: A Fine-Scale Comparison at the Extratropical SGP Site and Arctic NSA Site

The variations in the characteristics of the tropopause are sensitive indicators for the climate system and climate change. By using Atmospheric Radiation Measurement (ARM) radiosonde data that were recorded at the extratropical Southern Great Plains (SGP) and Arctic North Slope of Alaska (NSA) sites over an 18-year period (January 2003 to December 2020), this study performs a fine-scale comparison of the climatological tropopause features between these two sites that are characterized by different climates. The static stability increases rapidly above the tropopause at both sites, indicating the widespread existence of a tropopause inversion layer. The structures of both the tropopause inversion layer and the stability transition layer are more obvious at NSA than at SGP, and the seasonal variation trends of the tropopause inversion layer and stability transition layer are distinctly different between the two sites. A fitting method was used to derive the fitted tropopause height and tropopause sharpness (λ). Although this fitting method may determine a secondary tropopause rather than the primary tropopause when multiple tropopause heights are identified on one radiosonde profile, the fitted tropopause heights generally agree well with the observed tropopause heights. Broad tropopause sharpness values (λ > 2 km) occur more frequently at SGP than at NSA, resulting in a greater average tropopause sharpness at SGP (1.0 km) than at NSA (0.6 km). Significant positive trends are exhibited by the tropopause heights over the two sites, with rates of increase of 23.7 ± 6.5 m yr ⁻1 at SGP and 28.0 ± 4.0 m yr ⁻1 at NSA during the study period.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Evaluation of the Near-Surface Variables in the HRRR Weather Model Using Observations from the ARM SGP Site

Abstract The performance of version 4 of the NOAA High-Resolution Rapid Refresh (HRRR) numerical weather prediction model for near-surface variables, including wind, humidity, temperature, surface latent and sensible fluxes, and longwave and shortwave radiative fluxes, is examined over the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) region. The study evaluated the model’s bias and bias-corrected mean absolute error relative to the observations on different time scales. Forecasts of near-surface geophysical variables at five SGP sites (HRRR at 3-km scale) were found to agree well with observations, but some consistent observation–forecast differences also occurred. Sensible and latent heat fluxes are the most challenging variables to be reproduced. The diurnal cycle is the main temporal scale affecting observation–forecast differences of the near-surface variables, and almost all of the variables showed different biases throughout the diurnal cycle. Results show that the overestimation of downward shortwave and the underestimation of downward longwave radiative flux are the two major biases found in this study. The timing and magnitude of downward longwave flux, wind speed, and sensible and latent heat fluxes are also different with contributions from model representations, data assimilation limitations, and differences in scales between HRRR and SGP sites. The positive bias in downward shortwave and negative bias in longwave radiation suggests that the model is underestimating cloud fraction in the study domain. The study concludes by showing a brief comparison with version 3 of the HRRR and shows that version 4 has better performance in almost all near-surface variables. Significance Statement A correct representation of the near-surface variables is important for numerical weather prediction models. This study investigates the capability of the latest NOAA High-Resolution Rapid Refresh (HRRRv4) model in simulating the near-surface variables by comparing against the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) in situ observations. Among others, we find that the surface heat fluxes, such as sensible and latent heat fluxes, are the most difficult variables to be reproduced. This study also shows that the diurnal cycle has the dominant impact on the model’s performance, which means the majority of the outputted near-surface variables have the strong diurnal cycle in their bias errors.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

AmeriFlux FLUXNET-1F US-A32 ARM-SGP Medford hay pasture

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-A32 ARM-SGP Medford hay pasture. This is the FLUXNET version of the carbon flux data for the site US-A32 ARM-SGP Medford hay pasture produced by applying the standard ONEFlux (1F) software. Site Description - This site is located at the ARM SGP Extended Facility E32, 8 km West of Medford, OK

Billesbach, Dave↗
DOE OSTI2023

AmeriFlux FLUXNET-1F US-A74 ARM SGP milo field

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-A74 ARM SGP milo field. This is the FLUXNET version of the carbon flux data for the site US-A74 ARM SGP milo field produced by applying the standard ONEFlux (1F) software. Site Description - This site is located near the ARM SGP Central Facility at the intersection of Oklahoma highways 11 and 74, 16.5 km East of Medford, OK

Billesbach, Dave↗
DOE OSTI2025

AmeriFlux FLUXNET-1F US-A39 ARM-SGP-Morrison

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-A39 ARM-SGP-Morrison. This is the FLUXNET version of the carbon flux data for the site US-A39 ARM-SGP-Morrison produced by applying the standard ONEFlux (1F) software. Site Description - This site is located at ARM SGP Extended Facility 39 near Morrison, OK

Sullivan, Ryan [Argonne National Laboratory]↗
DOE OSTI2025

DTS data from SGP TBS

Distributed temperature-sensing data collected using a Silixa-XT DTS and 50/125 MM fiber. Data are calibrated using two water baths at the surface and an iMet aloft at the end of the fiber and tether. The data are then assigned an altitude for the TBS flight. Data collected prior to Febuary 11, 2020 were collected at the SGP Central Facility (CF). Data from 2/11/20 were collected with a Sensornet Oryx DTS at the E9 site, not at the CF. Data from May 2021 were collected with a Sensornet Oryx at the CF, and with a Silixa XT at the CF. Data from July 2021 were collected at the SGP CF, EF9, and EF36 with a Silixa XT. Data from October 2021 were collected at the SGP EF36 with a Silixa XT. Data from February 2022 were collected at the CF with a Silixa XT.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

University of Miami G-band Vapor Radiometer Calibration at SGP during November 2023

From October 13, 2023 until November 16, 2023, the GVR was deployed to the DOE ARM SGP site, to take advantage of their regular near-by radiosonde launches under clear-sky conditions. The latter were determined using the SGP total sky imagery data. The GVR brightness temperatures in these clear-sky conditions were compared to those calculated by a radiative transfer code (PAMTRA) based on the SGP radiosondes. During the campaign, 4 suitable clear-sky episodes occurred that could be used for the GVR calibration. While few in number, these proved to be enough to satisfy our goal.

airborne G-band Vapor Radiometer↗
NASA NTRS1998

Apparent Surface Reflectance of the DOE ARM SGP CART Central Site Derived from AVIRIS Spectral Images

The primary objective of the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Program at the Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) is to acquire in situ and remote sensing data to improve cloud and atmospheric radiative models and parameterizations. As a consequence of this program, a large number of atmosphere and surface measurements are being acquired at the ARM SGP CART central site. NASA's Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) overflew this site on August 1, 1997. AVIRIS measures the upwelling spectral solar radiance from 400 to 2500 nm at 10-nm intervals. From 20 km altitude, these calibrated spectra are acquired as images of 11 by up to 800 km with 20-by-20 m spatial resolution. These data were acquired at the ARM SGP CART Central Site to first investigate derivation of atmospheric parameters from the measured spectra, second study the variation of these parameters, and third demonstrate the inversion of the calibrated radiance spectra to apparent surface reflectance. These objectives have been pursued with AVIRIS data at other sites for atmospheric water vapor and derivation of apparent surface reflectance.

Green, Robert O.↗
NASA NTRS2003

Measurement and Modeling of Vertically Resolved Aerosol Optical Properties and Radiative Fluxes Over the ARM SGP Site

In order to meet one of its goals - to relate observations of radiative fluxes and radiances to the atmospheric composition - the Department of Energy's Atmospheric Radiation Measurement (ARM) program has pursued measurements and modeling activities that attempt to determine how aerosols impact atmospheric radiative transfer, both directly and indirectly. However, significant discrepancies between aerosol properties measured in situ or remotely remain. One of the objectives of the Aerosol Intensive Operational Period (TOP) conducted by ARM in May 2003 at the ARM Southern Great Plains (SGP) site in north central Oklahoma was to examine and hopefully reduce these differences. The IOP involved airborne measurements from two airplanes over the heavily instrumented SGP site. We give an overview of airborne results obtained aboard the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Twin Otter aircraft. The Twin Otter performed 16 research flights over the SGP site. The aircraft carried instrumentation to perform in-situ measurements of aerosol absorption, scattering, extinction and particle size. This included such novel techniques as the photoacoustic and cavity ring-down methods for in-situ absorption (675 nm) and extinction (675 and 1550 nm) and a new multiwavelength, filter-based absorption photometer (467, 530, 660 nm). A newly developed instrument measured cloud condensation nucleus concentration (CCN) concentrations at two supersaturation levels. Aerosol optical depth and extinction (354-2139 nm) were measured with the NASA Ames Airborne Tracking 14-channel sunphotometer. Furthermore, up-and downwelling solar (broadband and spectral) and infrared radiation were measured using seven individual radiometers. Three up-looking radiometers werer mounted on a newly developed stabilized platform, keeping the instruments level up to aircraft pitch and roll angles of approximately 10(exp 0). This resulted in unprecedented continuous vertical profiles of radiative fluxes, which we will compare to modeled fluxes using the aforementioned data as input.

Schmid, B.↗
DOE OSTI2021

The Diurnal Variation of the Aerosol Optical Depth at the ARM SGP Site

Abstract This study examines the diurnal variation of the aerosol optical depth (AOD) at 355 nm observed by Raman lidar (RL) at the Atmospheric Radiation Measurement Program Southern Great Plains (SGP) site under both clear and cloudy‐sky conditions. Here only cloudy‐skies when the lidar signal is not fully attenuated are considered. The daytime AOD and its variation from the RL showed an excellent agreement with the Aerosol Robotic Network, demonstrating that the RL‐retrieved AOD is not affected by solar background contamination. The climatological annual‐mean daytime‐mean AOD is only slightly larger than the nighttime‐mean AOD (by 1%–3%). However, day‐to‐day variations are observed such that the daytime‐ and nighttime‐mean AOD difference for a given day can be large (about 95% of days have differences within 0.2). The seasonal AOD diurnal range (i.e., the difference between the maximum and minimum values) relative to the mean was 10%–15% except in the winter when it was 44%. The seasonal‐mean cloudy‐sky AOD diurnal variation is similar to that for clear‐sky, except that the AODs are larger (the annual‐mean cloudy‐sky AOD is larger than the clear‐sky by 24%). The aerosol lidar ratio diurnal variations are also examined, which are 10%–20% for all seasons with a minimum near 9 a.m. to 15 p.m. for all seasons except winter. Also presented is the annual‐mean AOD from the Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite at SGP site: its daytime AOD is about 0.1 smaller than nighttime AOD because of daytime solar background contamination.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

AmeriFlux US-A39 ARM-SGP-Morrison

This is the AmeriFlux version of the carbon flux data for the site US-A39 ARM-SGP-Morrison. Site Description - This site is located at ARM SGP Extended Facility 39 near Morrison, OK

Sullivan, Ryan [Argonne National Laboratory]↗
DOE OSTI2025

AmeriFlux FLUXNET-1F US-A37 ARM-SGP-Waukomis

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-A37 ARM-SGP-Waukomis. This is the FLUXNET version of the carbon flux data for the site US-A37 ARM-SGP-Waukomis produced by applying the standard ONEFlux (1F) software. Site Description - The E37 site is located in the middle of a grassy field with a cultivated field to the South, near Waukomis, Oklahoma.

Sullivan, Ryan [Argonne National Laboratory]↗
DOE OSTI2025

Direct Radiative Effects of Aerosols at the ARM SGP and TWP Sites (DOE ASR Final Report)

This effort has examined and quantified aerosol direct radiative effects (DREs) and associated uncertainties at the Department of Energy Atmospheric Radiation Measurement (ARM) Southern Great Plain (SGP) and Tropical Western Pacific (TWP) sites under both clear and all sky conditions by taking advantage of the advanced ARM long-term comprehensive measurements of aerosol, cloud, radiation, and atmospheric state. This effort has filled the knowledge gap in aerosol DREs at the SGP and TWP under all sky conditions based on the ARM observations.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

ARM SGP PBLH and MLH datasets from Raman lidar and Doppler lidar

The planetary boundary layer (PBL) plays a critical role in the atmosphere by transferring heat, moisture, and momentum. The warm PBL has a distinct diurnal cycle including the daytime convective mixing layer (ML) and nighttime residual layer developments. Thus, simultaneous determinations of PBL height (PBLH) and ML height (MLH) are necessary for studying PBL characterization and processes. Here, new approaches are developed to provide reliable PBLH and MLH estimates to characterize warm PBL evolution. The approaches use Raman lidar (RL) water vapor mixing ratio (WVMR) and Doppler lidar (DL) vertical velocity measurements at the Southern Great Plains (SGP) atmospheric observatory, which was established by the Atmospheric Radiation Measurement (ARM) User Facility. Compared to widely used lidar aerosol measurements for PBLH, WVMR is a better tracer for PBL vertical mixing. For PBLH, the approach classifies PBL water vapor structures into a few general patterns, then uses a slope method and dynamic threshold method to determine PBLH. For MLH, wavelet analysis is used to reconstruct 2D variance from DL vertical wind velocity measurements according to the turbulence eddy size to minimize the impacts of gravity wave and eddy size on variance calculations; then, a dynamic threshold method is used to determine MLH. Remotely-sensed PBLHs and MLHs are compared with radiosonde measurements based on the Richardson number method. Good agreements between them confirm that the proposed new algorithms are reliable for PBLH and MLH characterization. The algorithms are applied to warm-season RL and ML measurements at the SGP site for five years to study warm-season PBL structure and processes. The weekly composited diurnal evolutions of PBLHs and MLHs in a warm climate were provided to illustrate diurnal and seasonal PBL evolutions. This reliable data set of PBLH and MLH values will be valuable for studying PBL processes, model evolution, and PBL parameterization improvements. The MLH dataset includes the MLH in values of km above ground level. The PBLH dataset includes the PBLH in values of km above ground level, along with a flag ("situation_PBLH") to determine the state of the PBL (1 = Cloudy Condition, 2 = Stable Layer, 3 = Multi-layer WVMR structure, 4 = Well-Mixed PBL, 5 = A de-coupled layer, 6 = Other).

mixing layer height↗
DOE OSTI2025

Mobile measurement of CH4 around the SGP ARM site during June 23-26, 2024

A mobile measurement campaign from June 23-26, 2024 was conducted to detect and quantify CH₄ emissions within about 8 km of the SGP site. Using a LI-COR LI-7810 tracer gas analyzer mounted on a vehicle, we sampled CH₄ along predefined routes surrounding a suspected source area around the SGP ARM site. Measurements were collected between 04:30 and 09:00 local time when the PBL was shallow, increasing sensitivity to surface emissions. Driving speeds were kept below 5 mph to minimize pressure-related artifacts.

{"Trace Gas Analyzer for methane","Measured mixing↗
NASA NTRS2000

ESTAR Measurements During SGP-99

The synthetic aperture radiometer, ESTAR, provided L-band brightness temperature maps of the experiment site during the Southern Great Plains Experiment in 1999. ESTAR flew on the NASA P-3 aircraft at an altitude of 7.6 km and mapped a swath about 50 km wide and about 300 km long. The area mapped extended west from Oklahoma City to El Reno and north from the Little Washita River watershed to the Kansas border. The flight lines and mapping were done in a manner similar to that used in 1997 during SGP-97. ESTAR is a prototype designed to develop the technology of aperture synthesis for passive microwave remote sensing. It is actually a hybrid that uses real aperture to obtain resolution along track and synthetic aperture to obtain resolution across track. ESTAR operates in the band at 1.413 GHz set aside for passive use and images at horizontal polarization in the equivalent of a cross-track scan. The scan is done in software as part of image reconstruction. Calibration consists of blackbody observed before and after each flight and a local body of water (Lake Kaw). ESTAR arrived in Oklahoma on July 7, 1999 and flew mapping missions on July 8,9, 11, 14, 15, 19 and 20. The aircraft was down on July 10 by design and was down again on July 12-13 and 16-18 due to mechanical problems. ESTAR data for July I I is questionable because of a hardware failure. The brightness temperature maps reflect the patterns of soil moisture observed in the SGP99 study area and compare well with measurements made by ESTAR in other experiments in this region (e.g. SGP -97 and Washita-92).

LeVine, D. M.↗