ARM Facilities Newsletter

Monthly newsletter discussing news and activities related to the Atmospheric Radiation Measurement Program, articles about weather and atmospheric phenomena, and other related topics

The Possible direct use of satellite radiance measurements by the Atmospheric Radiation Measurement Program

Mode of access: Internet

Science plan for the Atmospheric Radiation Measurement Program (ARM)

Mode of access: Internet

Stratocumulus Precipitation and Entrainment Experiment (SPEE) Field Campaign Report

The scientific focus of this project was to examine precipitation and entrainment processes in marine stratocumulus clouds. The entrainment studies focused on characterizing cloud turbulence at cloud top using Doppler cloud radar observations. The precipitation studies focused on characterizing the precipitation and the macroscopic properties (cloud thickness, and liquid water path) of the clouds. This project will contribute to the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s overall objective of providing the remote-sensing observations needed to improve the representation of key cloud processes in climate models. It will be of direct relevance to the components of ARM dealing with entrainment and precipitation processes in stratiform clouds. Further, the radar observing techniques that will be used in this study were developed using ARM Southern Great Plains (SGP) facility observations under Atmospheric System Research (ASR) support. The observing systems operating automatously from a site located just north of the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) aircraft hangar in Marina, California during the period of 1 May to 4 November 2015 included: 1. Microwave radiometer: ARM Microwave Radiometer, 3-Channel (MWR3C) with channels centered at 23.834, 30, and 89 GHz; supported by Dr. Maria Cadeddu. 2. Cloud Radar: CIRPAS 95 GHz Frequency Modulated Continuous Wave (FMCW) Cloud Radar (Centroid Frequency Chirp Rate [CFCR]); operations overseen by Drs. Ghate and Albrecht. 3. Ceilometer: Vaisala CK-14; operations overseen by Drs. Ghate and Albrecht

Desert-Urban System Integrated Atmospheric Monsoon (DUSTIEAIM) in the Southwestern United States Science Plan

The Desert-Urban System Integrated Atmospheric Monsoon (DUSTIEAIM) campaign is a groundbreaking, high-impact scientific mission that will transform how we understand and respond to energy and water challenges in one of America’s fastest-growing and most heat-stressed urban regions: Phoenix, Arizona. Starting in April 2026, this 18-month field campaign harnesses the full power of the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) user facility and an interdisciplinary science team including national laboratories, universities, and agencies with a broad range of subject-matter expertise. With cutting-edge instruments, active and passive ground-based sensors, radars, and integrated modeling, DUSTIEAIM will deliver the most comprehensive environmental data set ever collected for a desert-urban-agricultural interface

Validation of the ASCAT Soil Water Index using in situ data from the International Soil Moisture Network

tSoil moisture is an essential climate variable and a key parameter in hydrology, meteorology and agricul-ture. Surface Soil Moisture (SSM) can be estimated from measurements taken by ASCAT onboard Metop-Aand have been successfully validated by several studies. Profile soil moisture, while equally important,cannot be directly measured by remote sensing but must be modeled. The Soil Water Index (SWI) productdeveloped for near real time applications within the framework of the GMES project geoland2 aims toprovide such a modeled profile estimate using satellite data as input. It is produced from ASCAT SSMestimates using a two-layer water balance model which describes the relationship between surface andprofile soil moisture as a function of time. It provides daily global data about moisture conditions foreight characteristic time lengths representing different depths.The objective of this work was to assess the overall quality of the SWI data. Furthermore we tested theassumptions of the used water balance model and checked if ancillary information about topography,water fraction and noise information are useful for identifying observations of questionable quality. SWIdata from January 1st 2007 until the end of 2011 was compared to in situ soil moisture data from 664stations belonging to 23 observation networks which are available through the International Soil MoistureNetwork (ISMN). These stations delivered 2081 time series at different depths which were compared tothe SWI values.The average of the significant Pearson correlation coefficients was 0.54 while being greater than 0.5 for64.4% of all time series. It was found that the characteristic time length showing the highest correlationincreases with in situ observation depth, thus confirming the SWI model assumptions. Relationships ofthe correlation coefficients with topographic complexity, water fraction, in situ observation depth, andsoil moisture noise were found