ACRF Instrumentation Status: New, Current, and Future January 2007

TL;DR: In this article, an overview of Atmospheric Radiation Measurement Program Climate Research Facility instrumentation status is provided, divided into four sections: new instrumentation in the process of being acquired and deployed, existing instrumentation and progress on improvements or upgrades, proposed future instrumentation, and Small Business Innovation Research instrument development.

Abstract: The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Program Climate Research Facility instrumentation status. The report is divided into four sections: (1) new instrumentation in the process of being acquired and deployed, (2) existing instrumentation and progress on improvements or upgrades, (3) proposed future instrumentation, and (4) Small Business Innovation Research instrument development. New information is highlighted in blue text.

Summary

Introduction

• The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Program Climate Research Facility instrumentation status.
• New information is highlighted in blue text.

1.1 183 GHz Microwave Radiometer

• Radiometrics Corporation has proposed to deploy at NSA-Barrow a new 183 GHz microwave radiometer that they have developed under a DOE SBIR grant (ECO-00609).
• STATUS – The radiometer will be deployed in late January or early February as part of the Radiative Heating in Under-explored Bands Campaign .

1.2 High-Frequency (90/150 GHz) Microwave Radiometer

• In response to the need for greater sensitivity (and therefore higher frequency) microwave channels to more accurately measure liquid water paths in thin clouds than the current 23.8/31.4 GHz instruments permit, a new High-Frequency Microwave Radiometer has been acquired, and is currently deployed at SGP (ECO-00491).
• STATUS – Deployment of the new MWRHF to the NSA-Barrow site has been delayed due to funding limitations associated with the Continuing Resolution.
• A second instrument, to be deployed with the ARM Mobile Facility in Germany, is currently on order.

1.3.2 Upgrade Earlier Type-4 Micro-Pulse Lidars

• STATUS – All three of the upgraded systems have successfully completed acceptance testing.
• One was installed on Manus Island in early December.
• One will be sent to Germany with the AMF.

1.4 Radar Wind Profiler

• Rich Coulter, Argonne National Laboratory A 4-panel 1290 MHz RWP has been ordered from Vaisala for the 2007 AMF deployment in Germany, also known as Mentor.
• An operating frequency of 1290 MHz was selected to match EU and other global frequency allocations for boundary layer radar profilers (ECO-00513).
• In July the FAA denied a request for a license to operate the new RWP at the SGP for testing prior to the AMF deployment to Germany in April 2007.
• The new RWP is in storage at SGP awaiting shipment to Germany.

1.5 Infrared Sky Imager

• Mentor: Vic Morris, Pacific Northwest National Laboratory An IR sky imager from Blue Sky Imaging (http://www.aas.org/career/bluesky.html) was deployed at SGP in September 2005 to provide nighttime cloud cover measurements (ECO-00429).
• Problems with moisture infiltration of the imager necessitated its return to the manufacturer for repair/revision in October 2005.
• The unit was returned to SGP in late June and returned to service in August.
• December 2006 – At the Cloud Properties Working Group meeting in Annapolis, Vic recounted the difficulties with the instrument and also in obtaining support from the instrument manufacturer.
• Vic is looking into other IR sky imaging systems that may be more satisfactory.

1.6 Add Multi-Filter Radiometers to Cessna 206 (In-situ Aerosol Profiling aircraft)

• Currently, spectral albedo measurements are only possible at the SGP central facility using downward facing Multi-Filter Radiometers (MFR) on the 25-m level of the 60-m tower over a wheat field, and on a 10-m tower over the adjoining pasture.
• By adding a MFR to the Cessna 206 used for the In-situ Aerosol Profile (IAP), routine measurements of surface spectral albedo could be acquired over a broader area around the SGP central facility (ECO-00584).
• STATUS – A statement of work has been developed to modify the aircraft to mount the MFR in the wing-tip extenders and incorporate it into the data acquisition system.

1.7 Hot Plate Total Precipitation Sensor

• This is a new sensor developed by Roy Rasmussen at National Center for Atmospheric Research and commercialized by Yankee Environmental Systems.
• It offers the promise of handling under-catchment due to winds.
• If the first sensor compares well with the CRN measurements, a second TPS could be acquired for mounting on the 40-m tower at Barrow to discriminate between blowing and falling snow.
• STATUS – Data are available from the ARM Archive.

1.8 DigiCORA-III for Manus, Nauru

• The digiCORA is the ground station for the Vaisala balloon borne sounding system.
• In FY 2003-2004 new digiCORA-III systems were acquired and deployed at SGP-CF, NSA-Barrow, and AMF as the January 2007, DOE/SC-ARM/P-XX-XXX.X 3 primary ground station for those sites.
• January 2007, DOE/SC-ARM/P-XX-XXX.X 5 2 Existing Instrumentation.
• The information is abstracted primarily from the Instrument Mentor Monthly Summary reports (available from the instrument web pages) and from ECO status updates.

2.1 Atmospherically Emitted Radiance Interferometer

• Dave Turner, Space Science and Engineering Center, University of Wisconsin SGP – Both the OS/2-based AERI and the Windows XP-based AERI are operating nominally, also known as Mentor.
• Efforts to try to reduce the RFI noise in the NSA-C1 data via post-processing of the raw data are on going.
• TWP – This Windows XP-based AERI is operating nominally.
• The spare ER-AERI is being repaired and will be redeployed at Barrow in support of the Radiative Heating in Under-explored Bands Campaign .
• The OS/2-based spare AERI at SSEC would need to have the aging laser replaced in its interferometer before it could be sent to Darwin as a replacement.

2.1.1 Windows and Rapid-Sampling Upgrade

• Migration of the AERI software from OS/2 Warp to Windows XP and related computer hardware modernization to enable rapid sampling of the IR spectrum at 10-s intervals was begun in FY 2004 (ECO00286).
• In FY 2005, 2 AERI systems were upgraded and installed at NSA-Barrow and SGP-CF.
• The laser in the AERI at Darwin failed shortly after it was upgraded.
• December 2006 – The TWP AERI system at Nauru has been upgraded (using the upgraded electronics rack recently transferred from Darwin) and appears to be operating properly.
• Work will begin to update that electronics rack as soon as it is received at UW-SSEC.

2.2 Aerosol Observing System

• John Ogren and Anne Jefferson, National Oceanic and Atmospheric Administration/Earth System Research Laboratory/Global Monitoring Division The CPC (Condensation Particle Counter) at SGP has been giving periodic error signals that indicate a problem with the instrument laser, also known as Mentor.
• All other instrument parameters are within acceptable range and the particle counts track well with the aerosol scattering values from the nephelometer.
• The CPC has been returned to the mentor for diagnosis and repair.
• The mentor has loaned a CPC (same model) to SGP until the AOS CPC is repaired.

2.3.1 Make Atmospheric Radiation Measurement Program-Barrow Soundings Available to the Global Telecommunication System

• STATUS – Soundings from SGP and NSA are now available to the GTS.
• Soundings from TWP (Manus and Nauru) will also be available to the GTS once the new DigiCORA-III systems are installed and operational there.

2.4 Broadband Radiometers (SIRS, SKYRAD, GNDRAD, BRS)

• Tom Stoffel, National Renewable Energy Laboratory Broadband Radiation System (BRS) data for December 2006 were excellent with 100% data collection and more than 95% of the shortwave and 100% of the longwave data passing automated data quality tests, also known as Mentor.
• SKYRAD data for December 2006 was excellent with 100% data collection at all stations (NIM, NSA, and TWP).
• Measured global is generally less than the summed direct and diffuse.
• Similar discrepancies occur during partly cloudy conditions during any daylight period.
• Each of these measurement issues remains under study.

2.4.1 Pyrgeometer Calibration Improvements

• Tom Stoffel and Ibrahim Reda have initiated an investigation into the source of the bias in the ACRF pyrgeometer blackbody calibration system.
• At blackbody temperatures less than -20°C, the Dow Corning 200 fluid viscosity increases, which inhibits mixing and results in a temperature gradient of 1.5 to 2.0°C from the base to the top of the hemispherical blackbody.
• Additionally, a replacement fluid with better low-temperature characteristics has been identified.
• The data acquisition system in the Radiometer Calibration Facility (RCF) used for annual Broadband Outdoor Radiometer Calibration activities is over ten years old and needs to be updated.
• NREL has recently replaced their BORCAL data acquisition system using internal funds.

2.5 Carbon Dioxide Flux System

• Mentor: Marc Fischer, Lawrence Berkeley National Laboratory.
• The CO2FLX instruments at 4, 25, and 60 m on the SGP-CF tower are operating nominally with the exception of the net radiometers.
• During December, the CNR-lite net radiometer was returned to LBNL for re-calibration.
• It appears that the data from the downwelling long wave channel on the CNR-1 continues to be incorrect.

2.8.1 Internet Data Transfer

• The transfer of CSPHOT data from the Cimel instrument to AERONET using geostationary operational environmental satellite or Meteosat will be replaced with an Internet data transfer to improve reliability of the transfer, to permit ACRF personnel to monitor the transfer, and to allow the raw data to be acquired, ingested, and archived for use by ARM Science Team members (ECO-00555).
• December 2006 – Internet transfer of CSPHOT data to AEORNET has been initiated at TWP-Nauru and SGP sites.

2.10 Energy Balance Bowen Ratio Station

• David Cook, Argonne National Laboratory Most EBBR stations are operating nominally, also known as Mentor.
• The AEM at Earlsboro (E27) is scheduled for replacement in January.
• The schedule for recalibrating the EBBR sensors has been accelerated to ensure completion prior to the Cloud-LAnd Surface Interaction Campaign in June.
• Vaisala no longer supports the combined temperature and relative humidity probes in the EBBR (2 per system) but does still offer recalibration services.
• As the old probes are replaced they can be used as spares for the systems not yet upgraded to the new probes.

2.11 Eddy Correlation Station

• David Cook, Argonne National Laboratory SGP – All ECOR stations are operating nominally, also known as Mentor.
• The system at E10 (Tyro) was returned to service in January.
• The schedule for recalibrating the CO2 and H2O sensors has been accelerated to ensure completion prior to the Cloud-LAnd Surface Interaction Campaign in June.
• AMF – The CO2 concentration and flux data from the AMF ECOR are periodically affected by aircraft operations at the adjacent Niamey airport.

2.11.1 Add Wetness Sensors

• Periods of dew, frost, and precipitation often cause data from the CO2/H2O sensor and sonic anemometer to be incorrect.
• Adding a wetness indication would provide the data user with a more reliable source of information concerning this condition (ECO-00536).
• STATUS – Testing of a wetness sensor on an Argonne ECOR system similar to those deployed by ARM began in mid-January.

2.12 G-Band (183.3 GHz) Water Vapor Radiometer

• Maria Cadeddu, Argonne National Laboratory Occasional problems with the GVR software resulted in brief gaps in the data during December, also known as Mentor.
• GVR data are now available from the ARM Archive under the name nsagvrC1.
• The measurements are in agreement with model computations.

2.13 Global Positioning System (SuomiNet)

• None (external data provided by SuomiNet/COSMIC) SGP – Telecommunications problems at LeRoy (E3), Halstead (E5), and El Reno (E19) continue to affect data availability from these SuomiNet stations, also known as Mentor.
• The unit will be repaired under warranty but must be returned to the U.S. for warranty service.
• Following this repair, the GPS receivers at Manus and Darwin will be returned to the manufacturer to have the defective component replaced prior to failure.
• The temperature/relative humidity probe associated with the Barrow system failed in August 2005.
• The spare ARM GPS meteorological system currently in use at Barrow will be connected to this receiver once the UAF met system is repaired and returned to Barrow, then the Atqasuk station will be incorporated into SuomiNet to provide precipitable water vapor data.

2.14 In-situ Aerosol Profiling

• Mentor: John Ogren and Betsy Andrews, National Oceanic and Atmospheric Administration/Earth System Research Laboratory/Global Monitoring Division.
• The high (85%) relative humidity nephelometer continued to have problems after being replaced in September.
• Also, the engine pump that draws sample air through the optical instruments failed in late December.
• Data from those instruments (nephs+psap) will be invalid from December 21 until the pump is repaired.

2.15 InfraRed Thermometer

• Vic Morris, Pacific Northwest National Laboratory InfraRed Thermometers (IRTs) have been deployed at 12 SGP extended facilities (ECO-345), operating at 5 Hz sampling rate, also known as Mentor.
• IRTs are also part of the SKYRAD and GNDRAD systems at TWP, NSA, and AMF.
• Plans to increase the sampling rate of the SKYRAD IRTs to 5 The IRTs are operating nominally at all sites except SGP E13 and E19 where higher sky temperatures were measured than at other sites.
• An IRT and its enclosure were sent to the manufacturer for diagnosis.
• They did not find any problems with the design of the enclosure/mirror system and suggested that the influence of the mirror on the measured temperature be accounted for.

2.16 Multi-Filter Rotating Shadowband Radiometer and Related Systems (MFR, GNDMFR, NIMFR)

• Gary Hodges, National Oceanic and Atmospheric Administration/Earth System Research Laboratory/Global Monitoring Division; John Schmelzer, Pacific Northwest National Laboratory John Schmelzer has indicated he plans to retire in May, also known as Mentor.
• NSA – MFRSR, MFR, and NIMFR have been removed for the winter.
• John Schmelzer will refurbish and recalibrate them.
• January 2007, DOE/SC-ARM/P-XX-XXX.X 12 Twice-per-day cleaning of the Normal Incidence Multi-Filter Radiometer at SGP has been initiated to eliminate the step-change in the measurements observed following the current once-per-day cleaning events.
• November 2006 – Gary Hodges traveled to several SGP extended facilities in October to investigate recurring shading problems with the MFRSRs.

2.16.1 Filter-Detectors

• ACRF has ~50 multi-filter radiometers deployed in a variety of configurations including the MFRSR, the downward-facing MFR, and the NIMFR.
• The 6 narrow band (10 nm) filter-detectors in almost all of these sensors have degraded over time and are in urgent need of replacement.
• Perkin-Elmer has manufactured custom-designed and custom-built filter-detector assemblies to meet ACRF specifications (ECO-00580).
• STATUS – John Schemelzer has built 90 new sensor arrays using the new filter-detectors and has used 40 of these to refurbish 40 MFRSR heads.
• So far, 6 of these have completed the calibration process and 3 have been sent to SGP for installation along with new Campbell data loggers.

2.16.2 Multi-Filter Rotating Shadowband Radiometer Calibration and Data Processing Improvements

• Problems with the calibration and data processing of the MFRSRs were revealed during the ALIVE campaign (ECO-00571).
• Joe Michalsky convened a meeting at Pacific Northwest National Laboratory during the last week of January to discuss the calibration issues and develop a plan to address them.
• Nighttime measurements will be collected from the existing MFRSRs to derive an offset correction.
• New calibration processing will be implemented based on the consensus procedures developed during the meeting.
• Collection and ingest development are proceeding but have been delayed by the need to accommodate both the current proprietary data loggers and the new Campbell Scientific data loggers.

2.16.3 Data Logger Replacement

• The proprietary data loggers supplied with the MFRSRs and related instruments are to be replaced with Campbell Scientific CR1000 data loggers.
• This will permit them to be more easily maintained.
• It will also permit modifications to the operation of the instruments and data acquisition to be easily implemented (ECO-00350).
• January 2007, DOE/SC-ARM/P-XX-XXX.X 13 STATUS – John Schmelzer sent three new loggers and related equipment to SGP.
• Replacement of the MFRSR loggers will begin in January.

2.17.1 MMCR Processor Upgrades

• (ECO-00283) Spectral imaging problems with the PIRAQ-III processor have been resolved at Darwin by installing newly developed filter coefficients.
• The spare PIRAQ-III processor will be installed in the MMCR at Darwin to replace the PIRAQ-III that failed.
• The NSA upgrade will be delayed until the failed processor is repaired or another spare is purchased.

2.17.3 Spare Traveling Wave Tubes

• New traveling wave tubes (TWT) will be ordered to replace the TWTs originally delivered with the MMCRs, which are well beyond their rated lifetime and are beginning to fail (ECO-00425).
• The first TWT delivered to SGP was incorporated into a TWTA and sent to Nauru to repair the MMCR there.
• Two more TWTs have been received, which will go to Manus and Barrow.
• Two additional TWTs have been ordered as spares.

2.17.4 Millimeter Wave Cloud Radar Spectra Processing

• Spectra files produced by the upgraded MMCRs (C40 or PIRAQ-III processors) range from 8 to 15 Gigabytes per day.
• Algorithms for eliminating clear-sky periods and compressing the files need to be developed and implemented locally (ECO-00391).
• STATUS – The compression algorithms have been implemented at SGP.

2.17.5 Refurbish Millimeter Wave Cloud Radar Antennas

• Beginning in 2007, over a three-year period the MMCR antennas will be refurbished and characterized on an antenna range (ECO-00551).
• STATUS – The antenna is complete and the contract for the new feed and sub-reflector has been placed.
• Once these are complete, they will be installed on the antenna reflector and calibrated.
• The Barrow MMCR antenna will most like be refurbished first to avoid impacting planned IOPs at SGP.

2.18 Micro-Pulse Lidar

• Rich Coulter, Argonne National Laboratory New, polarized MPLs are operating at SGP, Darwin, Nauru, and Barrow, also known as Mentor.
• TWP – The new MPL at Nauru has been working well.
• The Darwin MPL has been producing excellent data in spite of decreasing energy output; however, in mid-December a series of artifacts beginning at approximately 10 km and repeating at roughly 1 km intervals became apparent.
• This may indicate detector problem similar to those with the Barrow system.
• 15 A VAP has been developed to produce a file with separated polarization states, averaged to 30 seconds.

2.18.1 Retrofit Spectra-Physics Lasers

• The type-1 and type-2 units use Spectra-Physics lasers that are no longer supported (except for the AMF unit, which uses a LiteCycles laser that is no longer supported).
• ARM has one spare Spectra-Physics laser head.
• Four old Spectra-Physics laser supplies have been retrofitted by Sigma Space to use Coherent F-System laser diode modules and two remain to be retrofitted (ECO-00362).
• STATUS – Sigma Space Corp has upgraded the laser diode supplies from the type-1 MPLs at SGP and NSA.
• This will allow these type-1 systems to serve as backup systems.

2.19 MicroWave Radiometer

• Differences of as much as 0.7 K in brightness temperatures at 23.8 GHz (corresponding to ~0.5 mm PWV) were observed between radiometers.
• AMF – Few RFI spikes were observed in the MWR data in December.
• SGP/B5 – In October this radiometer was sent to the SGP central facility for inclusion in the MWR Inter-comparison IOP.
• In December this radiometer was sent to Manus to replace the failed MWR there.
• A replacement circuit card failed to restore operation.

2.19.1 Unify MicroWave Radiometer Connectors

• The Impulse connectors on the 3 MWRs at the TWP sites make it difficult to substitute a spare MWR in case of a failure, as occurred in Darwin prior to TWP-ICE due to a lightning strike.
• Accordingly, the Impulse connectors are being replaced with the standard connectors used on all other MWRs.
• STATUS – The MWR on Nauru has been swapped and returned to Radiometrics for replacement of the connectors and for repair.
• The MWR on Manus has also been swapped and is being returned to Radiometrics for repair and connector replacement.

2.20 MicroWave Radiometer Profiller

• Maria Cadeddu, Argonne National Laboratory NSA – Data for this month are generally good and continuous, also known as Mentor.
• The retrieved 2-channel LWP is consistent with the MWR retrievals, however the 6-channel retrieval shows a progressive drift towards negative values, reaching a negative LWP ~ 0.05 mm by the end of the month.
• Because the drift is not observed in the two-channel retrieval it is likely that there is a drift in the 51-GHz channel, which requires recalibration with liquid nitrogen.
• On 5 May a power outage affected the calibration.
• Liquid nitrogen is required to recalibrate the 51-59 GHz channels, but is difficult to obtain in Niamey.

2.21 Narrow Field of View Radiometer (NFOV)

• None The Narrow Field of View (NFOV) radiometer has been removed from service at SGP and sent to NASA GSFC for calibration using the AERONET facilities, also known as Mentor.
• It will be deployed with the AMF in Germany.
• Christine Chiu reports that the calibration at NASA GSFC resulted in good agreement with a Cimel sunphotometer at 940 nm, but poor agreement at 673 nm.
• The NFOV will be returned to PNNL to replace the filter-detector at 673 nm.
• This may delay its deployment to Germany.

2.22.1 Add Automatic Alignment System

• Due to small thermal gradients in the laser and the lidar enclosure, the alignment of laser beam in the detectors’ field-of-view (FOV) changes with time, which can affect the data quality, sometimes substantially.
• To address this operationally, the laser beam is swept through the detectors’.
• This “alignment tweak” is scheduled to occur every 3 hours.
• It affects all measurements, but the aerosol extinction measurements and the temperature profiles seem to be the most sensitive.
• STATUS – Licel has recently made improvements to the alignment sensor and has exchanged the original sensor for a new one.

2.23 Rotating Shadowband Spectrometer

• Peter Kiedron, State University of New York at Albany The RSS is operating nominally, also known as Mentor.
• Automatic processing of calibration data is under development by Peter Kiedron and Jim Schlemmer.

2.24 Radar Wind Profiler – 915 MHz

• Rich Coulter, Argonne National Laboratory SGP – Currently, all systems at SGP are operating nominally, also known as Mentor.
• The SGP/C1 (central facility) and SGP/I3 have had the digital receiver upgrades successfully installed.
• The problem with RASS data being “reflected” at large range gates has mysteriously improved recently.
• Maybe the upgraded hardware, LAPXM software, and new computer will help resolve this problem.

2.24.1 Upgrade to Digital Receivers

• The four 915 MHz RWPs at the SGP are now 9-13 years old and are exhibiting increasingly frequent, strange, and expensive-to-repair failures.
• This may pose problems for CLASIC, scheduled in 2007.
• Due to the age of these systems, parts are increasingly difficult to obtain (Vaisala no longer has exact replacements for some items; the available parts must be modified for use in their systems).
• Vaisala offers an upgrade for these systems that will replace the present interface, receiver and computer (including DSP board) with new components and will include the latest version of LAPXM, the operating system.
• The systems at SGP/CF and SGP/I3 will be upgraded.

2.25 Radar Wind Profiler – 50 MHz

• In January the 50 MHz RWP at the SGP ceased transmitting.
• After reinstalling the transmitter the output power was still zero.
• Vaisala has loaned SGP test equipment to help diagnose the problem.
• STATUS – Discussions with Vaisala about this problem are on-going.

2.26.1 Replace In-Ground Sensor Arrays

• The in-ground sensors for the SWATS deployed at all 22 SGP Extended Facilities (EFs) are arranged in two redundant vertical arrays so that if/when a sensor fails, there is a redundant sensor at the same level.
• This is necessary because disturbing the soil to replace a failed sensor adversely affects the measurements January 2007, DOE/SC-ARM/P-XX-XXX.X 19 for 6-12 months afterward depending on soil type.
• At this time 8 of the 22 SWATS installations have at least one failed sensor, and 5 sites have 2 or more failed sensors.
• These will be installed in a phased manner: 5 sites per year over the next 4 years beginning in 2005 with the sites having multiple failed sensors given highest priority.
• In May, John Harris and Don Bond installed new sensor arrays at three Extended Facilities to replace old sensors that have ceased to function.

2.28 Surface Meteorological Instrumentation (SMET, SMOS, SURTHREF, THWAPS, MET, ORG, PWS)

• Mike Ritsche, Argonne National Laboratory SGP (SMOS) – TWP (SMET, ORG) – All systems are operating nominally, also known as Mentor.
• The barometer at Nauru failed in early December.
• Ice accumulates on the vane and causes the direction measurements to become sluggish (standard deviations at or near 0).
• AMF (MET, ORG) – The ORG continues to be underreport relative to the PWS and non-ACRF tipping bucket rain gauge.

2.28.1 Develop Dynamic Rain Gauge Calibration Facility

• The tipping bucket rain gauges at the 15 SGP/EF sites with SMOS are currently calibrated using only a “static” calibration: a measured volume of water is poured into the gauge and the number of bucket tips is checked to ensure they correspond.
• In reality, as the rain rate increases and the bucket tips more frequently some rain is not collected.
• The purpose of the dynamic calibration is to determine the correction factor as a function of rain rate to account for this behavior (ECO-00495).
• STATUS – Problems have developed with the software developed by the University of Iowa that have prevented successful calibrations from being obtained.
• An alternative approach has been proposed (ECR606) but will be deferred until higher priority instrument procurements are completed.

2.28.2 Create Atmospheric Radiation Measurement Program Climate Research Facility Wind Sensor Repair Facility

• Rather than return ACRF wind sensors to the manufacturer for repair, it is cost effective and far quicker to perform the repairs and calibrations on-site.
• Repair facilities will be established at the SGP central facility and the TWP Darwin site (ECO-00561).
• All necessary components have been received at SGP; spare parts are in route to TWP.
• Testing and repair procedures have been prepared and distributed to the SGP and TWP Site Operations Teams.
• SMOS and THWAPS wind sensor checks will begin soon.

2.28.3 Upgrade T/RH Probes and Wind Sensors for NSA Met Systems

• Ice develops on the wind vanes, cup anemoneters, and aspirator inlets for the temperature and relative humidity sensors, which clog and affect the data quality.
• To alleviate these problems the mentor has proposed to replace the wind speed and direction sensors at NSA (both Barrow and Atqasuk) with sonic anemometers, and to replace the temperature and relative humidity probes with new, heated probes designed to operate in cold environments (ECO-00595).
• STATUS – Deferred until higher priority instrument procurements are completed.

2.29 Tandem Differential Mobility Analyzer

• Mentor: Don Collins, Texas A&M University Don Collins presented a poster at the 9th Symposium on Atmospheric Chemistry at the American Meteorological Society meeting in San Antonio entitled “The Atmospheric Radiation Measurement Program tandem differential mobility analyzer: Instrument description and summary of the first year of data.”.
• Data from the Tandem Differential Mobility Analyzer (TDMA) are currently acquired and processed by Don Collins.
• Processed data are then delivered to ACRF on a monthly basis and stored in the IOP area of the Archive as “beta-data.”.
• An ingest is being developed to produce netcdf files for inclusion in the main Archive (ECO-587).

2.30 Total Sky Imager

• Vic Morris, Pacific Northwest National Laboratory SGP – Operating nominally, also known as Mentor.
• Birds occasionally perch on system, affecting the imagery.
• Communication with the mirror control board failed in late August.
• The instrument has been sent to Darwin for repair.
• On October 30 the TSI stopped collecting data because the sun will not rise more than 5° above the horizon until February.

2.31 Meteorological Tower Systems

• David Cook, Argonne National Laboratory 60-m tower at SGP C1 (central facility) – nominal operation, also known as Mentor.
• 40-m tower at NSA C1 – problems due to ice formation on temperature/humidity sensors and on the wind direction vanes continue.
• Replacement of these sensors with sonic anemometers and heated temperature/humidity probes has been proposedis being considered (ECO-00595).
• David has begun planning for annual tower maintenance at SGP and NSA.

2.33 W-band (95 GHz) Atmospheric Radiation Measurement Program Cloud Radar

• Kevin Widener, Pacific Northwest National Laboratory SGP – Operating nominally; 100% up time in December, also known as Mentor.
• The radar has been shipped to ProSensing for warranty repair then will be reinstalled at the AMF site in Germany.
• Acquisition of all new instrumentation is on hold pending the prioritization of instrument needs by the ARM Science Team Executive Committee and the resolution of the Federal budget situation.

3.1 Atmospheric Radiation Measurement Program Volume-Imaging Array

• The ARM Volume-Imaging Array (AVA) is a proposed radar system to be deployed at the ARM SGP site to address the ARM program’s need of mapping 3D cloud and precipitation structures at short to medium ranges (i.e., 20-75 km).
• The AVA system will provide time-resolved 3D precipitation fields, domain-averaged rainfall rate, cloud coverage throughout a volume, cloud-top heights, hydrometeor phase information (using polarization), horizontal and vertical variability of clouds and precipitation, and low-level convergence and divergence using dual-Doppler techniques.
• Principal elements of the AVA proposal prepared by Pavlos Kolias include: Three networked scanning radars arranged in a triangle with 20-30 km legs: one operating at 35 GHz (same 8.6-mm wavelength as the MMCR) and capable of scanning the vertical region probed by the current MMCR, and two radars operating at 9.4 GHz (3.2-cm wavelength, so-called “X-band”).
• Development of a useful 3D cloud Value Added Product (VAP) similar to the existing ARSCL but on a regular 3D grid.
• STATUS – Consideration of the AVA, as such, has been deferred until 2008 when simulations have been carried out to demonstrate its capabilities and further refine its requirements.

3.3 Absolute Scanning Radiometer

• To provide an absolute IR flux reference, which could be used to calibrate the Eppley PIRs, Ells Dutton has suggested that ARM develop an Absolute Scanning Radiometer (ASR).
• This instrument would be functionally equivalent to an ASR developed by Rolf Philipona for the WMO.
• As such it would participate in WMO inter-comparisons at Davos, Switzerland every five years.
• No successful proposals were received.
• Ells Dutton, Tom Stoffel, and Joe Michalsky are planning to develop a specification so that ACRF may send out a request for proposals to identify interest and cost for such an instrument.

3.4 High-Resolution Oxygen A-Band and Water-Band Spectrometer

• Qilong Min has submitted a proposal to build an A-band spectrometer for ARM following his presentation to the Cloud Properties working group in October 2004 on this topic.
• The 3-year proposal and budget were sent out for technical reviews.
• The technical reviews, along with the proposal and budget, were then provided to the STEC.
• The STEC directed Qilong to present his plan and budget to the Cloud Properties working group at their November 2005 meeting for prioritization.
• Qilong presented a revised work plan (water-band/cloud phase components removed) and has submitted a revised budget.

3.5 Rotating Shadowband Spectrometer Overhaul

• Peter Kiedron has demonstrated that the RSS built by Yankee Environmental System is capable of providing valuable measurements of direct, diffuse, and global spectral irradiance.
• Peter has also identified problems with the RSS that affect the stability of its calibration and the linearity of its response.
• Peter has recommended that the RSS be removed from service and sent to him at SUNY-Albany for a complete overhaul.

3.6 Add 1.6 :m Channel to Multi-Filter Rotating Shadowband Radiometer and Narrow Field of View

• Alexander Marshak has recommended that ARM support the development of a NFOV radiometer at 1.6 µm to permit the retrieval of droplet size distribution.
• Andy Lacis and colleagues have suggested a 1.6 µm channel be substituted for the unfiltered channel in the MFRSR.
• A cursory examination of Perkin-Elmer’s web pages reveals Indium-Galium-Arsinide detectors are available that operate in this spectral region.
• July 2006 – Two InGaAs detectors and two 1.6 µm filters have been purchased to determine the feasibility of implementing them in the MFRSR and/or NFOV.
• In the MFRSR this filter-detector would replace the unfiltered channel.

3.8 Future Microwave Radiometers

• The 2-channel MWRs range between 6-13 years old.
• They are no longer being manufactured; Radiometrics has replaced them with an instrument that sequentially tunes to 5 frequencies in the 22-30 GHz range.
• It is useful to begin considering replacements for these instruments.
• RPG offers a comparably priced 3-channel radiometer (23.8, 31.4, 90.0 GHz) that could also be considered because it increases the sensitivity to thin liquid water clouds.
• It is also desirable to acquire a final, “production” version of the 183 GHz microwave radiometer developed by ProSensing under a U.S. Department of Energy (DOE) SBIR Phase II award and deployed at Barrow since April 2005.

3.9 Modified Muti-Filter Rotating Shadowband Radiometer for Liquid Water Path

• Qilong Min has proposed to modify the existing MFRSRs to permit him to retrieve liquid water path.
• Software modifications would be required to position the shadow band at several additional angles near the solar disk; modifications to the shadow band would be needed to either narrow it or increase its distance from the diffuser.
• A narrower diffuser (and modification to the sensor head) and an improved stepper motor and motor controller have also been proposed.
• A first phase might utilize a Rotating Shadowband Radiometer loaned to Min from Brookhaven National Laboratory.

3.10 Infrared Thermometers for the Southern Great Plains Extended Facility Sites

• Some of these have been deployed with the AMF.
• Twelve SGP EF sites are currently equipped with IRTs; 10 additional IRTs would be needed to permit an IRT to be deployed at all 22 SGP extended facilities.
• January 2007, DOE/SC-ARM/P-XX-XXX.X 27 4 Small Business Innovation Research 4.1 Eye-Safe Ultraviolet Backscatter Lidar for Detection of Sub-visual Cirrus (FY 2006) Based on recommendations from the 2004 Cloud Properties working group meeting, this subtopic was substituted for the A-band spectrometer subtopic.

4.2 Instrumentation for Remotely Sensing Aerosol Optical Properties – Aerosol Phase Function (FY 2006)

• Based on recommendations from the Aerosol working group, this subtopic was added to the aerosol measurements subtopic.
• Phase I funding was awarded to Aerodyne Research, Inc.: “CAPS-Based Particle Single Scattering Albedo Monitor.”.

4.4 Radiometer Radiosonde (FY 2006 National Science Foundation Solicitation)

• The objective is to obtain a radiosonde with an onboard radiometer suitable for accounting for the radiative heating of the temperature sensor in the upper atmosphere.
• July 2006 – Matt Heun of Global Aerospace inquired about ARM’s requirements for heating rate profile measurements.
• Currently, there is a huge gap in spatial scale between in-situ measurements of cloud properties, typically from aircraft and balloons whose instruments have sample volumes on the order of cubic centimeters, and remote sensing retrievals of cloud properties, which have sample volumes ranging from tens of cubic meters (radar and lidar) to thousands of cubic meters .
• Since clouds are inhomogeneous down to centimeter scales, there is a complete lack of comparability between in-situ measurements and remote retrievals; simple assumptions of homogeneity to scale up the in-situ measurements are certainly false.

Full text

DOE/SC-ARM/P-07-002.1
ACRF Instrumentation Status:
New, Current, and Future
January 2007
James Liljegren
ACRF Instrument Team Coordinator
Work supported by the U.S. Department of Energy,
Office of Science, Office of Biological and Environmental Research

Summary
The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation
Measurement Program Climate Research Facility instrumentation status. The report is divided into four
sections: (1) new instrumentation in the process of being acquired and deployed, (2) existing
instrumentation and progress on improvements or upgrades, (3) proposed future instrumentation, and
(4) Small Business Innovation Research instrument development. New information is highlighted in
blue text.

January 2007, DOE/SC-ARM/P-XX-XXX.X
iii
Contents
1
New Instrumentation...........................................................................................................................1
1.1 183 GHz Microwave Radiometer.............................................................................................. 1
1.2 High-Frequency Microwave Radiometer.................................................................................. 1
1.3 Micro-Pulse Lidar...................................................................................................................... 1
1.3.1 New Micro-Pulse Lidars ..............................................................................................1
1.3.2 Upgrade Earlier Type-4 Micro-Pulse Lidars................................................................1
1.4 Radar Wind Profiler .................................................................................................................. 1
1.5 Infrared Sky Imager................................................................................................................... 2
1.6 Add Multi-Filter Radiometers to Cessna 206............................................................................ 2
1.7 Hot Plate Total Precipitation Sensor .........................................................................................2
1.8 DigiCORA-III for Manus, Nauru.............................................................................................. 2
2 Existing Instrumentation.....................................................................................................................5
2.1 Atmospherically Emitted Radiance Interferometer...................................................................5
2.1.1 Windows and Rapid-Sampling Upgrade......................................................................5
2.2 Aerosol Observing System........................................................................................................6
2.2.1 Reconfigure Southern Great Plains Aerosol Observing System ..................................6
2.3 Balloon-Borne Sound System ................................................................................................... 6
2.3.1 Make Atmospheric Radiation Measurement Program-Barrow Soundings
Available to the Global Telecommunication System...................................................6
2.4 Broadband Radiometers ............................................................................................................ 6
2.4.1 Pyrgeometer Calibration Improvements ......................................................................7
2.4.2 Radiometer Calibration Facility Data Acquisition System Replacement ....................7
2.5 Carbon Dioxide Flux System .................................................................................................... 7
2.6 Carbon Monoxide System......................................................................................................... 8
2.7 CO
2
System ...............................................................................................................................8
2.8 Cimel Sun Photometer...............................................................................................................8
2.8.1 Internet Data Transfer ..................................................................................................8
2.9 Disdrometer............................................................................................................................... 9
2.10 Energy Balance Bowen Ratio Station .......................................................................................9
2.11 Eddy Correlation Station........................................................................................................... 9
2.11.1 Add Wetness Sensors.................................................................................................10
2.12 G-Band Water Vapor Radiometer........................................................................................... 10
2.13 Global Positioning System...................................................................................................... 10
2.14 In-situ Aerosol Profiling..........................................................................................................11
2.15 InfraRed Thermometer............................................................................................................11
2.16 Multi-Filter Rotating Shadowband Radiometer and Related Systems.................................... 11
2.16.1 Filter-Detectors...........................................................................................................12
2.16.2 Multi-Filter Rotating Shadowband Radiometer Calibration and Data Processing
Improvements.............................................................................................................12
2.16.3 Data Logger Replacement..........................................................................................12
2.17 Millimeter Cloud Radar...........................................................................................................13
2.17.1 MMCR Processor Upgrades.......................................................................................13
2.17.2 Add Polarization at Barrow........................................................................................13
2.17.3 Spare Traveling Wave Tubes .....................................................................................13

January 2007, DOE/SC-ARM/P-XX-XXX.X
iv
2.17.4
Millimeter Wave Cloud Radar Spectra Processing....................................................14
2.17.5 Refurbish Millimeter Wave Cloud Radar Antennas ..................................................14
2.17.6 Radome or Radome Dryer..........................................................................................14
2.18 Micro-Pulse Lidar....................................................................................................................14
2.18.1 Retrofit Spectra-Physics Lasers..................................................................................15
2.19 MicroWave Radiometer .......................................................................................................... 15
2.19.1 Unify MicroWave Radiometer Connectors................................................................16
2.20 MicroWave Radiometer Profiller............................................................................................ 16
2.21 Narrow Field of View Radiometer.......................................................................................... 16
2.22 Raman Lidar............................................................................................................................16
2.22.1 Add Automatic Alignment System ............................................................................17
2.23 Rotating Shadowband Spectrometer ....................................................................................... 17
2.24 Radar Wind Profiler – 915 MHz............................................................................................. 18
2.24.1 Upgrade to Digital Receivers .....................................................................................18
2.25 Radar Wind Profiler – 50 MHz............................................................................................... 18
2.26 Soil Water and Temperature System....................................................................................... 18
2.26.1 Replace In-Ground Sensor Arrays .............................................................................18
2.27 Shortwave Spectrometer..........................................................................................................19
2.28 Surface Meteorological Instrumentation................................................................................. 19
2.28.1 Develop Dynamic Rain Gauge Calibration Facility...................................................20
2.28.2 Create Atmospheric Radiation Measurement Program Climate Research Facility
Wind Sensor Repair Facility ......................................................................................20
2.28.3 Upgrade T/RH Probes and Wind Sensors for NSA Met Systems..............................20
2.29 Tandem Differential Mobility Analyzer.................................................................................. 20
2.30 Total Sky Imager..................................................................................................................... 21
2.31 Meteorological Tower Systems............................................................................................... 21
2.32 Vaisala Ceilmeter ....................................................................................................................21
2.33 W-band Atmospheric Radiation Measurement Program Cloud Radar ...................................22
3 Future Instrumentation Planning.......................................................................................................23
3.1 Atmospheric Radiation Measurement Program Volume-Imaging Array................................ 23
3.2 Portable Raman Lidar..............................................................................................................24
3.3 Absolute Scanning Radiometer............................................................................................... 24
3.4 High-Resolution Oxygen A-Band and Water-Band Spectrometer.......................................... 24
3.5 Rotating Shadowband Spectrometer Overhaul .......................................................................24
3.6 Add 1.6 :m Channel to Multi-Filter Rotating Shadowband Radiometer and
Narrow Field of View.............................................................................................................. 25
3.7 Aerosol Particle Sizing Spectrometer to Replace Optical Particle Counter at
Southern Great Plains..............................................................................................................25
3.8 Future Microwave Radiometers .............................................................................................. 25
3.9 Modified Muti-Filter Rotating Shadowband Radiometer for Liquid Water Path ................... 25
3.10 Infrared Thermometers for the Southern Great Plains Extended Facility Sites ......................26

January 2007, DOE/SC-ARM/P-XX-XXX.X
v
4
Small Business Innovation Research ................................................................................................27
4.1 Eye-Safe Ultraviolet Backscatter Lidar for Detection of Sub-visual Cirrus ........................... 27
4.2 Instrumentation for Remotely Sensing Aerosol Optical Properties –
Aerosol Phase Function ..........................................................................................................27
4.3 Unmanned Aerospace Vehicle-Suitable Cloud Radar............................................................. 27
4.4 Radiometer Radiosonde ..........................................................................................................27
4.5 In-situ Measurement of Cloud Properties with Large Sample Volumes................................. 28

Frequently asked questions

Q1. Why is the PIRAQ processor on hold?

Because the PIRAQ processor does not support polarization, the installation of the orthomode transducer at Barrow is on hold until the next processor upgrade. 

Q2. Why is the unfiltered channel being used in a broadband radiometer?

Because the unfiltered channel is now being used in a broadband radiometer best estimate VAP for quality checking purposes, only a limited number of MFRSRs would be modified to accept a 1.6 µm channel. 

Q3. What is the name of the company that is proposing to deploy at NSA-Barrow?

Radiometrics Corporation has proposed to deploy at NSA-Barrow a new 183 GHz microwave radiometer that they have developed under a DOE SBIR grant (ECO-00609). 

Q4. What would be needed to position the shadow band at several additional angles near the solar disk?

Software modifications would be required to position the shadow band at several additional angles near the solar disk; modifications to the shadow band would be needed to either narrow it or increase its distance from the diffuser. 

Q5. How long will the MMCR antennas be refurbished?

Beginning in 2007, over a three-year period the MMCR antennas will be refurbished and characterized on an antenna range (ECO-00551). 

Q6. What is the status of the acquisition of the replacement cooling fluid?

STATUS – Acquisition of the replacement cooling fluid is on hold due to funding restrictions associated with the Continuing Resolution. 

Q7. Where is the spare ARM GPS system currently in use?

The spare ARM GPS meteorological system currently in use at Barrow will be connected to this receiver once the UAF met system is repaired and returned to Barrow, then the Atqasuk station will be incorporated into SuomiNet to provide precipitable water vapor data. 

Q8. What is the purpose of the new set of fluid dispersion manifolds?

A new set of fluid dispersion manifolds (perforated annuli) has been developed to reduce the temperature gradients in the blackbody. 

Q9. Why was the recovery at NSA reduced?

Reduced recovery at NSA was due to bad weather preventing either access to the Great White or launches because of blowing snow or high winds. 

Q10. Why is the drift not observed in the two-channel retrieval?

Because the drift is not observed in the two-channel retrieval it is likely that there is a drift in the 51-GHz channel, which requires recalibration with liquid nitrogen. 

Q11. What is the acute problem in the ARM program?

Most acute is the fact that in-situ measurements at a particular point give no information on the vertical distribution above and below that point, while active remote sensing retrievals typically give instantaneous vertically-resolved information. 

Q12. What is the name of the company that is proposing to develop an ASR?

To provide an absolute IR flux reference, which could be used to calibrate the Eppley PIRs, Ells Dutton has suggested that ARM develop an Absolute Scanning Radiometer (ASR). 

Q13. How many InGaAs detectors have been purchased?

July 2006 – Two InGaAs detectors and two 1.6 µm filters have been purchased to determine the feasibility of implementing them in the MFRSR and/or NFOV. 

Q14. What are the important measurements for cloud-climate applications?

Measurements of the following cloud properties are particularly wanted, in order of decreasing priority for cloud-climate applications: (a) extinction coefficient at one or more wavelengths in the solar spectrum away from strong water vapor absorption bands; (b) total water content (liquid plus ice); (c) liquid and ice water content separately; (d) effective radius, defined as the ratio of the 3rd to the 2nd moment of the drop size distribution; (e) absorption coefficient or single-scattering albedo at one or more wavelengths in the solar spectrum away from strong water vapor absorption bands; (f) the scattering phase function for ice clouds; (g) the drizzle and precipitation fraction of the total condensed water content; (h) the supersaturation; (i) the dispersion, a measure of the width of the drop size distribution. 

Q15. Who has demonstrated that the RSS is capable of providing valuable measurements of direct, diffuse, and global?

Peter Kiedron has demonstrated that the RSS built by Yankee Environmental System is capable of providing valuable measurements of direct, diffuse, and global spectral irradiance. 

Q16. How many sites will be installed in the next 4 years?

These will be installed in a phased manner: 5 sites per year over the next 4 years beginning in 2005 with the sites having multiple failed sensors given highest priority. 

Q17. Who is planning to develop a specification for an A-band spectrometer?

Ells Dutton, Tom Stoffel, and Joe Michalsky are planning to develop a specification so that ACRF may send out a request for proposals to identify interest and cost for such an instrument. 

Q18. What is the proposed solution to the problem of the wind speed and direction sensors?

To alleviate these problems the mentor has proposed to replace the wind speed and direction sensors at NSA (both Barrow and Atqasuk) with sonic anemometers, and to replace the temperature and relative humidity probes with new, heated probes designed to operate in cold environments (ECO-00595). 

Q19. What is the difference between in-situ measurements and remote retrievals?

Since clouds are inhomogeneous down to centimeter scales, there is a complete lack of comparability between in-situ measurements and remote retrievals; simple assumptions of homogeneity to scale up the in-situ measurements are certainly false.