Campaign : Fall 1997 Water Vapor IOP

1997.09.15 - 1997.10.05

Lead Scientist : Henry Revercomb

For data sets, see below.

Summary

The Water Vapor IOP was conducted as a follow-up to a predecessor IOP on water vapor held in September 1996. This IOP relied heavily on both ground-based guest and CART instrumentation and in-situ aircraft and tethered sonde/kite measurements. Primary operational hours were from 6 p.m. Central until at least midnight, with aircraft support normally from about 9 p.m. until midnight when available. However, many daytime measurements were made to support this IOP.

The first Water Vapor IOP primarily concentrated on the atmosphere's lowest kilometer. This IOP concentrated not only there but also on atmospheric layers up to 12 kilometers. A key goal of each Water Vapor IOPs was to reduce the uncertainties in water vapor observations integral to ARM spectroscopic analyses that contribute to better radiative transfer calculations for climate models. Each saw an assemblage of a wide array of both remote and in situ sampling platforms for observing water vapor profiles and precipitable water to ultimately learn how to best measure and characterize water vapor. Establishment of absolute calibration techniques and stability characterization for the CART Raman lidar was another prime goal of these IOPs.

Specific IOP objectives during fall 1997 included 1) evaluation of absolute calibration standards, 2) characterization of the accuracy of the routine CART water vapor measurements, 3) calibration of the CART Raman lidar independent of the BBSS, and 4) evaluation of methodologies for synthesizing more accurate measurements.

Guest ground-based instrumentation included the NASA/GSFC scanning Raman lidar, NOAA/CIRES microwave and infrared radiometers, Los Alamos National Laboratory (LANL) tethered balloon system with chilled mirror hygrometers, NOAA tethered kite and balloon system with chilled mirror hygrometers, ARM chilled mirror hygrometers at the 25- and 60-m levels on the 60-m tower and at the THWAPS (adjacent to BBSS launch station), NOAA GPS, capable of inferring integrated precipitable water vapor, University of Wisconsin AERI-00 and AERIbago, and NASA/Ames 6-channel tracking sunphotometer and two MICROTOPS hand-held sunphotometers. Critical ARM instrumentation for this IOP included the BBSS with dual sonde capability, Raman lidar, MWR, 60-m tower sensors, AERI, SMOS, MFRSR, and MPL.

All five IOP aircraft platforms were important for the Water Vapor IOP because each carried either a chilled mirror hygrometer (Citation, King Air, Gulfstream, and Twin Otter) and/or a frost-point hygrometer (Citation, Altus). Thus, every aircraft flight made during the Integrated IOP had benefit for the Water Vapor IOP. In addition, the DOE 7-channel microwave radiometer (DoER) and the 5-channel millimeter-wave imaging radiometer (MIR) were flown on the Twin Otter to support microwave radiometer comparisons.

The Citation and King Air flew special nighttime missions in direct support of the Water Vapor IOP. These flights, carrying the highly precise hygrometers, were coordinated especially with operations of the two Raman lidars, tethered systems, and dual package BBSS launches. In all, the Citation performed five such nighttime missions (September 17, 25, 30; October 1, 3), while the King Air participated in two (September 27; October 3). The evening of October 3 saw both aircraft flying in support of this IOP. A special wingtip-to-wingtip flight mission involving the King Air and Gulfstream-1 on September 29 afforded comparison of both the chilled mirror and wind sensors on those aircraft. Also, the joint flights of the Citation and King Air on the evening of October 3 allowed similar comparisons to be made between sensors on those two aircraft.

A substantial 2:00 p.m. Central meeting was held each day at the Central Facility to discuss/display results from the previous day/night and to make plans for the upcoming evening. A good deal of decision making was made based on which instrument(s) were/were not performing as anticipated. Data is being analyzed by the IOP's scientific focus groups throughout the rest of 1997 and early 1998 in anticipation of water vapor meetings at both the IRF Workshop in January 1998 and the ARM Science Team Meeting in March 1998. Decisions will then be made as to when and how to conduct a third Water Vapor IOP.

Description

Goals: The focus for the second Water Vapor IOP will be on the characterizing moisture in the lowest 9 km of the atmosphere. The purpose is to improve state-of-the-art in measuring water vapor in the vertical column: column integrated, range resolved, all conditions (clear/cloudy, day/night). Specific issues include:

  • Evaluate absolute calibration standards
  • Characterize accuracy of SGP CART measurements
  • Calibration of Raman lidar independent of radiosondes
  • Improvement of retrievals
  • Bring closure to open issues involving lowest 1 km from the first water vapor IOP
  • Examine 6-9 km layer (small errors have large effect on net radiation)

Additional Information

Management Structure: Water Vapor IOP Chief Scientist: Hank Revercomb, University of Wisconsin Office phone: (608) 263-6758 E-mail: hankr@ssecmail.ssec.wisc.edu Cellular phone: (630) 436-5011 Pager: (405) 699-6725

Logistical Support: Dave Turner, Pacific Northwest National Laboratory Office phone: (509) 375-2590 E-mail: dd_turner@pnl.gov

ARM DSIT Representatives: Dave Turner, Pacific Northwest National Laboratory Office phone: (509) 375-2590 E-mail: dd_turner@pnl.gov

Randy Peppler, CIMMS/University of Oklahoma Office phone: (405) 325-6667 E-mail: rpeppler@manatee.gcn.ou.edu Cellular phone: (630) 826-6030

Mike Splitt, CIMMS/University of Utah Office phone: (801) 581-7321 E-mail: msplitt@atmos.met.utah.edu Cellular phone: (630) 624-6166 Pager:

Data Single Point of Contact: Dave Turner, Pacific Northwest National Laboratory Office phone: (509) 375-2590 E-mail: dd_turner@pnl.gov

Participants: Principle Investigator: - Joe Michalsky, SUNY Albany Instrument/System: - MFRSR&RSS Research Participants: - Mark Beauharnois

Principle Investigator: - S.H. Melfi, U of Maryland-NASA/GFSC Instrument/System: - NASA GFSC Scanning Raman Lidar Research Participants: - Geary Schwemmer, Rich Ferrare, Keith Evans, Glenn Staley, Gerry McIntire, Dave Whiteman,&Martin Canderola

Principle Investigator: - William Porch, LANL Instrument/System: - Tethered Balloon Chilled Mirror Dew-Point System Research Participants: - John Archuleta, Alfred Fernandez,&William Spurgeon (Alfred&William - set-up&tear-down)

Principle Investigator: - Ben Balsley, CIRES/U of Colorado Instrument/System: - Parafoil Kite Research Participants: - Mike Jensen&1 other not yet determined

Principle Investigator: - Scott Richardson, OU Instrument/System: - Chilled Mirror Dew-Point Sensors Research Participants: - None

Principle Investigator: - Mike Poellot, U of N. Dakota Instrument/System: - Citation II Research Aircraft Research Participants: - Jeffrey Smith, Kent Streiber, Steve Shafer,&Martin Brown

Principle Investigator: - Gunnar Senum, BNL Instrument/System: - Twin Otter&Altus Chilled Mirror Research Participants:- Pete Daum

Principle Investigator: - Rob Calahan, NASA/Goddard Instrument/System: - Landsat Thematic Mapper Research Participants: - Guoyong Wen

Principle Investigator: - Ed Westwater, CIRES/U of Colorado/NOAA Instrument/System: - Microwave Radiometers&Infrared Radiometers Research Participants: - Duane Hazen, William Madsen, Yong Han,&Joseph Shaw

Principle Investigator: - Henry Revercomb, SSEC/U of Wisconsin Instrument/System: - AERIBAGO&AERI 00 Research Participants: - Wayne Feltz, David Tobin, Paul Van Deist, Robert Knuteson, Dan DeSlover, John Short, Ralph DeDecker, Fred Best, & Ray Garcia

Principle Investigator: - Beat Schmid, NASA AMES Research Center Instrument/System: - Ames 6 Channel Tracking Sunphotometer&2 MICROTOPS SPM Research Participants: - Monika Schmid

Principle Investigator: - Paul Racette&David Jones, NASA/GSFC Instrument/System: - DoER and MIR Research Participants: - Micheal Triesky

Principle Investigator: - Seth Gutman, NOAA-FSL Instrument/System: - GPS-IPW/GSOS Research Participants: - Daniel Wolfe (or Seth only-one or the other)

Campaign Data Sets

Campaign Participant Data Set Archived Data
Balsley, Ben Kite Order Data
Barnard, James MFRSR Order Data
Cook, David Met Order Data
Daum, Peter Gulfstream Order Data
Halthore, Rangasayi CIMEL Sunphotometer Order Data
Lesht, Barry BBSS Order Data
Liljegren, James MWR Order Data
Marwitz, John KingAir Order Data
Michalsky, Joseph RSS Order Data
Parsons, Dave GPS Order Data
Poellot, Michael Citation Order Data
Porch, William Teth. Balloon Order Data
Revercomb, Henry AERI00/BAGO Order Data
Richardson, Scott CM Order Data
Schmid, Beat Sunphotometer Order Data
Tobin, David Derived PWV Order Data
Tooman, Tim Altus Order Data
Tooman, Tim Twin Otter Order Data
Turner, David Raman Lidar Order Data
Westwater, Ed MWR Order Data
Whiteman, David Lidar Order Data
Widener, Kevin MMCR Images Order Data