Examples of relative humidity for SGP, NSA, and TWP-Darwin.
Examples of relative humidity for SGP, NSA, and TWP-Darwin.
The Merged Sounding evaluation product has moved into the ARM Data Archive as a value-added product (VAP). This Merged Sounding VAP, initially designed by Dr. Gerald Mace, was modified by software developer David Troyan under the scientific direction of Michael Jensen to better serve the ARM community. Data are available for the following sites:

  • Southern Great Plains (SGP) Central Facility
  • North Slope of Alaska (NSA) Barrow site
  • Tropical Western Pacific (TWP) Manus, Nauru, and Darwin sites
  • ARM Mobile Facility (AMF) Point Reyes, California, (PYE) deployment
  • AMF Niamey, Niger, (NIM) deployment
  • AMF Black Forest, Germany, (FKB) deployment
  • AMF Shouxian, China, (HFE) deployment
  • AMF Graciosa Island, Azores, (GRW) deployment.

There are currently 53 years of combined total data produced. All fixed sites have data through 2009; datastream availability begins between 1996 to 2002, depending on whether all necessary inputs are available at the ARM Data Archive.

The Merged Sounding VAP uses a combination of observations from radiosonde soundings, microwave radiometers, surface meteorological instruments, and European Centre for Medium Range Weather Forecasts (ECMWF) model output. Sophisticated scaling/interpolation/smoothing techniques are employed to define profiles of the atmospheric thermodynamic state at 1-minute intervals and at 266 altitude levels. The profiles start at ground level and reach 20 kilometers above ground level. Vertical resolution varies from 20 meters at lower levels to 200 meters at higher levels. Details of the algorithm are found in the Merged Sounding Value-Added Product report.

More information on MERGESONDE is available at the VAP web page. To access these data, log in to the Data Archive. (Go here to request an account.)