Instrument : Microwave Radiometer Profiler (MWRP)

Instrument Categories
Radiometric, Cloud Properties, Atmospheric Profiling

Picture of the microwave radiometer profiler (MWRP)
Picture of the microwave radiometer profiler (MWRP)

General Overview

The microwave radiometer profiler (MWRP) provides vertical profiles of temperature, humidity, and cloud liquid water content as a function of height or pressure at approximately 5-minute intervals for nearly all weather conditions. The profiles are derived from measurements of absolute microwave radiances (expressed as "brightness temperatures") obtained at twelve frequencies in the range of 22-30 GHz and 51-59 GHz. The data are useful for input to numerical weather forecast models and others that require continuous, high temporal resolution profiles. The microwave radiance measurements are useful for testing models of microwave radiation transfer used to derive the profiles.

Available Retrievals and Uncertainty

Statistical retrievals of precipitable water vapor, liquid water path, temperature and humidity profiles are available. The retrievals use seasonally derived linear regression coefficients. Seasonal rms errors of the retrievals depend on the location and can be found in the netcdf files variables. A rough estimate of the retrieval uncertainty is the following:

  • Temperature profile: varies from ~1-2 K in the first 2 km to ~3-4 K at 10 km
  • Water vapor density profile: varies from ~0.5-1 g/m3 in the first 2 km to ~0.01-0.05 g/m3 at 10 km
  • Liquid water profile: Approximately 0.1 g/m3 throughout the profile
  • Precipitable water vapor: ~ 0.5-0.7 mm
  • Liquid water path: ~0.03 mm

Additional retrievals of relative humidity and virtual temperature are available in the netcdf file. These retrievals are derived from the above retrievals, and therefore the rms error is not provided in the netcdf file. Uncertainty in the retrieved relative humidity and virtual temperature profiles can be placed at approximately 20% and 2 K respectively.

Summary Table:

Name of Variable in the Datastream Physical Quantity Approximate Uncertainty Datastream Uncertainty Variable in the Datastream
BrightnessTemperature Brightness temperatures

0.5 K (22-30GHz) K

1.5 K (51-59 GHz)

mwrp.b1 N/A
Temperature Retrieved temperature profile

~1-2 K in the first 2 km

 ~3-4 K at 10 km

 mwrlos.b1 temperatureRmsError
waterVaporDensity Retrieved vapor density profile

~0.5-1 g/m3 in the first 2 km

~0.01-0.05 g/m3 at 10 km

 mwrlos.b1 waterVaporDensityRmsError
liquidWaterContent Retrieved cloud liquid water profile 0.1 g/m3 throughout the profile mwrp.b1 liquidWaterContentRmsError
totalPrecipitableWater Retrieved precipitable water vapor from 5 channels (22-30 GHz) ~ 0.5-0.7 mm mwrp.b1 totalPrecipitableWaterRmsError
totalPrecipitableWater2 Retrieved precipitable water vapor from 2 channels (23.834 and 30 GHz) ~ 0.5-0.7 mm mwrp.b1 totalPrecipitableWater2RmsError
liquidWaterPath

Retrieved liquid water path from 5 channels (22-30 GHz)

 ~ 0.03 mm mwrp.b1 liquidWaterPathRmsError
liquidWaterPath2 Retrieved liquid water path from 2 channels (23.834 and 30 GHz) ~ 0.03 mm mwrp.b1 liquidWaterPath2RmsError
relativeHumidity Derived relative humidity profile 20% mwrp.b1 N/A
virtualTemperature Derived virtual temperature profile 2 K mwrp.b1 N/A

Output Datastreams

  • mwrp : Microwave Radiometer data (MWR Profiles - QME), water vapor, temp, cloud liquid water, precip water retrievals

Primary Measurements

The following measurements are those considered scientifically relevant.

Locations

  • North Slope Alaska (NSA)
    • Central Facility, Barrow AK (C1)
  • ARM Mobile Facility (FKB)
    • Black Forest, Germany (M1)
  • ARM Mobile Facility (GRW)
    • Graciosa Island, Azores, Portugal (M1)
  • ARM Mobile Facility (HFE)
    • Shouxian, Anhui, China (M1)
  • ARM Mobile Facility (NIM)
    • Niamey, Niger (M1)
  • ARM Mobile Facility (PGH)
    • ARIES Observatory, Nainital, Uttarkhand, India (M1)
  • ARM Mobile Facility (PVC)
    • Highland Center, Cape Cod MA; AMF 1 (M1)
  • ARM Mobile Facility (PYE)
    • Point Reyes, CA (M1)

Contact(s)

Maria Cadeddu
(630) 252-7408
mcadeddu@anl.gov