SCOUT-O3 Microwave Temperature Profiler (MTP)

Instrument:     
Geophysica Microwave Temperature Profiler (MTP) 

Principal Investigator: 
Michael J. ("MJ") Mahoney 

Organization:   
Jet Propulsion Laboratory 
Mail Stop 246-102 
4800 Oak Grove Drive 
Pasadena, CA 91109-8099 

Phone:             (818)-354-5584 
FAX:                (818)-393-0025
E-mail:             Michael.J.Mahoney@jpl.nasa.gov 
URL:                http:\\mtp.jpl.nasa.gov\
MTP located on a winglet below the Geophysica's right engine intake

Principle of Operation:
The Geophysica MTP is a passive microwave radiometer, which measures the natural thermal emission from oxygen molecules in the earth’s atmosphere for a selection of elevation angles between zenith and nadir. The current observing frequencies are 55.51, 56.65 and 58.80 GHz. The measured "brightness temperatures" versus elevation angle are converted to air temperature versus altitude using a quasi-Bayesian statistical retrieval procedure. An altitude temperature profile (ATP) is produced in this manner every 15 seconds (about 3 km) along the flight path, and these can be used to produce a color-coded temperature curtain (CTC) of the temperature field which the ER2 has flown through.

MTP data obtained during TC4 will be used to validate temperature profiles measured by Aura/MLS, /TES, and /HIRLDS. More generally, the MTP data are used to provide meteorological context for measurements made by in situ and remote sensors of atmospheric gases, hydrometeors and aerosols. In arctic regions for example, the ATP can be used to locate altitudes where the air is cold enough to condense nitric acid or water vapor to form polar stratospheric clouds. In addition, the temperature field can used to determine the tropopause altitude, which is extremely important to interpreting other measurements. The ATP can also be used to derive the altitudes of isentrope surfaces to look for the presence of meso- to synoptic-scale atmospheric waves. The "waviness" of isentropic surfaces is used to characterize the magnitude of temperature fluctuations, which is needed for deriving effective temperatures to be used in atmospheric chemistry calculations involving reaction rates and solubility.


Hardware Description:
The MTP on the Geophysica consists of two components: the sensor unit (located on the right engine intake in the figure above), and the data unit (which controls the sensor unit and records data from it). The data unit is located in the center of the fuselage, and is accessible through a hatch at the bottom of the aircraft. Data is stored on a Flashcard in the Data Unit.

MTP/ER2 Performance:
Accuracy:            Temperature accuracy is approximately 1 K within 3 km of the Geophysica's flight altitude,&
                            < 2K for an 6 km region centered on the flight altitude.
Response Time: Temperature profiles are obtained every 15 seconds.

For more information, go to the MTP Home Page ( http:\\mtp.jpl.nasa.gov\ )