IMPORTANT MESSAGE 10-19-2009:     TRMM PR Instrument Anomaly Update From TSDIS/PPS Help Desk

Dear Science User,

After an instrument anomaly on May 29, 2009 the TRMM PR resumed observations on June 17th, 2009. All TRMM PR production data is currently being held until a calibration effort is completed by JAXA. Our intention was to be able to release the calibrated, post-anomaly PR data by the end of Sept. 2009 but that has not been possible. The recalibration effort by JAXA has required internal and external calibrations utilizing the ground-based Active Radar Calibrator. The impact of the new calibration curve on the rain retrievals is being examined by JAXA and the PR Team. Particular attention is being given to any biases introduced and changes in noise levels that impact sensitivity to ensure that continuity of the retrievals can be preserved on either side of the anomaly date The TRMM PR is still recording observations which the ground system is receiving, all PR housekeeping indicate the radar is operating normally and the instrument is in good condition. Users can expect the only permanent gap in TRMM PR data due to this anomaly to start on May 29, 2009 and last through June 17-19, 2009. The exact dates and orbit numbers will be designated by JAXA. TRMM PR real-time data is continuing to be produced and made available to real-time users with the qualification that the retrievals are suspect.Real-time users should contact PPS for concerns regarding data quality. JAXA will be briefing the Joint Precipitation Science Team at the upcoming PMM meeting in Utah at the end of October, 2009. Be assured that JAXA, the PR Team and NASA are working to get high quality rain retrievals out to all users as soon as possible.

IMPORTANT MESSAGE 06-13-2009: From TSDIS/PPS Help Desk - As most of you are probably aware, TRMM experienced a PR instrument anomaly on May 29, 2009 which affected all TRMM PR data resulting in missing data since orbit# 65716.

If you have obtained any of the following TRMM PR products and associated products (browse, CSI, etc) since that time, either through your Standing Orders, Special Requests or through other means, please delete the following products if you have not already:

1A21, 1B21, 1C21, 2A21, 2A23, 2A25, 2B31, 3B31, 3A25, 3A26

NOTE: The latent heating products of TRMM 2A12 and 3A12 over ocean surfaces should be regarded as experimental.Please confer first with the algorithm developers (by contacting the GES DISC) when using the latent heating product over ocean.Over-land latent heating estimates from TRMM products 2A12 and 3A12 should not be used, as they have not been evaluated quantitatively or qualitatively.