| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 05/27/1992 | 0000 | 05/31/2002 | 2359 |
| Subject: | SGP/SONDE - Dry bias in sonde RH |
| DataStreams: | DsgpsondeB1.a0, sgpsondeB1.a1, sgpsondewrprC1.a0, DsgpsondeptuB5.00, sgpsondewrpnB5.a0, sgpsondeB4.00, sgpsondeB4.a1, DsgpsondeC1.a0, sgpsondewrpnB6.00, sgpsondeC1.a1, sgpsondewrpnB6.a0, sgpsondewrprB1.a1, sgpsondewrpnB4.a0, sgpsondewrpnB4.00, DsgpsondeptucalcC1.c1, sgpsondewrprC1.a1, sgpsondewnpnB5.a0, sgpsondewnpnB4.a1, sgpsondeB5.a1, sgpsondewrpnC1.a1, sgpsondewnpnB1.a0, DsgpsondeB5.a0, DsgpsondeptuB4.00, sgpsondewnpnB6.a0, sgpsondewrprB5.a1, DsgpsondenogcptucalcB4.c1, sgpsondewnprC1.a0, sgpsondeB1.00, DsgpsondeptucalcB4.c1, sgpsondewnpnB6.a1, sgpsondewrpnB4.a1, sgpsondewrprB1.00, DsgpsondenogcwrpnB5.c1, sgpsondewnpnC1.a0, DsgpsondeB5.00, DsgpsondeB4.a1, DsgpsondenogcwrpnC1.c1, sgpsondeB5.a0, sgpsondeC1.00, DsgpsondeB4.a0, DsgpsondeptuB1.00, DsgpsondenogcptucalcC1.c1, sgpsondewrprB4.00, sgpsondeB1.a0, sgpsondewrprB5.00, sgpsondeptuC1.00, sgpsondewrpnB5.a1, sgpsondewrpnB1.a1, sgpsondewrprB1.a0, sgpsondewrprC1.00, DsgpsondeB1.a1, DsgpsondenogcwrpnB1.c1, DsgpsondenogcptucalcB1.c1, DsgpsondeB4.00, DsgpsondeB5.a1, sgpsondewrpnB6.a1, DsgpsondeptuC1.00, sgpsondewrpnB1.00, DsgpsondeptucalcB5.c1, DsgpsondeC1.a1, DsgpsondenogcwrpnB4.c1, sgpsondeB6.00, sgpsondewnpnC1.a1, DsgpsondeptuB6.00, sgpsondewnpnB1.a1, sgpsondeB5.00, DsgpsondenogcptucalcB5.c1, sgpsondewnpnB5.a1, sgpsondewnpnB4.a0, DsgpsondeC1.00, sgpsondewrpnB1.a0, sgpsondeB4.a0, sgpsondewrprB4.a0, sgpsondewrpnC1.a0, sgpsondewrpnB5.00, sgpsondewnprC1.a1, sgpsondewrpnC1.00, sgpsondewrprB4.a1, DsgpsondeptucalcB1.c1, DsgpsondeB1.00, sgpsondeC1.a0, sgpsondewrprB5.a0 |
| Description: | Vaisala has confirmed ARM findings of an apparent dry bias in the relative humidity measured by RS-80H radiosondes. The cause of the dry bias is thought to be contamination of the humidity sensor by volatile organic substances originating from some plastic parts of the radiosonde. The amount of contamination is a function of the time between the date of sonde manufacture and its use. All RS-80H sondes manufactured before week 34 of 1998 will show this bias. After week 34 of 1998 Vaisala changed its packaging to reduce, but not eliminate the contamination problem. Starting with RS-80 radiosonde manufactured in late June 2000 Vaisala enclosed the sensor boom in an inert plastic shield, thereby eliminating the contamination that caused the dry bias. Starting in May 2001 at the SGP, May 2002 at the TWP, and later 2002 at the NSA, ARM has moved to using RS-90 radiosondes. These sondes are not subject to the contaminatino that caused the dry bias. Vaisala is in the process of developing an algorithm that can be used to estimate the correct RH from knowledge of the sonde age. All of the ARM sounding data have sufficient metadata available to apply the correction. Additionally, ARM has funded a Science Team effort (Milosevich) to develop a 'best' correction algorithm for the RS-80 radiosonde humidity data. When completed this algorithm will allow us to reprocess the accumulated RS-80 data and produce a new data platform with what we hope will be more accurate data. |
| Suggestions: | When the final algorithm is available, ARM sounding data should be reprocessed to obtain corrected RH data. A new data stream will be required. |
| Measurements: | DsgpsondeptuB5.00: more
sgpsondewrpnB6.a1: more DsgpsondeB1.a0: more sgpsondewrpnB6.a0: more DsgpsondeptuB1.00: more DsgpsondeB5.a1: more sgpsondewrprB4.00: more DsgpsondeC1.00: more DsgpsondeB1.a1: more sgpsondewnpnB6.a1: more sgpsondewnpnB6.a0: more DsgpsondeB5.a0: more DsgpsondenogcptucalcB1.c1: more DsgpsondenogcptucalcB5.c1: more DsgpsondeptuC1.00: more sgpsondewrpnC1.a0: more sgpsondeB5.a0: more sgpsondewrprB5.00: more DsgpsondeptuB4.00: more DsgpsondeptucalcB5.c1: more sgpsondeC1.a0: more sgpsondeB5.a1: more sgpsondeC1.a1: more sgpsondeB1.a0: more sgpsondeB1.a1: more sgpsondewrpnB5.a0: more sgpsondewrpnB5.a1: more sgpsondewnprC1.a1: more DsgpsondenogcwrpnB4.c1: more sgpsondewrpnB1.a1: more sgpsondewrprB1.00: more sgpsondewrpnB1.a0: more sgpsondewnpnB5.a0: more DsgpsondenogcptucalcB4.c1: more sgpsondewnpnB5.a1: more sgpsondeB6.00: more sgpsondewrprB4.a0: more sgpsondeptuC1.00: more sgpsondewrpnB6.00: more DsgpsondenogcptucalcC1.c1: more sgpsondewrprB4.a1: more DsgpsondenogcwrpnC1.c1: more sgpsondewrprC1.00: more DsgpsondeptucalcB4.c1: more sgpsondeB4.a1: more sgpsondeB4.a0: more sgpsondewrprC1.a0: more sgpsondewrpnB4.a0: more DsgpsondenogcwrpnB5.c1: more sgpsondewrprC1.a1: more DsgpsondenogcwrpnB1.c1: more sgpsondewnpnB1.a0: more sgpsondewrpnB4.a1: more sgpsondewnpnB1.a1: more sgpsondewrpnC1.00: more sgpsondewrprB5.a0: more sgpsondewrprB5.a1: more sgpsondewnprC1.a0: more sgpsondewnpnB4.a0: more sgpsondeB5.00: more sgpsondeC1.00: more sgpsondeB1.00: more sgpsondewnpnC1.a0: more sgpsondewrpnB5.00: more DsgpsondeptucalcB1.c1: more DsgpsondeB4.00: more sgpsondewnpnC1.a1: more sgpsondewrprB1.a0: more sgpsondewrpnB1.00: more sgpsondewrprB1.a1: more sgpsondewrpnC1.a1: more DsgpsondeptuB6.00: more DsgpsondeptucalcC1.c1: more DsgpsondeB4.a1: more DsgpsondeB4.a0: more sgpsondewnpnB4.a1: more sgpsondeB4.00: more DsgpsondeB5.00: more DsgpsondeC1.a0: more DsgpsondeC1.a1: more sgpsondewrpnB4.00: more DsgpsondeB1.00: more |