monitoring the jmr wet path delays
DESCRIPTION
Monitoring the JMR Wet Path Delays. Shailen Desai Bruce Haines Victor Zlotnicki. JMR versus ECMWF. +3-4 mm step between cycles 29-32 -5 mm step at cycle 2 caused by change to ECMWF model. Comparisons to GPS observations. Similar +4-5 mm step in JMR path delays found in comparisons to GPS. - PowerPoint PPT PresentationTRANSCRIPT
Monitoring the JMR Wet Path Delays
Shailen Desai
Bruce Haines
Victor Zlotnicki
November 18, 2003 Jason-1 Science Working Team MeetingCal/Val Splinter Session
SD/BH/VZ - 2
JMR versus ECMWF
• +3-4 mm step between cycles 29-32
• -5 mm step at cycle 2 caused by change to ECMWF model
-6
-4
-2
0
2
4
6
0 10 20 30 40 50 60 70
Differences of Wet Path Delay Corrections, (JMR-ECMWF) (mm)
Jason-1 Repeat Cycle
Smoothed
November 18, 2003 Jason-1 Science Working Team MeetingCal/Val Splinter Session
SD/BH/VZ - 3
Comparisons to GPS observations
• Similar +4-5 mm step in JMR path delays found in comparisons to GPS.
• ECMWF model relatively stable in comparison.
• Smaller scatter after cycle 36 when ECMWF model modified.– Smaller scatter in (JMR-
ECMWF) differences (from 1.5 to 1.25 cm).
November 18, 2003 Jason-1 Science Working Team MeetingCal/Val Splinter Session
SD/BH/VZ - 4
Comparison to SSM/I and TMI
-8
-6
-4
-2
0
2
4
6
8
0 100 200 300 400 500 600Daily Average of Differences of Wet PD Corrections, (JMR-SSMI) (mm)
Days Since Jan 1, 2002
-8
-6
-4
-2
0
2
4
6
8
0 100 200 300 400 500 600Daily Average of Differences of Wet
PD Corrections, (JMR-TMI) (mm)
Days Since Jan 1, 2002
November 18, 2003 Jason-1 Science Working Team MeetingCal/Val Splinter Session
SD/BH/VZ - 5
Attitude Dependence
• Attitude dependence of JMR wet PD correction may have returned after cycle 33.
– Verification by other methods pending (e.g. SSM/I and TMI).
-8
-6
-4
-2
0
2
4
6
8
0 100 200 300 400 500
Pass Averages of Wet PD
Differences, (ECMWF-JMR) (mm)
Passes Since Start of Cycle 48
Fixed to SineSine to Fixed
November 18, 2003 Jason-1 Science Working Team MeetingCal/Val Splinter Session
SD/BH/VZ - 6
Geographically Correlated Error?
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Cycles 29-59
Cycles 2-27
• Comparisons to SSM/I and TMI suggest possible geographically correlated errors in JMR wet PD.• Color scale is from -9 to +9 mm.
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