Monitoring the JMR Wet Path Delays Shailen Desai Bruce Haines Victor Zlotnicki
Dec 31, 2015
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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