N-LDAS Phone Conference Minutes

11 April 2002

 

I - Participants: Ken Mitchell, Dag Lohmann, Brian Cosgrove, Paul

Houser, Justin Sheffield, Eric Wood, Lifeng Luo, Alan Robock

(John Schaake and Qingyun Duan were on travel to the MOPEX Workshop at

U.Arizona).

 

II. - Participants were reminded of the next phone conference on April

18, and the face to face meeting arranged at OHD in Silver Spring on the

afternoon of May 3 (this was eventually cancelled, because of too few

participants, owing to some illness, and some unexpected competing

meeting obligations and travel).

 

III. - All four modeling groups reported on the status of their

executions of the following three 3-year retrospective experiments:

 

A - full N-LDAS grid

B - reduced grid run "000" (uses Brian Cosgrove's retrospective forcing,

at 123 grid points throughout the ARM and OU Mesonet regions of Kansas

and Oklahoma.

C - reduced grid run "111" (uses Lifeng's OU Mesonet-provided locally

observed station forcing, at 84 grid points corresponding to the 84 OU

Mesonet stations)

 

1 - Brian Cosgrove is finished: has completed the NASA MOSAIC model

retro runs for all of A, B, C

2 - Dag Lohmann is finished: has completed the NCEP NOAH model retro

runs for all of A, B, C

3 - Justin Sheffield is well along: has completed VIC runs for A and B,

and expects to finish C by April 18 (has 1 last simulation year of the 3

to go for C)

4 - Due to travel to MOPEX meeting, Yun Duan was not present to report

on SAC runs.

 

IV. - The group examined some very recent validations of MOSAIC, VIC,

and NOAH from runs A, B above at the NLDAS validation web site of Lifeng

Lou and Alan Robock of Rutgers. The earlier high bias in net solar in

the NOAH runs is indeed eliminated now, as is the high bias in soil

temperature. Moreover, VIC has substantially improved the time phasing

of its diurnal cycle of ground heat flux. The three models of MOSAIC,

NOAH, and VIC continue to show the now familiar trends of MOSAIC warm

season latent heat flux (LE) being modestly higher than observed, while

that of NOAH is modestly less than observed, and that of VIC is

substantially less than observed. Both VIC and NOAH show good agreement

with each other and with observed soil temperatures in the top soil

layer regime. The validation work and results provided by Rutgers

validation effort have been a goldmine of insight into the land models'

behaviour. Much credit also goes to the observational programs of

DOE/ARM and OU Mesonet.

 

V - All four modeling groups now have exercised direct remote login

access to the NCEP mass storage system on sgi017, via the so-called

"Grendel security access" protocol, as well as via login to sgi108. Dag

reports that the robotic tape data migration system on sgi108 is now

working rather smoothly again, and Dag has started realtime catch-up

runs of the NOAH model from the end of the 3-year Oct 96 to Sep 99

retrospective period of A,B,C above, to present realtime. After he

returns from travel and finishes the NOAH runs of the OHD DMIP project,

Dag will resume unified catch-up runs of all four land models from Sep

99 to present realtime. Brian and Justin have begun providing MOSAIC

and VIC related executeables, fixed fields, and scripts for Dag to fold

into his unified 4-model N-LDAS scripts.

 

VI - In the above catch-up runs, the group discussed at length was date

we should designate for the switch-over from use of Brian Cosgrove's

NASA retrospective reprocessed forcing and Dag Lohmann's NCEP realtime

forcing. Much of the discussion focused on the fact that the Higgin's

et al reprocessed and Unified Precipitation Analysis was available to

Brian (and others) only through the end of the calendar year 1998. It

was ultimately agreed to by the group that the switch-over to realtime

NCEP forcing in the "catch-up" runs to present realtime would be 01

February 2000, after the NESDIS GOES calibration glitch that persevered

from early July 1999 until late January 2000, was fixed by Dan

Tarpley's group of NESDIS.