N-LDAS Phone Conference Minutes

04 April 2002

 

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

Houser, Justin Sheffield, Qingyun Duan, Lifeng Luo, Alan Robock

 

II - This phone conference is the first of three weekly phone

conferences set up for April 4, 11, and 18 as the NLDAS group

accelerates their preparation and coordination of the NLDAS material to

be examined and presented at the upcoming 13-17 May annual GAPP

conference -- this year in New Orleans, as part of the larger

Mississippi River Climate Conference. Of order ten talks/posters from

our N-LDAS project herein are slated to be given at that conference.

 

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

and expects to finish C by April 18.

3 - Dag Lohmann is finished with NOAH runs for A today, will complete B

tomorrow, and expects to finish C by April 11.

4 - Yun Duan has not yet started SAC runs, because his SAC runs require

the EP output from the NOAH runs, which are only now underway

 

NOAH retro runs are just underway, because (the good news is) after

painstaking investigation, Dag just recently identified the longstanding

NOAH error wherein NOAH was showing a significantly higher net solar

forcing than MOSAIC and VIC in the validation results of Lifeng Luo of

Rutgers. This net solar forcing difference was too large to be

explained by the small differences in surface albedo that is calculated

by the three land models. The error turned out to be that Dag's NOAH

driver had a software glitch that resulted in erroneously reading in the

EDAS downward solar forcing, rather than the GOES-based solar forcing of

Pinker. As is widely known, the EDAS downward solar forcing has a

positive bias of order 8-14 percent.

 

IV - Ken Mitchell reported on the continuing long saga of obtaining

additional mass storage space for NLDAS output files in the face of the

failing robotic tape data migration hardware on the NCEP sgi108 NLDAS

computing platform. Ken has now arranged access by all four NLDAS

modelers to the alternative mass storage space on sgi107 (this platform

is the Regional Reanalysis platform). All four modeling groups were

able to successfully access sgi107 from sgi108, but were unsuccessful in

accessing sgi107 directly by remote login. Ken will work on getting

the NCEP network folks to establish the latter direct access.

 

V - Ken Mitchell requested that all four NLDAS modeling groups provide

numbers to him (via email) designating the total file storage space that

their land model requires over a period of one-year of output. (The

four modelers so responded.) Ken will use this info in his FY02

procurement of additional tera bytes of file storage space for the NLDAS

project.