# Presentation: 015737

## NCEP Regional ReanalysisFedor Mesinger1, Geoff DiMego2, Eugenia Kalnay3, Perry Shafran4, Wesley Ebisuzaki5, Yun Fan6, Robert Grumbine2, Wayne Higgins5, Ying Lin2, Kenneth Mitchell2, David Parrish2, Eric Rogers2, Wei Shi6, Diane Stokes2, and Jack Woollen41NCEP/EMC and UCAR, 2NCEP/EMC, 3Univ. Of MD, 4NCEP/EMC and SAIC/GSO, 5NCEP/CPC, 6NCEP/CPC and RSIS

## Motivation

- Create long-term set of consistent climate data on a regional scale on North American domain
- Use of the GR to drive the Regional Reanalysis (RR) system
- Superior to NCEP/NCAR Global Reanalysis (GR) due to:
- use of a regional model (the Eta model)
- Advances in modeling and data assimilation since 1995,  especially:
- Precipitation assimilation
- Direct assimilation of radiances
- Land-surface model updates

## ETA / NOAH LAND-SURFACE MODEL UPGRADES: 24 Jul 01

_**ETA / NOAH LAND-SURFACE MODEL UPGRADES**_**: ****24 Jul 01**

**- assimilation of hourly precipitation**
**  **-- hourly 4-km radar/gage analysis (Stage IV)
**- cold season processes**(*Koren et al 1999*)  -- patchy snow cover  -- frozen soil (new state variable)  -- snow density (new state variable)  **- bare soil evaporation refinements**
-   -- parameterize upper sfc crust cap on evap
**- soil heat flux**  -- new soil thermal conductivity
-     (*Peters-Lidard et al 1998*)  -- under snowpack (*Lunardini, 1981*)  -- vegetation reduction of thermal cond.    (*Peters-Lidard et al 1997*)
**- surface characterization****  **-- maximum snow albedo database
-     (*Robinson & Kukla 1985*)  -- dynamic thermal roughness length
-     refinements
**- vegetation**
-   -- deeper rooting depth in forests
-   -- canopy resistance refinements

- NOAH LSM tested in various land-model
- intercomparison projects, e.g., GSWP, PILPS
-  2a, 2c, 2d, 2e, Rhone, and (near-future) DMIP.

## System Design

- Fully cycled 3-hr EDAS
- Lateral boundary conditions supplied by Global Reanalysis 2
- Free forecasts will be done out to 72 hr every 2.5 days
- Pilot resolution: 80-km, 38 layers
- Production resolution: 32-km, 45 layers
- RR time period: 1979-2004 (continued later in near-real time, as in CDAS)

## For the Eta, a 32 km run takes 178 times the work of a 180 km run!

- 180 km                            80 km                                32 km

## Domain Coverage of NARR

## Data Used in Global Reanalysis and Regional Reanalysis

| Dataset | Details | Source |
| --- | --- | --- |
| Radiosondes | Height, temperature, winds, moisture | NCEP/NCAR Global Reanalysis (GR) |
| Dropsondes | Same as above | GR |
| Pibals | Wind | GR |
| Aircraft | Temp. and wind | GR |
| Surface | Pressure | GR |
| Cloud drift winds | Geostationary satellite | GR |

## Data Added or Improved Upon for Regional Reanalysis

| Dataset | Details | Source |
| --- | --- | --- |
| Precipitation | CONUS (with PRISM), Mexico, Canada, CMAP over oceans | NCEP/CPC |
| TOVS-1B radiances | Winds, precipitable water over oceans | NESDIS |
| Surface | Temperature, wind, moisture | GR |
| COADS | Ship and buoy data | NCEP/EMC |
| Air Force Snow | Snow depth | COLA and NCEP/EMC |
| SST | 1-degree Reynolds, with Great Lakes SSTs | NCEP/EMC, GLERL |
| Sea and lake ice | Contains data on Canadian lakes, Great Lakes | NCEP/EMC, GLERL, Canadian Ice Center |
| Tropical cyclones | Locations used for blocking of CMAP Precipitation | Lawrence Livermore National Laboratory |

## Results: Upper-Air

- Compared both GR and RR against fits to raobs
- Root-mean-square (RMS) analysis fits significantly better for temperatures and vector wind speeds for RR
- Wind speed improvement greatest in the upper troposphere, especially in winter
- First guess (3-hr forecast, pre-3DVAR) temperatures not as favorable for RR compared to GR, winds improved
- Relative humidity improved for RR for both analysis and first guess
- Note: July 1988 results are at present inadvertently without precipitation assimilation

## Analysis

- T

- VWND

- T

- January 1988

- VWND

- July 1988

- T

- VWND

## First Guess

- January 1988

- T

- VWND

- July 1988

- T

- VWND

## January 1988

- RH

- Relative Humidity Analysis

- RH

- July 1988

## Relative Humidity First Guess

- January 1988

- July 1988

- RH

- RH

## Results: Near Surface

- Surface temperatures RMS favorable for RR in both winter and summer
- Temperature RR biases closer to zero and little diurnal variation problem in summer
- 10-m wind RMS in RR analysis a little better, 1st guess neither better nor worse compared to GR (remarkably similar!)
- Slow wind biases improved in RR in both seasons
- RR advantage greater in analysis than in the first guess

## January 1988

- July 1988

- 2-m Temperature Analysis

- RMS

- RMS

- Bias

- Bias

## January 1988

- July 1988

- 10-m Vec. Wnd Speed Analysis

- RMS

- RMS

- Bias

- Bias

## July 1988

- RMS

- Bias

- RMS

- January 1988

- 2-m  Temperature 1st Guess

- Bias

## 10-m Vec. Wnd. Spd. 1st Guess.

- 10-m Vec. Wnd. Spd. 1st Guess.

- January 1988

- July 1988

- RMS

- RMS

- Bias

- Bias

## Results: Precipitation

- Several sources of precipitation
- CONUS data with PRISM (Mountain Mapper) to improve orographic effects
- Canada
- Mexico
- CMAP (combination of satellite and gauge data) over oceans; CMAP is blocked:
- Near central areas of hurricanes (7.5 by 7.5 deg)
- Observed precipitation > 100 mm/day
- North of 50 degrees North

## Results: Precipitation (cont’d)

- Precipitation observations used to prescribe the latent heat profile in Eta model
- Model uses given latent heat profile to simulate precipitation
- Resulting precipitation pattern looks very much like the observed precipitation pattern in both summer and winter

## July 1987 Precipitation Results

## July 1987 Precipitation Results

## January 1988 Precipitation Results

## January 1988 Precipitation Results

## Achievements: RR System/Development

- Precipitation assimilation in EDAS
- Revised 3DVAR to run using the satellite bias corrections for all the satellites
- Updated the land-surface model
- Converted RR system from 80-km pilots to 32-km production mode
- Acquired computing resources to run RR in production mode

## Achievements:  Data acquisition/processing

- Acquired precipitation dataset with use of PRISM (Mountain Mapper); disaggregated data to hourly
- Acquired TOVS-1B data for 1979-1997 time period
- Acquired Air Force snowdepth dataset
- Created a high-resolution sea-ice field

## Achievements: RR runs

- Completed numerous 80-km pilots
- Completed 18 months of 32-km RR on SGI Origin 3000
- Re-running the 32-km RR on SGI using precipitation assimilation

## Achievements: Outreach

- Presented RR-related work at several conferences
- AMS Annual Meeting in Orlando, FL, in January
- GEWEX Mississippi River Hydrology & Climate Conference in New Orleans, LA, in May
- Numerous contacts with potential users

## Work in Progress

- Creation of a monitoring system that will alert of problems in the running of the RR
- Data processing is ongoing so that all the data is processed before the production RR runs
- Production is in progress; two streams will be running on Class VIII machine once available

## Goals for Next Year

- Complete most of the production by 31 August 2003, the last day that Class VIII machine will be available
- Transition plan for continuation in post-IBM Class VIII time
- RR presentations at the AMS Meeting and Climate Diagnostics Workshop
- RR Users’ Workshop