# Presentation: 220751

## CFS Test and Evaluation Team

- Team Mission
- Perform sensitivity experiments and evaluate the results.
- 	Experiments are designed to accelerate the development of
- 	CFS.
- Team Membership: EMC and CPC federal and contract employees,
- 	and CTB funded investigators.
- Two types of experiments are performed on the CTB computer
- 	i.	 CTB funded projects
- 	ii.	 Internal projects proposed by CTB T & E Team members,
- 	       reviewed and approved by CST
- 	Balance will shift from ii) to i) as CTB grants increase.

## FY07 accomplishments 

- 	- 17 experiments proposed and approved by CST.
- 	- Most experiments finished and preliminary
- 	   evaluation done.
- 	- CTB T&E Team has fostered successful collaboration
- 	   between EMC and CPC.
- 	- This should evolve further in FY08 as the competitive
- 	   grants program grows and additional PIs join CTB.
- FY07 experiments have provided some insight and recommendations
- towards the next CFS.

## Selected results from experiments and evaluations

##  CFS subseasonal hindcast run (Vintzileos and Pan )

-  CFS subseasonal hindcast run (*Vintzileos and Pan* )
- 60-day forecast runs in 5-day intervals during May-August,
- 	2002-2006.
- 2.	Impact of horizontal resolution (T62, T126, T254)
- 	and initial condition (GDAS, CDAS2) examined.
- Principal findings and recommendations
- 1.	New CFS needs to be accompanied by its own  reanalysis.
- 2.	Impact of model resolution detected in tropical Atlantic and
- 	Africa - downscaling of operational forecasts could be
- 	beneficial in those sectors.

## Lead times from 0 to 25 days

- Because we validate against CDAS (starting from 06Z)

- √2 x Climatological Forecast (i.e., anomaly=0)

- GDAS initialized T254 hindcasts are the best

- CDAS initialized T62 hindcasts are the worst

**Lead times from 0 to 25 days**

## Test of RRTM shortwave radiation code (Hou and Saha)

- AER RRTM-SW radiation scheme has been incorporated into the new GFS/CFS. Also included are other physical processes such as solar-cycle, aerosol effect (including historical volcanic origin) and historical CO2.
- T126/MOM3 version was run from  01/01/1948 for 60 years.
-  Comparison of global mean SST, T2m anomalies, and global map of SST climatology shows promising improvement over the control model.
- - Served as a benchmark for other GFS evaluations.

## RRTM run 

- RRTM run
- shows reduced
- SST warm bias

## Slide 8

## JJA Precip Correlation Skills w Different LSM/ICs over NA

_**JJA**_** Precip Correlation Skills w Different LSM/ICs over NA**

**Noah/GLDAS**

**Noah/GR2**

**Noah/GLDAS CLM**

**OSU/GR2**

## Ops

**Ops**
**CFS**

**  ****Noah/**
**GLDAS**

** ****Noah/**
**GLDAS**
** ****Climo**

**OSU/**
** ****GR2**

## 10 Members each case (same initial dates)

**  ****Noah/**
**GLDAS**

** ****Noah/**
**GLDAS**
** ****Climo**

**OSU/**
** ****GR2**

**Noah/**
**GR2**

**10 Members each case (same initial dates)**

## Rerun of the offline Noah Land Model for 1948-2006

-  (*Fan and van den Dool*)
- Improvements in the model, vegetation class table and input precipitation datasets.
- Homogeneous input for both retrospective (from 1948) and real-time analysis.
_*Main findings*_
- Soil moisture anomalies and annual cycles are improved in top two layers,
- 	but the dry end of annual cycles are about 1~2 month late.
- Anomalies in lower layers are comparable with old run, however,
- 	the amplitudes of annual cycles much larger than Obs as in older version.
- Slight changes in evaporation and runoff are found in northern US.
- 	About 10~20 mm/mon increase (decrease) in evaporation (runoff)
- 	is seen in southeastern US.

## NLDAS Re-run

## T382 CFS runs for hurricane season (Saha, Thiaw)

- AGCM -  2007 operational NCEP GFS
- LSM - Noah LSM
- OGCM - GFDL MOM3
- All runs initialized with NCEP/DOE R2 and NCEP GODAS at 0Z, May 15, 1981-2006.
- AGCM spatial resolution in T382L64. Companion runs made in T126L64 and T62L64 also.
- This experiment has been extensively analyzed by the Evaluation Team members (*L. Long, H. Wang, Schemm, W. Wang*)

## Examples of Storm Tracks for 4 NH Basins

## Atlantic

- Basin

_**Correlations**_
- Total:     r=0.38
- ’81-’93:  r=0.15
- ’94-’06:  r=0.37

## Eastern

- Pacific
- Basin

_**Correlations**_
- Total:     r=0.16
- ’81-’93:  r=0.04
- ’94-’06:  r=0.02

## New CFS Runs

**SSTA in MDR        ASO      2 month lead**

- Year

- Co

**T62**
**T126**
**T382**
**OBS**

**New CFS Runs**
**3 different resolutions**
**ICs: May 15  (1 member)**

**Correlation (CFS, OBS)**

**T62 ****T126**** ****T382**

**T62 ****T126**** ****T382**

**Linear trend**
**removed**

**.75  .69  .74**

**.66  .54  .65**

***Warming trend contributes to the high correlation.***

**SST**

## New CFS Runs

**U200–U850 in MDR     ASO  2 month lead**

- Year

- m/s

**T62 ****T126**** ****T382**

**T62 ****T126**** ****T382**

**New CFS Runs**
**3 different resolutions**
**ICs: May 15  (1 member)**

**T62**
**T126**
**T382**
**OBS**

**.62  .57  .48**

**.58  .34  .42**

**Correlation (CFS, OBS)**

**Linear trend**
**removed**

***Lower resolution           better wind shear (single run)***

**U200–U850**

## 			Summary

-  CFS in T382 resolution exhibits fairly robust climatological
-     seasonal cycle of tropical cyclone over four NH basins.
-  Warming trend and intensification of hurricane activity in the
-     Atlantic basin captured.
-  Increased horizontal resolution may lead to improved vertical
-    wind  shear prediction over the Atlantic MDR.
-  Ensemble members needed for better depiction of  large scale
-     circulation.
-  Coupled air-sea interaction: important

## CFS E. Pacific SST bias corrections (Xie, Wang)

- Impact of radiation flux error over the Southeastern     Pacific examined.
-       SST bias reduced by half from surface radiation
-       bias correction.

## Correction of SEP radiation errors improves double ITCZ in coupled and uncoupled runs

- Annual mean precipitation

**Impacts of radiation flux errors over the Southeastern Pacific (SEP)**

- Coupled without SEP radiation errors

- Coupled with SEP radiation errors

- AMIP without SST errors

- AMIP with SST errors associated with radiation errors

## 	CFS hindcast rerun with corrected GODAS

- (*W. Wang, Xue, Schemm*)
- Reruns with June and December initial conditions -
-       Evaluations on SST and atmospheric variables performed.
- Mean SST is reduced by 0.2-0.4 degree due to GODAS corrections - reduces warm biases but worsens cold biases, particularly for June IC’s.
- Changes in precipitation bias are confined in the Tropics.
-       SST hindcast skill is improved, most prominent in
-       the Pacific and Indian Ocean for December IC’s and in the Atlantic Ocean for June IC’s.
- No significant changes in skill over North America for 2m temperature and precipitation.
- Provided analysis with April IC’s for hurricane seasonal outlook issued in May 2007.

## JAS

- JFM

- OND

**SST Indices Hindcast Skill in 1981-2005 (****red ******** improvement****)**

## SST hindcast averaged in the hurricane main development region (MDR) for July-November starting from June 11-31 I.C.. The SST hindcast is reduced (green) in 1981-1990 and increased (red) in 1991-2005 due to GODAS corrections. CFS realistically simulated the peaks of the index in 1987, 1995, 1998 and 2003-2005, and valleys in 1984-1986 and 1994, which suggests a potential contribution of the CFS forecast for the hurricane outlook.

**SST hindcast averaged in the hurricane main development region (MDR) for July-November starting from June 11-31 I.C.. The SST hindcast is reduced (green) in 1981-1990 and increased (red) in 1991-2005 due to GODAS corrections. CFS realistically simulated the peaks of the index in 1987, 1995, 1998 and 2003-2005, and valleys in 1984-1986 and 1994, which ****suggests a potential contribution of the CFS forecast for the hurricane outlook****.**

## North America

## Summary

- CTB T&E Team has fostered successful collaboration between EMC and CPC.
- This successful collaboration should evolve further in FY08 with funded projects for the next+1 CFS.
- FY07 experiments provided some insight and recommendations towards the next CFS.

- For FY08
- 	- Main focus : To participate in CFS reanalyasis and 			         reforecasts
- 	- To experiment with and evaluate the impact of  	                            suggested changes to CFS by funded external proposals.