# Presentation: 947806

## Using GLDAS/LIS to DeriveOptimal Land States forCFS/Noah Initialization in CTB

**Using GLDAS/LIS to Derive****Optimal Land States for****CFS/Noah Initialization in CTB**

**1988**

**1993**

**July**

**Jesse Meng, Kenneth Mitchell, Helin Wei, and Jon Gottschalck**
***Jesse.Meng@noaa.gov***

## When do we need initialization?

** ****Cold start a new simulation****        ****e.g., flood, drought**** **
** ****Model upgrade****        ****e.g., physics, parameters, resolution**** **
** ****Model bias constrain**
** ****coupled – e.g., 4DDA, Reanalysis**
** ****uncoupled – e.g., GLDAS**

## CFS

**Current CFS **
**T62**
**25-year hindcast**
**OSU LSM**
**Initial land states from Global Reanalysis 2 (GR2)****- T62, 25-year reanalysis, OSU LSM**
**Anticipated in Next-Generation CFS**
**T126**
**25-year hindcast**
**Noah LSM**
**Initial land states from Global Reanalysis 3 (GR3)****- T126, 25-year reanalysis, Noah LSM******              ** ****Not yet available**** **
**While awaiting coupled GR3:****   **_**Uncoupled**_** **_**T126**_** **_**GLDAS**_** with **_**Noah LSM**_**   will provide **_**25-year**_** initial land states for****   **_**T126 CFS/Noah**_

## GR2  vs  GLDAS

**  ****T62 (194 x 94) ******** T126 (384**** x ****190)**
** ****Land component vertical resolution**
**  ****2 soil layers (10, 190 cm) ******** 4 soil layers (10, 30, 60, 100 cm)**
** ****OSU LSM ******** Noah LSM**
**  ****Addition of frozen soil physics**
**  ****Improved physics:****	****snowpack****	****evaporation****	****ground heat flux****	****infiltration & runoff**
** ****Precipitation forcing: **
**  ****Both use CPC CMAP precipitation, but different methodology**
** ****Other non-precip surface forcing****:**
**  ****Both from GR2**

**GR2  vs  GLDAS**

## NCEP Reanalysis2 2-Layer Soil Moisture00Z 01 Jan 1979

**NCEP Reanalysis2 2-Layer Soil Moisture****00Z 01 Jan 1979**

**0-10 cm**

**10-200 cm**

**T62**

**GLDAS also needs a cold start initial condition**

## GLDAS 4-Layer Soil Moisture(mapped from GR2 for 01 Jan 1979 cold start)

**GLDAS 4-Layer Soil Moisture****(mapped from GR2 for 01 Jan 1979 cold start)**

**T126**

## GLDAS 4-Layer Soil Moisture(after 5-year spinup with repeated 1979 GR2 forcing)

**GLDAS 4-Layer Soil Moisture****(after 5-year spinup with repeated 1979 GR2 forcing)**

**T126**

## NCEP Reanalysis2 vs GLDAS spinup 

**NCEP Reanalysis2 vs GLDAS spinup**** **

**GR2/OSU**

**GLDAS/Noah**

**January**

## NCEP Reanalysis2 vs GLDAS spinup 

**NCEP Reanalysis2 vs GLDAS spinup**** **

**January**

**GR2/OSU**

**GLDAS/Noah**

## NCEP Reanalysis2 vs GLDAS spinup 

**NCEP Reanalysis2 vs GLDAS spinup**** **

**July**

**GR2/OSU**

**GLDAS/Noah**

## CONUS SubRegions

**CONUS SubRegions**

## Vol. Soil Moisture 0-10cmFive annual cycles spinup of 1979

## Vol. Soil Moisture 10-40cmFive annual cycles spinup of 1979

**Deeper soil layers require longer spinup**

## Vol. Soil Moisture 40-100cmFive annual cycles spinup of 1979

**Deeper soil layers require longer spinup**

## Vol. Soil Moisture 100-200cmFive annual cycles spinup of 1979

**Has bottom soil layer in the West fully spunup?**

## Vol. Soil Moisture 0-200cmFive annual cycles spinup of 1979

## Optimal Precipitation Forcing

_**Purpose**_**:****	****Create a 6-hourly global land-only precipitation dataset primarily****	****based on rain gauge observations**
_**Datasets**_**:****	****CMAP ******** Spatial: 2.5****°**** x 2.5****°****, Temporal: Pentad**
**	****	****GTS land only ******** Spatial: 0.5****°**** x 0.5****°****, Temporal: Daily**
**	****	****GR2 ******** Spatial: 2.5****°**** x 2.5****°****, Temporal: 6-hourly**
_**Approach**_**: **
**	****(1)****	****Disaggregate CMAP pentad precipitation to daily 0.5****° ****x 0.5****°**** resolution**
**	****	****using the GTS dataset**
**	****(2)****	****Disaggregate dataset created in (1) to 6-hourly 0.5****° ****x 0.5****°**** resolution****	****using GR2 dataset**** **
- For both (1) and (2) above:
- 	(a) Higher temporal resolution data is summed for the lower temporal resolution data period
- 	(b) Weights are calculated for each period of the higher temporal resolution data
- 	(c) These weights are applied to the lower temporal resolution data
- 	(d) Additional rules:
- If precipitation for the lower temporal resolution data > 0 but the precipitation of the higher temporal resolution data is = 0, a search is conducted in a 5° x 5° area starting from the inside out to find a suitable weight.
- If precipitation for the lower temporal resolution data = 0, final precipitation is = 0
_**References**_**:***** Xie P., and P. A. Arkin, 1996: Global precipitation: a 17-year monthly analysis based on gauge observations, satellite estimates, and numerical model outputs. Bull. Amer. Meteor. Soc., 78, 2539-2558******.***

**Optimal Precipitation Forcing**

## GR2                                CMAP

**GR2                                CMAP**

## CONUS SubRegions

**CONUS SubRegions**

## Daily Precipitation [mm]1979

**GR2            ****CMAP**

## 25-year simulation forced withGR2 + CMAP

## Total Column Vol. Soil Moisture (0-200cm)25 years (1979-2003)

**GR2          ****GLDAS**

## Vol. Soil Moisture Anomaly 0-200cm1979-2003

**GR2          ****GLDAS**

## Vol. Soil Moisture 4 Layers1979-2003

## Vol. Soil Moisture 4 Layers1979-2003Northern Central US

- Vol. Soil Moisture 4 Layers1979-2003Northern Central US

## GLDAS/Noah 4-Layer Soil Moisture

**GLDAS/Noah 4-Layer Soil Moisture**

**July 1988**

## GLDAS/Noah 4-Layer Soil Moisture

**GLDAS/Noah 4-Layer Soil Moisture**

**July 1988**
**anomaly**

## GLDAS/Noah 4-Layer Soil Moisture

**GLDAS/Noah 4-Layer Soil Moisture**

**July 1993**
**anomaly**

## Summary

** ****25-year T126 GLDAS/Noah land states****	****forced with GR2+CMAP**
** ****Resulting soil moisture structure is****	****different from GR2/OSU**
** ****Results will be used to initialize****	****CFS/Noah hindcast testing**
** ****Plan:**
-  **Implement Higgins/Shi CPC****	****CONUS+Mexico gauge-only daily precip**
** ****Spinup strategy****	****e.g., annual or monthly cycles **
** ****Initialization strategy****	****e.g., anomaly rescaling**

## Thank you!

***Jesse.Meng@noaa.gov***

## GLDAS/Noah 4-Layer Soil Moisture

**GLDAS/Noah 4-Layer Soil Moisture**

**April**

## GLDAS/Noah 4-Layer Soil Moisture

**GLDAS/Noah 4-Layer Soil Moisture**

**July**

## GLDAS/Noah 4-Layer Soil Moisture

**GLDAS/Noah 4-Layer Soil Moisture**

**October**

## NCEP Reanalysis2 vs GLDAS spinup 

**NCEP Reanalysis2 vs GLDAS spinup**** **

**July**

**GR2/OSU**

**GLDAS/Noah**

## GLDAS/Noah Total Soil Moisture

**GLDAS/Noah Total Soil Moisture**

## GLDAS/Noah 4-Layer Soil Moisture

**GLDAS/Noah 4-Layer Soil Moisture**

**July 1988**

## GLDAS/Noah 4-Layer Soil Moisture

**GLDAS/Noah 4-Layer Soil Moisture**

**July 1993**