# Presentation: 554320

##      Regional Reanalysis Climatology

**The Regional Reanalysis Team at the Climate Prediction Center**
**Marco Carrera, Kingtse Mo, **
**Wayne Higgins, Jae Schemm, **
**Muthuvel Chelliah, Wesley Ebisuzaki,**** **
**Wei Shi, Hyun-Kyung Kim, **
**Evgeney Yarosh, and Yucheng Song**

**North American Regional Reanalysis Workshop**
**11 January 2005 San Diego, CA**

## Investigate the seasonal cycle of precipitation, surface  temperature and the large-scale aspects of the hydrological cycle over North America from the perspective of the Regional Reanalysis (RR) analysis and forecast products.
Outline
Examine the seasonal cycle of precipitation and surface temperature;
Moisture budget terms;
Low-level jets;
Conclusions.

_**Outline**_
**Examine the seasonal cycle of precipitation and surface temperature;**
**Moisture budget terms;**
**Low-level jets;**
**Conclusions.**

_**Objectives and Outline**_

## Model : Eta regional model and data assimilation system;
Resolution : 32km, 45 vertical levels, 3hourly;
Base Period for climatology : 1 Jan 1979 – 31 Dec 2001;
Domain : North America and adjacent oceans.

Precipitation assimilation: 
US : PRISM corrected gauge analysis; 
Mexico, Canada : Rain gauge analysis; 
other areas (equatorward of 42.5oN) 
 CMAP pentad analysis  (1979 - 2002)
 CMORPH  hourly precipitation analysis (2003 - )

**Resolution : 32km, 45 vertical levels, 3hourly;**
**Base Period for climatology : 1 Jan 1979 – 31 Dec 2001;**
**Domain : North America and adjacent oceans.**
**Precipitation assimilation: **
**US : PRISM corrected gauge analysis; **
**Mexico, Canada : Rain gauge analysis; **
**other areas (equatorward of 42.5****o****N) **
** ****CMAP pentad analysis  (1979 - 2002)**
** ****CMORPH  hourly precipitation analysis (2003 - )**

_**Regional Reanalysis (RR)**_

## Precipitation and surface temperature from the RR compare favorably with observations. 
Surface temperatures are not assimilated over land.
The seasonal cycle of precipitation is well captured by  the RR;
Relationships between E and P in the RR are consistent with those reported by Rasmusson (1967, 1968) and Berbery et al. (1996).

***Surface temperatures are not assimilated over land.***
**The seasonal cycle of precipitation is well captured by  the RR;**
**Relationships between E and P in the RR are consistent with those reported by Rasmusson (1967, 1968) and Berbery et al. (1996).**

**Precipitation and Surface Temperature**

## Annual Cycle of Precipitation (mm day-1) Warm  Season

**June:** **P reaches a maximum over the Central US, while monsoon rainfall spreads northward along the western slopes of the ****Sierra Madre Occidental****.**
**July:**  **Monsoon P shifts northward into AZ/NM by early July while P decreases in Central US.**
**August:** **Monsoon P reaches a maximum over SW and then starts to retreat.  The demise of the monsoon  is more gradual than the onset.   **

**Annual Cycle of Precipitation (mm day****-1****) Warm  Season**

## Precipitation Difference (mm day-1)

**Largest differences are over southern Mexico where the difference is about 8%.**

**Precipitation Difference (mm day****-1****)**

**(RR-Unified US/Mexico) : Warm Season**

## Comparison between Free Forecasts and the RR (1998-2002)

**The differences between 3-hr Fcst and the RR can be as large as 4 mm day****-1****.**
**Some of the differences are due to spin up. The differences between the 12-hr Fcst and the RR show the same pattern but magnitudes are smaller.**

**Comparison between Free Forecasts and the RR (1998-2002)**

## Annual Cycle of Precipitation (mm day-1) Cold  Season

**Nov-Dec**
**Precipitation extends from the Pacific Northwest southward to California**
**Jan- Feb**
**Rainy season in California**
**March-April**
**Rainfall retreats northward**

**Annual Cycle of Precipitation (mm day****-1****) Cold  Season**

## Precipitation Difference (mm day-1)

**Large differences over the western regions of the US may be due to the PRISM correction. **
**PRISM is used for the assimilated precipitation in the RR, but not for the Unified analyses.**

**Precipitation Difference (mm day****-1****)**

**(RR-Unified US/Mexico) : Cold Season**

## Annual cycle of Precipitation (mm day-1) in Various Regions

**Winter regime:** **Pacific Northwest and California**

**Summer Regime:** **Central US & Mexico**

**Mid-Summer Minimum:**
-  **Southern Mexico,**
**Southern Plains**

**RR(****red****) ; Unified US/Mexico (****black****)**

**Weak seasonal cycle:**
**Southeast**

## Annual Cycle of 

**2 meter air Temperature (T2m) (°C)**
**(warm season)**

##  Temperature Difference (oC) 

** ****(RR T2m –OBS Surface Temp)**
**(Warm Season)**

**Largest differences found over the high terrain of the western US where the RR possesses a cold bias.**

**RR possesses a positive bias over the central part of the US.**

##   Annual cycle of  T2m  Temperature (oC) cold season

##       Temperature Difference (oC) 

** ****(RR T2m –OBS surface Temp)**
**(Cold Season)**

**Largest differences found over the high terrain of the western US where the RR again possesses a cold bias.**

## Cold Season (DJF) Moisture Terms

**E**

**P-E**

**-DQ**

**Over the western region, contribution to P is from DQ, E   is  small.**** **

**Two branches of moisture fluxes: one to the Pacific Northwest and another to California**

**Cold Season (DJF) Moisture Terms**

## Warm Season (JAS) Moisture Terms

**E**

- E

- qflux

**E>P over the central US.**

**-D(Q)**
**3 Low level Jets**
**CALLJ: Caribbean**
**GPLLJ:Great Plains**
**GCLLJ: Gulf of California**

-    **P**

**Warm Season (JAS) Moisture Terms**

## P

- D(Q) contribution over the central US is small
- Both E and D(Q) contribute to rainfall over the Southwest

**Results are consistent with Rasmusson (1967,1968).**

**P**

**E**

**(E-P)**

**-DQ**

**Seasonal Cycle of Moisture Budget Parameters (32****o****N-36****o****N)**

## The LLJ from the Caribbean (CALLJ) is well captured by the RR.

The Great Plains LLJ (GPLLJ) in the RR is similar to that in the operational EDAS and compares well to the wind profiler data.

The Gulf of California LLJ (GCLLJ) is too strong compared to observations.  

**The Great Plains LLJ (GPLLJ) in the RR is similar to that in the operational EDAS and compares well to the wind profiler data.**
**The Gulf of California LLJ (GCLLJ) is too strong compared to observations.  **

_**Low-Level Jets (LLJ)**_

## Wind            profiler

**Wind            profiler**

**RR**

**Higgins et al. 1997**

**Max: **
**RR 900-950 hPa**
**Profiler:**
**Below 950 hPa**

**Mean Diurnal Cycle of Meridional Wind (m s****-1****) at (36****o****N,97.5****o****W) (GPLLJ)**
**JJA 1994**

## Meridional Wind (m s-1) at       (36oN,97.5oW) (GPLLJ)

**Meridional Wind (m s****-1****) at       (36****o****N,97.5****o****W) (GPLLJ)**

**RR**

**Wind Profiler**

**Higgins et al. (1997)**

- 1

**Strong**** ****diurnal cycle: max 250-500 m AGL**

**Strong**** ****diurnal cycle: max 930-960 hPa **

## When the RR is compared to the operational EDAS, the GCLLJ appears to be too strong and less variable. 
The largest values in the RR are concentrated in the northern Gulf of California. The RR captures the diurnal cycle of the meridional winds as indicated by the sounding data at Puerto Peñasco, but the magnitude is about 3 - 4 m s-1 higher .
Vertically, the jet depicted by the RR extends above 850 hPa while the operational EDAS shows a more shallow jet confined below 850 hPa. 

**The largest values in the RR are concentrated in the northern Gulf of California. The RR captures the diurnal cycle of the meridional winds as indicated by the sounding data at Puerto Pe****ñ****asco, but the magnitude is about 3 - 4 m s****-1**** higher .**
**Vertically, the jet depicted by the RR extends above 850 hPa while the operational EDAS shows a more shallow jet confined below 850 hPa. **

_**GCLLJ as depicted by [qv]**_

## Vertically Integrated Meridional                      Moisture Flux [kg (ms)-1] (1995-2000)

**RR**

** ****RR - OpEDAS**

**RR [qv]**
**Over the Gulf of California the vertically integrated meridional moisture fluxes are stronger in the RR when compared with the  EDAS**
**Differences can be as large as **
**60 kg m****-1****s****-1**

**June**

**July**

**August**

**September**

## RR, pilot balloon and soundings at Puerto Peñasco (31.3oN,113.6oW)

- 252-m observed wind
- (Douglas et al. 1998)

- RR v-wind captures the diurnal cycle but it is 3 m s-1 higher than observed

**Profile of v-wind (obs)**

- 1 LT

- 16 LT

- 1LT

- 16LT

- RR

**RR, pilot balloon and soundings at Puerto Pe****ñ****asco (31.3****o****N,113.6****o****W)**

**31 July – 14 August 1995**

**31 July – 14 August 1995**

## Vertical cross-section of qv at 30oN

**RR**

**Operational EDAS**

**Vertical cross-section of qv at 30****o****N**
**  ****1998-2000**

**GPLLJ**
- RR compares well with EDAS
**GCLLJ**
- RR: Large qv  values extend above 850 hPa
- EDAS: Large qv  values are confined below 850hPa

**July**

**Aug**

**Sep**

## The NAME (North American Monsoon Experiment) data will give guidance to: 
the location, strength and variability of the GCLLJ,
the structure and diurnal cycle of P and the GCLLJ, 
relationships between P and the GCLLJ.
We need to understand:
The reason why the GCLLJ is stronger in the RR when compared with the operational EDAS?  

**the location, strength and variability of the GCLLJ,**
**the structure and diurnal cycle of P and the GCLLJ, **
**relationships between P and the GCLLJ.**
**We need to understand:**
**The reason why the GCLLJ is stronger in the RR when compared with the operational EDAS?  **

_**Challenges**_

## RR Climatology is available from UCAR JOSS
http://www.joss.ucar.edu/name/dm/archive/
3 hourly climatology of a limited number of fields;
Daily climatology;
Monthly mean climatology;
Detailed information on the climatologies can be found on the RR website at:
http://wwwt.emc.ncep.noaa.gov/mmb/rreanl/

_**[http://www.joss.ucar.edu/name/dm/archive/](http://www.joss.ucar.edu/name/dm/archive/)**_
**3 hourly climatology of a limited number of fields;**
**Daily climatology;**
**Monthly mean climatology;**
**Detailed information on the climatologies can be found on the RR website at:**
**http://wwwt.emc.ncep.noaa.gov/mmb/rreanl/**

**Availability of the CPC RR Climatology**

## Comparison of Various Parameters at Empalme

**Douglas and Leal (2003)**

**RR**

**Comparison of Various Parameters at Empalme**