# Presentation: 149278

##       Regional Reanalysis       Climatology

- _The NAME Team at CPC:_
**Kingtse Mo, Wayne Higgins,**
** ****Jae Schemm, Muthuvel Chelliah,**
**Wesley Ebisuzaki, Marco Carrera, **
**Wei Shi, Hyun Kyung Kim **
**Evgeney Yarosh, and Yucheng Song**

## Regional Reanalysis(Mesinger et al. 2004)

**Model: Eta 32km, 45 vertical levels**
**Base Period for climatology: 1 Jan 1979 – 31 Dec 2001**
**Domain: North America and adjacent oceans**
**Precipitation assimilation: **
***U.S.: PRISM corrected gauge analysis; ***
***Mexico: Rain gauge analysis; ***
***other areas: CMAP pentad analysis  (1979-2002)***
***                   ******: CMORPH  hourly precipitation analysis (2003- present)***

## Precipitation and Surface Temperature

**Precipitation and Surface Temperature from the RR compare favorably with observations. **
***Surface Temperature is 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 (1968, 1969) and Rasmusson and Berbery (1996)**

## Annual Cycle of Precipitation (mm day-1)    (warm season)

**May:** Heaviest P in the western Gulf Coast and lower Mississippi Valley.
**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.

## Precipitation Difference (mm day-1)   (RR – Unified US/Mexico) : Warm Season 

- RR assimilates observed P, so the differences between  RR and observed are expected to be small.

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

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

- 0-3 hr forecasts have more rain over land and are dryer over oceans.
- The differences between 3-hr Fcst and the RR can be as large as 4 mm day-1.
- Some of differences are due to spin up. The differences between 12-hr Fcst and the RR show the same pattern but magnitudes are smaller

## Annual cycle of precipitation (mm day-1) cold season

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

## Precipitation Difference (mm day-1)(RR - Unified US/Mexico) : Cold Season

- Large differences over the western region may be due to the PRISM correction.
- PRISM is used for the assimilated precipitation, but not for  the Unified analyses

## 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)**

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

-   **Annual cycle of  T2m  Temperature (****o****C) cold season**

##       Temperature Difference (oC) 

-       **Temperature Difference (****o****C) **
** ****(RR T2m –OBS surface Temp)**
**(Cold Season)**

## Cold season moisture terms

**P**

**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**

## Warm season moisture terms

- P-E

- 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

## Seasonal cycle of Moisture Budget Parameters (32N-36N)

- E> P over the central US in summer
- 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 1968,1969**

**P**

**E**

**(E-P)**

**-DQ**

## Low Level Jets (LLJ)

**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 wind profiler data.**
**The Gulf of California LLJ (GCLLJ) is too strong compared to observations.  **

## LLJ from the Caribbean

**May**

**June**

**July**

** ****August**

**  ****September**

**October**

**925-hPa Zonal Wind (m s****-1****)**

**Compares well with Amador (1998)**

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

**Wind            profiler**

**RR**

**Higgins et al. 1997**

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

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

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

- Strong diurnal cycle
- MAX :950-975 hPa

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

**RR**

**Wind Profiler**

**Higgins et al. (1997)**

- 1

## GCLLJ as depicted by [qv]

**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 Penasco, 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 **

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

**RR**

** ****RR - OpEDAS**

**RR [qv]**
**Over the Guf of California are stronger than  EDAS**
**Differences can be as large as 60kg/(ms)**

## Comparison of Various Parameters at Empalme

**Douglas and Leal (2003)**

**RR**

**Comparison of Various Parameters at Empalme**

## RR and pilot balloon and soundingsat Puerto Penasco(31.3N,113.6W)

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

- RR v-wind captures the diurnal cycle but it is 3m/s higher than obs,

- Profile of v-wind (obs)

- 1 LT

- 16 LT

- 1LT

- 16LT

- RR

## Vertical cross section of qv at 30N

**RR**

**Operational EDAS**

-       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

## Challenges

**The NAME data will give guidance to:**** **
**the location, strength and variation of the GCLLJ,**
**the structure and diurnal cycle of P and the GCLLJ, **
**relationship between P and the GCLLJ.**
**We need to understand:**
**The reason why  the GCLLJ is stronger in RR than it is in the operational EDAS?  **