# Presentation: 573996

## Assimilation of MLS and SABER Temperature and MLS Water Vapor Throughout the Stratosphere and Mesosphere during the Northern Summer of 2007 in Meteorological Support of the Aeronomy of Ice in the Mesosphere (AIM) Mission

- S. D. Eckermann1, K. W. Hoppel2, L. Coy1, J. P. McCormack1, D. E. Siskind1, K. Nielsen3, A. Kochenash3, M. H. Stevens1, C. R. Englert1, W. Singer4, and M. Hervig5
*1 **Space Science Division, Naval Research Laboratory, Washington, DC*
*2 **Remote Sensing Division, Naval Research Laboratory, Washington, DC*
*3 **Computational Physics, Inc., Springfield, VA*
*4 **Leibniz Institute of Atmospheric Physics, Kühlungsborn, Germany*
*5 **GATS, Inc., Driggs, ID*

## AIM: Aeronomy of Ice in the Mesosphere

**AIM: Aeronomy of Ice in the Mesosphere**

**6 min**

**SOFIE**
- T, H2O, ice...

**CIPS**
- PMC nadir imagery

**To Understand Polar Mesospheric **
**Clouds (PMCs)**

*z*~83 km

**PMCs**

## NOGAPS-ALPHA

- Navy Operational Global Atmospheric Prediction System (DoD NWP System)

- Advanced-Level Physics & High Altitude NWP Prototype

**NAVDAS**: NRL Atmospheric (3D) Variational Data Assimilation System

## Practical Assimilation Issues

- SABER V1.07 includes vibrational exchange between CO2 isotopes which is critical for accurate temperatures in summer mesopause [*Remsberg et al*., 2008]
- Global-mean SABER-MLS temperature bias calculated and used to correct an ~2 K SABER warm bias at altitudes below 2.7 hPa [*Remsberg et al., *2008]
- At higher altitudes remove structured stratopause bias and systematic mesospheric cold bias based on MLS validation study of *Schwartz et al*. [2008]
- Perform 3-point along-track smoothing of MLS H2O at p<0.02 hPa to beat down measurement errors at these heights [*Lambert et al*., 2007]
- Forecast model includes parameterized O3 and H2O photochemistry but no parameterized PMC microphysics
- Extensive tuning of parameterized nonorographic gravity wave drag to minimize model-data bias (O-Fs) in polar summer mesosphere
- Assimilation period focused on here is 1 June to 15 July 2007 when SABER was yawed to view the northern hemisphere polar summer (first AIM PMC season)

- For more details, see...
- Eckermann, S. D., K. W. Hoppel, L. Coy, J. P. McCormack, D. E. Siskind, K. Nielsen, A. Kochenash, M. H. Stevens, C. R. Englert, and M. Hervig, High-altitude data assimilation system experiments for the northern summer mesosphere season of 2007, *J. Atmos. Sol.-Terr. Phys. (in press),  2008.*

## NOGAPS-ALPHA vs. NASA GEOS-4 AnalysisJune 2007

**Ozone (ppmv)**

**Zonal Winds (m s****-1****)**

## Validation Against Independent AIM DataTemperature

## NLC Outbreak over northwestern USA19 June 2007

**NLC Outbreak over northwestern USA****19 June 2007**

- NLC = noctilucent cloud
- photo by Kellen Harrel
- Portland, Oregon (45.5oN)
- 19 June 2007
- 10:30 pm

## NOGAPS-ALPHA Assimilated Fields20 June 2007 0600 UTC0.006 hPa (~83 km)

- Temperature ***T***            Water Vapor ***χ******H2O******         ***Saturation Ratio ***S***** **

***S***=*p*H2O/*p*ice            *p*H2O = *p* *χ*H2O
- log *p*ice = 9.550426 -5723.265/*T* + 3.53068 log *T* -0.00728332 *T*
- [*Murphy and Koop*, 2005]

## NOGAPS-ALPHA Assimilated Fields30 June 2007 0000 UTCSaturation Ratio at 0.006 hPa (~83 km)

**NOGAPS-ALPHA Assimilated Fields****30 June 2007 0000 UTC****Saturation Ratio at 0.006 hPa (~83 km)**

- Palmela, Portugal

- Budapest, Hungary

- Durham, UK

- Vallentuna, Sweden

## Mean PMC Frequency During Season

**SOFIE PMC Observations**

**NOGAPS-ALPHA Saturation Ratios**

## 2D Wavenumber Frequency Spectra

- Quasi 5-day Wave (Rossby [1,1] Normal Mode)

- Solar Migrating Diurnal Tide

- Solar Migrating Semidiurnal Tide

## Mesospheric Wind Validation

-           Zonal Wind                                Meridional Wind

## Summary

- NOGAPS-ALPHA was run as a global DAS extending to ~100 km and used to assimilate MLS and SABER data to 0.002 hPa during the first AIM PMC season of June-July 2007
- 0.006 hPa saturation ratios derived diagnostically from analyzed temperature and humidity show skill in locating observed PMC and NLC outbreaks
- Strong planetary wave and tidal signals arise that agree reasonably well with climatologies and available independent observations
- Analysis fields show promise in providing analysis fields for AIM science
- Eckermann, S. D., K. W. Hoppel, L. Coy, J. P. McCormack, D. E. Siskind, K. Nielsen, A. Kochenash, M. H. Stevens, C. R. Englert, and M. Hervig, High-altitude data assimilation system experiments for the northern summer mesosphere season of 2007, *J. Atmos. Sol.-Terr. Phys. *(in press),  2008.
- Downloadable at _[http://uap-www.nrl.navy.mil/uap/?content=publications;code=7646](http://uap-www.nrl.navy.mil/uap/?content=publications;code=7646)_

## Backup Slides Follow

## NLC Outbreak over western Europe29-30 June 2007

**NLC Outbreak over western Europe****29-30 June 2007**

- photo by Paulo Casquinha,
- Palmela, Portugal (38.5oN)
- 30 June 2007
- ~1 hour before sunrise

## NOGAPS-ALPHA AnalysisSupport of Mesospheric Cloud (MC) Science

- All 236 UV limb brightness profiles acquired by SHIMMER on STPSat-1 between 40o-50oN on 13 June 2007.
- Three mesospheric clouds (MCs) are detected (see opposite): their locations are shown as red dots on map lower-right (_credit Mike Stevens & Chris Englert for SHIMMER data_).

_**SHIMMER**_
**13 June 2007**

## Validation Against Independent AIM DataWater Vapor

**Validation Against Independent AIM Data****Water Vapor**

## Data Assimilation System (DAS)

**N****RL ****A****tmospheric ****V****ariational ****D****ata ****A****ssimilation ****S****ystem**

## NAVDAS NRL Atmospheric Variational Data Assimilation System

**NAVDAS**** *****N****RL ****A****tmospheric ****V****ariational ****D****ata ****A****ssimilation ****S****ystem*

- Numerically minimize the scalar cost function

- observation
- vector **y**

- obs. error
- covariance

- forward obs.
- operator

- background
- vector **x****b**

- bgnd. error
- covariance

**analysis vector ****x****a**

- NAVDAS computes the observation-space solution

**innovations**

**corrections**

- Solution converts ***“innovation” vectors*** in the observation space into ***“correction” or “increment” vectors*** in the model/analysis space.               .

## Dynamical Core & Operational NWP Setup

**Dynamical Core**
- Eulerian, hydrostatic and spectral in horizontal
- Vertical finite difference using a hybrid -p generalization of the Lorenz-grid  discretization of *Arakawa and Schubert* (1983)
- Three-time (leapfrog) scheme, semi-implicit treatment of gravity wave propagation (increases *t*), Robert (Asselin) time filtering.
- Variable horizontal (T79-T479) and vertical resolution (L30-L84)
- Runs operationally at FNMOC at T239L30 (T119L30 for ensembles)
**Tropospheric Physics for Numerical Weather Prediction (NWP)**
*Louis* PBL mixing and diffusive transport scheme
- Land surface model with analyzed snow, ice and ground/SSTs
- orographic gravity-wave, flow-blocking and turbulent drag
*Emanuel *deep convection scheme, *Tiedtke* shallow convection scheme
*Harshvardhan et al*. radiation
- Convective, stratiform and boundary-layer cloud & precipitation schemes

## Details/Observations for AIM Test Period

**Standard Operational METOC Observations**
-     Geostationary winds				AMSU-A radiances channels 4-10
-     MODIS AQUA & TERRA winds		QuickSCAT (ocean winds)
-     Ground-based: and, ship, buoy, rawinsonde, radar wind profilers, pibal, aircraft...
**New Experimental Observations for NOGAPS-ALPHA Assimilation Experiments**
-     MLS v2.2 Temperatures:			32-0.002 hPa
-     SABER v1.07 Temperatures:		32-0.002 hPa
-     MLS v2.2 and SBUV/2 Ozone:		300-0.3 hPa
-     MLS v2.2 Water Vapor:				215-0.002 hPa
-     AMSU Channels 11-14:				20-2 hPa
**First Test Assimilations**
_**“**__***Warming***__**” Runs**_: 1 January – 28 February 2006 	[*Hoppel et al*., ACP, 2008]
_**“**__***AIM***__**” Runs**_:		   15 May – 31 August, 2007 		[*Eckermann et al*., JATP, 2008]
- 	NOGAPS-ALPHA Model Resolution: T79L68 (top=0.0005 hPa)‏

*Not used yet in test runs*

_**MLS**_** is an instrument on NASA’s Aura satelite**
_**SABER**_** is an instrument on NASA’s TIMED satellite**

## NOGAPS-ALPHA Analysis1-10 January vs. 10-20 February 2007

**Vertical EP Flux (10****-3****kg m****-1****s****-2****)**

**Zonal Winds (m s****-1****)**

**EP Flux Vectors**

**Residual Circulation (*****v******,*****w******)**

-  Longwave radiation extended to *p*<0.01hPa using Fomichev parameterization of **non-LTE CO****2**** cooling**
-  **near-IR CO****2**** heating** corrected for non-LTE
-  Fully **prognostic ozone and water vapor**
-  3D initialization & spectral advection
-  Linearized odd-oxygen and water vapor photochemistry schemes (former transitioned to NCEP GFS August 2006)
-  Prognostic ozone and water feed into radiation to modify radiative heating/cooling (fully interactive)
-  “Cold tracer” for PSC (or PMC) formation and heterogeneous ozone loss
-  **prognostic CH****4**** and N****2****O** capabilities added, via initialization, advection & parameterized chemistry
-  new MLT parameterizations of **nonorographic gravity wave drag and diffusion**
-  and _many_ other additions too.....

**New Physics, Dynamics & Chemistry for the Mesosphere & Lower Thermosphere (MLT)**