# Presentation: 077664

## Assimilation of OMI Ozone for Air Quality Prediction

- Brad Pierce1, Jay Al-Saadi2, Jim Szykman3, Todd Schaack4, P.K. Bhartia5, Anne Thompson6
*NOAA NESDIS*
*NASA Langley Research Center*
*US Environmental Protection Agency*
*University of Wisconsin/SSEC*
*NASA GSFC*
*Penn State University*
- Presented by Jay Al-Saadi

## RAQMSglobal (2x2) 2006 Ozone Assimilation/Forecast Procedure

**RAQMS Global Met/Chem **

**RAQMS****global**** (2x2) 2006 Ozone Assimilation/Forecast Procedure**

**MODIS Rapid Response**
**Wild fire locations**

**5-day RAQMS **
**Global Met/Chem**
**Forecast**

**Real-time OMI Cloud-cleared column OI assimilation conducted at 2x2 degrees for**
**Feb 01-Oct 15, 2006. Analysis increment applied as **_**percentage adjustment to mixing ratio**_** resulting in minimal impact on troposphere. **

**NOAA GFS Global Met**

**Ecosystem/Severity Based wildfire emissions**

## Total Column Ozone Timeseries August 01- October 15, 2006

- temporal and latitudinal variations. RAQMS analysis underestimates mid-September
- through mid-October (Julian day 260-290) Antarctic ozone loss by 17%

**Total Column Ozone Timeseries August 01- October 15, 2006**

## Tropospheric Ozone Column (subtracting RAQMS stratosphere) August 2006

**Tropospheric Ozone Column (subtracting RAQMS stratosphere) August 2006**

- Analyzed Tropospheric Ozone Column (TOC) _well correlated_ with OMI - RAQMSSTRAT (r=0.84 globally, 0.90 CONUS). TOC _median high bias of 3.6 Dobson Units over CONUS_. Globally, median bias is negative due to low tropical values.

## Comparison of RAQMS NRT OMI analysis 

**PI: ANNE M. THOMPSON**
**Penn State**

**RAQMS NRT OMI Tropospheric Ozone Column**
**(August 01-31, 2006)**

**Large high bias (50-100%) in upper troposphere/lower stratosphere**

**Comparison of RAQMS NRT OMI analysis **
**with IONS ozonesondes (373 sondes, August, 2006)**

## TexAQS 2006: RAQMS O3 vs NOAA P3 all flights

**TexAQS 2006: RAQMS O****3**** vs NOAA P3 all flights**

- In East Texas, RAQMS analysis has approx 15 ppb high bias through free troposphere. No median bias near the surface although variance is underestimated.

## O3 timeseries from monitoring locations in Houston and Dallas show that the RAQMS analysis captures the temporal behavior of surface O3 at these sites (1-hour and 24-hour r values above 0.8) but has a persistent high bias. 

- O3 timeseries from monitoring locations in Houston and Dallas show that the RAQMS analysis captures the temporal behavior of surface O3 at these sites (1-hour and 24-hour r values above 0.8) but has a persistent high bias.

**TexAQS, Aug-Sep 2006: Assessment of O3 Analysis with Hourly Surface O3 Measurements**

## National maps of time averaged site statistics show RAQMS 18Z surface O3 analysis is high by 15 ppbv through most of the SE US and by 30 ppbv over the Ohio River valley and Northeast (left) but is highly correlated with measurements over most of the Eastern US (right). 

- National maps of time averaged site statistics show RAQMS 18Z surface O3 analysis is high by 15 ppbv through most of the SE US and by 30 ppbv over the Ohio River valley and Northeast (left) but is highly correlated with measurements over most of the Eastern US (right).

**TexAQS, Aug-Sep 2006: Assessment of O3 Analysis with Hourly Surface O3 Measurements**

**18Z Bias (model-obs) (ppbv)**

**18Z Correlation**

## Histograms show the changes in bias and temporal correlation through the 5-day forecast period. There is little change in the distribution of biases or median bias during the forecast period (left). Temporal correlation coefficients (right) show significant skill through 30 hours (median correlation 0.6) and a systematic degradation at forecast periods of 54 hours and beyond.

**TexAQS, Aug-Sep 2006: Assessment of O3 Forecasts with Hourly Surface O3 Measurements**

**18Z Bias (model-obs) (ppbv)**

**18Z Correlation**

## Extra slides

## RAQMS August, 2006 Mean OMI O3 O3 Analysis Increments (total column)

- Assimilation of OMI total column O3 measurements results in small (1-1.5%) mean increases in total column O3 over CONUS.