# Presentation: 808721

## The GFS+GOCART dust and aerosol modeling

- Ho-Chun Huang, Sarah Lu, Jeff McQueen, Mark Iredell, Geoff DiMego, and Steve Lord
- NOAA/NWS/NCEP/EMC

## Acknowledgment

- Shrinivas Moorthi (for adding convective variables)

## GFS+GOCART Offline System

- GFS
- NCEP/EMC Global Forecast System
- GOCART
- NASA Goddard Global Ozone Chemistry Aerosol Radiation and Transport Model
- Steps
- (1) dust modeling
- (2) aerosol modeling

## GOAL

- To serve as an initial benchmark for future inline work
- To provide initial first guess aerosol fields for AQF Lateral boundary conditions
- To provide initial first guess aerosol fields for GSI development
- To meet NWS global dust forecasting goals

## 1 The aerosol modeling will be added later

- 1 The aerosol modeling will be added later

**Notes:**
The schematic of the offline system information passage. 

## GFS+GOCART Tasks

**To study the GFS input and output structure**
**Conduct sample and random short term GFS simulations**
**Learn to read the GFS output data**
*To conduct GOCART run with sample data*
**Produce GOCART executable on DEW** **(compiler-script modification)**
*Run GOCART executable with GSFC sample data (run-script modification)*
- Compare output with GSFC Sample output data
*To conduct GOCART run with GFS data*
**Compared and located GOCART input variables in the GFS routines**
**Modified GFS code for additional variable output**
**Modified routines to GFS to compute new variable (from Moorthi)**
*Convert instantaneous to time-average quantities.*
*Write interface to convert GFS output to GOCART input (in binary)*
*Modify GOCART I/O to receive GFS input*
- Project GOCART emissions and input dataset on the GFS grid
- Perform GFS+GOCART Offline Runs and Examine the output
- Send Initial 3-D output to Pius and Tang for BC mapping and initial CMAQ-NAM test runs
*Verification and model evaluation (work with Pius, Marina, and Tang)*
*Collect available AOD products from AERONET, MODIS, GOES, CALIPSO, as well as 3-D profile of concentration*
- Coordinate with CMAQ LBC tests

**Bold face – done**, *italic – in progress*, to be performed

**Notes:**
GOCART requires some input that are time-averaged, this allow the computation of mean state during the hourly or 6-hourly periods.  Using instantaneous values may bias the mean toward the first or the last time-step.
We can go ahead to use the instantaneous values for testing the overall model procedures, while modifying code to convert instantaneous to averaged fields.

## GFS Variable Usage

- Surface geopotential

- matched

- surface pressure

- converted from SIG I/O*

- Specific humidity

- converted from SIG I/O*

- Temperature

- converted from SIG I/O*

- Meridional wind

- converted from SIG I/O*

- Zonal wind

- computed in interface routines

- Q tendency - moist physics

- added output

- Vertical diffusion diffusivities (heat/moisture)

*computed in interface routine*

- Rain production rate - large-scale

- modified GFS routines and added output

- Detrainment cloud mass flux

- modified GFS routines and added output

- Cloud mass flux

- matched

- 3-D Cloud fraction

- matched

- 2-D Column Cloud fraction

- computed in interface routines

- Land, Water, ICE

- produced by interface routines

- Leaf area index

*convert to averaged*

- Roughness length, momentum

*convert to averaged*

- Meridional wind interpolated to 10 meters

*convert to averaged*

- Zonal wind interpolated to 10 meters

*convert to averaged*

- Planetary boundary layer height

*convert to averaged*

- Friction velocity

- matched

- Surface albedo

- computed in interface routines

- Net downward shortwave flux at the ground

*convert to averaged*

- Skin temperature

- matched

- Sensible heat flux (positive upward)

*convert to averaged*

- Top soil layer wetness

- matched with unit conversion

- Convective precipitation rate

- matched with unit conversion

- Total precipitation rate

- Description of GOCART input

_*Color code -In progress*_

**Notes:**
* From spectral space to girded space.

## VERIFICATION

- GOCART coupled with NASA GEOS global met model extensively evaluated with MODIS AOD, AERONET, field campaigns (see Chin, et al., 2000, 2002, 2004)
- Propose to evaluate GOCART performance when driven by T384, hybrid sigma coordinate GFS
- Follow methods & performance measures used previously by NASA & Navy/NRL for NAAPS implementation (Wesphal, et al....)

## Verification of GFS+GOCARTData Sources

- Total column** aerosol optical thickness (depth)
**GOES** (NESDIS)
**MODIS** (http://modis.gsfc.nasa.gov, NESDIS)
**AERONET** (http://aeronet.gsfc.nasa.gov/index.html)
- ** Can not distinguish surface layer aerosol and upper air dust layer
- Vertical profile of extinction coefficient
**Lidar** (NOAA/CAS Howard Univ., MPLNET: http://mplnet.gsfc.nasa.gov/data.html); ship- or land-based
- Aerosol Vertical Structure
- Aerosol Backscatter, Extinction, and Optical Depth Profiles
**CALIPSO** (http://www-calipso.larc.nasa.gov)

**Notes:**
Description of available observations and example of comparisons. Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) 

## Verification

- The time and area of verification depends on the availability of data
- Data obtained from NESDIS are more accessible, e.g., AOD data of GOES and MODIS
- Others depends on the relationship with the owner (MPLNET) and institution, e.g., it may be easier to obtain data from Howard University (NOAA CAS) than from NASA
- Possible verification cases
- Saharan dust events (HU, land- and ship-based lidar)
- Long distance transport of Asian aerosols and dusts
- Selected sites in various continents (MPLNET, AERONET, CALIPSO)
- US air quality campaign; TEXAQS, AEROSE
- Special lidar observation events, e.g., summer of 2007 at Howard University Greenbelt site (land-based lidar, A-train)
- Daily real time comparison with NESDIS products

## Table 1. CALIPSO Level 2 Aerosol Measurements 

**Table 1. CALIPSO Level 2 Aerosol Measurements **

- Source : http://www-calipso.larc.nasa.gov/products/

**Notes:**
The high resolution of CALIPSO data are valuable for vertical profile comparison

## GOCART, MODIS and AERONET

- Comparison of MODIS and GOCART AOT with AERONET measurements

**Source : Mian Chin (GSFC)**

**Notes:**
Adopt the global comparison for GFS+GOCART verification, only after dust and aerosol are modeled together (Column integrated AOD)

## Validation Intercomparisons: AerosolsAugust 10, 2006

***Source : “*****Initial observations from CALIPSO”, *****Dave Winker,***
*** ******NASA Langley Research Center***

**Notes:**
Comparisons of aerosol measurements between the LaRC HSRL (High Spectral Resolution Lidar) and CALIPSO conducted during CC-VEX show excellent matching at both wavelengths.  Same method can be used to verify vertical profile of GFS+GOCART against Satellite and Lidar data, especially for dust that transport above surface aerosol layer.

## Real-time AOD verification between GOES and CMAQ

**Notes:**
Daily real-time NESDIS AOD product of GOES and MODIS can be used to verify GFS+GOCART AOD results, only after dust and aerosol are modeled together (Column integrated AOD)