# Presentation: 261085

## Algorithm Refinement and Validation of Cloud and Radiation Products

**Derived from MODIS and CERES Using Ground-Based and**
**Aircraft Data**

- Jay Mace, University of Utah

- Development of relational database on the web for cloud property retrieval validation
- Use of MODIS Cloudmask in the cloudsat geometrical profile operational product
- Development of an algorithm suite for cirrus property retrieval with A-Train data

## Cloud property retrieval algorithm enhancement activity:

- Case Study Evaluation

- Overpass Matching

- Statistical Comparison

## Goal:  Extend/expand this study:

- From a dozen overpasses of ARM ground sites to thousands
- From thin cirrus to all cloud types and situations
- Make the validation/intercomparison process easy – foster science investigations

- Approach:  Construct a relational database that brings together MODIS cloud products and ground based cloud products with web acess
- Prototype:
- http://www.met.utah.edu/cgi-bin/mace/cgalli/mysql/eos_avg_query.pl

## Current Prototype Status:

- Includes Terra MOD06 IWP, effective radius, and optical depth retrievals of
- Cirrus events from 2001 and 2002 – 300 events
- ZV cirrus algorithm results from ARM MMCR data.

- Prototype
- Interface:

## A Case of Good Agreement – 10/18/2001

## A case of not-so-good agreement – 10/15/2000

## CloudSat Geometrical Profile Product

- Goal:  To combine the spatial information provided by the MODIS CloudMask with the vertical profile information provided by the active sensors

- Issues:  1)  CloudSat does not detect certain clouds that contribute to radiance field
-               2)   MODIS radiance field suggests a highly variable local cloud field

- Approach:  Use the MOD35 Cloud Mask bit tests to identify (where possible) cloud type – goal is to identify spatial coherence consistent with cloudsat profile observations.

## MODIS visible Imagery

- --- Variably thick clouds surrounding the ARM SGP (the green point).

- CloudSat-Like MMCR
- --- Thick cirrus clouds

- An Example:  April 3, 2001 – SGP ARM Site

## MOD35 Bit Tests in a 10X10 pixel array surrounding the SGP

**MOD35 Bit Tests in a 10X10 pixel array surrounding the SGP**
- Purple: NO, Green: yes, RED: no test

- CO2 and 1.38 test suggest cirrus. High cloud is detected over the entire box by 1.38 but it appears to be variably thick as indicated by the visible reflectance and CO2 test.  Certain tests such as the 6.7 micron test curiously do not find cloud in this case

## 2B GeoProf Output

| 
Data Granule | CloudSat Metadata |  |  | TBD |  |
| --- | --- | --- | --- | --- | --- |
|  | CPR Metadata  |  |  | TBD |  |
|  | Swath Data | Time |  | Table: nray
10 bytes |  |
|  |  | Geolocation |  | 2  nray
4-byte float |  |
|  |  | SEM | Radar Reflectivity | 125  nray
2-byte integer |  |
|  |  |  | Quality assurance QA | 125  nray
1 byte integer |  |
|  |  |  | CPR Cloud Mask | 125  nray
1 byte integer |  |
|  |  | SEM-MODIS | MODIS scene characterizations (Table 3) | 1 byte | nray |
|  |  |  | CPR echo top characterizations (Table 4) | 1 byte |  |
|  |  |  | MODIS scene variability (Table 5) | 1 byte |  |
|  |  |  | MODIS 250m cloud fraction | 1 byte |  |

## A Cirrus Retrieval Algorithm Suite for the A-Train

## Algorithm using MODIS 13 micron combined with MMCR Z compared to ground-based ZR

##   Development of relational database on the web for cloud property retrieval validation and basic exploration of the data sets

-   Use of MODIS Cloudmask in the cloudsat geometrical profile operational product
-   Development of an algorithm suite for cirrus property retrieval with A-Train data

- Summary:
- Our use of MODIS data and products is very diverse and continuing to expand: