# Presentation: 396421

## Satellite Upper Air Network (SUAN)andthe Climate Retrieval Problem

- Tony  Reale
- NOAA/NESDIS, Suitland, Md.
- (tony.reale@noaa.gov)
- Frank  Tilley
- Raytheon Corporation, Landover Md.
- Workshop On Upper Air Observations
- Boulder, Co.
- February  8-10,  2005

## What is the Mission of the Radiosondes ?

- ( *Past  vs  Present  vs  Future *)
- Is There an Optimal Sampling Strategy ?
- ( *Synoptic  vs  Satellite Coincident  vs  ???* )

## Satellite  Upper  Air  Network                   (SUAN) 

- Global network of radiosonde sites providing ***“standard”*** measurements coincident with NOAA polar satellite overpass
- SUAN Report  (Reale and Thorne)
- “http://www.orbit.nesdis.noaa.gov/smcd/opdb/poes/suan”

## History   

**UKMO Workshop on Vertical Temperature Trends  (September, 2004) **
**WMO/AOPC  (Geneva, April, 2004)**
*Subset of GUAN ... “supersites***”**
**International ATOVS Study Conference  (November, 2003)**
*Recommendation to pursue deployment through WMO Document*
**White Paper: Creating Climate Data Records from NOAA Operational Satellites (August, 2003).  (Goldberg and Bates)**
*Section 4.2.1, Observing System Performance Monitoring (visit ITSC web page:  *http://cimss.ssec.wisc.edu/itwg/)
**Workshop to Improve Usefulness of  Radiosondes  (March, 2003)**
*formal “unveiling” of SUAN, underlying concepts and evolving compensatory roles of global radiosondes and polar satellites to serve as transfer standards ... *
**NOAA Council on Long-Term Climate Monitoring  (Jan., 2003)**
*includes specific recommendations for “integrated global observing systems which include reference radiosonde and overflying satellite observations ... ****with goal of accurate, long term monirtoring of global temperature and moisture**** ...*

## CANDIDATE SITE SELECTION

- Subset of GUAN (150) ... “*super-sites*”
- Active and Reliable ( Green, Blue, Red )                                (***UKMO, w/McCarthy;   NESDIS, w/Tilley***)
- Global/Robust
- Low terrain (500m; 950mb)
- Non-coastal
*ARM  Sites* (Black)
***SHIPS ***

## 20 Sea

-    NWS sites (11)
- # ARM sites (5)

- 18 Land
- 4 Sea-Ice

## Primary SUAN  Candidates

## Alternate  SUAN  Sites

## Super-Sites  

- Standard Reference Sondes
- Temperature, *moisture, w*ind, surface ...
- 5 mb
- Ground Measurements
- Lidars, GPS, clouds, surface  ...
- R  & D
- dual launches ...

**WMO/AOPC  in  April 2004 :**

## Program  To  Include:

- Generation and Distribution of Launch Schedules                       (...45 minutes before overpass)
- Fixed sites
- Ships
- Metadata Records ... corrections, site protocols ...
- Network Performance Monitoring/Feedback
- International  Coordination  ...  WMO

## Program  (continued):

- Integration into NESDIS Operational Sounding Product Systems      (ATOVS, METOP, NPP, NPOESS ... )
- Relational Collocation File Structure (Raobs,  raw satellite, level 1 ...)
- Open to Expansion, i.e.,  other satellites (i.e., GPS ...) and data (i.e., Ground, ACARS,  Dropsondes ...)
- Accessible Archive  (Data,  Software readers) ... Web-based ?
***R &  D  Impact ...   ***

## How Many Observations

- 40 sites (not including Alternates and Ships)
***One launch per day!****** ...  ****(minimal requirement)*
- 2 (or 3) operational (NOAA and METOP ...) satellites
- 15 (or 10) observations per satellite, per site, per month
***over 600*** ***(or 400)*** observations globally, per satellite, per month
***over 6000***  ***(or 4000)*** observations globally, per satellite, per year
***COST:***
-  **$ 5 million **  (... @ $300 per sonde )

## SHIPS

- The NOAA science vessel RHB provides radiosonde launch, insitu measurement, cloud  observation and polar satellite direct receipt capabilities ...  ***an optimal platform for SUAN demonstration / support !***

- At about $250 per raob, twice per day, 250 days per year, estimated SUAN support is $125K yearly; ***very cost effective*** at fraction of RHB and NOAA polar program budget ...

## WHY  SUAN ?

***Operational polar satellite  ***
- Measurements/Products require  (*long-term*)  “scientific”  Monitoring/Tuning ... *using collocated radiosonde and satellite observations *
***Radiative Transfer*** ***(RT) models***
- require coincident T, H20 and Radiometric profiles
*“**key to absolute accuracy”  !?*
***Global*** ***Radiosondes***
- “can” provide necessary ground truth data, but have problems ...
***Standard Baseline Dataset Needed  (since 1979 ...)***
- currently available collocated radiosonde and satellite observations are ***Not Adequate******  ***

## Global   Radiosondes

- June 17-19  2003

##                        Satellite  and  Radiosonde  Collocations              (Radiosondes launched within 1 hour “prior” to satellite overpass)

## Operational Satellite and Radiosonde Collocations                (+/- 5hrs sea, +/- 3hrs land;   100km)

## NOAA-17

- (Satellite – Radiosonde)
-  Temperature statistics
-  Tropical land
-  (30N to 30S)
-  June 7-14, 2003
***Results  “skewed” by regional sampling differences***

- NOAA-16

- NOAA-15

## 60N to 60S   

- 60N to 60S

## 60N to 60S   Moisture

## SUAN Minimizes “Artificial” (not Same-Same) Sampling Related Errors to Better Monitor “Real” Sensor and Product Performance/Uncertainty 

## Slide 22

## Slide 23

## Slide 24

## Slide 25

## Slide 26

## RT Models

- Critical for Cross-validation of Satellite, Radiosonde, Climate and NWP Data
- Require consistent, reliable and robust collocations in support of R & D, validation
- Are “***Key”*** to ascertaining absolute accuracy ... resolve calculated (from Raob) vs observed (from satellite) radiance ... (*and climate retrieval problem)*
***SUAN sites optimal in support of  long-term RT model validation and development ... ***

##  AMSU Sounding Channels 

## RT  Bias  Adjustments

***AMSU-B at  183 +/- 1 gHz***
- (upper troposhere moisture)
- 12-hour time composites
- Adjustments are ***regressed from collocated satellite and radiosonde data***
***Magnitude and inter-satellite variability “skewed” by systematic radiosonde sampling differences, ***

- NOAA-17

- NOAA-16

- NOAA-15

## Radiosondes

- Satellite radiometers can serve as transfer standard for radiosonde monitoring via RT  (McMillin et.al. 1988)
***SUAN sites would provide: ***
***validating radiosondes ****(intersonde experiments, non-SUAN, ...****) ***
***deriving radiation and inter-sonde “corrections” ***
***demonstration of new technologies (ie, upper tropospheric moisture, drop-sondes ...)***
***balloon drift and local weather impacts***
***other***

## Radiometer Sensor Bias
Systematic per satellite 
Sensor response changes
Satellite drift 

Science Bias
RT model
Processing Approach 
Measurement  vs  Derived Product
Tuning

- Systematic per satellite
- Sensor response changes
- Satellite drift
- Science Bias
- RT model
- Processing Approach
- Measurement  vs  Derived Product
- Tuning

- Climate  Applications

**Problems Include:**

**         ****End  Result: **
***   ******Uncertainty Outweighs the Signal  (Seidel et al., 2004,  Christy ...)***

##        Climate Applications  Formula  “Real-time”  Database Compilation Effort         ...satellite data, ground truth collocations ...                  (during satellite operational lifetime)                         to serve as input for              “Retrospective” Processing Effort                  ...T, H2O, Clouds, Measurements ...               (at conclusion of satellite operational lifetime)

## SUAN can provide “long-term” records which “anchor” satellite and radiosonde performance (over time) for more effective utilization in retrospective climate applications ... 

## Radiosonde  and  TOVS-1b   History  from 1979 ...                                  (correcting the past ...)

- GTS Radiosondes ... (***NCEP, ERA-40, IGRA***...)
- Special Field Experiment Radiosondes:
- ARM
- JOSS (NCAR)
*SHIPS*
*Other ?*
- TOVS  Historical 1b-level  data
**Goals:**
- Relational Data Base of Collocations, Directories, Metadata ...
- TOVS , ATOVS ...  make operational
***Reprocess TOVS for Climate !!!***
***Costly and time consuming process***
***Ongoing “Arctic” NOAA-SEARCH (w/ Francis) ***http://www.orbit.nesdis.noaa.gov/smcd/opdb/poes/polarsearch
***looking  for  funding***

## BENEFITS 

- Monitor/Quantify  ***Satellite Measurement and Derived Product***  Error/Accuracy/Uncertainty  (*ATOVS ... NPP ... METOP ... NPOESS ...) *
- Monitor/Quantify  ***RT Model   ***Error/Accuracy/Uncertainty
- Monitor/Quantify  ***Radiosonde*** ***(and in-situ)***  Error/Accuracy/Uncertainty
- “Long-term”  ***Performance***  Record
***Positive Impacts on Climate and NWP ***

## Slide 36

## EXTRAS

## Ongoing  Activities

**New WMO Working Group under AOPC  to address GUAN future and network design   .... Peter Thorne chair**
**NOAA Workshop  ...  improve quality of future upper air observations for climate (Seidel/Murray) :**
***Phase-1 :***** Winter 2005 to define requirements**
***Phase-2 :***** Spring 2005, potential networks and deployments to meet requirements**
***Phase-3 :***** Summer 2005, definition of integrated observing system **
**TOVS 1b-level and radiosonde collocations since 1979**

## Primary SUAN  Candidates

## SATELLITE  COLLOCATIONS     (+/- 3hrs, land;   +/- 5hrs, sea) (used operationally at NESDIS) 

## Calculated (from RT) minus Observed AMSU-A measurements for channels 4 through 14 (NOAA-16) over Land, Ice and Snow, Coastal, and Sea terrains

**Calculated (from RT) minus Observed AMSU-A measurements for channels 4 through 14 (NOAA-16) over ****Land****, ****Ice and Snow,**** ****Coastal,**** and ****Sea**** terrains**

## SATELLITE  COLLOCATIONS     (+/- 3hrs, land;   +/- 5hrs, sea) (used operationally at NESDIS) 

## Satellites can

- VIZ B to Vaisala (RS80) at  Chuuck Island

- serve as transfers standards to monitor radiosondes

## Slide 44

## Collocated Radiosonde and Satellite Observations

-                          provide basis for the
-                             ***Monitoring***
***                            ******Validating and ***
***                            ******Tuning ***
-           of ***Operational Satellite Data Systems***
-        (... *critical for climate retrieval problem)*

## Radiosonde  and  TOVS-1b   Collocation  History          from 1979  (... correcting the past ...)

***Costly and time consuming process***
***Pending FY-05 “GCC” proposal (w Goldberg, Thorne)***
***Ongoing NOAA-SEARCH (w/ Francis) ***
- GTS Radiosondes ... (NCEP, ERA-40, IGRA...)
- Special Field Experiment Radiosondes:
- ARM
- JOSS (NCAR)
*SHIPS*
*Other ?*
- TOVS  historical 1b-level  data
**Goals:**
- Relational Data Base of Collocations, Directories, Metadata ...
- TOVS , ATOVS ... operational
*Useful for Climate*

## Accuracy Statistics vs Radiosondes (Guess (light) vs  Retrieval (heavy)) Tuning to Errors

- Clear

- Cloudy

- Collocations
- provide
- independent
- validation (heavy)
- and tuning (light)
- per satellite
- NOAA-16
- (60N to 60S)

## NWP

- Significant positive impact of satellite data on NWP reported over last 5 years  (McNally et.al. 2000, etc)
- Associated NWP-based adjustment of incoming satellite data (“cooking”) may include systematic  NWP error  (Reale, 1995, 2001, 2002)
***SUAN can potentially segregate such errors ...      ***

## SUAN can provide  an NWP independent platform for “bias tuning” 

***SUAN can provide  an NWP independent platform for “bias tuning” ***
***leading to  improved satellite data impact in frontal zones?***

## Attempts to use 20+ years of TOVS (MSU) yield no meaningful overlap (Christy et.al, Mears et.al, Vinnikov and Grody; 2003)

Conclude that  “uncertainties” inherent in historical satellite and radiosonde data make them unsuitable for detecting long-term trends (Seidel et.al, 2004) 

- Conclude that  “uncertainties” inherent in historical satellite and radiosonde data make them unsuitable for detecting long-term trends (Seidel et.al, 2004)

- Climate

_**The Problem:**_

***SUAN can provide optimal data sets for maintaining the “long-term” records of satellite and radiosonde performance necessary to effectively utilize them in climate applications. ***

## GUAN   Sites