# Presentation: 174201

## The “U.S. Climate Reference Network” Developments  

- The “U.S. Climate Reference Network” Developments
- Presentation for the
- Office of Federal Coordinator for Meteorology
- Dr. Sharon Leduc
- NOAA/NESDIS
- National Climatic Data Center
- October 24, 2003

##  How has the climate of the U.S. changed over the past 50 years on national, regional and local levels? 

*** ******How has the climate of the U.S. changed over the past 50 years on national, regional and local levels******?****** ***

** **An observing system that 50 years from now can, with the highest degree of confidence, answer the question...

**Notes:**
The vision of the USCRN program is to provide an observing.....

## Primary Instrumentation

**T1**

**T2**

**T3**

**Two  precipitation gauges **
**        ****inside a double windshield**

**Three temperature sensors, T1, T2, & T3**

**Notes:**
We do this by first and foremost making high quality observations of temperature and precipitation.

## Precipitation Gauge & Small DFIR w/Single Alter

**Notes:**
The engineer is not standard equipment.

DFIT = Double-fence IntercomparisonReference

Outer – 8-meters

Inner – 4-meters

## Standard Measurements

**  **_Primary Sensors_
- 	Air Temperature   (3 separate aspirated sensors)
- 	Precipitation         (4 separate sensors)
*  *_Secondary Sensors_
- 	Wind Speed
- 	Global Solar Radiation
- 	Ground Surface (Skin) Temperature
- Power  AC/DC
- Solar panels & Wind power (optional)
- Extended Range Operating Envelopes

## Ten climate Principles

- Management of Network Change
- Parallel Testing
- Meta Data
- Data Quality and Continuity
- Integrated Environmental Assessment
- Historical Significance
- Complementary Data
- Climate Requirements
- Continuity of Purpose
- Data and Meta Data Access

**Notes:**
In 1999, the National Research Council (NRC) recommended these ten climate monitoring principles be applied to climate monitoring systems. 

Tom Karl et. al. proposed them in 1995.  

I could go through them all one by one (click on the yellow comment card for paragraph on each), but more important the CRN PROGRAM meets all 10 in its design, development, and operations. 

## Network Characteristics

- Benchmark Network for temperature and precipitation
- Anchor points for USHCN and full COOP network
- Long-Term Stability of Observing Site (50+ years) likely to be free from human encroachment
- Sensors Calibrated to Traceable Standards
- Planned redundancy of sensors and selected stations
- Network Performance Monitoring - Hourly and Daily
- Strong Climate Science & Research Component

**Notes:**
Applying these 10 climate principals gives us a number of Outstanding Characteristics for the CRN network.

USHCN – U.S. Historical Climate Network

COOP – Cooperative Network

## USCRN Program Documentation

- Incorporates 10 climate Principles
- Defines standards, procedures
- Provides long-term program continuity
- Under configuration management
- On-line accessible

**Notes:**
These program characteristics are extensively Documented.  

The documentation produced by this program includes some of these shown here, but also all the programmatic documentation

- Functional Requirements Document** **
- Systems - parameters, ranges, accuracies, resolutions, expandability, design life, maintainability
- Program - number of systems, cost and schedule targets, communications
- Commissioning Plan
- Defines decision point – when data are official
- Sustained operation, data from each site 95% of the time within one hour and/or successful entry into the archives within 30 days
- Configuration Management Plan ** **
- Change management of hardware and software items, metadata management
- responsibilities and procedures for CCB

**Notes:**
Extensive Documentation has been developed.  

Documentation on the program not only shows how the 10 climate principles but perhaps more importantly here provides complete understanding of the development and operations of the network which is important for network inter-operability.

## Test and Evaluation Phase Completed

- Conducted by Evaluation Team
- Reviewed by Ad Hoc Science Working Group
- Six areas Evaluated
- Site Selection
- Site Installation
- Field Equipment and Sensors
- Communications
- Data Processing and Quality Control
- Maintenance
- 30 sites in varied climate regimes

**Notes:**
First of all, I would like to announce the successful conclusion of the Test and Evaluation Phase of the Program.  An Extensive Test and Evaluation was conducted and reviewed.  (Read the Slide)  Each of the Six areas of evaluation has its own documentation in addition to the documents I mentioned on the previous slide.)  Next I would like to highlight two areas of the program that were evaluated and speak next to Siting Standards (the site selection and site installation bullets) and Data Processing and Quality Control, two aspects of the program that might speak to standardization within OFCM.

## CRN Station Sit Selection Standards

- Site Density methodology
- Michel Leroy basis for site classification
- Objective site scoring
- Trained site surveyors
- Exceeds WMO standards
- Possible OFCM standard for climate monitoring stations

**Notes:**
I can go through each of these now, or in the interest of time, save this for another specific discussion on siting standards.  The next 6 slides speak to each of these.

## Site Density

- Statistical analysis for network to maximize the reduction in uncertainty of the change in the climate signal
- 300 stations; 2.5-degree grid
- 100 stations; 5-degree grid
- Minor deviations from the grid to capture climatic regimes

## Michel Leroy Method

- Methods used as basis for site classification exceeds the WMO standards
- Method of classification presented at:
-  	AMS conference
*	**Tenth Symposium on Meteorological Observations and Instrumentation*, Phoenix, AZ, January 11-16, 1998

## WMO Standards

- WMO Guide to Climatological Practices*   "The Siting of Climatological Stations" Chapter 4 paragraph 2.4, pages 45-50*

## Objective Site Scoring

- An objective scoring sheet was developed based on the Leroy method.  The score for a station becomes part of the metadata for the station
- Re-scoring of stations is part of the annual maintenance visit; allows tracking time change in representativeness of station meteorology

## Trained Site Surveyors

- Regional Climate Centers (RCCs)
- Responsible for site surveys of potential CRN sites
- Trained on the objective scoring system
- Complete the scoring sheet as part of the site survey process
- Score becomes part of the station metadata.

## Possible OFCM Standard

- NCDC believes that the siting standards used in the USCRN program should be considered by the OFCM as the standard for locating climate monitoring stations
- Could also be adopted as a standard for other networks (COOP, etc.)

## Siting Standards Documents

- Network Plan
- CRN Site Acquisition Plan
- Site Information Handbook
- CRN Site Survey Plan
- Site Survey Handbook
- Site Survey Checklist
- Site Acquisition Checklist

**Notes:**
And there is of course extensive documentation of the Siting and so on.  And that concludes my remarks on the Siting Standards.  Now I want to move on to another area of the Test and Evaluation and that is Quality control.

## Data Management  Documented Ingest to Access

- 	Access to Data & Metadata

- Ingest

- Automatic

- Manual

- ATS

- Maintenance

- Quality Assurance/Control

- Raw

- Flagged

- Metadata

- Users

**Notes:**
Much of what was listed in the agenda for me to talk about involves data management, data assimilation, processing, quality control, formats, the standards we are using.  And much of that is documented in the Data Management Document – Ingest to Access, which is available on our web page.  I want to say here, before I get on to Quality Control, that Users have access to data, both raw and flagged data and to Metadata, as well as all the program and technical documentation.

## QA/QC 

- Quality Assurance of Instruments
- Documented in* Anomaly Tracking System Users Manual*
- Reports of Incidences collected, evaluated, maintenance as needed
- Metadata records updated
- Quality Control Data
- Documented in *Data Management – Ingest to Access*
- Data ingest
- Tests for proper message form, communication errors, etc.
- Automated
- Limits - Gross limits check
- Variance - Limits for individual parameters
- Redundancy - Data inter-comparison relies on multiple sensors
- Manual 	--     *Handbook of Manual Monitoring*

## QA/QC (Continued)

- Integration of QC
- Health of the Network
- Instrument and equipment records
- Documented *Metatdata Management – Survey to Operations*
- Post analysis of measurement records
- TempVal	PrecipVal
- CRN data used in validation of coop data
- Transfer functions

## Metadata ManagementSurvey to Operations

**Notes:**
Metadata are critical to the QA/QC process.  Every item of metadata has been defined.  Some station metadata are shown here such as the calibration coefficient of the rain gauge instrument.  Every item of metadata, from the time of the site survey through operations, are recorded, tracked and are under configuration management.  The Metadata Management  document is on-line on the CRN site.

## Status

- Successfully Completed Demonstration Test and Evaluation phase
- January-June 2003
- In “pre-commissioning” phase
- July-December 2003
- Data and Metadata for all sites on-line restricted access
- Network commissioning announcement at AMS

**Notes:**
(Read the slide)  During the pre-commissioning phase we are re-doubling our efforts to have a community of users accessthe data and metadata as we get ready to put everything on-line for public access.

**Location of 100-station USCRN**
**September 2005 (100* stations)**

*** Includes 2 in Alaska**

**Installed Paired Locations**

**Installed Single Locations**

## Regional Impact

**Preliminary analysis (Dr. Bomin Sun)****Significance level of a linear temperature trend (1951-2002)** **Red: upward trend      Blue: downward trend**

**Notes:**
The CRN network is now budgeted to a size of 100 stations – which will allow us to explain the variance in the climate signal on a national level.  Measuring the significance of the climate signal on a Regional Level requires a network of  300-400 stations.  A preliminary analysis of the regional impact (Bomin Sun) indicates some lesser impact in Texas, for example than in Florida.

## Dinosaur National Monument CRN Site

**RAWS Site**

**Proposed CRN Site**

**COOP Site**

**Dinosaur National Monument CRN Site**

**Notes:**
Network interoperability is an important item.  We identify other observing system in the vicinity of every CRN as we look towards CRN data becoming a reference point for the operations of these other network and also as we develop our transfer functions to stations with long term records.

## Network Integration

**Notes:**
Working with the NOAA Observing Systems Architecture or NOSA we are able to identify stations in NOAA owned and operated networks.  For example, Shown here are HCN temperature stations within  a hundred miles of CRN sites along with Nexrad stations.  

## 7-Yr Vision

- Sufficient CRN stations deployed ( ~ 300) for capture
-         	of CONUS National & Regional Climate Signals
- Inter-network (Coop, SCAN, SNOTEL, RAWS)
-        	transfer functions give increased, homogeneous spatial 	coverage.
- Inter-database (HCN, some Coop, NADP)
-        	 transfer functions extend high-confidence
-         	Length-of-Record Observations.
- Sufficient CRN data stream & confidence supports                 	broad scientific analyses of climate  trends.
- CRN data on-line within one hour of receipt at NCDC.
- CRN data and metadata public access