U.S. Climate Reference Network Developments

Research-To-Operations:

Midway To NOAA’s Model Climate Monitoring Network

Presentation for the

Committee for Climate Analysis, Monitoring, and Services

Dr. Michael R. Helfert

NOAA/NESDIS

National Climatic Data Center

May 3, 2005

The Question, Principles, & Network• Performance Measures, Nat’l & Regional

• Sensor Suites/Instruments

• Site Survey Primer

• Cross-Network Transfer Functions

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• Products and Product Development

• Where’s the Information?

• Where We Want To Be in 2010.

Climate Reference Network

How has the climate of the U.S. changed over the past 50 years on national,

regional and local levels?

Just what is the Climate Reference Network?An observing system that 50 years from now can, with

the highest degree of confidence, answer the question…

U.S. Climate

Reference Network

National Climatic Data Center

Basic Principles of the CRN

• U. S. Benchmark Network for Temp/Precip• Adheres to the “Climate Monitoring Principles” • Satisfy Requirements of Observing Systems• Anchors the U. S. Historical Climate Network (HCN)• Strong Climate Science & Research Component• Long-Term Stability of Observing Site (50+ years)• Sensors Annually Calibrated to Traceable Standards • Network Performance Monitoring - Hourly and Daily• Climatically representative & stable station sites

using rigorous, systematic site selection

Program Status• 70 Commissioned Stations operational of 114 planned.• Data and Metadata for all commissioned sites on-line.• FY05 USCRN budget 0%; 50% funding recovered for O&M.• Revised Performance Measures necessitated (T&P).• FY06-08: 42 stations planned, budgets pending.• 108 of the 114 station sites have been identified; 90 approved; 18 in review; last 6 site surveys underway.

• Outyr interest – AL, PA, CA, NC, GCOS, IPY, & DOD.

• FY2005 Non-CONUS stations to HI & AK (GCOS).• Outyr GCOS deploys possible: Great American Cordillera,

Caribbean, Africa, IPY Arctic Ring; Antarctic region, Europe, Equatorial & WPAC, Himalayas, 7 Sisters Rgn, Kamchatka-Kuriles.

U.S. Climate

Reference Network

Annual Maintenance Visit• Exchange datalogger• Exchange one PRT• Exchange one aspirated shield fan• Exchange anemometer• Exchange pyranometer• Calibrate precipitation gauges• Complete maintenance checklist• Take compass-platte photographs• Bring station up to current configuration

U.S. Climate

Reference Network

114 CONUS Geographic Locations Required

• Captures 98% of variance in monthly temperature,

95% in annual precipitation for CONUS.• Average annual error <0.1ºC for temperature,

<1.5% for precipitation• Trend “errors” <0.05ºC per decade• IPCC: projects warming of 0.1-0.3ºC/decade and

precipitation changes of 0–2%/decade for CONUS.

Performance Measures U.S. Climate

Reference Network

Determine the Actual Long-term Changes in Temperature and Precipitation of the Contiguous U.S. (CONUS)

Uncertainty of Twentieth Century CONUS precipitation trends is large (5% of total annual precipitation), as calculated trends range from 38.1 to 77.2 mm/Century. Goal is to reduce USCRN trend uncertainty from 19.2 (FY04) to 7.7 (FY08) mm per century (reduction equates to 40% of water in Great Lakes).

Current CONUS temperature trend uncertainty (0.1o C per century, FY04) will be further reduced, enablingthe capture of any acceleration or deceleration of trends now estimated to be increasing by about 0.2o C per decade since mid-1970s.

FY2005 Target: Capture more than 96.9% and 91.1% of the temperature and precipitation trends.

April 05 Actual

Planned CRN Stations

(September 2008)

Regional Impact

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

National Climatic Data Center

Minimum Observing Requirements

• Primary MeasurementsAir Temperature Precipitation Accumulation

• Supporting MeasurementsWind SpeedGlobal Solar RadiationGround Surface (Skin) Temperature

---------------------------------------------------------------------------Relative Humidity Soil Moisture & Soil Temperature Barometric Pressure

Sensor Suites/Instruments

National Climatic Data Center

Sensor Suites/Instruments

Geonor and Small DFIR w/Single Alter

National Climatic Data Center

Sensor Suites/InstrumentsPrimary and Supporting Sensors

Sensor Suites/InstrumentsInhomogeneity Adjustment Issue

Site Survey Primer

U.S. Climate

Reference Network

Kestersen CA site looking north from south. Road along canal is elevated about 5 feet. Standing in Bureau of Reclamation land.

Controlled Superfund Site for next 200+ yrs.

Major Principles of Climate Station Siting

• Site is representative of climate of region.

• Minimal microclimatic influences.

• Long-term (50-100 year) land tenure

• Minimal prospects for human development

• Avoids agriculture, major water bodies, major forested areas, basin terrain.

• Accessible for calibration & maintenance.

• Stable Host Agency or Organization.

• Follows WMO Climate Station Siting Guidelines

WMO Standards

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

CRN Site Information Handbook, CRN Survey Checklist, CRN Scoring Sheets.

-------------------------------------------------------------------WMO Initial Guidance To Obtain Representative

Meteorological Observations At Urban SitesTD-1250, 47 pp. 2004.

Site Survey PrimerAvoiding Microclimates

Pinnacles RAWS site looking to east from west. Uncontrollable burns on 2-5 yr cycle. High creosote chaparral environment with dry grasses understory.

Site Survey Primer

Avoiding Microclimates

Schwardt Lab Site,40m distant, height 8mMinimum of 80 mtrs separation is needed.

Rock Springs, Emergin Corn Crop <10 m away. Crop annually rotates w/Soy & Wheat.180 mtrs separation from non-irrig agricultureis required

Pacific Northwest Federal Area,

co-location with Cooperative Station (HCN)

USCRN StationsSeptember 2004 (69 stations)

Installed Paired Locations

Installed Single Locations

Planned USCRN Stations at end of 2008 (114* stations)

* Does not Include Alaska, Canada, Hawaii, & GCOS stations

Installed Paired Locations

Installed Single Locations

As of April 26, 2005

Cross-Network Transfer FunctionsU.S. Climate

Reference Network

Cooperative Observer Network (~10,000 Stations)

USCRN Site Survey 10/19/04 Pasture 3 Site

USHCN Site, 1909, at Cottonwood Headquarters(also one of Helmut Landsberg’s 21 RCS’s)

RAWS Site

CRN Site

COOP Site

Dinosaur National Monument CRN Site w/co-locations

Installed Pair (14)

Installed Single (59)

Alaskan & Canadian Stations (3)

not included in portrayal.

USCRN Network Configuration

As of May 4, 2005

(May 4, 2005)

CRN Data Management Activities:Flow of Data from Station To Users

NCDC

Communications Network

Field Sites

Instrument Suite

Communications Device

Processing Unit

Internet

User Community

Access

Ingest

Processing

Quality Control

Maintenance Notification

Maintenance Provider

Flagged-Data Archive

Raw-Data Archive

online

offline

PRODUCTS• Ingesting into routine Drought Monitoring and

Climate Monitoring activities & products at NCDC

• Prelim Normals (3-Yr) being used for older CRN’s

• Transfer functions for up to 3-Yr POR being run on routine basis. Updated each successive yr.

• Forthcoming Energy/Agriculture Applications by using Traditional vs 5-min/hourly corrected HDD/CDD & mean weighted max/min T’s for new LCD. Both LCD portrayals will be user accessible.

• CRN Data being now used in TempVal & PrecipVal (Primary NCDC QA/QC Routine for ASOS, COOP, MMTS, ISD, etc. – in other words, it’s already there, you just don’t see it…)

Pushing Too Fast – an Experimental Product with Insufficient POR and Insufficient Station Density:

Tmax Anomaly of July 2004

ºC

USCRN CONUS Deployments

With Network Co-locations*

*Colocations witin 10 km.

Data as of April 26, 2054

No Co-location Known

Coop or HCN Co-located Coop + Another Network Co-located (SURFRAD, RAWS, NADP, etc.)

NADP Co-located

RAWS/SCAN Co-located

SURFRAD Co-located

Estimating CRN T & P Normals

1. Places current USCRN observations into historical perspective for operational climate monitoring activities.

2. Allows inter-network transfer function determination (e.g., CRN <–> COOP) 3. Provides stable & leveraged data core for

NOAA & other agency climate products

STABLE, HIGH-CONFIDENCE CRN Normals require a min of a 5 yrs POR; 10 yrs POR desired.

Shorter POR’s produce poor-quality, low-confidence transfer functions & normals. Definitely not one of our goals…

USCRN Estimated Temperature Normals Product and Error Ranges, 1 – 3 yrs Period-of-Record

Example, October T normals, ºCelsius

Stations Estimated normalsTmin Tmax Tmean

ErrorsTmin Tmax Tmean

Yrs of data

Asheville NC

6.0 19.3 12.7 0.24 0.22 0.17 3

Old Town ME

1.4 13.4 7.3 0.40 0.22 0.25 2

St. Mary MT

0.5 10.4 5.3 0.44 0.32 0.37 1

Web Access

USCRN Homepage URL:

http://www.ncdc.noaa.gov/oa/climate/uscrn/

5-Yr CRN Vision• Sufficient CRN stations deployed ( ~ 114) for capture of CONUS

National Climate T & P Signals for stations with 5-yr POR for normals & extremes estimation (high-confidence products).

• Inter-network (HCN, Coop, SCAN, SNOTEL, RAWS) transfer functions give increased, homogeneous density coverage, and allow CRN to “steal time” backwards (integrated normals).

• Inter-network (esp. using CRN + ~615 “best” HCN-M) transfer functions determination will extend high-confidence T & P

normals sufficiently as to allow Regional Climate T&P Signal determinations for all 11 U.S. Standard Climate Regions.

• Sufficient CRN data stream & confidence supports broad scientific analyses and debate of climate trends, envelopes, and extremes.

• CRN 5-minute data on-line within one hour of receipt at NCDC.

• CRN data and metadata continue to have full public access.