USCRN Density Study Summary and Proposed Deployment Plan by Fiscal Year (FY) (as of June ’02) Captures the National Signal

USCRN Research Questions How many locations are required to capture the National temperature trend? How many locations are required to capture the National precipitation trend? How many locations are required to capture Regional trends across the U. S.?

Why Space USCRN Sites Evenly? One attractive solution for National trends is an evenly spaced grid. Grids capture anomalies of a given spatial extent, regardless of where they occur.

USCRN Performance Measures Capture 95% of National variance in Monthly Temperature, 95% in Annual Precipitation for CONUS Average Annual Error <0.1 º C for temperature, <1.5% for precipitation Trend “errors” <0.05 º C per decade IPCC: Projects warming of º C per decade and precipitation changes of 0 - 2% per decade for CONUS.

Capturing the National Annual Climate Signal Initial USCRN CONUS Locations (40 Paired/95 Single = 175 Instrument Suites) Paired Sites Single Sites

Capturing the National Annual Climate Signal Initial USCRN Alaska Locations (8 Paired/25 Single = 41 Instrument Suites) Paired Sites Single Sites

Summary: USCRN Sites (~221 minimum) Paired: 40 in CONUS, 8 in Alaska, 1 Hawaii (49 paired = 98 instrument station) - Foundation captures National temperature signal and ensure against potential unforeseen station closure. Single: 95 in CONUS, 25 in Alaska, 1 in Hawaii, 1 each in PR & VI (123 instrument stations) - Paired & Singles Capture National precipitation signal. Additional sites needed to improve monitoring regional scale signals and better contribute to homogeneity adjustments for existing networks, e.g. COOP & ASOS

Proposed USCRN Station Deployment Schedule by Fiscal Year (FY) Contiguous U.S. (CONUS) Alaska Hawaii and the Caribbean

USCRN FY Deployment Summary (Capturing the National Signal) ~221 Total Instrument Stations Deployment Plan meets National Performance Measures for each fiscal year. ~40 stations by end of CY 2002 ~55 stations added in FY 2004 ~61 stations added in FY 2005 ~65 stations added in FY 2006

Initial USCRN CONUS Plan (National Signal) 40 paired sites to capture the National temperature signal Another 95 single sites to capture the National precipitation signal 135 geographic locations (175 total instrument sites)

135 General CONUS Locations(175 Stations)

Proposed USCRN CONUS Deployment Plan End of Calendar Year existing + 24 new = 36 stations End of Fiscal Year existing + 45 new = 81 stations End of Fiscal Year existing + 60 new = 141 stations End of Fiscal Year existing + 34 new = 175 stations Existing pair of stationsExisting single stationNew single stationNew pair of stations

Initial USCRN AK, HI, PR, VI Plan (National Signal) 8 Paired sites and 25 Single sites in Alaska 1 Pair and 1 Single in Hawaii 1 Single site each in Puerto Rico and Virgin Islands

Proposed USCRN Alaska Deployment Plan End of Calendar Year new = 2 stations End of Fiscal Year existing + 8 new = 10 stations End of Fiscal Year existing new = 10 stations End of Fiscal Year existing + 31 new = 41 stations Existing pair of stationsExisting single stationNew single stationNew pair of stations

Hawaii and the Caribbean Proposed USCRN Station Deployment 1 Single Site on Kauai, HI (CY 2002) 1 Single Site, Mauna Loa, Hawaii (CY 2002) Second site planned for Mauna Kea, HI in FY 05 1 Single Site in Puerto Rico (FY 2004) 1 Single Site in the Virgin Islands (FY 2004)

Proposed Initial USCRN Locations (~221 Stations Capture the National Annual Climate Signal) 175 stations in CONUS (fully deployed by end of FY 2006) 41 stations in Alaska (fully deployed by end of FY 2006) 3 stations in Hawaii (Kauai and Mauna Loa in 2002, Mauna Kea in 2005) 2 stations, One each in Puerto Rico and the Virgin Islands (both in 2004) PR VI (49) (123)