Just Chill for an Hour: Mapping Suitable Apple Growing Regions in Washington

Earthzine2015 Spring VPS, Assessing Agriculture and Ecosystems, DEVELOP Virtual Poster Session

Category: Assessing Agriculture and Ecosystems

Project Team: Northwest US Agriculture II

Team Location: NASA Langley Research Center ‰ÛÒ Hampton, Virginia

Air temperature for the state of Washington, as derived from MODIS Land Surface Temperature. This calculated air temperature was used to calculate accumulated chill hours.
Image Credit: Northwest US Agriculture II Team


Lydia Cuker

Laura Lykens

Alyssa Walzak

Timothy Stelter


Dr. Kenton Ross (NASA DEVELOP National Program Science Advisor)

Dr. Noel Baker (NASA Langley Research Center)

Past/Other Contributors:

Lauren Makely

Idamis Del Valle-Martinez

Clarence Kimbrell

Zachariah Long

Chad Smith

Matthew Smith


Washington is the top apple-producing state in the U.S., contributing over half of the nation’s apples. Washington’s climate is ideal for apple growth, but as climate fluctuates, concerns are rising over the continued suitability of the region for apple cultivation. Apple trees require 400 to 1,000 hours between 1.4 and 12.5 degrees Celsius, known as chill hours, to break dormancy and homogenously bloom in the spring. Accumulated chill hours were identified as a key factor contributing to the success of apples, which may change due to climate fluctuations. Thus, understanding how climate change may affect chill hours will provide growers with insight as to how their orchards may eventually be affected. Connections to the apple growers in Washington were established through a partnership with the U.S. Department of Agriculture – Agriculture Research Service (USDA-ARS). Data for 2003 to 2013 were acquired from NASA Earth observations measured by Aqua and Terra Moderate Resolution Imaging Spectroradiometer (MODIS). Accumulated chill hours were calculated for 2003 to 2013 using the Land Surface Temperature product. Future climate model air temperature forecasts from the Coupled Model Intercomparison Project phase 5 (CMIP5) were used to project accumulated chill hours to the year 2065. Resultant maps of current and forecasted accumulated chill hours benefit orchard managers by detailing regions that are currently optimal for apple production and how those regions will shift with forecasted changes in climate.

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