|ANANDHI, AAVUDAI - Kansas State University|
|PERUMAL, SRIRAM - Kansas State University|
|LAMSAL, ABHISHES - Kansas State University|
|HUTCHINSON, STACY - Kansas State University|
|HARRINGTON, JOHN - Kansas State University|
|TOMLINSON, PETER - Kansas State University|
|KIRKHAM, MARY - Kansas State University|
|RICE, CHARLES - Kansas State University|
Submitted to: Journal of Climate Change
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/28/2013
Publication Date: 8/15/2013
Citation: Anandhi, A., Perumal, S., Gowda, P., Lamsal, A., Hutchinson, S., Harrington, J., Tomlinson, P., Kirkham, M.B., Rice, C.W. 2013. Long term spatial and temporal trends in frost day indices in Kansas, USA. Journal of Climate Change. 120(1-2)169-181.
Interpretive Summary: Frost days affect natural and managed ecosystems. They can also be indicative of changes in climate over time. In this study, frost indices were developed for Kansas, using long-term daily minimum air temperature data. Results indicated that in general there was an increase in minimum air temperature, number of frost days, and length of the growing season. Trends in the indices were found to vary across the state, period, and time scales. Detailed geographical and temporal variations of the frost indices revealed in this study can be beneficial for updating management decisions and planting date recommendations for local and regional agricultural productions.
Technical Abstract: Frost day indices such as number of frost days (nFDs), frost free days (nFFDs), last spring freeze (LSF), first fall freeze (FFF), and growing-season length (GSL), were calculated using daily minimum air temperature (Tmin) values from 23 centennial weather stations spread across Kansas during four time periods (up to 1919, 1920-1949, 1950-1979, and 1980-2009). Frost day is defined as a day having Tmin <0 deg C. The long and short-term trends in each of four indices were analyzed at monthly, seasonal, and annual timescales. Results indicated a general increase in Tmin from 1900 to 2009, causing LSF earlier and FFF later in the year, and thereby causing a decrease in nFDs and an increase in GSL. In general, northwestern Kansas recorded the greatest nFD and lowest Tmin, whereas southeast Kansas has the lowest nFD and highest Tmin. However, the magnitudes of the trend in these indices were found to vary with location, time period, and time scales. This analysis provides a more comprehensive perspective on climatic change compared with the traditional focus on central tendency. Detailed geographical and temporal variations of the frost day indices revealed in this study can be beneficial for updating management decisions and planting date recommendations for local and regional agricultural productions.