Daytime temperature sum — a new thermal variable describing growing season characteristics and explaining evapotranspiration
The effective temperature sum, the sum of the positive differences between diurnal mean temperatures and 5 °C, is used in ecology, agriculture, forestry, and hydrology. It does not differentiate between day and night. However, most assimilation and evapotranspiration occurs in the daytime. A "d...
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2024
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ftunivhelsihelda:oai:helda.helsinki.fi:10138/578243 2024-09-15T18:00:09+00:00 Daytime temperature sum — a new thermal variable describing growing season characteristics and explaining evapotranspiration Solantie, R. 2024-06-27T13:44:51Z 319-333 application/pdf http://hdl.handle.net/10138/578243 eng eng Boreal Environment Research Publishing Board Boreal Environment Research 1239-6095 1797-2469 4 9 http://hdl.handle.net/10138/578243 Suomen ympäristökeskus CC BY 4.0 openAccess Artikkeli lehdessä 2024 ftunivhelsihelda 2024-08-21T23:48:04Z The effective temperature sum, the sum of the positive differences between diurnal mean temperatures and 5 °C, is used in ecology, agriculture, forestry, and hydrology. It does not differentiate between day and night. However, most assimilation and evapotranspiration occurs in the daytime. A "daytime temperature sum" is presented that is better related to assimilation. First, temperatures above 7 °C were integrated during the period, starting when the sun rises five degrees above the horizon, and ending when it descends to two degrees. The sums of these values were then reduced to be, on average, equal to the traditional ones. The new variable appeared to smooth out much of the spatial variation caused by night-time temperatures. It also gives a more distinct start and end to the thermal vegetation period. When using the daytime temperature sum instead of the traditional sum in explaining evapotranspiration, a better result was obtained. Article in Journal/Newspaper Boreal Environment Research HELDA – University of Helsinki Open Repository |
institution |
Open Polar |
collection |
HELDA – University of Helsinki Open Repository |
op_collection_id |
ftunivhelsihelda |
language |
English |
description |
The effective temperature sum, the sum of the positive differences between diurnal mean temperatures and 5 °C, is used in ecology, agriculture, forestry, and hydrology. It does not differentiate between day and night. However, most assimilation and evapotranspiration occurs in the daytime. A "daytime temperature sum" is presented that is better related to assimilation. First, temperatures above 7 °C were integrated during the period, starting when the sun rises five degrees above the horizon, and ending when it descends to two degrees. The sums of these values were then reduced to be, on average, equal to the traditional ones. The new variable appeared to smooth out much of the spatial variation caused by night-time temperatures. It also gives a more distinct start and end to the thermal vegetation period. When using the daytime temperature sum instead of the traditional sum in explaining evapotranspiration, a better result was obtained. |
format |
Article in Journal/Newspaper |
author |
Solantie, R. |
spellingShingle |
Solantie, R. Daytime temperature sum — a new thermal variable describing growing season characteristics and explaining evapotranspiration |
author_facet |
Solantie, R. |
author_sort |
Solantie, R. |
title |
Daytime temperature sum — a new thermal variable describing growing season characteristics and explaining evapotranspiration |
title_short |
Daytime temperature sum — a new thermal variable describing growing season characteristics and explaining evapotranspiration |
title_full |
Daytime temperature sum — a new thermal variable describing growing season characteristics and explaining evapotranspiration |
title_fullStr |
Daytime temperature sum — a new thermal variable describing growing season characteristics and explaining evapotranspiration |
title_full_unstemmed |
Daytime temperature sum — a new thermal variable describing growing season characteristics and explaining evapotranspiration |
title_sort |
daytime temperature sum — a new thermal variable describing growing season characteristics and explaining evapotranspiration |
publisher |
Boreal Environment Research Publishing Board |
publishDate |
2024 |
url |
http://hdl.handle.net/10138/578243 |
genre |
Boreal Environment Research |
genre_facet |
Boreal Environment Research |
op_relation |
Boreal Environment Research 1239-6095 1797-2469 4 9 http://hdl.handle.net/10138/578243 Suomen ympäristökeskus |
op_rights |
CC BY 4.0 openAccess |
_version_ |
1810437279840206848 |