Soil temperature and soil moisture dynamics in winter and spring under heavy snowfall conditions in North‐Eastern Japan

Abstract

Warm winters and high precipitation in north‐eastern Japan generate snow covers of more than three meters depth and densities of up to 0.55 g cm−3. Under these conditions, rain/snow ratio and snowmelt have increased significantly in the last decade under increasing warm winters. This study aims at understanding the effect of rain‐on‐snow and snowmelt on soil moisture under thick snow covers in mid‐winter, taking into account that snowmelt in spring is an important source of water for forests and agriculture. The study combines three components of the Hydrosphere (precipitation, snow cover and soil moisture) in order to trace water mobility in winter, since soil temperatures remained positive in winter at nearly 0.3°C. The results showed that soil moisture increased after snowmelt and especially after rain‐on‐snow events in mid‐winter 2018/2019. Rain‐on‐snow events were firstly buffered by fresh snow, increasing the snow water equivalent (SWE), followed by water soil infiltration once the water storage capacity of the snowpack was reached. The largest increase of soil moisture was 2.35 vol%. Early snowmelt increased soil moisture with rates between 0.02 and 0.035 vol% hr−1 while, rain‐on‐snow events infiltrated snow and soil faster than snowmelt and resulted in rates of up to 1.06 vol% hr−1. These results showed the strong connection of rain, snow and soil in winter and introduce possible hydrological scenarios in the forest ecosystems of the heavy snowfall regions of north‐eastern Japan. Effects of rain‐on‐snow events and snowmelt on soil moisture were estimated for the period 2012–2018. Rain/snow ratio showed that only 30% of the total precipitation in the winter season 2011/2012 was rain events while it was 50% for the winter 2018/2019. Increasing climate warming and weakening of the Siberian winter monsoons will probably increase rain/snow ratio and the number of rain‐on‐snow events in the near future.

Quantitative Impact of Organic Matter and Soil Moisture on Permafrost

“…Soil temperature can be a direct indicator of the effects of organic matter and soil moisture on permafrost (Brandt et al., 2020; Hu et al., 2019; Y. Zhang et al., 2005). Soil temperature differences between the control experiment and the sensitivity simulations at the different depths show that the influence of organic matter and soil moisture is greater on shallow soil temperature than on the deep soil.…”

“…Soil temperature can be a direct indicator of the effects of organic matter and soil moisture on permafrost (Brandt et al, 2020;Hu et al, 2019;Y. Zhang et al, 2005).…”

Soil Moisture Distribution and Time Stability of Aerially Sown Shrubland in the Northeastern Margin of Tengger Desert (China)

“…The temporal stability of soil moisture is a result of the interaction of vegetation, topography, climate, soil and many other factors. The dynamics of soil moisture in arid and semi-arid regions are mainly affected by precipitation infiltration, vegetation root absorption and soil evaporation [38][39][40]. Precipitation infiltration is determined by precipitation characteristics and soil characteristics.…”

Variation characteristics of soil temperature, moisture, and heat flux in the understorey of evergreen broadleaf forest in South China

“…At present, scholars have examined the characteristics of soil temperature and moisture as well as heat uxes in arctic alpine environments (Aalto et al 2013), northeastern Japan (Brandt et al 2020), eastern Brazil and in tropical rainforests and savannas (Grimm et al 2007;Rocha et al 2009) and temperate grasslands (Carlyle et al 2011). Soil temperature and moisture patterns are also often analysed in conjunction with corresponding models to reduce uncertainty in regional predictions (Bhattacharya et al 2015;Müller et al 2016;Purdy et al 2016;Cheruy et al 2017;Vogel et al 2017).…”