detection of soil freeze/thaw processes using smos and elbara-ii finnish meteorological institute...

Detection of Soil Freeze/Thaw Processes

using SMOS and ELBARA-II

Finnish Meteorological Institute (FMI)

K. Rautiainen, J. Lemmetyinen, J. Pulliainen, A. Kontu, J. Ikonen, J. Vehviläinen

SMOSSMOS

ELBARA-IIELBARA-II

ELBARA-II measurements vs frost tube observations

Inc. angle: 50

Snow Snow

Frost Frost

Two winter time-series: ELBARA-II and frost/snow

Winter 2009-10Winter

2009-10

Winter 2010-11Winter

2010-11

Snow Snow

Frost Frost

Two winter time-series: ELBARA-II and frost/snow

Snow Snow

Frost Frost

Freezing period 2009

Freezing period 2009

Freezing period 2010

Freezing period 2010

Two winter time-series: ELBARA-II and frost/snow

Snow Snow

Frost Frost

Early spring 2010

Early spring 2010

Early spring 2011

Early spring 2011

Two winter time-series: ELBARA-II and frost/snow

Snow Snow

Frost Frost

Snow melt-off 2010

Snow melt-off 2010

Snow melt-off 2011

Snow melt-off 2011

Soil freezing and ELBARA-II • Frost depth from frost tube observations (blue circles)

• Triangles: soil freezing state defined using ELBARA-II data

• L-band signal saturates as the soil frost depth reaches ~ 50 cm

Detecting frost using SMOS data• From ELBARA-II to SMOS data

• SMOS incidence angles 50-60 degrees used

• L1C data – H,V polarizations

• Test area: Finland

• Over 2000 smos grid pixels within the area

• Each pixel checked with the Frost algorithm to monitor the soil freezing state

Here used soil frost depths of 10, 20 and 30 cm and no frost

Soil frost maps over Finland

Soil Frost map vs ECMWF surface temperature• Frost information derived from SMOS data

• Surface (2m) temperature (20 day moving average) interpolated from ECMWF 2m temperature observations

Frost map Temperature map

Soil Frost map vs ECMWF surface temperature

Frost map Temperature map

Soil Frost map vs ECMWF surface temperature

Frost map Temperature map

Soil Frost map vs ECMWF surface temperature

Frost map Temperature map

Soil Frost map vs ECMWF surface temperature

Frost map Temperature map

Soil Frost map vs ECMWF surface temperature

Frost map Temperature map

Soil Frost map vs ECMWF surface temperature

Frost map Temperature map

Soil Frost map vs ECMWF surface temperature

Frost map Temperature map

Soil Frost map vs ECMWF surface temperature

Frost map Temperature map

Soil Frost map vs ECMWF surface temperature

Frost map Temperature map

Soil Frost map vs ECMWF surface temperature

Frost map Temperature map