Longterm atmospheric and pedo-climatic observations along an upper treeline ecotone in the Himalayas, Nepal TREELINE

Example illustration with two monthly temperatures from the tree line project. Copyright: UHH/CEN/AJB

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UNRESTRICTED:

Get TREELINE data via Download at FDR

RESTRICTED: This link to the data set is only available for a restricted user group. The data set is only accessible in CEN/MPI net or accessible from external nets with a customer account. Please contact ICDC if you would like to access this data from outside the network.

Access TREELINE data via OPeNDAP
Data access via file system: /data/icdc/atmosphere/treeline

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Description

This data set includes meteorological and pedo-climatic data obtained from a study area in central Himalayas, Nepal. The study area is located in the Rolwaling valley along the Rolwaling Himal in the Gaurishankar Conservation Area (GCA) in the Dolakha district. In this region the upper treeline ecotone is located in a subtropical high-altitude alpine forest zone with strong differences in land cover on opposing valley slopes. South-facing slopes are traditionally highly shaped by anthropogenic practice and dominant tree species forming the treeline are Juniperus spp. On north-facing slopes dense forests are consisting primarily of Betula utilis and Abies spectabilis with Rhododendron campanulatum, Sorbus microphylla, Acer caudatum and Prunus rufa communities. On the upper end of the main study site the forests are locked with a wide Rhododendron campanulatum krummholz belt which is followed by Rhododendron spp. dwarf shrubs and alpine tundra in higher areas. Within the east-west extending valley eight automatic weather stations (AWS) were installed since April 2013. These were mounted on different slopes and positions stretching from around 3700m up to over 5000m a.s.l. In 2m above surface (sensor type in brackets) incoming solar radiation [Wm-²] (ONS-S-LIB-M003), air temperature [°C] (ONS-S-THB-M002) and relative humidity [%] (ONS-S-THB-M002), wind speed [ms-1] (ONS-S-WSB-M003) and wind direction [°] (ONS-S-WDA-M003) as well as precipitation [mm] (ONS-S-RGB-M002) are measured every 3min and logged every 15min. Four AWS are positioned in the main study site in the valley representing two altitudinal transects along different slope expositions in north-western and north-eastern directions. Additionally 34 pedo-climatic Koubachi combined soil temperature [°C] and soil moisture [pF] loggers were installed from April 2013 until September 2015 in four different altitudinal belts along the transects in 10cm depth. These also follow the aforementioned pattern with different expositions and both parameters were logged in hourly intervals.

Last update of data set at ICDC: October 6, 2021

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Parameters

Parameters of the TREELINE data set
Name	Unit
solar radiation	W/m²
air temperature	°C
relative humidity	%
wind speed	m/s
wind direction	°
precipitation	mm/time
soil temperature	°C
soil moisture	pF

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Coverage, spatial and temporal resolution

Atmospheric sensors of AWS

2m above surface: incoming solar radiation [Wm-²]; air temperature [°C]; relative humidity [%]; wind speed [ms-1]; wind direction [°]; precipitation [mm];
measuring interval: 3min;
logging interval: 15min.

Locations of automated weather stations (ONSET)
Station	Longitude [°E]	Latitude [°N]	Altitude [m.a.s.l.]	Instal. Date
NW bottom	86.3762	27.9009	3718.9	2013-04-18
NW top	86.3742	27.8967	4035.9	2013-04-15
NE bottom	86.3791	27.8986	3734.2	2013-04-18
NE bottom	86.3791	27.8986	3734.2	2013-04-18
NE top	86.3759	27.8934	4158.3	2013-10-17
Beding Gompa	86.3755	27.9050	3886.0	2013-04-19
Na	86.4337	27.8782	4192.1	2013-04-21
Dudgunda	86.4604	27.8756	4532.2	2016-09-29
Yalun	86.4338	27.8590	5005.2	2013-10-20

Pedo-climatic sensors of Koubachis

10cm sensor soil depth: soil temperature [°C]; soil moisture [pF];
measuring and logging interval: 60min.

Locations of pedo-climatic loggers (Koubachi AG)
Belt / Logger groups	Altitudinal range [m a.s.l]	Altitudinal zone	Number of functional loggers (in 06/2015)
NE-2 A	3750 - 3900 m	closed forest	4 (100%)
NE-2 B	3900 - 4000 m	uppermost closed forest	2 (50%)
NE-2 C	4000 - 4100 m	krummholz belt	4 (100%)
NE-2 D	4100 - 4250 m	dwarf scrub heath / alpine tundra	3 (75%)
NW-1 A	3750 - 3800 m	closed forest	3 (75%)
NW-1 B	3800 - 3900 m	uppermost closed forest	3 (75%)
NW-1 C	3900 - 4050 m	krummholz belt	3 (75%)
NW-1 D	4100 - 4250 m	dwarf scrub heath / alpine tundra	3 (75%)
NE-2 sp	4000 - 4050 m	Abies spectabilis / Betula utilis individuals	2 (100%)

Format:

.csv files in UTF-8 encoding.

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Data quality

Winter precipitation is underestimated due to non-heated rain gauges. During the project start several vandalism incidents resulted in data loss and gaps in the time series. For hydrological modelling temperature and precipitation data sets are available in a gap filled version.

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Contact

Johannes Weidinger
Geographie / CEN / University of Hamburg
E-Mail: juergen.boehner (at) uni-hamburg.de

Prof. Jürgen Böhner
Geographie / CEN / University of Hamburg
E-Mail: juergen.boehner (at) uni-hamburg.de

Annika Jahnke-Bornemann
ICDC / CEN / University of Hamburg
E-Mail: annika.jahnke-bornemann"AT"uni-hamburg.de

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References

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Data citation, License, and Acknowledgments

Please cite the data as follows:

Weidinger, Johannes, Gerlitz, Lars, Bobrowski, Maria, Böhner, Jürgen, Chaudhary, Ram Prasad, Schickhoff , Udo, Schwab, Niels, Scholten, Thomas. (2021). TREELINE - Longterm atmospheric and pedo-climatic observations along an upper treeline ecotone in the Himalayas, Nepal [Data set]. http://doi.org/10.25592/uhhfdm.9563

and with the following acknowledgments:

Thanks to ICDC, CEN, University of Hamburg for data support.

License

The data was published under the Creative Commons Attribution 4.0 International License (CC-BY-4.0).

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