Data Descriptions

Data Descriptions#

(10 minutes)

Campaigns are participant driven and produce community wide data. Without our vast community, we wouldn’t have the robust ground-based observations that are part of the SnowEx collection. Discover the ground-based calibration and validation measurements central to the SnowEx field campaigns. Collecting in situ measurements require hours of manual labor and attention to detail. While observers adhere to standard protocols, they often rely on their best judgment and collective expertise when facing challenging sampling conditions.

Learning Objectives

Become familiar with measurements available for calibration/validation
Know the sampling strategy and naming conventions behind the campaign design
Learn where to find and search for SnowEx data

Ground Observations#

What ground-based data sets are central for snow field campaigns?#

Figure 1. Ground-based measurements central to the SnowEx campaigns. (Left to Right panels) 1). Depth Transects: Observer uses the MagnaProbe to measure snow depths. 2). Snow Pit: Vertical density cuts show the dual profile sampling protocol. 3). Interval Board/SWE Tube: Overnight snow being measured in a snow tube to record the daily change during the IOP campaign. 4). Specific Surface Area (SSA) being collected at a shallow tundra snow pit with the IceCube. 5). SnowMicroPen (SMP) penatrating the snowpack to record snow stratigraphy over a range of intervals (10-50m) away from the centralized snow pit.

Additional detail on depth transects and snow pit sampling procedures#

Depth Transects
Here you can see a summary of some of the depth sampling patterns you might discover in the snow depth data sets. Typically the pattern is a result of what instrument collection technique is deployed.

Figure 2. Examples of snow depth measurements taken in different spatial patterns, representing different spatial extents. a). shows pit-depth, square-depths with L-depths from a study plot. b). captures spiral-depths collected using a MagnaProbe. c). Includes spiral-depths and a single transect, ~10km in total length. Note the difference in scale across each panel. Background images are courtesy of @ 2020 Maxar Technologies Inc., Alaska Geospatial Office, USGS.

Snow Pits
There are a lot of measurements in a single snow pit. This diagram helps explain what all is measured at a snow pit.

Figure 3. Description of parameters that come from a single snow pit visit. The colored ovals on the images correspond to the colored measurements on the left side.

Sampling Strategy and Naming Conventions#

I: 2020 Grand Mesa, CO IOP#

Figure 4. Nine-member snow and vegetation matrix used to sample and name snow pits during the Grand Mesa IOP campaign

Vegetation Classes

1-3 = treeless (0% tree cover)
4-6 = sparse (1-30% tree cover)
7-9 = dense (31-100% tree cover)

Snow Depth Classes

1, 4, 7 = shallow (<90cm)
2, 5, 8 = medium (90-122cm
3, 6, 9 = deep (>122cm)

Flight Lines

‘C’ = Crossline
‘N’ = North
‘S’ = South

Figure 5. Grand Mesa, Colorado IOP 2020 sampling design. The rectangles are the SWESAR, UAVSAR, Thermal IR, and Gamma flight lines. The point markers are the locations of snow pits.

II: 2020/2021 Western U.S Time Series#

Location ⇨ Regional Location with existing long-term monitoring infrastructure.
Site ⇨ Averaged unique snow pit site to represent the progression of Time Series snow pits.
PitID ⇨ 6-letter code unique to all snow pit sites; 2-letter state, 2-letter Location; 2-letter site name (e.g Idaho, Boise River, Bogus Upper = IDBRBU
Unique PitID ⇨ 6-letter site code and timestamp (e.g. format: XXXXXX_yyyymmdd_hhmm, example: IDBRBU_20200116_1345)

Table 1. Comprehensive Site Summary for 2020 and 2021 Time Series Campaign

State	Location	Site	PitID	Latitude	Longitude	Pit Count	Snow Class
CA	American River Basin	Caples Lake	CAAMCL	38.71029	-120.04186	7	3
CA	Mammoth Lakes	CUES	CAMLCP	37.64324	-119.02906	9	5
CA	Mammoth Lakes	Panorama Dome	CAMLPD	37.61964	-119.00029	6	6
CA	Sagehen Creek	Forest	CASHFO	39.42956	-120.24211	7	6
CA	Sagehen Creek	Open	CASHOP	39.43037	-120.23982	7	6
CA	Sagehen Creek	Tower 4	CASHT4	39.42216	-120.29898	6	3
CO	Cameron Pass	Cameron Peak	COCPCP	40.56381	-105.86761	16	6
CO	Cameron Pass	Joe Wright	COCPJW	40.52406	-105.89345	8	2
CO	Cameron Pass	Michigan River	COCPMR	40.51864	-105.89193	22	2
CO	East River	Aspen	COERAP	38.92529	-106.97109	9	6
CO	East River	Forest 12	COER12	38.92973	-106.97824	12	2
CO	East River	Forest 13	COER13	38.92943	-106.97777	9	6
CO	East River	Forest 14	COER14	38.92894	-106.97757	12	6
CO	East River	Gothic	COERGT	38.95925	-106.99053	9	6
CO	East River	Irwin Barn	COERIB	38.88812	-107.10796	13	2
CO	East River	Open 2	COERO2	38.92661	-106.97848	9	2
CO	East River	Open 4	COERO4	38.92627	-106.97907	12	2
CO	East River	Open 6	COERO6	38.92669	-106.97988	9	2
CO	East River	Trench 13	COERTR	38.92920	-106.97770	5	6
CO	East River	Upper	COERUP	38.93331	-106.98994	12	2
CO	Fraser Experimental Forest	JPL 1	COFEJ1	39.90556	-105.88282	35	6
CO	Fraser Experimental Forest	JPL 2	COFEJ2	39.90612	-105.88255	26	6
CO	Fraser Experimental Forest	SNB 1	COFEB1	39.90699	-105.87786	23	6
CO	Fraser Experimental Forest	SNB 2	COFEB2	39.90703	-105.87904	18	6
CO	Grand Mesa	County Line Open	COGMCO	39.03053	-108.03220	12	2
CO	Grand Mesa	County Line Tree	COGMCT	39.03223	-108.03438	10	2
CO	Grand Mesa	Mesa West Open	COGMWO	39.03399	-108.21390	10	2
CO	Grand Mesa	Mesa West Trees	COGMWT	39.03282	-108.21291	7	2
CO	Grand Mesa	Skyway Open	COGMSO	39.04511	-108.06209	21	2
CO	Grand Mesa	Skyway Tree	COGMST	39.04565	-108.06333	18	2
CO	Niwot Ridge	C1	CONWC1	40.03317	-105.54616	9	6
CO	Niwot Ridge	Forest Flat	CONWFF	40.03186	-105.54667	12	6
CO	Niwot Ridge	Forest North	CONWFN	40.03337	-105.55380	11	2
CO	Niwot Ridge	Forest South	CONWFS	40.04021	-105.55701	13	2
CO	Niwot Ridge	Open Flat	CONWOF	40.03579	-105.55205	15	6
CO	Niwot Ridge	Saddle	CONWSA	40.05497	-105.59065	7	1
CO	Senator Beck	Senator Beck	COSBSB	37.90705	-107.72626	5	1
CO	Senator Beck	Swamp Angel	COSBSA	37.90714	-107.71121	19	2
ID	Boise River Basin	Banner Open	IDBRBO	44.30456	-115.23601	11	6
ID	Boise River Basin	Banner Snotel	IDBRBS	44.30362	-115.23457	23	6
ID	Boise River Basin	Bogus Lower	IDBRBL	43.76434	-116.10660	17	6
ID	Boise River Basin	Bogus Lower Trees	IDBRBT	43.76057	-116.08979	13	6
ID	Boise River Basin	Bogus Upper	IDBRBU	43.75881	-116.09019	11	6
ID	Boise River Basin	LDP Open	IDBRLO	43.73707	-116.12179	19	6
ID	Boise River Basin	LDP Tree	IDBRLT	43.73634	-116.12053	17	6
ID	Boise River Basin	Mores Creek Summit	IDBRMC	43.94735	-115.67666	3	6
MT	Central Ag Research Center	SnowEx-1	MTCASX	47.05836	-109.95688	4	5
MT	Central Ag Research Center	Wheat	MTCAWH	47.05942	-109.95176	1	5
MT	Central Ag Research Center	Wx	MTCAWX	47.06062	-109.95693	4	5
NM	Jemez River	BA Flux Tower	NMJRBA	35.88859	-106.53184	8	5
NM	Jemez River	HQ Met Station	NMJRHQ	35.85791	-106.52137	8	5
UT	Little Cottonwood Canyon	Alta Collins	UTLCAC	40.57210	-111.62997	17	2
UT	Little Cottonwood Canyon	Atwater	UTLCAW	40.59125	-111.63759	20	5

Note - If a site was repeated (e.g. Cameron Pass, Michigan River) then the Pit Count column is the sum of the observations for two years). The Snow Class column was extracted from the 300 m Snow Classification data set (Liston, 2021 and can be accessed here at NSIDC). See the previous notebook to characterize the Snow Classes.

This table can be accessed as a geojson from Megan’s github gists

To use this as a geojson in your project:

Navigate to the link above
Check out the map of data (zoom in, zoom out, etc.)
Select the ‘Raw’ button from the top right corner
Copy/Paste the URL (it’s longer now)
Use the code block below to import

import geopandas as gpd
import requests
url = "https://gist.githubusercontent.com/meganmason/dde13c46a90875e364b1c25a31bff1d8/raw/d361e1a56eeb867bd89c87b4dc13ed431ffff6f6/SNEX_TS_SP_avg_prelim_Hackweek.geojson"
gdf = gpd.read_file(url)
gdf.head()

	State	Location	Site	PitID	Latitude	Longitude	Pit Count	Snow Class	geometry
0	CA	American River Basin	Caples Lake	CAAMCL	38.71029	-120.04186	7	3	POINT (-120.04186 38.71029)
1	CA	Mammoth Lakes	CUES	CAMLCP	37.64324	-119.02906	9	5	POINT (-119.02906 37.64324)
2	CA	Mammoth Lakes	Panorama Dome	CAMLPD	37.61964	-119.00029	6	6	POINT (-119.00029 37.61964)
3	CA	Sagehen Creek	Forest	CASHFO	39.42956	-120.24211	7	6	POINT (-120.24211 39.42956)
4	CA	Sagehen Creek	Open	CASHOP	39.43037	-120.23982	7	6	POINT (-120.23982 39.43037)

III: Arctic Tundra and Boreal Forest, Alaska IOP#

Figure 6. SnowEx 2023 site locations in Interior Alaska (boreal forest) and on the North Slope (tundra) of Alaska. The flight lines for SWESARR (turquoise areas) and lidar/stereo (red boxes). SWE/snow depth measurement periods studied five locations: three in the boreal forest and two in the arctic tundra. The albedo/snow melt campaign period studied three sites in the boreal forest.

SWE/snow depth focused campaign (Oct 2022, March 2023, Oct 2023)#

Fairbanks area / Interior Alaska –> Boreal Forest

FLCF - Farmer’s Loop and Creamer’s Field (001-108)
CPCRW - Caribou-Poker Creek Research Watershed (200-283)
BCEF - Bonanza Creek Experimental Forest (300-482)

Vegetation Classes: (National Land Cover Dataset) D - Deciduous, E - Evergreen, S - Shrub, W - Wetland, C - Crop

Snow Depth Classes: B - Below Average, N - Average (neutral), A - Above Average

North Slope Alaska –> Arctic Tundra

UKT - Upper Kuparuk-Toolik (500-566)
ACP - Alaska Coastal Plain (600-800)

Vegetation Classes (Not used for Tundra sites)

Snow Depth Classes (SnowModel terrain, land cover, and snow depth output)
N - Neutral (windward), A - Above Neutral (leeward), D - Snow Drift, I - Ice Cover (lake/river) - only visited March 2023

Flight Lines

FLCF (2): North, SW
BCEF (3): NE, SW, North
CPCRW (1): East
UKT (3): North, East, South
ACP (1): NNE

Albedo/snow melt focused campaign (Apr/May 2023)#

Interior Alaska –> Boreal Forest

FLCF - Farmer’s Loop and Creamer’s Field
CPCRW - Caribou-Poker Creek Research Watershed
DEJU - Delta Junction Research Area

Figure 7. Farmers Loop Creamers Field (FLCF) field site (one of five SWE/depth focused study sites for the Alaska IOP). Snow pit study plots (colored points) distributed within the SWESARR flight swaths (green rectangle) and lidar flight box (red line). Pit sites are marked with October 2022 (white triangle) and March 2023 (black circle) site visits.

Figure 8. SWESARR science lines (yellow boxes) and associated flight lines (red line) over each site.

Figure 9. Represenative land cover classes for the boreal forests taken from the Southeast corner of the 5x5 m study plot.

Figure 10. The study plot sampling design for the SWE/snow depth focused campaign. Field crews marked the Southeast corner and measured square-depths around the 5x5 m perimeter on a 1m interval. Snow depths were collected on a north and west transect of 20 m (15 m addition to the study plot perimeter) or a spiral pattern was used depending on depth instrument availability. The snow pit was excavated in the center of the study plot. SSA measurements were collected inside the ~1x1 m snow pit. SMP measurments were taken at the front of the snow pit and up to 50 m from the snow pit.

Where can I find data?#

1. SnowEx data sets are stored and archived at the National Snow and Ice Data Center (NSIDC) in Boulder, Colorado.#

Table 2. Summary of Core Data Sets with DOI links for applicable data sets

Core Data Sets	Parameters Available	Instruments	NSIDC Access
Snow Pits	Depth, Density, Temp., LWC, Stratigraphy, Grain Size, Wetness, Hand Hardness, Qualitative Environment, SWE	Standard pit kit	SNEX17_SP_GMIOP SNEX20_SP_GMIOP SNEX20_SP_TS SNEX21_SP_TS SNEX23_SP_Oct22 SNEX23_SP_Mar23 (prelim. avail.) SNEX23_SP_Oct23
Depth Transects	Snow Depth - various sampling designs	MagnaProbe, Mesa2/Geode, Pit Ruler	SNEX17_SD SNEX20_SD SNEX20_SD_TS SNEX21_SD_TS (in prep.) SNEX23_SD_Mar22 SNEX23_SD_Oct22 (prelim. avail.) SNEX23_SD_Mar23 SNEX23_SD_Oct23
Interval Boards/ SWE Tubes	New (or total) snow, SWE, density	Tube, ruler and scale	SNEX20_ST_GMIOP SNEX20_IB_GMIOP SNEX20_IB_TS SNEX21_IB_TS SNEX23_IB_Mar23 SNEX23_ST_Mar23
SSA	Snow reflectance, Specific surface area	IceCube, IRIS, InfraSnow	SNEX17_SSA_GMIOP SNEX20_SSA_GMIOP SNEX23_SSA_Oct22 SNEX23_SSA_Mar23 SNEX23_SSA_Oct23
SMP	Depth, Force (snow microstructure)	SnowMicroPen	SNEX17_SMP_GMIOP SNEX17_SMP_SBIOP SNEX20_SMP_GMIOP SNEX20_SMP_BoiseRiver SNEX23_SMP_Mar23

Visit NSIDC’s SnowEx Overview page to see a full table of all available 2017, 2020, 2021 and 2023 products.

2. SnowEx SQL Database (preview in next tutorial!)#

Recap#

You know which measurements we have a LOT of and are consistent between multiple field campaigns
You are aware of the basic sampling strategy for the various campaigns
You have a few tools at your finger tips to access and learn more about the data