site_data <- readr::read_csv("https://raw.githubusercontent.com/eco4cast/neon4cast-targets/main/NEON_Field_Site_Metadata_20220412.csv") |>
dplyr::filter(terrestrial == 1)2 Theme: Terrestrial Ecosystems
What: Net ecosystem exchange(NEE) of CO2 and evapotranspiration in terrestrial ecosystems
Where: 47 NEON sites across the U.S. and Puerto Rico.
When: Daily forecasts for at least 30-days in the future are accepted at any time. The only requirement is that submissions are predictions of the future at the time the forecast is submitted.
Why: Carbon and water cycling are fundamental for climate and water regulation services provided by ecosystems
2.1 Overview
The exchange of water and carbon dioxide between the atmosphere and the land is akin to earth’s terrestrial ecosystems breathing rate and lung capacity. One of the best ways to monitor changes in the amount of carbon and water in an ecosystem is the eddy-covariance method. This method observes the net amount of carbon and water entering and exiting ecosystems at half-hourly timesteps, which is important because it can provide information on ecosystem processes such as photosynthesis, respiration, and transpiration, their sensitivities to ongoing climate and land use change, and greenhouse gas budgets for carbon accounting and natural climate solutions. Forecasts of carbon uptake and release along with water use can provide insights into future production of food, fiber, timber, and carbon credits. Additionally, forecasts will highlight the influence that stress and disturbance have on carbon and water cycling.
2.2 Challenge
This forecasting challenge asks teams to forecast net ecosystem exchange of carbon dioxide (NEE) and latent heat flux of evapotranspiration (LE) across 47 NEON sites with differing climates. Forecasts can be submitted the 30-minute and/or daily time step over the next 30-days.
Teams are asked to submit their forecast of NEE and LE, along with uncertainty estimates. Any existing NEE and LE data may be used to build and improve the models used to generate forecasts. Other data can be used to generate forecasts.
2.3 Data: Targets
The challenge uses the following NEON data products:
DP4.00200.001: Bundled data products - eddy covariance
A file with previously released NEON data that has been processed into “targets” is provided below. The same processing will be applied to new data that are used for forecast evaluation.
2.3.1 Net ecosystem exchange
Definition
Net ecosystem exchange (NEE) is the net movement of carbon dioxide from the atmosphere to the ecosystem. At the 30-minute time resolution it is reported as \(\mu\)mol CO2 m-2 s-1. At the daily time resolution it is reported as g C m-2 day-1. Negative values correspond to an ecosystem absorbing CO2 from the atmosphere, positive values correspond to an ecosystem emitting CO2 to the atmosphere.
Motivation
NEE quantifies the net exchange of CO2 between the ecosystem and the atmosphere over that 30-minute or daily time period. Assessing skill at predicting 1/2 hourly - sub daily measurements provides more insight into ability to capture diel processes. The diel curve contains information on how plants and soil immediately respond to variations in meteorology.
Making daily predictions will allow us to rapidly assess skill and provide information in a timeframe pertinent to inform and implement natural resource management. It also allows for models that do not produce sub-daily estimates to participate
2.3.2 Latent heat flux
Definition
Latent heat flux is the movement of water as water vapor from the ecosystem to the atmosphere. It is reported as W m-2 (equivalent to J m-2 s-1). At the daily time resolution it is reported as mean W m-2. Positive values correspond to a transfer of water vapor from the ecosystem to the atmosphere.
Motivation
Latent heat measures the water loss from an ecosystem to the atmosphere through evapotranspiration (transpiration through plants + evaporation from surfaces).
Forecasting latent heat (evapotranspiration) can provide insights to water stress for plants and the efficiency that plants are using water relative to NEE, and to the amount of liquid water remaining in the soil for soil moisture forecasting
2.3.3 Focal sites
Information on the sites can be found here:
with full site table at the end of this page.
The distribution of sites across ecosystems types is:
| Vegetation type | Count |
|---|---|
| Evergreen Forest | 4 |
| Evergreen Forest|Shrub/Scrub | 4 |
| Deciduous Forest|Evergreen Forest|Mixed Forest|Woody Wetlands | 3 |
| Evergreen Forest|Grassland/Herbaceous|Shrub/Scrub | 3 |
| Grassland/Herbaceous | 3 |
| Cultivated Crops | 2 |
| Deciduous Forest|Evergreen Forest|Mixed Forest | 2 |
| Deciduous Forest|Evergreen Forest|Pasture/Hay | 2 |
| Deciduous Forest|Grassland/Herbaceous | 2 |
| Deciduous Forest|Mixed Forest|Woody Wetlands | 2 |
| Deciduous Forest|Pasture/Hay | 2 |
| Shrub/Scrub | 2 |
| Cultivated Crops|Deciduous Forest | 1 |
| Cultivated Crops|Deciduous Forest|Evergreen Forest|Mixed Forest | 1 |
| Cultivated Crops|Grassland/Herbaceous|Pasture/Hay | 1 |
| Deciduous Forest | 1 |
| Deciduous Forest|Evergreen Forest | 1 |
| Deciduous Forest|Woody Wetlands | 1 |
| Dwarf Scrub|Evergreen Forest|Shrub/Scrub | 1 |
| Dwarf Scrub|Shrub/Scrub | 1 |
| Emergent Herbaceous Wetlands | 1 |
| Emergent Herbaceous Wetlands|Evergreen Forest|Woody Wetlands | 1 |
| Emergent Herbaceous Wetlands|Grassland/Herbaceous | 1 |
| Evergreen Forest|Grassland/Herbaceous | 1 |
| Evergreen Forest|Shrub/Scrub|Woody Wetlands | 1 |
| Evergreen Forest|Woody Wetlands | 1 |
| Grassland/Herbaceous|Shrub/Scrub | 1 |
| Pasture/Hay|Woody Wetlands | 1 |
2.3.4 30-minute target data calculation
To create the data for evaluation (and training) for NEE and LE we extract NEE and LE that pass the turbulence quality control flags (qfqm.fluxCo2.turb.qfFinl = 0 ) provided by NEON and has flux values between -50 and 50 umol CO2 m-2 s-1.
2.3.5 Daily target data calculation
To evaluate the models that produce daily flux forecasts, we select only days with at least 24 of 48 half-hours that pass the quality control flags. For these days, we average the half-hours and convert carbon to daily units (gC/m2/day).
2.4 Flux data latency
NEON data officially releases the flux data on their data portal and API in monthly data packages. Data for a given month is scheduled to be released around the 15th of the following month.
NEON is also processing flux data with only a 5 day delay (latency). Any data that has been processed but not included in a released monthly package is available on NEON s3 storage. The list of files that can be downloaded can found here.
Our targets file is the combination of NEON’s monthly releases and the files on the s3 bucket. As a result, flux data within 5-days of the restart of a forecast are available to inform the forecast.
The reduction of the latency from monthly to 5-days allows this theme to forecast in real-time - a major advancement for this forecasting challenge. Thank you NEON!
2.5 Site table
| siteID | site name | vegetation type | latitude | longtitude | NEON site URL |
|---|---|---|---|---|---|
| ABBY | Abby Road NEON | Evergreen Forest|Grassland/Herbaceous|Shrub/Scrub | 45.76244 | -122.33032 | https://www.neonscience.org/field-sites/abby |
| BARR | Utqiaġvik NEON | Emergent Herbaceous Wetlands | 71.28241 | -156.61936 | https://www.neonscience.org/field-sites/barr |
| BART | Bartlett Experimental Forest NEON | Deciduous Forest|Evergreen Forest|Mixed Forest | 44.06389 | -71.28737 | https://www.neonscience.org/field-sites/bart |
| BLAN | Blandy Experimental Farm NEON | Deciduous Forest|Pasture/Hay | 39.03370 | -78.04179 | https://www.neonscience.org/field-sites/blan |
| BONA | Caribou-Poker Creeks Research Watershed NEON | Deciduous Forest|Evergreen Forest|Mixed Forest|Woody Wetlands | 65.15401 | -147.50258 | https://www.neonscience.org/field-sites/bona |
| CLBJ | Lyndon B. Johnson National Grassland NEON | Deciduous Forest|Grassland/Herbaceous | 33.40123 | -97.57000 | https://www.neonscience.org/field-sites/clbj |
| CPER | Central Plains Experimental Range NEON | Grassland/Herbaceous | 40.81554 | -104.74559 | https://www.neonscience.org/field-sites/cper |
| DCFS | Dakota Coteau Field Site NEON | Grassland/Herbaceous | 47.16165 | -99.10656 | https://www.neonscience.org/field-sites/dcfs |
| DEJU | Delta Junction NEON | Evergreen Forest|Shrub/Scrub|Woody Wetlands | 63.88112 | -145.75136 | https://www.neonscience.org/field-sites/deju |
| DELA | Dead Lake NEON | Evergreen Forest|Woody Wetlands | 32.54173 | -87.80388 | https://www.neonscience.org/field-sites/dela |
| DSNY | Disney Wilderness Preserve NEON | Pasture/Hay|Woody Wetlands | 28.12505 | -81.43619 | https://www.neonscience.org/field-sites/dsny |
| GRSM | Great Smoky Mountains National Park NEON | Deciduous Forest|Evergreen Forest | 35.68896 | -83.50195 | https://www.neonscience.org/field-sites/grsm |
| GUAN | Guanica Forest NEON | Evergreen Forest | 17.96955 | -66.86870 | https://www.neonscience.org/field-sites/guan |
| HARV | Harvard Forest & Quabbin Watershed NEON | Deciduous Forest|Evergreen Forest|Mixed Forest|Woody Wetlands | 42.53691 | -72.17265 | https://www.neonscience.org/field-sites/harv |
| HEAL | Healy NEON | Dwarf Scrub|Evergreen Forest|Shrub/Scrub | 63.87580 | -149.21335 | https://www.neonscience.org/field-sites/heal |
| JERC | The Jones Center At Ichauway NEON | Cultivated Crops|Deciduous Forest|Evergreen Forest|Mixed Forest | 31.19484 | -84.46862 | https://www.neonscience.org/field-sites/jerc |
| JORN | Jornada Experimental Range NEON | Shrub/Scrub | 32.59069 | -106.84254 | https://www.neonscience.org/field-sites/jorn |
| KONA | Konza Prairie Agroecosystem NEON | Cultivated Crops | 39.11045 | -96.61293 | https://www.neonscience.org/field-sites/kona |
| KONZ | Konza Prairie Biological Station NEON | Deciduous Forest|Grassland/Herbaceous | 39.10077 | -96.56307 | https://www.neonscience.org/field-sites/konz |
| LAJA | Lajas Experimental Station NEON | Cultivated Crops|Grassland/Herbaceous|Pasture/Hay | 18.02126 | -67.07689 | https://www.neonscience.org/field-sites/laja |
| LENO | Lenoir Landing NEON | Deciduous Forest|Woody Wetlands | 31.85386 | -88.16118 | https://www.neonscience.org/field-sites/leno |
| MLBS | Mountain Lake Biological Station NEON | Deciduous Forest | 37.37831 | -80.52485 | https://www.neonscience.org/field-sites/mlbs |
| MOAB | Moab NEON | Evergreen Forest|Shrub/Scrub | 38.24828 | -109.38827 | https://www.neonscience.org/field-sites/moab |
| NIWO | Niwot Ridge NEON | Evergreen Forest|Grassland/Herbaceous | 40.05425 | -105.58237 | https://www.neonscience.org/field-sites/niwo |
| NOGP | Northern Great Plains Research Laboratory NEON | Grassland/Herbaceous | 46.76972 | -100.91535 | https://www.neonscience.org/field-sites/nogp |
| OAES | Marvin Klemme Range Research Station NEON | Grassland/Herbaceous|Shrub/Scrub | 35.41060 | -99.05878 | https://www.neonscience.org/field-sites/oaes |
| ONAQ | Onaqui NEON | Evergreen Forest|Shrub/Scrub | 40.17760 | -112.45245 | https://www.neonscience.org/field-sites/onaq |
| ORNL | Oak Ridge NEON | Deciduous Forest|Evergreen Forest|Pasture/Hay | 35.96413 | -84.28259 | https://www.neonscience.org/field-sites/ornl |
| OSBS | Ordway-Swisher Biological Station NEON | Emergent Herbaceous Wetlands|Evergreen Forest|Woody Wetlands | 29.68928 | -81.99343 | https://www.neonscience.org/field-sites/osbs |
| PUUM | Pu’u Maka’ala Natural Area Reserve NEON | Evergreen Forest | 19.55309 | -155.31731 | https://www.neonscience.org/field-sites/puum |
| RMNP | Rocky Mountains NEON | Evergreen Forest | 40.27590 | -105.54596 | https://www.neonscience.org/field-sites/rmnp |
| SCBI | Smithsonian Conservation Biology Institute NEON | Deciduous Forest|Evergreen Forest|Pasture/Hay | 38.89292 | -78.13949 | https://www.neonscience.org/field-sites/scbi |
| SERC | Smithsonian Environmental Research Center NEON | Cultivated Crops|Deciduous Forest | 38.89013 | -76.56001 | https://www.neonscience.org/field-sites/serc |
| SJER | San Joaquin Experimental Range NEON | Evergreen Forest|Grassland/Herbaceous|Shrub/Scrub | 37.10878 | -119.73228 | https://www.neonscience.org/field-sites/sjer |
| SOAP | Soaproot Saddle NEON | Evergreen Forest|Shrub/Scrub | 37.03337 | -119.26219 | https://www.neonscience.org/field-sites/soap |
| SRER | Santa Rita Experimental Range NEON | Shrub/Scrub | 31.91068 | -110.83549 | https://www.neonscience.org/field-sites/srer |
| STEI | Steigerwaldt-Chequamegon NEON | Deciduous Forest|Mixed Forest|Woody Wetlands | 45.50894 | -89.58637 | https://www.neonscience.org/field-sites/stei |
| STER | North Sterling NEON | Cultivated Crops | 40.46189 | -103.02929 | https://www.neonscience.org/field-sites/ster |
| TALL | Talladega National Forest NEON | Deciduous Forest|Evergreen Forest|Mixed Forest | 32.95047 | -87.39326 | https://www.neonscience.org/field-sites/tall |
| TEAK | Lower Teakettle NEON | Evergreen Forest|Shrub/Scrub | 37.00583 | -119.00602 | https://www.neonscience.org/field-sites/teak |
| TOOL | Toolik Field Station NEON | Dwarf Scrub|Shrub/Scrub | 68.66109 | -149.37047 | https://www.neonscience.org/field-sites/tool |
| TREE | Treehaven NEON | Deciduous Forest|Evergreen Forest|Mixed Forest|Woody Wetlands | 45.49369 | -89.58571 | https://www.neonscience.org/field-sites/tree |
| UKFS | University of Kansas Field Station NEON | Deciduous Forest|Pasture/Hay | 39.04043 | -95.19215 | https://www.neonscience.org/field-sites/ukfs |
| UNDE | University of Notre Dame Environmental Research Center NEON | Deciduous Forest|Mixed Forest|Woody Wetlands | 46.23391 | -89.53725 | https://www.neonscience.org/field-sites/unde |
| WOOD | Chase Lake National Wildlife Refuge NEON | Emergent Herbaceous Wetlands|Grassland/Herbaceous | 47.12820 | -99.24133 | https://www.neonscience.org/field-sites/wood |
| WREF | Wind River Experimental Forest NEON | Evergreen Forest | 45.82049 | -121.95191 | https://www.neonscience.org/field-sites/wref |
| YELL | Yellowstone National Park NEON | Evergreen Forest|Grassland/Herbaceous|Shrub/Scrub | 44.95348 | -110.53914 | https://www.neonscience.org/field-sites/yell |