USA National Phenology Network gridded products documentation

Crimmins, Theresa M.; Marsh, Rob; Switzer, Jeff; Crimmins, Michael A.; Gerst, Katharine L.; Rosemartin, Alyssa

doi:10.3133/ofr20171003

Cited by 10 publications

(6 citation statements)

References 13 publications

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“…The USA-NPN generates forecasts of leaf-out and flowering in lilacs up to six days in the future as a part of the Spring Leaf and Bloom Index models (Schwartz 1997;Schwartz et al 2006;Crimmins et al 2017b). These models use daily temperature and weather events as inputs to predict when individual lilacs will first undergo leaf-out and bloom at a location (Schwartz et al 2006;Schwartz et al 2013;Ault et al 2015).…”

Section: Methods Lilac Leaf-out and Bloom Forecastsmentioning

confidence: 99%

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Do Carefully Timed Email Messages Increase Accuracy and Precision in Citizen Scientists’ Reports of Events?

Crimmins

Posthumus

2022

Citizen Science: Theory and Practice

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Engaging and retaining participants present major challenges for citizen science programs, especially those that seek to engage participants across a large region. Periodic messages are a commonly used tactic for reminding citizen science program participants to take a desired action such as collecting observations. In this study, we evaluate the impact of such messages on the accuracy and precision of observations contributed to Nature's Notebook, a citizen science phenology observing program. To encourage participants in Nature's Notebook to log the timing of leaf-out and flowering with maximum accuracy and precision, we email observers three days prior to when the events are expected to occur based on forecast models. Unplanned interruptions to the scripts driving these email prompts allowed us to evaluate whether the messages had the intended impacts. The messages significantly improved the precision of observers' reports of leaf-out by five to eight days and the accuracy by one to two days, though these improvements were present only for participants that opened the messages. Accuracy and precision of reports of bloom were not impacted in the same positive ways. These findings demonstrate the importance of timely messages to prompt action and underscore the impact of the first messages sent in the season-both of which have utility for other citizen science programs. Because these findings emerged opportunistically, we cannot establish that the messages caused the changes in participant behavior. A more rigorous evaluation to determine the impact of messaging on volunteer observer behavior is merited.

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Section: Methods Lilac Leaf-out and Bloom Forecastsmentioning

confidence: 99%

“…Forecasts of lilac leaf-out and bloom are updated nightly based on daily minimum and maximum temperature data (Crimmins et al 2017b). Locations of registered lilac plants under observation in Nature's Notebook are intersected with these forecast maps through a nightly process.…”

Section: Cuing Participants To Observementioning

confidence: 99%

Do Carefully Timed Email Messages Increase Accuracy and Precision in Citizen Scientists’ Reports of Events?

Crimmins

Posthumus

2022

Citizen Science: Theory and Practice

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“…Most datasets we evaluated use NDVI or EVI calculated from the surface reflectance of the Moderate Resolution Imaging Spectroradiometer (MODIS) or Advanced Very High Resolution Radiometer (AVHRR) sensors (Table 1). We also evaluated one dataset, the National Phenology Network first leaf spring index, hereinafter referred to as NPN, that models spatially explicit temperature measurements parametrized via an extensive network of in situ phenological observations [41]. This is the only dataset evaluated that does not incorporate optical satellite imagery, but we included it because it is readily available and provides annual SOS estimates across the contiguous United States (CONUS).…”

Section: Methodsmentioning

confidence: 99%

Comparative Quality and Trend of Remotely Sensed Phenology and Productivity Metrics across the Western United States

et al. 2020

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Vegetation phenology and productivity play a crucial role in surface energy balance, plant and animal distribution, and animal movement and habitat use and can be measured with remote sensing metrics including start of season (SOS), peak instantaneous rate of green-up date (PIRGd), peak of season (POS), end of season (EOS), and integrated vegetation indices. However, for most metrics, we do not yet understand the agreement of remotely sensed data products with near-surface observations. We also need summaries of changes over time, spatial distribution, variability, and consistency in remote sensing dataset metrics for vegetation timing and quality. We compare metrics from 10 leading remote sensing datasets against a network of PhenoCam near-surface cameras throughout the western United States from 2002 to 2014. Most phenology metrics representing a date (SOS, PIRGd, POS, and EOS), rather than a duration (length of spring, length of growing season), better agreed with near-surface metrics but results varied by dataset, metric, and land cover, with absolute value of mean bias ranging from 0.38 (PIRGd) to 37.92 days (EOS). Datasets had higher agreement with PhenoCam metrics in shrublands, grasslands, and deciduous forests than in evergreen forests. Phenology metrics had higher agreement than productivity metrics, aside from a few datasets in deciduous forests. Using two datasets covering the period 1982–2016 that best agreed with PhenoCam metrics, we analyzed changes over time to growing seasons. Both datasets exhibited substantial spatial heterogeneity in the direction of phenology trends. Variability of metrics increased over time in some areas, particularly in the Southwest. Approximately 60% of pixels had consistent trend direction between datasets for SOS, POS, and EOS, with the direction varying by location. In all ecoregions except Mediterranean California, EOS has become later. This study comprehensively compares remote sensing datasets across multiple growing season metrics and discusses considerations for applied users to inform their data choices.

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“…There is a specific number of GDDs that must be accumulated to trigger a change in phenological status such as budburst in plants. CGDD can assess how soon that transition is likely to be reached [46]. We employed the Parameter-elevation Relationships on Independent Slopes Model (PRISM) climate dataset [47] to obtain the daily T max and T min needed for GDD calculation at every LFM site.…”

Section: Meteorological Variable Preparationmentioning

confidence: 99%

Estimating Live Fuel Moisture Using SMAP L-Band Radiometer Soil Moisture for Southern California, USA

et al. 2019

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Live fuel moisture (LFM) is a field-measured indicator of vegetation water content and a crucial observation of vegetation flammability. This study presents a new multi-variant regression model to estimate LFM in the Mediterranean ecosystem of Southern California, USA, using the Soil Moisture Active Passive (SMAP) L-band radiometer soil moisture (SMAP SM) from April 2015 to December 2018 over 12 chamise (Adenostoma fasciculatum) LFM sites. The two-month lag between SMAP SM and LFM was utilized either as steps to synchronize the SMAP SM to the LFM series or as the leading time window to calculate the accumulative SMAP SM. Cumulative growing degree days (CGDDs) were also employed to address the impact from heat. Models were constructed separately for the green-up and brown-down periods. An inverse exponential weight function was applied in the calculation of accumulative SMAP SM to address the different contribution to the LFM between the earlier and present SMAP SM. The model using the weighted accumulative SMAP SM and CGDDs yielded the best results and outperformed the reference model using the Moderate Resolution Imaging Spectroradiometer (MODIS) Visible Atmospherically Resistance Index. Our study provides a new way to empirically estimate the LFM in chaparral areas and extends the application of SMAP SM in the study of wildfire risk.

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USA National Phenology Network gridded products documentation

Cited by 10 publications

References 13 publications

Do Carefully Timed Email Messages Increase Accuracy and Precision in Citizen Scientists’ Reports of Events?

Do Carefully Timed Email Messages Increase Accuracy and Precision in Citizen Scientists’ Reports of Events?

Comparative Quality and Trend of Remotely Sensed Phenology and Productivity Metrics across the Western United States

Estimating Live Fuel Moisture Using SMAP L-Band Radiometer Soil Moisture for Southern California, USA

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