Future precipitation variability during the early rainfall season in the El Yunque National Forest

Ramseyer, Craig A.; Miller, Paul W.; Mote, Thomas L.

doi:10.1016/j.scitotenv.2019.01.167

Cited by 21 publications

(29 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A monotonic upward (downward) trend indicates that the variable consistently increases (decreases) over time, but it may not be a linear trend. Results are summarized seasonally via three four-month periods: December-March (DJFM), April-July (AMJJ), and August-November (ASON), which correspond closely to observed precipitation seasonality in the eastern Caribbean (Miller et al 2019;Miller and Ramseyer 2020), a region often influenced by the TWI (Jury and Winter, 2010). Although different seasonal definitions may be suggested, the size of the analysis domain captures a large variability in hydroclimatic regimes.…”

Section: Methodssupporting

confidence: 52%

“…More specific to the TNA and Caribbean, the Saharan air layer (SAL) acts as a seasonal TWI modifier as it can influence and modulate the TWI, particularly during the spring and early summer (Prospero and Carlson, 1972, 1981; Dunion and Velden, 2004; Evan et al ., 2006; Wong et al ., 2009; Chen et al ., 2010; Mote et al ., 2017; Miller et al ., 2021). The direct and indirect aerosol effects associated with the SAL, arising from its high mineral dust concentration, can lead to drought and precipitation reductions across the TNA, even as far as the Caribbean (Mote et al ., 2017; Ramseyer et al ., 2019). Recent Caribbean hydroclimate studies have shown that precipitation and drought strongly respond to moisture changes in the mid‐troposphere (~850–700 hPa) and wind shear through the low‐ and mid‐troposphere (Ramseyer and Mote, 2016, 2018).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Historical trends in the trade wind inversion in the tropical North Atlantic Ocean and Caribbean

Ramseyer

Miller

2021

Intl Journal of Climatology

Self Cite

View full text Add to dashboard Cite

The trade wind inversion (TWI) serves as an important stabilizing mechanism in the tropical North Atlantic (TNA) region, including the Caribbean basin. Previous studies have diagnosed the TWI using in situ observations and radiosondes, typically over tropical islands. However, studies relying on these point measurements are unable to discern the climatology and evolution of the TWI over the rest of the TNA. This study addresses this gap in the literature through the use of high‐resolution ERA5 reanalysis model level data. Due to the advances in the ERA line of reanalysis products, ERA5 now provides vertical level resolution as fine as ~4 mb in the lower troposphere, enabling the identification of shallow inversions, such as the TWI, consistently on a climatological time scale in remote regions of the world. While still coarser than observed soundings, this reanalysis‐based approach provides a first attempt in understanding TNA TWI variability and its strength and frequency trends from 1979 to 2019. The TWI climatology constructed here finds consilience with previous modelling and observational studies in terms of the spatial variability of the TWI base and strength across this domain. Stronger and more frequent TWIs are noted across the central TNA across all seasons. Results from a Mann–Kendall analysis reveals increasing trends in TWI frequency and strength that vary spatially across the domain based on season. The most widespread and strongest increasing TWI frequency and strength signal is over the central TNA from December to July. Due to the regionalization of trends noted, potential regional forcing mechanisms responsible for these changes are discussed.

show abstract

Section: Methodssupporting

confidence: 52%

Section: Introductionmentioning

confidence: 99%

Historical trends in the trade wind inversion in the tropical North Atlantic Ocean and Caribbean

Ramseyer

Miller

2021

Intl Journal of Climatology

Self Cite

View full text Add to dashboard Cite

show abstract

“…For some of the wetter regions of Puerto Rico, especially in the Luquillo Mountains where mean annual rainfall is >3500 mm, decreases in precipitation are expected to occur earlier than in other regions of the island. Precipitation during the wettest months (i.e., April-July) is expected to decrease from the long-term average of 1042 to 771 mm at mid-century, which is a decline of 26% (Ramseyer et al 2019). These declines in rainfall will probably cause stream ecosystems to desiccate, which will severely impact their habitat and ecosystem function.…”

Section: Discussionmentioning

confidence: 99%

When the rainforest dries: Drought effects on a montane tropical stream ecosystem in Puerto Rico

et al. 2020

View full text Add to dashboard Cite

Global climate change predictions include decreased precipitation and more frequent droughts in many world regions. In the aseasonal wet tropics, predicting potential impacts is particularly challenging because droughts are rare and therefore poorly understood. In 2015, the Caribbean islands experienced the most severe drought within the past 5 decades. Here, we use this extreme event as an opportunity to assess how tropical stream ecosystems draining the Luquillo Experimental Forest (LEF) in Puerto Rico respond to severe drought. During 2015, precipitation was 45% lower than the long-term (1975-2016) average for the LEF, resulting in a 54% reduction in stream discharge. After 5 mo of declining discharge (April-August 2015), one branch of our focal study stream system became a series of isolated pools and a few riffle-type runs, while the other branch had greatly reduced flow between its pools. Concentrated biotic activity within pools resulted in elevated and highly-variable nutrient (5.1-12.1 lg PO 4 32-P/L; 12.9-57.2 lg NH 4 1-N/L; 80.0-160.0 lg NO 3 2-N/L) and specific conductance (95-114 lS/cm) levels among pools. However, the algal standing crop was 14Â lower than the previous 15-y average despite increases in nutrient levels, reflecting intense grazing pressure of insect and shrimp consumers, potentially due to decreased pool volume. Higher nutrient levels in stream pools did increase biofilm productivity, and at the peak of the drought daily fluctuations in dissolved oxygen ranged from ∼1.0 to 6.5 mg/L. Significantly-higher riparian inputs of organic matter (7.6Â the longterm average) occurred during a 15-d period in May. The drought caused a general increase in macroinvertebrate density, with collector-gatherers and some grazer taxa increasing significantly at the peak of the drought, but taxonomic richness did not change. Omnivorous shrimp abundance increased slightly in response to decreased stream flow in one branch of our focal stream. Our study highlights the marked effects of severe droughts on neotropical streams in the wet tropics, with large effects on basal resources and consequent changes in trophic dynamics. Ultimately, our findings underline the need for a whole-ecosystem perspective to understand how streams respond to increased frequencies of extreme events associated with climate change.

show abstract

“…10.1029/2020JD032909 4 of 16 tool in several previous studies (e.g., Miller, Kumar, et al, 2019;Ramseyer et al, 2019) The MODIS AOD and ERA5 GDI across the tropical North Atlantic (TNA) and WRF-Chem output are compared for each of the eight and nine simulations, respectively. (The no-chemistry simulation will not generate AOD.)…”

Section: Methodsmentioning

confidence: 99%

Modeled Atmospheric Optical and Thermodynamic Responses to an Exceptional Trans‐Atlantic Dust Outbreak

2021

View full text Add to dashboard Cite

Long‐range aerosol transport is an important physical mechanism for ecological, biological, and hydrological elements of the earth system. Regarding the latter, regional climate models have no way of assimilating future aerosol concentrations, so dust aerosol emissions must be parameterized using local landscape and meteorological conditions. The purpose of this study is to evaluate the accuracy of different dust emission settings within the Weather Research and Forecasting model coupled with chemistry (WRF‐Chem) to facilitate future dynamical downscaling work. This study performs nine WRF‐Chem hindcasts, each utilizing a different dust emission configuration, from 1 March to 31 May 2015, coinciding with a Saharan air layer (SAL) dust outbreak during the 2015 Caribbean drought. WRF‐Chem aerosol optical depth (AOD) and Gálvez‐Davison Index (GDI), a convective forecasting parameter, are validated against analogous MODIS, AERONET, and ERA5 products. In aggregate, the GOCART dust emission scheme with Air Force Weather Agency modifications (GOCART‐AFWA) achieved the best balance between AOD and GDI accuracy when employing the default tuning constant (1.00). As the schemes emitted dust more aggressively, WRF‐Chem produced warming at 500 hPa, reducing GDI over the central and eastern Atlantic near the modeled dust trajectory. Though AOD was generally too low over the southwest Atlantic, the eastern Caribbean occupies a transition zone between negative and positive AOD biases where this field was hindcast with relative accuracy. Meanwhile, areas with positive AOD biases were associated with negative GDI biases (and vice versa) indicating the covariability between SAL dust loadings and thermodynamic conditions in the tropical north Atlantic.

show abstract

Future precipitation variability during the early rainfall season in the El Yunque National Forest

Cited by 21 publications

References 43 publications

Historical trends in the trade wind inversion in the tropical North Atlantic Ocean and Caribbean

Historical trends in the trade wind inversion in the tropical North Atlantic Ocean and Caribbean

When the rainforest dries: Drought effects on a montane tropical stream ecosystem in Puerto Rico

Modeled Atmospheric Optical and Thermodynamic Responses to an Exceptional Trans‐Atlantic Dust Outbreak

Contact Info

Product

Resources

About