Large-scale comparison of biomass and reproductive phenology among native and non-native populations of the seagrass Zostera japonica

Large-scale analysis along latitude or temperature gradients can be an effective method for exploring the potential roles of light and temperature in controlling seagrass phenology. In this study, we investigated effects of latitude and temperature on seagrass biomass and reproductive seasonality. Zostera japonica is an intertidal seagrass with a wide latitudinal distribution expanding from tropical to temperate zones in its native range in Asia, with an additional non-native distribution in North America. We collated available data on phenological traits (timings of peak biomass or reproduction, durations of biomass growth and reproductive season, and maximum biomass or reproductive ratio) from publications and our own observations. Traits were compared among geographic groups: Asia-tropical, Asia-temperate, and North America-temperate. We further examined relationships between traits and latitude and temperature for 3 population groups: Asian, North American, and all populations. Our analysis revealed significant variation among geographic groups in maximum biomass, peak reproductive timing, and maximum reproductive ratio, but not in other traits. Maximum biomass and peak reproductive timing for Asian and all populations were significantly correlated with latitude and temperature. Maximum biomass was highest at mid-latitudes or intermediate temperatures and decreased toward distribution range limits, and peak reproductive timing occurred later in the year at higher latitudes or cooler sites. North American populations showed shorter growth durations and greater reproductive ratios at higher latitude. Different responses observed for North American populations may reflect effects of introduction. Our study demonstrates potential variation among geographic regions and between native and non-native populations.

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Interannual Variability of North American Winter Temperature Extremes and Its Associated Circulation Anomalies in Observations and CMIP5 Simulations

Journal of Climate ◽

10.1175/jcli-d-19-0404.1 ◽

2020 ◽

Vol 33 (3) ◽

pp. 847-865 ◽

Cited By ~ 1

Author(s):

B. Yu ◽

H. Lin ◽

V. V. Kharin ◽

X. L. Wang

Keyword(s):

North America ◽

Surface Temperature ◽

Atmospheric Circulation ◽

North American ◽

North Pacific ◽

Large Scale ◽

Temperature Extremes ◽

Temperature Extreme ◽

Central Canada ◽

Leading Mode

AbstractThe interannual variability of wintertime North American surface temperature extremes and its generation and maintenance are analyzed in this study. The leading mode of the temperature extreme anomalies, revealed by empirical orthogonal function (EOF) analyses of December–February mean temperature extreme indices over North America, is characterized by an anomalous center of action over western-central Canada. In association with the leading mode of temperature extreme variability, the large-scale atmospheric circulation features an anomalous Pacific–North American (PNA)-like pattern from the preceding fall to winter, which has important implications for seasonal prediction of North American temperature extremes. A positive PNA pattern leads to more warm and fewer cold extremes over western-central Canada. The anomalous circulation over the PNA sector drives thermal advection that contributes to temperature anomalies over North America, as well as a Pacific decadal oscillation (PDO)-like sea surface temperature (SST) anomaly pattern in the midlatitude North Pacific. The PNA-like circulation anomaly tends to be supported by SST warming in the tropical central-eastern Pacific and a positive synoptic-scale eddy vorticity forcing feedback on the large-scale circulation over the PNA sector. The leading extreme mode–associated atmospheric circulation patterns obtained from the observational and reanalysis data, together with the anomalous SST and synoptic eddy activities, are reasonably well simulated in most CMIP5 models and in the multimodel mean. For most models considered, the simulated patterns of atmospheric circulation, SST, and synoptic eddy activities have lower spatial variances than the corresponding observational and reanalysis patterns over the PNA sector, especially over the North Pacific.

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Scientific drilling of Lake Chalco, Basin of Mexico (MexiDrill)

Scientific Drilling ◽

10.5194/sd-26-1-2019 ◽

2019 ◽

Vol 26 ◽

pp. 1-15 ◽

Cited By ~ 1

Author(s):

Erik T. Brown ◽

Margarita Caballero ◽

Enrique Cabral Cano ◽

Peter J. Fawcett ◽

Socorro Lozano-García ◽

...

Keyword(s):

North America ◽

North American ◽

Large Scale ◽

Volcanic Eruptions ◽

Winter Precipitation ◽

City Region ◽

Northern Margin ◽

Scientific Drilling ◽

Societal Relevance ◽

Basin Of Mexico

Abstract. The primary scientific objective of MexiDrill, the Basin of Mexico Drilling Program, is development of a continuous, high-resolution ∼400 kyr lacustrine record of tropical North American environmental change. The field location, in the densely populated, water-stressed Mexico City region gives this record particular societal relevance. A detailed paleoclimate reconstruction from central Mexico will enhance our understanding of long-term natural climate variability in the North American tropics and its relationship with changes at higher latitudes. The site lies at the northern margin of the Intertropical Convergence Zone (ITCZ), where modern precipitation amounts are influenced by sea surface temperatures in the Pacific and Atlantic basins. During the Last Glacial Maximum (LGM), more winter precipitation at the site is hypothesized to have been a consequence of a southward displacement of the mid-latitude westerlies. It thus represents a key spatial node for understanding large-scale hydrological variability of tropical and subtropical North America and is at an altitude (2240 m a.s.l.), typical of much of western North America. In addition, its sediments contain a rich record of pre-Holocene volcanic history; knowledge of the magnitude and frequency relationships of the area's explosive volcanic eruptions will improve capacity for risk assessment of future activity. Explosive eruption deposits will also be used to provide the backbone of a robust chronology necessary for full exploitation of the paleoclimate record. Here we report initial results from, and outreach activities of, the 2016 coring campaign.

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The Impact of Large-Scale Orography on Northern Hemisphere Winter Synoptic Temperature Variability

Journal of Climate ◽

10.1175/jcli-d-19-0129.1 ◽

2019 ◽

Vol 32 (18) ◽

pp. 5799-5814 ◽

Cited By ~ 4

Author(s):

Nicholas J. Lutsko ◽

Jane Wilson Baldwin ◽

Timothy W. Cronin

Keyword(s):

North America ◽

Northern Hemisphere ◽

North American ◽

Large Scale ◽

Temperature Variability ◽

Temperature Gradients ◽

Northwest Pacific ◽

Near Surface ◽

The North ◽

The Impact

Abstract The impact of large-scale orography on wintertime near-surface (850 hPa) temperature variability on daily and synoptic time scales (from days to weeks) in the Northern Hemisphere is investigated. Using a combination of theory, idealized modeling work, and simulations with a comprehensive climate model, it is shown that large-scale orography reduces upstream temperature gradients, in turn reducing upstream temperature variability, and enhances downstream temperature gradients, enhancing downstream temperature variability. Hence, the presence of the Rockies on the western edge of the North American continent increases temperature gradients over North America and, consequently, increases North American temperature variability. By contrast, the presence of the Tibetan Plateau and the Himalayas on the eastern edge of the Eurasian continent damps temperature variability over most of Eurasia. However, Tibet and the Himalayas also interfere with the downstream development of storms in the North Pacific storm track, and thus damp temperature variability over North America, by approximately as much as the Rockies enhance it. Large-scale orography is also shown to impact the skewness of downstream temperature distributions, as temperatures to the north of the enhanced temperature gradients are more positively skewed while temperatures to the south are more negatively skewed. This effect is most clearly seen in the northwest Pacific, off the east coast of Japan.

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North American Winter Dipole: Observed and Simulated Changes in Circulations

Atmosphere ◽

10.3390/atmos10120793 ◽

2019 ◽

Vol 10 (12) ◽

pp. 793 ◽

Cited By ~ 2

Author(s):

Yu-Tang Chien ◽

S.-Y. Simon Wang ◽

Yoshimitsu Chikamoto ◽

Steve L. Voelker ◽

Jonathan D. D. Meyer ◽

...

Keyword(s):

North America ◽

North American ◽

Large Scale ◽

Climate Model ◽

Model Simulations ◽

The North ◽

Weather Events ◽

The Pacific ◽

Climate Model Simulations ◽

Northwestern North America

In recent years, a pair of large-scale circulation patterns consisting of an anomalous ridge over northwestern North America and trough over northeastern North America was found to accompany extreme winter weather events such as the 2013–2015 California drought and eastern U.S. cold outbreaks. Referred to as the North American winter dipole (NAWD), previous studies have found both a marked natural variability and a warming-induced amplification trend in the NAWD. In this study, we utilized multiple global reanalysis datasets and existing climate model simulations to examine the variability of the winter planetary wave patterns over North America and to better understand how it is likely to change in the future. We compared between pre- and post-1980 periods to identify changes to the circulation variations based on empirical analysis. It was found that the leading pattern of the winter planetary waves has changed, from the Pacific–North America (PNA) mode to a spatially shifted mode such as NAWD. Further, the potential influence of global warming on NAWD was examined using multiple climate model simulations.

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Impacts of climate change on forest product markets: Implications for North American producers

The Forestry Chronicle ◽

10.5558/tfc81669-5 ◽

2005 ◽

Vol 81 (5) ◽

pp. 669-674 ◽

Cited By ~ 21

Author(s):

Brent Sohngen ◽

Roger Sedjo

Keyword(s):

Climate Change ◽

North America ◽

North American ◽

Forest Fires ◽

Large Scale ◽

Impact Analysis ◽

Climate Change Impacts ◽

Key Words Climate Change ◽

Increase Productivity ◽

Timber Markets

This paper examines potential climate change impacts in North American timber markets. The results indicate that climate change could increase productivity in forests in North America, increase productivity in forests globally, and reduce timber prices. North American consumers generally will gain from the potential changes, but producers could lose welfare. If dieback resulting from additional forest fires, increased pest infestation, or storm damage increases appreciably and has market effects, consumers will gain less and producers will lose more than if climate change simply increases the annual flow of timber products by raising forest productivity. Annual producers' surplus losses from climate change in the North American timber sector are estimated to range from $1.4 – $2.1 billion per year on average over the next century, with the higher number resulting from potential large-scale dieback. Within North America, existing studies suggest that producers in northern regions are less susceptible to climate change impacts than producers in southern regions because many climate and ecological models suggest that climates become dryer in the U.S. South. Key words: climate change, impact analysis, timber markets, forest ecosystems

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Vegetable Grafting: History, Use, and Current Technology Status in North America

HortScience ◽

10.21273/hortsci.43.6.1664 ◽

2008 ◽

Vol 43 (6) ◽

pp. 1664-1669 ◽

Cited By ~ 88

Author(s):

Chieri Kubota ◽

Michael A. McClure ◽

Nancy Kokalis-Burelle ◽

Michael G. Bausher ◽

Erin N. Rosskopf

Keyword(s):

North America ◽

North American ◽

Crop Production ◽

Large Scale ◽

Arable Land ◽

Vegetable Production ◽

Late 20Th Century ◽

Technical Data ◽

Greenhouse Growers ◽

Vegetable Seedlings

Grafting of vegetable seedlings is a unique horticultural technology practiced for many years in East Asia to overcome issues associated with intensive cultivation using limited arable land. This technology was introduced to Europe and other countries in the late 20th century along with improved grafting methods suitable for commercial production of grafted vegetable seedlings. Later, grafting was introduced to North America from Europe and it is now attracting growing interest, both from greenhouse growers and organic producers. Grafting onto specific rootstocks generally provides resistance to soilborne diseases and nematodes and increases yield. Grafting is an effective technology for use in combination with more sustainable crop production practices, including reduced rates and overall use of soil fumigants in many other countries. Currently, over 40 million grafted tomato seedlings are estimated to be used annually in North American greenhouses, and several commercial trials have been conducted for promoting use of grafted melon seedlings in open fields. Nevertheless, there are issues identified that currently limit adoption of grafted seedlings in North America. One issue unique to North America is the large number of seedlings needed in a single shipment for large-scale, open-field production systems. Semi- or fully-automated grafting robots were invented by several agricultural machine industries in the 1990s, yet the available models are limited. The lack of flexibility of the existing robots also limits their wider use. Strategies to resolve these issues are discussed, including the use of a highly controlled environment to promote the standardized seedlings suitable for automation and better storage techniques. To use this technology widely in North American fresh vegetable production, more information and locally collected scientific and technical data are needed.

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Aerosol Responses to Precipitation Along North American Air Trajectories Arriving at Bermuda

10.5194/acp-2021-471 ◽

2021 ◽

Author(s):

Hossein Dadashazar ◽

Majid Alipanah ◽

Miguel Ricardo A. Hilario ◽

Ewan Crosbie ◽

Simon Kirschler ◽

...

Keyword(s):

North America ◽

North American ◽

Large Scale ◽

East Coast ◽

Aerosol Particles ◽

Air Mass ◽

Wet Scavenging ◽

The Impact ◽

The U.S ◽

Volume Size

Abstract. North American pollution outflow is ubiquitous over the western North Atlantic Ocean, especially in winter, making this location an ideal natural laboratory for investigating the impact of precipitation on aerosol particles along air mass trajectories. We take advantage of observational data collected at Bermuda to seasonally assess the sensitivity of aerosol mass concentrations and volume size distributions to accumulated precipitation along trajectories (APT). The mass concentration of particulate matter with aerodynamic diameter less than 2.5 µm normalized by the enhancement of carbon monoxide above background (PM2.5/∆CO) at Bermuda was used to estimate the degree of aerosol loss during transport to Bermuda. Results for December–February (DJF) show most trajectories come from North America and have the highest APTs, resulting in significant reduction (by 53 %) in PM2.5/∆CO under high APT conditions (> 13.5 mm) relative to low APT conditions (< 0.9 mm). Moreover, PM2.5/∆CO was most sensitive to increases in APT up to 5 mm (−0.044 µg m−3 ppbv−1 mm−1) and less sensitive to increases in APT over 5 mm. While anthropogenic PM2.5 constituents (e.g., black carbon, sulfate, organic carbon) decrease with high APT, sea salt in contrast was comparable between high and low APT conditions owing to enhanced local wind and salt emissions in high APT conditions. The greater sensitivity of the fine mode volume concentrations (versus coarse mode) to wet scavenging is evident from AERONET volume size distribution data. A combination of GEOS-Chem model simulations of 210Pb submicron aerosol tracer and its gaseous precursor 222Rn reveal that (i) surface aerosol particles at Bermuda are most impacted by wet scavenging in winter/spring (due to large-scale precipitation) with a maximum in March, whereas convective scavenging plays a substantial role in summer; and (ii) North American 222Rn tracer emissions contribute most to surface 210Pb concentrations at Bermuda in winter (~75–80 %), indicating that air masses arriving at Bermuda experience large-scale precipitation scavenging while traveling from North America. A case study flight from the ACTIVATE field campaign on 22 February 2020 reveals a significant reduction in aerosol number and volume concentrations during air mass transport off the U.S. East Coast associated with increased cloud fraction and precipitation. These results highlight the sensitivity of remote marine boundary layer aerosol characteristics to precipitation along trajectories, especially when the air mass source is continental outflow from polluted regions like the U.S. East Coast.

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