scholarly journals MJO teleconnections to crop growing seasons

2020 ◽  
Vol 54 (3-4) ◽  
pp. 2203-2219 ◽  
Author(s):  
Weston Anderson ◽  
Ángel G. Muñoz ◽  
Lisa Goddard ◽  
Walter Baethgen ◽  
Xandre Chourio
Keyword(s):  
Soil Moisture ◽  
Daily Precipitation ◽  
Maximum Temperature ◽  
Growing Seasons ◽  
Air Temperatures ◽  
Summer Hemisphere ◽  
Leaf Level ◽  
Maximum Temperatures ◽  
The Tropics

AbstractWhile many Madden–Julian Oscillation (MJO) teleconnections are well documented, the significance of these teleconnections to agriculture is not well understood. Here we analyze how the MJO affects the climate during crop flowering seasons, when crops are particularly vulnerable to abiotic stress. Because the MJO is located in the tropics of the summer hemisphere and maize is a tropical, summer-grown crop, the MJO teleconnections to maize flowering seasons are stronger and more coherent than those to wheat, which tends to be grown in midlatitudes and flowers during the spring. The MJO significantly affects not only daily average precipitation and soil moisture, but also the probability of extreme precipitation, soil moisture and maximum temperatures during crop flowering seasons. The average influence on the probability of extreme daily precipitation, soil moisture, and maximum temperature events is roughly equal. On average the MJO modifies the probability of a 5th or 95th, 10th or 90th, and 25th or 75th percentile event by $$\sim $$∼ 2.5%, $$\sim $$∼ 4% and $$\sim $$∼ 7%, respectively. This means that an exceptionally dry (10th percentile) soil moisture value, for example, would become $$\sim $$∼ 40% more common (happening 14% of the time) during certain MJO phases. That the MJO can simultaneously dry soils and raise maximum air temperatures may be particularly damaging to crops because without available soil water during times of heat stress, plants are unable to transpire to cool leaf-level temperatures as a means of avoiding long-term damage. As a result, even though teleconnections from the MJO last only a few days to a week, they likely affect crop growth.

scholarly journals Climatic modeling of the distribution of Oxytropis triphylla (Fabaceae) by maximum entropy method

2018 ◽  
Vol 11 ◽  
pp. 00002
Author(s):  
Konstantin Baikov ◽  
Denis Krivenko
Keyword(s):  
Maximum Entropy ◽  
Maximum Entropy Method ◽  
Spatial Models ◽  
Entropy Method ◽  
Air Temperatures ◽  
Variable Contribution ◽  
Key Variables ◽  
The Republic ◽  
Maximum Temperatures

Predictive spatial models of the distribution of Oxytropis triphylla (Pall.) Pers. (Fabaceae), an endemic species of Baikal Siberia, were generated in MAXENT computer program using maximum entropy method. Long-term data of air temperatures for every month of the year were downloaded from the world database of open access WorldClim. Modeling was performed separately for minimum, average and maximum temperatures. Each variable contribution to the modeling was the basis to select the key variables having higher influence on the obtained models. The selected 10 key variables are the following: minimum temperatures of December and January; average temperatures of October, December, January and February; maximum temperatures of November, December, January and February. Then a model of the second level was calculated using only the ten key variables. There are three northern localities in the zone of adverse temperature effects: cape Malyi Cheremshanyi, Chencha and Sakhuli villages (all of them are in the Republic of Buryatia). It has been experimentally confirmed that the values of the key variables along the coasts of the Maloe More of Lake Baikal (Irkutskaya Oblast) are the most favorable for habitation of O. triphylla in this part of its range.

scholarly journals Photosynthetic acclimation and sensitivity to short- and long-term environmental changes

2021 ◽  
Author(s):  
Leonie Schönbeck ◽  
Charlotte Grossiord ◽  
Arthur Gessler ◽  
Jonas Gisler ◽  
Katrin Meusburger ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Gas Exchange ◽  
Environmental Changes ◽  
Leaf Gas Exchange ◽  
Soil Drought ◽  
List Type ◽  
Evaporative Demand ◽  
Leaf Level ◽  
Short And Long Term

SummaryThe future climate will be characterized by an increase in frequency and duration of drought and warming that exacerbates atmospheric evaporative demand. How trees acclimate to long-term soil moisture changes and whether these long-term changes alter trees’ sensitivity to short-term (day to months) variations of vapor pressure deficit (VPD) and soil moisture is largely unknown.Leaf gas exchange measurements were performed within a long-term (17 years) irrigation experiment in a Scots pine-dominated forest in one of Switzerland’s driest areas on trees in naturally dry (control), irrigated, and‘irrigation-stop’ (after 11 years of irrigation) conditions.Seventeen years of irrigation increased photosynthesis (A) and stomatal conductance (gs) and reduced the gs sensitivity to increasing VPD but not to soil drying. Following irrigation-stop, gas exchange did not decrease immediately, but after three years, had decreased significantly in irrigation-stop trees. Vcmax and Jmax recovered after five years.These results suggest that long-term release of soil drought reduces the sensitivity to atmospheric evaporative demand and that atmospheric constraints may play an increasingly important role in combination with soil drought. In addition, they suggest that structural adjustments lead to an attenuation of initially strong leaf-level acclimation to strong multiple-year drought.

scholarly journals CPLFD-GDPT5: high-resolution gridded daily precipitation and temperature dataset for two largest Polish river basins

2015 ◽  
Vol 8 (2) ◽  
pp. 1021-1060 ◽  
Author(s):  
T. Berezowski ◽  
M. Szcześniak ◽  
I. Kardel ◽  
R. Michałowski ◽  
T. Okruszko ◽  
...  
Keyword(s):  
Assessment Tool ◽  
Daily Precipitation ◽  
Hydrological Modelling ◽  
Indicator Kriging ◽  
Maximum Temperature ◽  
System Modelling ◽  
Climatic Data ◽  
Air Temperatures ◽  
Spatial Coverage ◽  
Precipitation And Temperature

Abstract. The CHASE-PL Forcing Data-Gridded Daily Precipitation and Temperature Dataset-5 km (CPLFD-GDPT5) consists of 1951–2013 daily minimum and maximum air temperatures and precipitation totals interpolated onto a 5 km grid based on daily meteorological observations from Institute of Meteorology and Water Management (IMGW-PIB; Polish stations), Deutscher Wetterdienst (DWD, German and Czech stations), ECAD and NOAA-NCDC (Slovak, Ukrainian and Belarus stations). The main purpose for constructing this product was the need for long-term aerial precipitation and temperature data for earth-system modelling, especially hydrological modelling. The spatial coverage is the union of Vistula and Odra basin and Polish territory. The number of available meteorological stations for precipitation and temperature varies in time from about 100 for temperature and 300 for precipitation in 1950 up to about 180 for temperature and 700 for precipitation in 1990. The precipitation dataset was corrected for snowfall and rainfall under-catch with the Richter method. The interpolation methods were: kriging with elevation as external drift for temperatures and indicator kriging combined with universal kriging for precipitation. The kriging cross-validation revealed low root mean squared errors expressed as a fraction of standard deviation (SD): 0.54 and 0.47 for minimum and maximum temperature, respectively and 0.79 for precipitation. The correlation scores were 0.84 for minimum temperatures, 0.88 for maximum temperatures and 0.65 for precipitation. The CPLFD-GDPT5 product is consistent with 1971–2000 climatic data published by IMGW-PIB. We also confirm good skill of the product for hydrological modelling by performing an application using the Soil and Water Assessment Tool (SWAT) in the Vistula and Odra basins. Link to the dataset: http://data.3tu.nl/repository/uuid:e939aec0-bdd1-440f-bd1e-c49ff10d0a07

scholarly journals Long-term changes in precipitation phase in Czechia

Geografie ◽  
2019 ◽  
Vol 124 (1) ◽  
pp. 41-55
Author(s):  
Martin Hynčica ◽  
Radan Huth
Keyword(s):  
Air Temperature ◽  
Daily Precipitation ◽  
Sharp Decrease ◽  
Total Precipitation ◽  
Solid Precipitation ◽  
The Past ◽  
Air Temperatures ◽  
Long Term Changes ◽  
Precipitation Phase

Long-term changes in precipitation phase are investigated at ten stations in Czechia. Trends are calculated from 1983 to 2018 for the period between November and April. Daily SYNOP reports and daily precipitation totals are used at every station, where number and occurrence of specific codes in SYNOP report determine daily precipitation totals as solid, combined (which represents, to a large extent, category of mixed precipitation), or liquid. Thereafter, it is possible to calculate trends of all precipitation phases as well as the proportion of solid to total precipitation (S/P; in %). The average S/P trend over all Czech stations is significantly negative (−0.60%·year-1) and accompanied by a sharp decrease in solid precipitation (−1.66 mm·year-1) and an increase in combined precipitation (1.50 mm·year-1). Thus, our results show a ship of precipitation phase from solid to combined. Because of the dependence of S/P on air temperature, we suppose that the current S/P decline is a manifestation of rising air temperatures in the past decades.

The increasing of maximum lake water temperature in lowland lakes of central Europe: case study of the Polish Lakeland

2019 ◽  
Vol 55 ◽  
pp. 6 ◽  
Author(s):  
Mariusz Ptak ◽  
Mariusz Sojka ◽  
Michał Kozłowski
Keyword(s):  
Cluster Analysis ◽  
Water Temperature ◽  
Warming Trend ◽  
Maximum Temperature ◽  
Average Value ◽  
Temperature Trends ◽  
Air Temperatures ◽  
Maximum Water Temperature ◽  
Maximum Water ◽  
Maximum Temperatures

The paper presents the results of time-related changes in maximum temperatures in lakes. The analysis was carried out on the basis of 9 lakes located in the northern part of Poland. The analysis was based on daily water and air temperatures in the period 1971–2015. Mann–Kendall's and Sen's tests were applied to determine the directions and rates of change of maximum air and water temperatures. The average increase of maximum water temperature in analysed lakes was found to be 0.39 °C dec–1, while the warming trend of the maximum air temperature was 0.48 °C dec–1. Cluster analysis (CA) was used to group lakes characterised by similar changes of maximum water temperature. The first group included five lakes in which the values of the maximum temperature trends were 0.41 °C dec–1. In the second cluster the average value of maximum water temperature increase was smaller than in the first cluster (0.36 °C dec–1). Comparing the results of cluster analysis with morphometric data show that in the first cluster lakes are having a greater average depth, maximum depth and water transparency in comparison to the lakes of the second cluster.

scholarly journals Changing Climatic Averages and Variance: Implications for Mesophication at the Eastern Edge of North America’s Eastern Deciduous Forest

Forests ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 605 ◽  
Author(s):  
Evan Kutta ◽  
Jason Hubbart
Keyword(s):  
Deciduous Forest ◽  
Fire Suppression ◽  
Maximum Temperature ◽  
Eastern Deciduous Forest ◽  
Temperature Variance ◽  
Forest Ecosystem Services ◽  
Maximum Temperatures ◽  
Eastern Edge ◽  
Climate Variance

Observed conversion of xerophytic warm genera species to mesophytic cool genera species in North America’s Eastern Deciduous Forest (EDF) suggests species composition is in disequilibrium with recent climatic warming. However, increasing annual average temperatures is an oversimplification of long-term climatic change and the importance of climate variance is often neglected. Seven-year moving averages and standard deviations of annually averaged maximum temperatures, minimum temperatures, daily precipitation, and vapor pressure deficits (VPD) in West Virginia, USA were quantified over a 111-year period of record (1906–2016). Maximum temperatures decreased significantly (−5.3%; p < 0.001), minimum temperatures increased significantly (7.7%; p < 0.001), and precipitation increased (2.2%; p = 0.107). Additionally, maximum temperature variance decreased (−17.4%; p = 0.109), minimum temperature variance decreased significantly (−22.6%; p = 0.042), and precipitation variance increased significantly (26.6%; p = 0.004). Results indicate a reduced diurnal temperature range and significant reductions in estimated VPD (10.3%; p < 0.001) that imply increased relative humidity, cloud cover, and soil moisture that may support increasingly abundant mesophytic cool genera species. Feedback mechanisms associated with extensive changes in land use, fire suppression, and browser population may have exacerbated climatic changes. Long-term assessments of changing climatic averages and variance are needed to ensure sustainability of forest ecosystem services, health, and productivity in a swiftly changing climate across the broader EDF region and similar temperate forest ecosystems globally.

A 2000-year temperature reconstruction in the Animaqin Mountains of the Tibet Plateau, China

The Holocene ◽  
2016 ◽  
Vol 26 (12) ◽  
pp. 1904-1913 ◽  
Author(s):  
Feng Chen ◽  
Yong Zhang ◽  
Xuemei Shao ◽  
MingQi Li ◽  
Zhi-Yong Yin
Keyword(s):  
Ring Width ◽  
Temperature Reconstruction ◽  
Warming Trend ◽  
Tibet Plateau ◽  
Maximum Temperature ◽  
Eastern Tibetan Plateau ◽  
Recent Period ◽  
Variation Patterns ◽  
Maximum Temperatures

A 2665-year ring-width chronology was developed based on Qilian juniper from the upper treeline of the Animaqin Mountains on the eastern Tibetan Plateau. Correlation analysis results showed that the chronology was significantly negatively correlated with April–June maximum temperature at nearby meteorological stations, indicating that maximum temperature is the factor that limits tree growth in this area. Accordingly, we reconstructed the average April–June maximum temperature variations since 261 BC. Our regression model explained 37.9% of the total variance for the whole calibration period of 1960–2012. Our reconstruction revealed that the maximum temperature started to increase from approximately 1750 without a rapid warming trend, and the warmest period was from AD 890 to 947, as opposed to the recent period, whereas the period from AD 351–483 was the coldest. Significant periods in the wavelet power spectrum were approximately 2–8 years, 20–30 years, 30–60 years, and 60–130 years, as well as some long-term periods (more than 200 years). Comparisons with other temperature series from neighboring regions and the Northern Hemisphere as a whole support the validity of our reconstruction and suggest that it provides a representation of the temperature change for the Animaqin area, although asymmetric variation patterns in minimum and maximum temperatures were found.

Taking China's Temperature: Daily Range, Warming Trends, and Regional Variations, 1955–2000

2004 ◽  
Vol 17 (22) ◽  
pp. 4453-4462 ◽  
Author(s):  
Binhui Liu ◽  
Ming Xu ◽  
Mark Henderson ◽  
Ye Qi ◽  
Yiqing Li
Keyword(s):  
Atmospheric Aerosols ◽  
Solar Irradiance ◽  
Cloud Cover ◽  
Maximum Temperature ◽  
Daily Maximum ◽  
Climate Data ◽  
Temperature Range ◽  
Temperature Trends ◽  
Air Temperatures ◽  
Maximum Temperatures

Abstract In analyzing daily climate data from 305 weather stations in China for the period from 1955 to 2000, the authors found that surface air temperatures are increasing with an accelerating trend after 1990. They also found that the daily maximum (Tmax) and minimum (Tmin) air temperature increased at a rate of 1.27° and 3.23°C (100 yr)−1 between 1955 and 2000. Both temperature trends were faster than those reported for the Northern Hemisphere, where Tmax and Tmin increased by 0.87° and 1.84°C (100 yr)−1 between 1950 and 1993. The daily temperature range (DTR) decreased rapidly by −2.5°C (100 yr)−1 from 1960 to 1990; during that time, minimum temperature increased while maximum temperature decreased slightly. Since 1990, the decline in DTR has halted because Tmax and Tmin increased at a similar pace during the 1990s. Increased minimum and maximum temperatures were most pronounced in northeast China and were lowest in the southwest. Cloud cover and precipitation correlated poorly with the decreasing temperature range. It is argued that a decline in solar irradiance better explains the decreasing range of daily temperatures through its influence on maximum temperature. With declining solar irradiance even on clear days, and with decreases in cloud cover, it is posited that atmospheric aerosols may be contributing to the changing solar irradiance and trends of daily temperatures observed in China.

scholarly journals Strengthening tropical influence on heat generating circulation over Australia through spring

2021 ◽  
Author(s):  
Roseanna C. McKay ◽  
Julie M. Arblaster ◽  
Pandora Hope
Keyword(s):  
Linear Regression Analysis ◽  
Seasonal Prediction ◽  
Southern Annular Mode ◽  
Maximum Temperature ◽  
Low Level ◽  
Tropical Variability ◽  
High Maximum ◽  
Maximum Temperatures ◽  
The Tropics ◽  
Spring Maximum

Abstract. Extreme maximum temperatures during Australian spring can have deleterious impacts on a range of sectors from health to wine grapes to planning for wildfires, but are relatively understudied compared to spring rainfall. Spring maximum temperatures in Australia have been rising over recent decades, and, as such, it is important to understand how Australian spring maximum temperatures develop. Australia’s climate is influenced by variability in the tropics and extratropics, but some of this influence impacts Australia differently from winter to summer, and, consequently, may have different impacts on Australia as spring evolves. Using linear regression analysis, this paper explores the atmospheric dynamics and remote drivers of high maximum temperatures over the individual months of spring. We find that the drivers of early spring maximum temperatures in Australia are more closely related to low-level wind changes, which in turn are more related to the Southern Annular Mode than variability in the tropics. By late spring, Australia’s maximum temperatures are proportionally more related to warming through subsidence than low-level wind changes, and more closely related to tropical variability. This increased relationship with the tropical variability is linked with the breakdown of the subtropical jet through spring and an associated change in tropically-forced Rossby wave teleconnections. However, much of the maximum temperature variability cannot be explained by either tropical or extratropical variability. An improved understanding of how the extratropics and tropics projects onto the mechanisms that drive high maximum temperatures through spring may lead to improved sub-seasonal prediction of high temperatures in the future.

scholarly journals Global Warming, Advancing Bloom and Evidence for Pollinator Plasticity from Long-Term Bee Emergence Monitoring

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 457
Author(s):  
James Cane
Keyword(s):  
Global Warming ◽  
Field Experiments ◽  
Adult Emergence ◽  
Social Bees ◽  
Growing Seasons ◽  
Direct Observations ◽  
Air Temperatures ◽  
Peponapis Pruinosa ◽  
Substrate Temperatures

Global warming is extending growing seasons in temperate zones, yielding earlier wildflower blooms. Short-term field experiments with non-social bees showed that adult emergence is responsive to nest substrate temperatures. Nonetheless, some posit that global warming will decouple bee flight and host bloom periods, leading to pollination shortfalls and bee declines. Resolving these competing scenarios requires evidence for bees’ natural plasticity in their annual emergence schedules. This study reports direct observations spanning 12–24 years for annual variation in the earliest nesting or foraging activities by 1–4 populations of four native ground-nesting bees: Andrena fulva (Andrenidae), Halictus rubicundus (Halictidae), Habropoda laboriosa and Eucera (Peponapis) pruinosa (Apidae). Calendar dates of earliest annual bee activity ranged across 25 to 45 days, approximating reported multi-decadal ranges for published wildflower bloom dates. Within a given year, the bee H. rubicundus emerged in close synchrony at multiple local aggregations, explicable if meteorological factors cue emergence. Emergence dates were relatable to thermal cues, such as degree day accumulation, soil temperature at nesting depth, and the first pulse of warm spring air temperatures. Similar seasonal flexibilities in bee emergence and wildflower bloom schedules bodes well for bees and bloom to generally retain synchrony despite a warming climate. Future monitoring studies can benefit from several simple methodological improvements.

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