scholarly journals Large-scale Cloud Distributions and their Seasonal Variations as Derived from GMS-IR Observations

1988 ◽  
Vol 66 (1) ◽  
pp. 87-101 ◽  
Author(s):  
Yasumasa Kodama ◽  
Tomio Asai
Keyword(s):  
Seasonal Variations ◽  
Large Scale

Global mapping of seasonal variations in tides from tide gauge and satellite altimeter data

2021 ◽  
Author(s):  
Inger Bij de Vaate ◽  
Henrique Guarneri ◽  
Cornelis Slobbe ◽  
Martin Verlaan
Keyword(s):  
Seasonal Variation ◽  
Sea Level ◽  
Seasonal Variations ◽  
Large Scale ◽  
Arctic Region ◽  
The Arctic ◽  
Altimeter Data ◽  
Tide Gauges ◽  
Tidal Constituents ◽  
The Arctic Region

<p>The existence of seasonal variations in major tides has been recognized since decades. Where Corkan (1934) was the first to describe the seasonal perturbation of the M2 tide, many others have studied seasonal variations in the main tidal constituents since. However, most of these studies are based on sea level observations from tide gauges and are often restricted to coastal and shelf regions. Hence, observed seasonal variations are typically dominated by local processes and the large-scale patterns cannot be clearly distinguished. Moreover, most tide models still perceive tides as annually constant and seasonal variation in tides is ignored in the correction process of satellite altimetry. This results in reduced accuracy of obtained sea level anomalies. </p><p>To gain more insight in the large-scale seasonal variations in tides, we supplemented the clustered and sparsely distributed sea level observations from tide gauges by the wealth of data from satellite altimeters. Although altimeter-derived water levels are being widely used to obtain tidal constants, only few of these implementations consider seasonal variation in tides. For that reason, we have set out to explore the opportunities provided by altimeter data for deriving seasonal modulation of the main tidal constituents. Different methods were implemented and compared for the principal tidal constituents and a range of geographical domains, using data from a selection of satellite altimeters. Specific attention was paid to the Arctic region where seasonal variation in tides was expected to be significant as a result of the seasonal sea ice cycle, yet data availability is particularly limited. Our study demonstrates the potential of satellite altimetry for the quantification of seasonal modulation of tides and suggests the seasonal modulation to be considerable. Already for M2 we observed changes in tidal amplitude of the order of decimeters for the Arctic region, and centimeters for lower latitude regions.</p><p> </p><div>Corkan, R. H. (1934). An annual perturbation in the range of tide. <em>Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character</em>, <em>144</em>(853), 537-559.</div>

scholarly journals Seasonal Sleep Variations and Their Association With Meteorological Factors: A Japanese Population Study Using Large-Scale Body Acceleration Data

2021 ◽  
Vol 3 ◽  
Author(s):  
Li Li ◽  
Toru Nakamura ◽  
Junichiro Hayano ◽  
Yoshiharu Yamamoto
Keyword(s):  
Sleep Quality ◽  
Seasonal Variations ◽  
Japanese Population ◽  
Large Scale ◽  
Meteorological Factors ◽  
Sleep Onset ◽  
Sleep Time ◽  
Population Based ◽  
Wake Time ◽  
Sleep Parameters

Seasonal changes in meteorological factors [e.g., ambient temperature (Ta), humidity, and sunlight] could significantly influence a person's sleep, possibly resulting in the seasonality of sleep properties (timing and quality). However, population-based studies on sleep seasonality or its association with meteorological factors remain limited, especially those using objective sleep data. Japan has clear seasonality with distinctive changes in meteorological variables among seasons, thereby suitable for examining sleep seasonality and the effects of meteorological factors. This study aimed to investigate seasonal variations in sleep properties in a Japanese population (68,604 individuals) and further identify meteorological factors contributing to sleep seasonality. Here we used large-scale objective sleep data estimated from body accelerations by machine learning. Sleep parameters such as total sleep time, sleep latency, sleep efficiency, and wake time after sleep onset demonstrated significant seasonal variations, showing that sleep quality in summer was worse than that in other seasons. While bedtime did not show clear seasonality, get-up time varied seasonally, with a nadir during summer, and positively correlated with the sunrise time. Estimated by the abovementioned sleep parameters, Ta had a practically meaningful association with sleep quality, indicating that sleep quality worsened with the increase of Ta. This association would partly explain seasonal variations in sleep quality among seasons. In conclusion, Ta had a principal role for seasonality in sleep quality, and the sunrise time chiefly determined the get-up time.

Modelling large-scale seasonal variations in water table depth over tropical peatlands in Riau, Sumatra

2019 ◽  
Author(s):  
Symon Mezbahuddin ◽  
Tadas Nikonovas ◽  
Allan Spessa ◽  
Robert Grant ◽  
Muhammad Imron
Keyword(s):  
Water Table ◽  
Seasonal Variations ◽  
Large Scale ◽  
Water Table Depth ◽  
Tropical Peatlands

scholarly journals Airmass Origin in the Arctic. Part I: Seasonality

2015 ◽  
Vol 28 (12) ◽  
pp. 4997-5014 ◽  
Author(s):  
Clara Orbe ◽  
Paul A. Newman ◽  
Darryn W. Waugh ◽  
Mark Holzer ◽  
Luke D. Oman ◽  
...  
Keyword(s):  
Boundary Layer ◽  
North America ◽  
Seasonal Variations ◽  
Large Scale ◽  
Climate Model ◽  
The Arctic ◽  
Boreal Winter ◽  
Earth Observing System ◽  
The Western Pacific ◽  
System Chemistry

Abstract The first climatology of airmass origin in the Arctic is presented in terms of rigorously defined airmass fractions that partition air according to where it last contacted the planetary boundary layer (PBL). Results from a present-day climate integration of the Goddard Earth Observing System Chemistry–Climate Model (GEOSCCM) reveal that the majority of air in the Arctic below 700 mb last contacted the PBL poleward of 60°N. By comparison, 62% (±0.8%) of the air above 700 mb originates over Northern Hemisphere midlatitudes (i.e., “midlatitude air”). Seasonal variations in the airmass fractions above 700 mb reveal that during boreal winter air from midlatitudes originates primarily over the oceans, with 26% (±1.9%) last contacting the PBL over the eastern Pacific, 21% (±0.87%) over the Atlantic, and 16% (±1.2%) over the western Pacific. During summer, by comparison, midlatitude air originates primarily over land, overwhelmingly so over Asia [41% (±1.0%)] and, to a lesser extent, over North America [24% (±1.5%)]. Seasonal variations in the airmass fractions are interpreted in terms of changes in the large-scale ventilation of the midlatitude boundary layer and the midlatitude tropospheric jet.

scholarly journals Finding the missing stratospheric Br<sub>y</sub>: a global modeling study of CHBr<sub>3</sub> and CH<sub>2</sub>Br<sub>2</sub>

2010 ◽  
Vol 10 (5) ◽  
pp. 2269-2286 ◽  
Author(s):  
Q. Liang ◽  
R. S. Stolarski ◽  
S. R. Kawa ◽  
J. E. Nielsen ◽  
A. R. Douglass ◽  
...  
Keyword(s):  
Seasonal Variations ◽  
Large Scale ◽  
Climate Model ◽  
Sensitivity Study ◽  
Airborne Measurements ◽  
Tropical Tropopause ◽  
Emission Estimate ◽  
Wet Scavenging ◽  
High Concentrations ◽  
Modeling Study

Abstract. Recent in situ and satellite measurements suggest a contribution of ~5 pptv to stratospheric inorganic bromine from short-lived bromocarbons. We conduct a modeling study of the two most important short-lived bromocarbons, bromoform (CHBr3) and dibromomethane (CH2Br2), with the Goddard Earth Observing System Chemistry Climate Model (GEOS CCM) to account for this missing stratospheric bromine. We derive a "top-down" emission estimate of CHBr3 and CH2Br2 using airborne measurements in the Pacific and North American troposphere and lower stratosphere obtained during previous NASA aircraft campaigns. Our emission estimate suggests that to reproduce the observed concentrations in the free troposphere, a global oceanic emission of 425 Gg Br yr−1 for CHBr3 and 57 Gg Br yr−1 for CH2Br2 is needed, with 60% of emissions from open ocean and 40% from coastal regions. Although our simple emission scheme assumes no seasonal variations, the model reproduces the observed seasonal variations of the short-lived bromocarbons with high concentrations in winter and low concentrations in summer. This indicates that the seasonality of short-lived bromocarbons is largely due to seasonality in their chemical loss and transport. The inclusion of CHBr3 and CH2Br2 contributes ~5 pptv bromine throughout the stratosphere. Both the source gases and inorganic bromine produced from source gas degradation (BryVSLS) in the troposphere are transported into the stratosphere, and are equally important. Inorganic bromine accounts for half (2.5 pptv) of the bromine from the inclusion of CHBr3 and CH2Br2 near the tropical tropopause and its contribution rapidly increases to ~100% as altitude increases. More than 85% of the wet scavenging of BryVSLS occurs in large-scale precipitation below 500 hPa. Our sensitivity study with wet scavenging in convective updrafts switched off suggests that BryVSLS in the stratosphere is not sensitive to convection. Convective scavenging only accounts for ~0.2 pptv (4%) difference in inorganic bromine delivered to the stratosphere.

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