Review of “The influence of sea- and land-breeze circulations on the diurnal variability of precipitation over a topical island”

Abstract Aerosol radiative forcing in the Persian Gulf region is derived from data collected during the United Arab Emirates (UAE) Unified Aerosol Experiment (UAE2). This campaign took place in August and September of 2004. The land–sea-breeze circulation modulates the diurnal variability of the aerosol properties and aerosol radiative forcing at the surface. Larger aerosol radiative forcing is observed during the land breeze in comparison to the sea breeze. The aerosol optical properties change as the onshore wind brings slightly cleaner air. The mean diurnal value of the surface aerosol forcing during the UAE2 campaign is about −20 W m−2, which corresponds to large aerosol optical thickness (0.45 at 500 nm). The aerosol forcing efficiency [i.e., broadband shortwave forcing per unit optical depth at 550 nm, W m−2 (τ500)−1] is −53 W m−2 (τ500)−1 and the average single scattering albedo is 0.93 at 550 nm.

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The influence of sea- and land-breeze circulations on the diurnal variability of precipitation over a tropical island

10.5194/acp-2017-332 ◽

2017 ◽

Author(s):

Lei Zhu ◽

Zhiyong Meng ◽

Fuqing Zhang ◽

Paul M. Markowski

Keyword(s):

Diurnal Variation ◽

Numerical Simulations ◽

Diurnal Cycle ◽

Lower Troposphere ◽

Sea Breeze ◽

Hainan Island ◽

Dominant Factor ◽

Land Breeze ◽

Moist Convection ◽

Diurnal Variability

Abstract. This study examines the diurnal variation of precipitation over Hainan Island in the South China Sea using gauge observations from 1950 to 2010 and CMORPH satellite estimates from 2006 to 2015, as well as numerical simulations. Precipitation is most significant from April to October, and exhibits a strong diurnal cycle resulting from land/sea breeze circulations. More than 60 % of the total annual precipitation over the island is attributable to the diurnal cycle, with a significant monthly variability as well. The CMORPH and gauge datasets agree well, except that the CMORPH data underestimates precipitation and has a 1-h delay of peaks. The diurnal cycle of the rainfall and the related land/sea breeze circulations during May and June were well captured by convection-allowing numerical simulations with WRF, which were initiated from 10-year average ERA-interim reanalysis, despite slightly overall overestimation and 1-h delay of the rainfall peak. The diurnal precipitation is due to a diurnal cycle of moist convection, which initiates around noontime owing to low-level convergence associated with the sea breeze circulation. The precipitation intensifies rapidly thereafter and peaks in the afternoon with the collisions of sea breeze fronts from different sides of the island. Cold pools of the convective storms contribute to the inland propagation of the sea breeze. The precipitation dissipates quickly in the evening owing to the cooling and stabilization of the lower troposphere and decrease of boundary-layer moisture. Interestingly, the rather high island orography is not a dominant factor in the diurnal variation of the precipitation over the island.

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The influence of sea- and land-breeze circulations on the diurnal variability in precipitation over a tropical island

Atmospheric Chemistry and Physics ◽

10.5194/acp-17-13213-2017 ◽

2017 ◽

Vol 17 (21) ◽

pp. 13213-13232 ◽

Cited By ~ 13

Author(s):

Lei Zhu ◽

Zhiyong Meng ◽

Fuqing Zhang ◽

Paul M. Markowski

Keyword(s):

Diurnal Variation ◽

Numerical Simulations ◽

Diurnal Cycle ◽

Wrf Model ◽

Lower Troposphere ◽

Sea Breeze ◽

Dominant Factor ◽

Land Breeze ◽

Moist Convection ◽

Diurnal Variability

Abstract. This study examines the diurnal variation in precipitation over Hainan Island in the South China Sea using gauge observations from 1951 to 2012 and Climate Prediction Center MORPHing technique (CMORPH) satellite estimates from 2006 to 2015, as well as numerical simulations. The simulations are the first to use climatological mean initial and lateral boundary conditions to study the dynamic and thermodynamic processes (and the impacts of land–sea breeze circulations) that control the rainfall distribution and climatology. Precipitation is most significant from April to October and exhibits a strong diurnal cycle resulting from land–sea breeze circulations. More than 60 % of the total annual precipitation over the island is attributable to the diurnal cycle with a significant monthly variability. The CMORPH and gauge datasets agree well, except that the CMORPH data underestimate precipitation and have a 1 h peak delay. The diurnal cycle of the rainfall and the related land–sea breeze circulations during May and June were well captured by convection-permitting numerical simulations with the Weather Research and Forecasting (WRF) model, which were initiated from a 10-year average ERA-Interim reanalysis. The simulations have a slight overestimation of rainfall amounts and a 1 h delay in peak rainfall time. The diurnal cycle of precipitation is driven by the occurrence of moist convection around noontime owing to low-level convergence associated with the sea-breeze circulations. The precipitation intensifies rapidly thereafter and peaks in the afternoon with the collisions of sea-breeze fronts from different sides of the island. Cold pools of the convective storms contribute to the inland propagation of the sea breeze. Generally, precipitation dissipates quickly in the evening due to the cooling and stabilization of the lower troposphere and decrease of boundary layer moisture. Interestingly, the rather high island orography is not a dominant factor in the diurnal variation in precipitation over the island.

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Influences of Lake Malawi on the spatial and diurnal variability of local precipitation

Hydrology and Earth System Sciences ◽

10.5194/hess-23-2795-2019 ◽

2019 ◽

Vol 23 (7) ◽

pp. 2795-2812 ◽

Cited By ~ 1

Author(s):

Shunya Koseki ◽

Priscilla A. Mooney

Keyword(s):

Diurnal Cycle ◽

Water Resource Management ◽

Moisture Flux ◽

Atmospheric Model ◽

Lake Malawi ◽

Land Breeze ◽

Surrounding Area ◽

Breeze Circulation ◽

Flux Divergence ◽

Diurnal Variability

Abstract. We investigate how the intensity and spatial distribution of precipitation vary around Lake Malawi on a diurnal timescale, which can be valuable information for water resource management in tropical south-eastern African nations. Using a state-of-the-art satellite product and regional atmospheric model, the well-defined diurnal cycle is detected around Lake Malawi with harmonic and principle component analyses: the precipitation is intense during midnight to morning over Lake Malawi and the precipitation peaks in the daytime over the surrounding area. This diurnal cycle in the precipitation around the lake is associated with the lake–land breeze circulation. Comparisons between the benchmark simulation and an idealized simulation in which Lake Malawi is removed reveal that the diurnal variations in precipitation are substantially amplified by the presence of Lake Malawi. This is most evident over the lake and surrounding coastal regions. Lake Malawi also enhances the lake–land breeze circulation; the nocturnal lakeward land breeze generates surface convergence effectively and precipitation intensifies over the lake. Conversely, the daytime landward lake breeze generates the intense divergence over the lake and precipitation is strongly depressed over the lake. The lake–land breeze and the background vapour enriched by Lake Malawi drive primarily a diurnal variation in the surface moisture flux divergence/convergence over the lake and surrounding area which contributes to the diurnal cycle of precipitation in this region.

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Boundary Layer Marine Stratus: Diurnal Variability in Microphysics

10.21236/ada634933 ◽

2002 ◽

Author(s):

Steven K. Chai ◽

Melanie A. Wetzel ◽

Darko R. Koracin

Keyword(s):

Boundary Layer ◽

Diurnal Variability ◽

Marine Stratus

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Study of Temporal Variations of Equivalent Black Carbon in a Coastal City in Northwest Spain Using an Atmospheric Aerosol Data Management Software

Applied Sciences ◽

10.3390/app11020516 ◽

2021 ◽

Vol 11 (2) ◽

pp. 516

Author(s):

María Piñeiro-Iglesias ◽

Javier Andrade-Garda ◽

Sonia Suárez-Garaboa ◽

Soledad Muniategui-Lorenzo ◽

Purificación López-Mahía ◽

...

Keyword(s):

Data Management ◽

Black Carbon ◽

Light Absorption ◽

Atmospheric Aerosol ◽

Urban Areas ◽

Radiative Properties ◽

Anthropogenic Sources ◽

Biomass Combustion ◽

Management Support ◽

Diurnal Variability

Light-absorbing carbonaceous aerosols (including black carbon (BC)) pose serious health issues and play significant roles in atmospheric radiative properties. Two-year measurements (2015–2016) of aerosol light absorption, combined with measurements of sub-micrometric particles, were continuously conducted in A Coruña (northwest (NW) Spain) to determine their light absorption properties: absorption coefficients (σabs) and the absorption Ångström exponent (AAE). The mean and standard deviation of equivalent black carbon (eBC) during the period of study were 0.85 ± 0.83 µg m−3, which are lower than other values measured in urban areas of Spain and Europe. High eBC concentrations found in winter are associated with an increase in emissions from anthropogenic sources in combination with lower mixing layer heights and frequent stagnant conditions. The pronounced diurnal variability suggests a strong influence from local sources. AAE had an average value of 1.26 ± 0.22 which implies that both fossil fuel combustion and biomass burning influenced optical aerosol properties. This also highlights biomass combustion in suburban areas, where the use of wood for domestic heating is encouraged, as an important source of eBC. All data treatment was gathered using SCALA© as atmospheric aerosol data management support software program.

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Simulation of diurnal variability in vertical density structure using a coupled model

Scientific Reports ◽

10.1038/s41598-021-90426-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

B. Yadidya ◽

A. D. Rao ◽

Sachiko Mohanty

Keyword(s):

Mixed Layer ◽

3D Model ◽

Coupled Model ◽

Wave Model ◽

Andaman Sea ◽

Surface Mixed Layer ◽

Diurnal Variability ◽

Rama Buoy ◽

Vertical Displacements ◽

Primary Advantage

AbstractThe changes in the physical properties of the ocean on a diurnal scale primarily occur in the surface mixed layer and the pycnocline. Price–Weller–Pinkel model, which modifies the surface mixed layer, and the internal wave model based on Garrett–Munk spectra that calculates the vertical displacements due to internal waves are coupled to simulate the diurnal variability in temperature and salinity, and thereby density profiles. The coupled model is used to simulate the hourly variations in density at RAMA buoy (15° N, 90° E), in the central Bay of Bengal, and at BD12 (10.5° N, 94° E), in the Andaman Sea. The simulations are validated with the in-situ observations from December 2013 to November 2014. The primary advantage of this model is that it could simulate spatial variability as well. An integrated model is also tested and validated by using the output of the 3D model to initialize the coupled model during January, April, July, and October. The 3D model can be used to initialize the coupled model at any given location within the model domain to simulate the diurnal variability of density. The simulations showed promising results which could be further used in simulating the acoustic fields and propagation losses which are crucial for Navy operations.

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Influences of offshore background wind on the formation of sea-land breeze and the characteristics of pollutant diffusion

Environmental Science and Pollution Research ◽

10.1007/s11356-021-15339-7 ◽

2021 ◽

Author(s):

Jiajia Xu ◽

Hongwei Jia ◽

Huayuan Zhou ◽

Yanming Kang ◽

Ke Zhong

Keyword(s):

Land Breeze ◽

Background Wind ◽

Pollutant Diffusion

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Identifying Diurnal Variability of Brain Connectivity Patterns Using Graph Theory

Brain Sciences ◽

10.3390/brainsci11010111 ◽

2021 ◽

Vol 11 (1) ◽

pp. 111

Author(s):

Farzad V. Farahani ◽

Magdalena Fafrowicz ◽

Waldemar Karwowski ◽

Bartosz Bohaterewicz ◽

Anna Maria Sobczak ◽

...

Keyword(s):

Resting State ◽

Network Architecture ◽

Inferior Frontal Gyrus ◽

Brain Network ◽

Time Of Day ◽

Precentral Gyrus ◽

Network Organization ◽

Diurnal Variability ◽

Sleep Inertia ◽

Brain Functions

Significant differences exist in human brain functions affected by time of day and by people’s diurnal preferences (chronotypes) that are rarely considered in brain studies. In the current study, using network neuroscience and resting-state functional MRI (rs-fMRI) data, we examined the effect of both time of day and the individual’s chronotype on whole-brain network organization. In this regard, 62 participants (39 women; mean age: 23.97 ± 3.26 years; half morning- versus half evening-type) were scanned about 1 and 10 h after wake-up time for morning and evening sessions, respectively. We found evidence for a time-of-day effect on connectivity profiles but not for the effect of chronotype. Compared with the morning session, we found relatively higher small-worldness (an index that represents more efficient network organization) in the evening session, which suggests the dominance of sleep inertia over the circadian and homeostatic processes in the first hours after waking. Furthermore, local graph measures were changed, predominantly across the left hemisphere, in areas such as the precentral gyrus, putamen, inferior frontal gyrus (orbital part), inferior temporal gyrus, as well as the bilateral cerebellum. These findings show the variability of the functional neural network architecture during the day and improve our understanding of the role of time of day in resting-state functional networks.

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Variability of Urinary Creatinine in Healthy Individuals

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18063166 ◽

2021 ◽

Vol 18 (6) ◽

pp. 3166

Author(s):

Gerd Sallsten ◽

Lars Barregard

Keyword(s):

Flow Rate ◽

Excretion Rate ◽

Time Of Day ◽

Urinary Flow Rate ◽

Urinary Flow ◽

Diurnal Variability ◽

Creatinine Excretion ◽

Blood Samples ◽

Urinary Creatinine ◽

Creatinine Excretion Rate

Many urinary biomarkers are adjusted for dilution using creatinine or specific gravity. The aim was to evaluate the variability of creatinine excretion, in 24 h and spot samples, and to describe an openly available variability biobank. Urine and blood samples were collected from 60 healthy non-smoking adults, 29 men and 31 women. All urine was collected at six time points during two 24 h periods. Blood samples were also collected twice and stored frozen. Analyses of creatinine in urine was performed in fresh urine using an enzymatic method. For creatinine in urine, the intra-class correlation (ICC) was calculated for 24 h urine and spot samples. Diurnal variability was examined, as well as association with urinary flow rate. The creatinine excretion rate was lowest in overnight samples and relatively constant in the other five samples. The creatinine excretion rate in each individual was positively correlated with urinary flow rate. The creatinine concentration was highest in the overnight sample and at 09:30. For 24 h samples the ICC was 0.64, for overnight samples it was 0.5, and for all spot samples, it was much lower. The ICC for urinary creatinine depends on the time of day of sampling. Frozen samples from this variability biobank are open for researchers examining normal variability of their favorite biomarker(s).

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