Surface Insolation Research Articles

Towards modeling growth rates of cyanobacteria in the Baltic Sea

Potential influences of various environmental factors (light conditions, mixed layer depth, water temperature) on growth rates of different cyanobacteria in the Baltic Sea (BS) are discussed. Growth rates were modeled as a function of quanta absorbed by phytoplankton. This in turn depends on phytoplankton exposition to light, which we simulated to represent realistic conditions encountered in the Baltic Sea in summer. We considered eight realistic scenarios (two cases of water clarity and four depths of the mixed layer). According to our calculations, exposition of phytoplankton to photosynthetically available radiation (PAR) in the BS can change about five times in case of the same solar surface insolation and water turbidity, solely due to changes in the mixed layer depth from 2 to 20 m. When we additionally accounted for differences in water turbidity, phytoplankton PAR exposition changed by one order of magnitude and this resulted in one order of magnitude differences in absorbed quanta for the same species of phytoplankton. Knowledge of single-species absorption characteristics allowed us to show that under the same water column conditions, the number of absorbed quanta varies significantly between different species of cyanobacteria, because of differences in their absorptive properties. The effectiveness of light absorption translated to different growth rates estimated for each phytoplankton species. Our research shows that further progress in phytoplankton modeling requires incorporating in the models improved information about optical properties, growth rates, and temperature and nutrient dependencies for different phytoplankton types.

Validation of GOES-Based Surface Insolation Retrievals and Its Utility for Model Evaluation

AbstractIncident solar radiation at Earth’s surface, also called surface insolation, plays an important role in the Earth system as it affects surface energy balance, weather, climate, water supply, biochemical emissions, photochemical reactions, etc. The University of Alabama in Huntsville (UAH) and the NASA Short-term Prediction Research and Transition Center (SPoRT) have been generating and archiving several products, including insolation, from the Geostationary Operational Environmental Satellite (GOES) Imager for over a decade. The NASA/UAH insolation product has been used in studies to improve air quality simulations, biogenic emission estimates, correcting surface energy balance, and for cloud assimilation, but has not been thoroughly evaluated. In this study, the NASA/UAH insolation product is compared to surface pyranometer measurements from the Surface Radiation Budget Network (SURFRAD) and the U.S. Climate Reference Network (USCRN) for a 12-month period from March 2013 to February 2014. The insolation product has normalized bias values within 6% of the mean observation, a root-mean-square error between 6% and 16%, and correlation coefficients greater than 0.96 for hourly insolation estimates. It also shows better performance without the presence of clouds. However, erroneous estimates may be produced for persistent snow-covered surfaces. Further, this study attempts to demonstrate the use of such a satellite-based insolation product for model evaluation. The NASA/UAH insolation product is compared to the downward shortwave radiation from the Rapid Refresh, version 1 (RAPv1), and successfully captures the overestimation tendency in surface energy input as mentioned in previous studies. Finally, future plans for improving the retrieval algorithm and developing a GOES-16 insolation product are discussed.

Earth System Model Response to Large Midlatitude and High‐latitude Volcanic Eruptions

AbstractWe used the Meteorological Research Institute Earth System Model to simulate the climate response to massive sulfur dioxide (SO2) emission from the volcanic eruptions of Paektusan (China/North Korea) and Eldgjá (Iceland) into the stratosphere in the tenth century Common Era (CE). Assuming 3 times the SO2 emission of the 1883 Krakatau eruption, as recorded by Greenland ice core sulfate concentrations, simulations of Paektusan and Eldgjá had roughly similar global mean impacts within 2 years of erupting: decreases in surface insolation (−10 W/m2, −5%), surface air temperature (−1 °C), land net primary production (NPP; −3 GtC/year, −5%), and soil respiration (−5 GtC/year, −10%). While both simulations had severe impacts on the extratropical Northern Hemisphere, the simulated response to Paektusan is twice as strong as Eldgjá in the tropics (cooling [1 °C], precipitation decrease [10%], and NPP increase [7%]). Simulation‐Eldgjá had almost no impact on the extratropical Southern Hemisphere because of its initial latitude. These regional differences combine so that Simulation‐Paektusan has slightly larger global mean impacts, including an atmospheric CO2 decrease of ~2 ppm. Tropical NPP primarily increases due to the fact that photosynthesis maximizes at temperatures below the tropical mean temperature and secondarily to the cooling‐induced decrease in respiration, which indicates relatively rich tropical harvests despite large volcanic eruptions. In contrast, the severe cooling (−2.5 °C) and decreased NPP (−20%) in the northern extratropics could mean poor harvests and famines, which can lead to social turmoil such as a rebellion in northeast Japan around the same time as the eruptions.

Astronomical Cycles in the Climatic and Geophysical Characteristics of Crimea

Climatic characteristics of the Crimean peninsula were analyzed on the basis of climatic parameters measured every day onboard NASA satellites for the period of 1983−2005. An accelerated increase in the insolation of Earth’s surface at the Kara-Dag site (as compared to that at other sites in Crimea) and an abnormal decrease in the surface temperature at the Fonar site have been revealed. The results of frequency−time wavelet analysis of local data on the insolation and temperature of the terrestrial surface enabled us to isolate periodic oscillations, the periods of which coincide with astronomical cycles, and determine an era of anomalous deviations from general trends of 1990−1995. From the analysis of corrections for vertical deformations of Earth’s surface at the Katsiveli site, a seasonal component was detected and parameters of this oscillation were calculated. Coherent variations with periods of approximately 10−12 and 60−70 years, which were found here, are inherent in the processes of different physical nature. They can be attributed to the global cycles in the Solar System, the manifestation of which in climatic and geophysical local processes is a result of the general trend towards synchronization. In this process, coherent variations of multiple or commensurate frequencies, may appear.

Interactions between Convection and a Moist Vortex Associated with an Extreme Rainfall Event over Southern West Africa

Abstract An intense mesoscale convective system (MCS) in the Guinea Coast region caused one of the highest ever recorded daily rainfall amounts at the Nigerian station Abakaliki on 12 June 2016 (223.5 mm). This paper provides a detailed analysis of the meso- and synoptic-scale factors leading to this event, including some so far undocumented dynamical aspects for southern West Africa. The MCS formed over the Darfur Mountains due to diurnal heating, then moved southwestward along a mid- to lower-tropospheric trough, and developed into a classical West African squall line in a highly sheared environment with pronounced midlevel dryness. Strong moisture flux convergence over Nigeria prior to the MCS passage led to extreme values in precipitable water and was caused by the formation of a local, short-lived heat low. According to the pressure tendency equation, the latter resulted from tropospheric warming due to MCS-forced subsidence as well as surface insolation in the resulting almost cloud-free atmosphere. In this extremely moist environment, the MCS strongly intensified and initiated the formation of a lower-tropospheric vortex, which resulted in a deceleration of the MCS and high rainfall accumulation at Abakaliki. Following the vorticity equation, the vortex formation was realized through strong low-level vortex stretching and upper-level vertical vorticity advection related to the MCS, which became “dynamically large” compared to the Rossby radius of deformation. Eventually, moisture supply and lifting associated with the vortex are suggested to promote the longevity of the MCS during the subsequent westward movement along the Guinea Coast.

The Influences of Urban Building Complexes on the Ambient Flows over the Washington–Reston Region

AbstractThis paper examines the collective impacts of urban building complexes on the planetary boundary layer (PBL) winds using both observations and a mesoscale model. Horizontal winds measured on the rooftops of federal buildings over the regions of Washington, D.C., and a small city nearby (i.e., Reston, Virginia) show the blocking effects of urban building complexes on the downstream winds during the daytime of 9 July 2007. A modeling study of the case using a coupled version of the Weather Research and Forecasting (WRF)–multilayer urban canopy model in which the observed building height and density information is implemented to advance the calculations of momentum and heat, reproduces the rooftop-observed wind patterns and the related urban heat island effects, especially the wake flows on the downstream sides of the above-mentioned two cities. Results show that under daytime conditions the building complexes can collectively form a mesoscale wake on the downwind side of each city, about 2–10 km away, horizontally from the edge of the building complexes. The wake flow may extend to much higher levels than the building tops, depending on the incoming flow strength, the static stability in the PBL, the height of the building complexes, and the time of the day because of the strength of surface insolation.

МОДЕЛЬ ИНСОЛЯЦИИ ПОВЕРХНОСТИ ЗЕМЛИ В ПУНКТЕ "КАРАДАГ" ПО ДАННЫМ SSE

Anomalous enhancement of solar insolation of the earth's surface in the presence of foci of excitation in its depths can cause a response at local sites. Such foci include, first of all, recent and past (retro) volcanoes, such as the ancient volcano on the territory of Kara-Dag in the Crimea. The authors of this article have found increased, in comparison with other localities of the Crimea, general insolation according to SSE. According to the 22-year linear trend, the rate of insolation growth falling on the earth's surface at Kara-Dag has been calculated, which is 2,69 kWh/m2 per century, being more than 2 times higher than insolation growth in other areas of the Crimea. This phenomenon has been the subject of discussion, and additional research is needed, both on the geological structure of Kara-Dag and on the impact of external and internal forces. At the stage of studying the structure of data on insolation of the earth's surface at Kara-Dag, we have built a 6-order sine-wave model. The most powerful (amplitudes more than an order of magnitude higher than the noise level) regular oscillations on the 22-year interval have periods of 365,3 and 365,7 days. Statistical estimates of the degree of approximation by a sinusoidal model (R2 = 0,9, RMSE = 0,7) indicate that, in addition to regular periodic oscillations, there are irregular fluctuations in the data at time intervals determined by a continuous time-frequency wavelet analysis. The wavelet transformation graph highlights the interval of insolation energy growth at Kara-Dag locality after 1995. In order to analyze the statistical relationship of changes in local insolation of the Earth's surface with the Earth's rotation around the axis and its orbital movement, solar activity and global temperature, autoregression models of the power spectral density were calculated using which coherent oscillations were found between variations in Kara-Dag paragraph and variations in the data: on the length of the day (LOD) with a period of 11,8 years and a square modulus of coherence of 0,85; about solar activity with periods of 10,5, 3,6 years and a squared coherence modulus of 0,8 and 0,85; about global temperature indices with periods of 2,3, 3,5 years and squares of coherence modulus 0,7 and 0,9, respectively. The increased growth of insolation and the temperature of the earth at Kara-Dag locality that we found requires additional research and observations.

Polygon “Simeiz-Katsively” - the cycles in the climatic and the geophysical characteristics of the Crimea

Coherent variations are established with periods of about 10–12 years and 60–70 years, which are found in processes of different physical nature and can be attributed to global cycles in the solar system, the manifestation of which in climatic and geophysical local processes is the result of a general tendency to synchronize. Coherent variations with multiple or comparable frequencies are possible in this process. Analysis of climatic characteristics on the Crimean peninsula for the period 1983 - 2005 revealed an accelerated increase (in comparison with other points of the Crimea) with the insolation of the earth's surface in Kara -Dag and an abnormal decrease in the temperature of the Earth’s surface at Lantern

High temperatures cause reduced growth, plant death and metabolic changes in eelgrass Zostera marina

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 604:121-132 (2018) - DOI: https://doi.org/10.3354/meps12740 High temperatures cause reduced growth, plant death and metabolic changes in eelgrass Zostera marina Kathrine Jul Hammer1, Jens Borum1,*, Harald Hasler-Sheetal2,3, Erin C. Shields4, Kaj Sand-Jensen1, Kenneth A. Moore4 1Freshwater Biological Laboratory, Biological Institute, University of Copenhagen, 2100 Copenhagen, Denmark 2Nordcee, Department of Biology, University of Southern Denmark, 5230 Odense M, Denmark 3Villum Center for Bioanalytical Sciences, University of Southern Denmark, 5230 Odense M, Denmark 4Virginia Institute of Marine Science, School of Marine Science, College of William and Mary, Gloucester Point, VA 23062, USA *Corresponding author: jborum@bio.ku.dk ABSTRACT: We investigated temperature effects on eelgrass Zostera marina L. growing close to its southern distribution limit along the eastern coast of North America in Virginia, USA. We combined growth and survival experiments with microelectrode measurements of internal meristematic oxygen and analyses of metabolic compounds. Eelgrass shoots were grown at 3 different temperatures (22, 26 and 30°C) and field equivalent light levels (23% of sea surface insolation) for 28 d while water column oxygen concentration was kept at air saturation. Meristematic oxygen concentrations did not vary significantly with temperature, and meristems maintained a relatively high oxygen concentration (average: 38% air saturation) during dark hours. Despite high meristematic oxygen concentrations, shoots growing at 30°C exhibited increased mortality, reduced growth and reduced leaf production compared to shoots growing at 22 and 26°C. The leaf metabolome was significantly altered at 30°C, indicating an increase of reactive oxygen species. In addition, total nitrogen and metabolites related to the nitrogen cycle (amino acids, urea and γ-aminobutyric acid [GABA]) were low in the heat-stressed shoots, whereas soluble sugars increased. In conclusion, high temperature (30°C) has strong negative effects on eelgrass in the lower Chesapeake Bay, affecting growth, tissue integrity, nitrogen metabolism and protein/enzyme synthesis. Future global warming may likely deteriorate populations of eelgrass at its present southern distribution limit. KEY WORDS: Zostera marina · Temperature stress · Growth · Metabolomics · Climate change Full text in pdf format Supplementary material PreviousNextCite this article as: Hammer KJ, Borum J, Hasler-Sheetal H, Shields EC, Sand-Jensen K, Moore KA (2018) High temperatures cause reduced growth, plant death and metabolic changes in eelgrass Zostera marina. Mar Ecol Prog Ser 604:121-132. https://doi.org/10.3354/meps12740 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 604. Online publication date: October 04, 2018 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2018 Inter-Research.

The Antarctic Centennial Oscillation: A Natural Paleoclimate Cycle in the Southern Hemisphere That Influences Global Temperature

We report a previously-unexplored natural temperature cycle recorded in ice cores from Antarctica—the Antarctic Centennial Oscillation (ACO)—that has oscillated for at least the last 226 millennia. Here we document the properties of the ACO and provide an initial assessment of its role in global climate. We analyzed open-source databases of stable isotopes of oxygen and hydrogen as proxies for paleo-temperatures. We find that centennial-scale spectral peaks from temperature-proxy records at Vostok over the last 10,000 years occur at the same frequencies (±2.4%) in three other paleoclimate records from drill sites distributed widely across the East Antarctic Plateau (EAP), and >98% of individual ACOs evaluated at Vostok match 1:1 with homologous cycles at the other three EAP drill sites and conversely. Identified ACOs summate with millennial periodicity to form the Antarctic Isotope Maxima (AIMs) known to precede Dansgaard-Oeschger (D-O) oscillations recorded in Greenland ice cores. Homologous ACOs recorded at the four EAP drill sites during the last glacial maximum appeared first at lower elevations nearest the ocean and centuries later on the high EAP, with latencies that exceed dating uncertainty >30-fold. ACO homologs at different drill sites became synchronous, however, during the warmer Holocene. Comparative spectral analysis suggests that the millennial-scale AIM cycle declined in period from 1500 to 800 years over the last 70 millennia. Similarly, over the last 226 millennia ACO repetition period (mean 352 years) declined by half while amplitude (mean 0.67 °C) approximately doubled. The period and amplitude of ACOs oscillate in phase with glacial cycles and related surface insolation associated with planetary orbital forces. We conclude that the ACO: encompasses at least the EAP; is the proximate source of D-O oscillations in the Northern Hemisphere; therefore affects global temperature; propagates with increased velocity as temperature increases; doubled in intensity over geologic time; is modulated by global temperature variations associated with planetary orbital cycles; and is the probable paleoclimate precursor of the contemporary Antarctic Oscillation (AAO). Properties of the ACO/AAO are capable of explaining the current global warming signal.

Solar-insolation-induced changes in the coma morphology of comet 67P/Churyumov-Gerasimenko

Context. 67P/Churyumov-Gerasimenko (67P/C-G) is a short-period Jupiter family comet with an orbital period of 6.55 years. Being the target comet of ESA’s Rosetta mission, 67P/C-G has become one of the most intensively studied minor bodies of the Solar System. The Rosetta Orbiter and the Philae Lander have brought us unique information about the structure and activity of the comet nucleus, as well as its activity along the orbit, composition of gas, and dust particles emitted into the coma. However, as Rosetta stayed in very close proximity to the cometary nucleus (less than 500 km with a few short excursions reaching up to 1500 km), it could not see the global picture of a coma at the scales reachable by telescopic observations (103 - 105 km). Aims. In this work we aim to connect in-situ observations made by Rosetta with the morphological evolution of the coma structures monitored by the ground-based observations. In particular, we concentrate on causal relationships between the coma morphology and evolution observed with the Nordic Optical Telescope (NOT) in the Canary Islands, and the seasonal changes of the insolation and the activity of the comet observed by the Rosetta instruments. Methods. Comet 67P/C-G was monitored with the NOT in imaging mode in two colors. Imaging optical observations were performed roughly on a weekly basis, which provides good coverage of short- and long-term variability. With the three dimensional modeling of the coma produced by active regions on the Southern Hemisphere, we aim to qualify the observed morphology by connecting it to the activity observed by Rosetta. Results. During our monitoring program, we detected major changes in the coma morphology of comet 67P/C-G. These were longterm and long-lasting changes. They do not represent any sudden outburst or short transient event, but are connected to seasonal changes of the surface insolation and the emergence of new active regions on the irregular shaped comet nucleus. We have also found significant deviations in morphological changes from the prediction models based on previous apparitions of 67P/C-G, like the time delay of the morphology changes and the reduced activity in the Northern Hemisphere. According to our modeling of coma structures and geometry of observations, the changes are clearly connected with the activity in the Southern Hemisphere observed by the Rosetta spacecraft.

Assessment of simulation of radiation in NCEP Climate Forecasting System (CFS V2)

The objective of this study is to identify and document the radiation biases in the latest National Centers for Environment Prediction (NCEP), Climate Forecasting System (CFSv2) and to investigate the probable reasons for these biases. This analysis is made over global and Indian domain under all-sky and clear-sky conditions. The impact of increasing the horizontal resolution of the atmospheric model on these biases is also investigated by comparing results of two different horizontal resolution versions of CFSv2 namely T126 and T382. The difference between the top of the atmosphere and surface energy imbalance in T126 (T382) is 3.49 (2.78) W/m2. This reduction of bias in the high resolution model is achieved due to lesser low cloud cover, resulting more surface insolation, and due to more latent heat fluxes at the surface. Compared to clear sky simulations, all sky simulations exhibit larger biases suggesting that the cloud covers are not simulated well in the model. The annual mean high level cloud cover is over estimated over the global as well as the Indian domain. This overestimation over the Indian domain is also present during JJAS. There is also evidence that both of the models have insufficient water vapour in their atmosphere. This study suggests that in order to improve the model's mean radiation climatology, simulation of clouds in the model also needs to be improved, and future model development activities should focus on this aspect.

Moist convection and its upscale effects in simulations of the Indian monsoon with explicit and parametrized convection

In common with many global models, the Met Office Unified Model (MetUM) climate simulations show large errors in Indian summer monsoon rainfall, with a wet bias over the equatorial Indian Ocean, a dry bias over India, and with too weak low‐level flow into India. The representation of moist convection is a dominant source of error in global models, where convection must be parametrized, with the errors growing quickly enough to affect both weather and climate simulations. Here we use the first multi‐week continental‐scale MetUM simulations over India, with grid spacings that allow explicit convection, to examine how convective parametrization contributes to model biases in the region.Some biases are improved in the convection‐permitting simulations with more intense rainfall over India, a later peak in the diurnal cycle of convective rainfall over land, and a reduced positive rainfall bias over the Indian Ocean. The simulations suggest that the reduced rainfall over the Indian Ocean leads to an enhanced monsoon circulation and transport of moisture into India. Increases in latent heating associated with increased convection over land deepen the monsoon trough and enhance water vapour transport into the continent. In addition, delayed continental convection allows greater surface insolation and, along with the same rain falling in more intense bursts, generates a drier land surface. This increases land–sea temperature contrasts, and further enhances onshore flow. Changes in the low‐level water vapour advection into India are dominated by these changes to the flow, rather than to the moisture content in the flow. The results demonstrate the need to improve the representations of convection over both land and oceans to improve simulations of the monsoon.

Aerosol and monsoon climate interactions over Asia

AbstractThe increasing severity of droughts/floods and worsening air quality from increasing aerosols in Asia monsoon regions are the two gravest threats facing over 60% of the world population living in Asian monsoon regions. These dual threats have fueled a large body of research in the last decade on the roles of aerosols in impacting Asian monsoon weather and climate. This paper provides a comprehensive review of studies on Asian aerosols, monsoons, and their interactions. The Asian monsoon region is a primary source of emissions of diverse species of aerosols from both anthropogenic and natural origins. The distributions of aerosol loading are strongly influenced by distinct weather and climatic regimes, which are, in turn, modulated by aerosol effects. On a continental scale, aerosols reduce surface insolation and weaken the land‐ocean thermal contrast, thus inhibiting the development of monsoons. Locally, aerosol radiative effects alter the thermodynamic stability and convective potential of the lower atmosphere leading to reduced temperatures, increased atmospheric stability, and weakened wind and atmospheric circulations. The atmospheric thermodynamic state, which determines the formation of clouds, convection, and precipitation, may also be altered by aerosols serving as cloud condensation nuclei or ice nuclei. Absorbing aerosols such as black carbon and desert dust in Asian monsoon regions may also induce dynamical feedback processes, leading to a strengthening of the early monsoon and affecting the subsequent evolution of the monsoon. Many mechanisms have been put forth regarding how aerosols modulate the amplitude, frequency, intensity, and phase of different monsoon climate variables. A wide range of theoretical, observational, and modeling findings on the Asian monsoon, aerosols, and their interactions are synthesized. A new paradigm is proposed on investigating aerosol‐monsoon interactions, in which natural aerosols such as desert dust, black carbon from biomass burning, and biogenic aerosols from vegetation are considered integral components of an intrinsic aerosol‐monsoon climate system, subject to external forcing of global warming, anthropogenic aerosols, and land use and change. Future research on aerosol‐monsoon interactions calls for an integrated approach and international collaborations based on long‐term sustained observations, process measurements, and improved models, as well as using observations to constrain model simulations and projections.

Aerosol optical depth distribution in extratropical cyclones over the Northern Hemisphere oceans

AbstractUsing Moderate Resolution Imaging Spectroradiometer and an extratropical cyclone database, the climatological distribution of aerosol optical depth (AOD) in extratropical cyclones is explored based solely on observations. Cyclone‐centered composites of aerosol optical depth are constructed for the Northern Hemisphere midlatitude ocean regions, and their seasonal variations are examined. These composites are found to be qualitatively stable when the impact of clouds and surface insolation or brightness is tested. The larger AODs occur in spring and summer and are preferentially found in the warm frontal and in the postcold frontal regions in all seasons. The fine mode aerosols dominate the cold sector AODs, but the coarse mode aerosols display large AODs in the warm sector. These differences between the aerosol modes are related to the varying source regions of the aerosols and could potentially have different impacts on cloud and precipitation within the cyclones.

Assured Solar Energy Hot-Spots over Indian Landmass Detected through Remote Sensing Observations from Geostationary Meteorological Satellite

Quantification of assured solar energy potential is essential to select locations for solar photovoltaic, thermal power plants and to quantify solar power potential. The use of remote sensing observations from geostationary satellite sensors is ideal to capture space-time variability of surface insolation. The annual clear solar energy exposure over India was determined using three years' insolation data at 8 km spatial resolution from Kalpana-1 satellite. High density solar energy pockets were diagnosed in western, central and southern India including Gujarat, Rajasthan, Madhya Pradesh, Karnataka, Tamil Nadu and Chhattisgarh states with annual solar energy exposure ranging from 2500 to 3500 kW h m -2 yr -1 .

CLIMATE AND NEWBORN INFANTS BIRTH GROWTH AND WEIGHT IN RUSSIA

Aim. The aim of the study was to monitor the correlation between the infants birth growth weight and the climatic characteristics using regional statistical indices. Materials and methods. Mean birth growth and birth weight values of 790 276 newborn infants from 42 subjects of the Russian Federation with the share of the Russian population not less than 85 % (2007) were taken from the database of Social Insurance Fund. Mean temperature of July and January, mean wind speed, average annual horizontal surface insolation (kw·day/m2) were used as the parameters characterizing climatic conditions of the region. Climate severity was estimated by Bodman index values and annual temperature difference. Results. Newborn infant’s birth weight is decreasing with climate severity growing: it correlates with the average temperature of January ( r = + 0,56), Bodman index values ( r = -0,49) and interseasonal (July-January) temperature difference ( r = -0,54). Newborn infant’s birth growth is directly connected with insolation level ( r = 0,31) that agrees with the notion of the role of UV-radiation in metabolism of fetal bone tissue. Conclusions. 1. Newborn infant’s birth weight is decreasing with fall in a mean temperature of January, increase in climate severity and growth of season temperature difference. 2. Newborn infant’s birth growth is increasing with rise in an average annual insolation level.

Analysis of Thermal Environment over a Small-Scale Landscape in a Densely Built-Up Asian Megacity

Many studies have found that larger parks might be needed to counteract the Urban Heat Island effects typical in densely populated Asian megacities. However, it is not easy to establish large parks to serve as urban cool islands in Asian megacities, where little space exists for large urban neighborhood parks. Officials in these cities would rather use small areas by replacing heat-absorbing artificial land cover with natural cover. The main objective of this study was to understand the cooling effect of changes in land cover on surface and air temperatures in urban micro-scale environments for supporting sustainable green-space planning and policy in densely built-up areas. This was achieved using measurements at different heights (ground surface, 0.1 m, and 1.5 m) for five land cover types (LCTs) and modeling with the micro-scale climate model ENVI-met. At all vertical measuring points, the average temperature over the entire measurement period had the same hot-to-cold order: asphalt > soil > grass > water > forest. However, the value dramatically decreased as the measuring points became higher. The intensity of hot and cool spots showed the highest value at surface by 18.2 °C, and declined with the height, showing 4.1 °C at 0.1 m and 3.1 °C at 1.5 m. The modeling results indicated that the well-known diurnal variation in surface insolation also occurred in our small domain, among the various LCTs. Based on these findings, providing small-scale green infrastructure in densely built-up areas could be an effective way to improve urban micro-scale thermal conditions.

A Retrospective, Iterative, Geometry-Based (RIGB) tilt-correction method for radiation observed by automatic weather stations on snow-covered surfaces: application to Greenland

Abstract. Surface melt and mass loss of the Greenland Ice Sheet may play crucial roles in global climate change due to their positive feedbacks and large fresh-water storage. With few other regular meteorological observations available in this extreme environment, measurements from automatic weather stations (AWS) are the primary data source for studying surface energy budgets, and for validating satellite observations and model simulations. Station tilt, due to irregular surface melt, compaction and glacier dynamics, causes considerable biases in the AWS shortwave radiation measurements. In this study, we identify tilt-induced biases in the climatology of surface shortwave radiative flux and albedo, and retrospectively correct these by iterative application of solar geometric principles. We found, over all the AWS from the Greenland Climate Network (GC-Net), the Kangerlussuaq transect (K-transect) and the Programme for Monitoring of the Greenland Ice Sheet (PROMICE) networks, insolation on fewer than 40 % of clear days peaks within ±0.5 h of solar noon time, with the largest shift exceeding 3 h due to tilt. Hourly absolute biases in the magnitude of surface insolation can reach up to 200 W m−2, with respect to the well-understood clear-day insolation. We estimate the tilt angles and their directions based on the solar geometric relationship between the simulated insolation at a horizontal surface and the observed insolation by these tilted AWS under clear-sky conditions. Our adjustment reduces the root mean square error (RMSE) against references from both satellite observation and reanalysis by 16 W m−2 (24 %), and raises the correlation coefficients with them to above 0.95. Averaged over the whole Greenland Ice Sheet in the melt season, the adjustment in insolation to compensate station tilt is ∼ 11 W m−2, enough to melt 0.24 m of snow water equivalent. The adjusted diurnal cycles of albedo are smoother, with consistent semi-smiling patterns. The seasonal cycles and inter-annual variabilities of albedo agree better with previous studies. This tilt-corrected shortwave radiation data set derived using the Retrospective, Iterative, Geometry-Based (RIGB) method provide more accurate observations and validations for surface energy budgets studies on the Greenland Ice Sheet, including albedo variations, surface melt simulations and cloud radiative forcing estimates.

Solar Radiation Received by Slopes Using COMS Imagery, a Physically Based Radiation Model, and GLOBE

This study mapped the solar radiation received by slopes for all of Korea, including areas that are not measured by ground station measurements, through using satellites and topographical data. When estimating insolation with satellite, we used a physical model to measure the amount of hourly based solar surface insolation. Furthermore, we also considered the effects of topography using the Global Land One-Kilometer Base Elevation (GLOBE) digital elevation model (DEM) for the actual amount of incident solar radiation according to solar geometry. The surface insolation mapping, by integrating a physical model with the Communication, Ocean, and Meteorological Satellite (COMS) Meteorological Imager (MI) image, was performed through a comparative analysis with ground-based observation data (pyranometer). Original and topographically corrected solar radiation maps were created and their characteristics analyzed. Both the original and the topographically corrected solar energy resource maps captured the temporal variations in atmospheric conditions, such as the movement of seasonal rain fronts during summer. In contrast, although the original solar radiation map had a low insolation value over mountain areas with a high rate of cloudiness, the topographically corrected solar radiation map provided a better description of the actual surface geometric characteristics.