A one-parameter family of clear-sky solar irradiance models adapted for different aerosol types

2021 ◽  
Vol 13 (2) ◽  
pp. 023701
Author(s):  
Robert Blaga ◽  
Delia Calinoiu ◽  
Marius Paulescu
Keyword(s):  
Solar Irradiance ◽  
Parameter Family ◽  
Clear Sky ◽  
Aerosol Types

scholarly journals Albedo and estimates of net radiation for green beans under polyethylene cover and field conditions

1999 ◽  
Vol 34 (10) ◽  
pp. 1763-1774 ◽  
Author(s):  
José Leonaldo de Souza ◽  
João Francisco Escobedo ◽  
Maria Terezinha Trovareli Tornero
Keyword(s):  
Solar Irradiance ◽  
Field Conditions ◽  
Net Radiation ◽  
Phaseolus Vulgaris L ◽  
Green Beans ◽  
Phenological Stages ◽  
Independent Variables ◽  
Clear Sky ◽  
Solar Elevation ◽  
Global Irradiance

This paper describes the albedo (r) and estimates of net radiation and global solar irradiance for green beans crop (Phaseolus vulgaris L.), cultivated in greenhouse with cover of polyethylene and field conditions, in Botucatu, SP, Brazil (22º 54' S; 48º 27' W; 850 m). The solar global irradiance (Rg) and solar reflected radiation (Rr) were used to estimate the albedo through the ratio between Rr and Rg. The diurnal curves of albedo were obtained for days with clear sky and partially cloudy conditions, for different phenological stages of the crop. The albedo ranged with the solar elevation, the environment and the phenological stages. The cloudiness range have almost no influence on the albedo diurnal amount. The estimation of radiation were made by linear regression, using the global solar irradiance (Rg) and net short-waves radiation (Rc) as independent variables. All estimates of radiation showed better adjustment for specific phenological periods compared to the entire crop growing cycle. The net radiation in the greenhouse has been estimated by the global solar irradiance measured at field conditions.

scholarly journals Quasi-biennial and longer-term changes in clear sky UV-B solar irradiance

1998 ◽  
Vol 25 (23) ◽  
pp. 4345-4348 ◽  
Author(s):  
C. Zerefos ◽  
C. Meleti ◽  
D. Balis ◽  
K. Tourpali ◽  
A. F. Bais
Keyword(s):  
Solar Irradiance ◽  
Clear Sky

Improvement of clear sky models for direct solar irradiance considering turbidity factor variable during the day

2020 ◽  
Vol 161 ◽  
pp. 559-569 ◽  
Author(s):  
Camelia Liliana Moldovan ◽  
Radu Păltănea ◽  
Ion Visa
Keyword(s):  
Solar Irradiance ◽  
Clear Sky ◽  
Factor Variable

scholarly journals Technical note: A low-cost albedometer for snow and ice measurements – Theoretical results and application on a tropical mountain in Bolivia

2018 ◽  
Author(s):  
Thomas Condom ◽  
Marie Dumont ◽  
Lise Mourre ◽  
Jean Emmanuel Sicart ◽  
Antoine Rabatel ◽  
...  
Keyword(s):  
Solar Irradiance ◽  
Low Cost ◽  
Spectral Response ◽  
Lateral Moraine ◽  
Clear Sky ◽  
Direct Observations ◽  
Right Hand ◽  
The Right ◽  
Theoretical Results ◽  
Daily Time

Abstract. This study presents a new instrument called a low-cost albedometer (LCA) composed of two illuminance sensors that are used to measure in-situ incident and reflected illuminance values on a daily timescale. The ratio between reflected vs. incident illuminances is called the albedo index and can be compared with actual albedo values. Due to the shape of the sensor, the direct radiation for zenith angles ranging from 55° to 90° is not measured. The spectral response of the LCA varies with the solar irradiance wavelengths within the range 0.26 to 1.195 µm, and the LCA detects 85 % of the total spectral solar irradiance for clear sky conditions. We first consider the theoretical results obtained for 10 different ice and snow surfaces with clear sky and cloudy sky incident solar irradiance that show that the LCA spectral response may be responsible for an overestimation of the theoretical albedo values by roughly 9 % at most. Then, the LCA values are compared with two classical albedometers over a one-year measurement period (2013) for two sites in a tropical mountainous catchment in Bolivia. One site is located on the Zongo Glacier (i.e. snow and ice surfaces) and the second one is found on the right-hand side lateral moraine (bare soil and snow surfaces). The results, at daily time steps (256 days), given by the LCA are in good agreement with the classic albedo measurements taken with pyranometers with R2 = 0.83 (RMSD = 0.10) and R2 = 0.92 (RMSD = 0.08) for the Zongo Glacier and the right-hand side lateral moraine, respectively. This demonstrates that our system performs well and thus provides relevant opportunities to document spatio-temporal changes in the surface albedo from direct observations at the scale of an entire catchment at a low cost. Finally, during the period from September 2015 to June 2016, direct observations were collected with 15 LCAs on the Zongo Glacier and successfully compared with LANDSAT images showing the surface state of the glacier (i.e. snow or ice). This comparison illustrates the efficiency of this system to monitor the daily time step changes in the snow/ice coverage distributed on the glacier.

scholarly journals Satellite-Based Estimation of Temporally Resolved Dust Radiative Forcing in Snow Cover

2016 ◽  
Vol 17 (7) ◽  
pp. 1999-2011 ◽  
Author(s):  
Steven D. Miller ◽  
Fang Wang ◽  
Ann B. Burgess ◽  
S. McKenzie Skiles ◽  
Matthew Rogers ◽  
...  
Keyword(s):  
Solar Irradiance ◽  
Radiative Forcing ◽  
Hydrological Cycle ◽  
Clear Sky ◽  
Operational Management ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Sky Conditions

Abstract Runoff from mountain snowpack is an important freshwater supply for many parts of the world. The deposition of aeolian dust on snow decreases snow albedo and increases the absorption of solar irradiance. This absorption accelerates melting, impacting the regional hydrological cycle in terms of timing and magnitude of runoff. The Moderate Resolution Imaging Spectroradiometer (MODIS) Dust Radiative Forcing in Snow (MODDRFS) satellite product allows estimation of the instantaneous (at time of satellite overpass) surface radiative forcing caused by dust. While such snapshots are useful, energy balance modeling requires temporally resolved radiative forcing to represent energy fluxes to the snowpack, as modulated primarily by varying cloud cover. Here, the instantaneous MODDRFS estimate is used as a tie point to calculate temporally resolved surface radiative forcing. Dust radiative forcing scenarios were considered for 1) clear-sky conditions and 2) all-sky conditions using satellite-based cloud observations. Comparisons against in situ stations in the Rocky Mountains show that accounting for the temporally resolved all-sky solar irradiance via satellite retrievals yields a more representative time series of dust radiative effects compared to the clear-sky assumption. The modeled impact of dust on enhanced snowmelt was found to be significant, accounting for nearly 50% of the total melt at the more contaminated station sites. The algorithm is applicable to regional basins worldwide, bearing relevance to both climate process research and the operational management of water resources.

scholarly journals Global Clear-Sky Aerosol Speciated Direct Radiative Effects over 40 Years (1980–2019)

Atmosphere ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1254
Author(s):  
Marios-Bruno Korras-Carraca ◽  
Antonis Gkikas ◽  
Christos Matsoukas ◽  
Nikolaos Hatzianastassiou
Keyword(s):  
Global Climate ◽  
Regional Scale ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Radiative Effect ◽  
Clear Sky ◽  
Order Of Magnitude ◽  
Carbon Aerosols ◽  
Aerosol Types

We assess the 40-year climatological clear-sky global direct radiative effect (DRE) of five main aerosol types using the MERRA-2 reanalysis and a spectral radiative transfer model (FORTH). The study takes advantage of aerosol-speciated, spectrally and vertically resolved optical properties over the period 1980–2019, to accurately determine the aerosol DREs, emphasizing the attribution of the total DREs to each aerosol type. The results show that aerosols radiatively cool the Earth’s surface and heat its atmosphere by 7.56 and 2.35 Wm−2, respectively, overall cooling the planet by 5.21 Wm−2, partly counterbalancing the anthropogenic greenhouse global warming during 1980–2019. These DRE values differ significantly in terms of magnitude, and even sign, among the aerosol types (sulfate and black carbon aerosols cool and heat the planet by 1.88 and 0.19 Wm−2, respectively), the hemispheres (larger NH than SH values), the surface cover type (larger land than ocean values) or the seasons (larger values in local spring and summer), while considerable inter-decadal changes are evident. These DRE differences are even larger by up to an order of magnitude on a regional scale, highlighting the important role of the aerosol direct radiative effect for local and global climate.

Radiative effect of different aerosol types in clear sky conditions according to COSMO-Ru model

2018 ◽  
Author(s):  
Marina Shatunova ◽  
Gdaliy Rivin ◽  
Aleksander Makshtas ◽  
Aleksei Poliukhov ◽  
Natalia Chubarova ◽  
...  
Keyword(s):  
Radiative Effect ◽  
Clear Sky ◽  
Sky Conditions ◽  
Aerosol Types

A posteriori clear-sky identification methods in solar irradiance time series: Review and preliminary validation using sky imagers

2019 ◽  
Vol 109 ◽  
pp. 412-427 ◽  
Author(s):  
Christian A. Gueymard ◽  
Jamie M. Bright ◽  
David Lingfors ◽  
Aron Habte ◽  
Manajit Sengupta
Keyword(s):  
Time Series ◽  
Solar Irradiance ◽  
A Posteriori ◽  
Identification Methods ◽  
Clear Sky ◽  
Preliminary Validation
Sign in / Sign up

Export Citation Format

Share Document