nasa-gesdisc/es-publications-researchareas huggingface dataset:
Different photovoltaic power potential variations in East and West China (2023)

Photovoltaic (PV) technology can help reduce carbon emissions significantly, but its benefits may be affected by climate change. Few studies have reported on the impact of climate change on the spatial and temporal distribution of solar energy in China based on the latest Coupled Model Intercomparison Project Phase 6 (CMIP6) models, and few have explored the rooftop PV potential. In this study, 16 CMIP6 models are used for evaluation of the inter-annual and seasonal changes of solar irradiance and PV capacity factor under low (SSP12.6), medium (SSP24.5) and high (SSP58.5) greenhouse gas emission scenarios. The effects on the variation of solar irradiance of three factors are examined: clouds, aerosol optical thickness (AOT) and specific humidity. Furthermore, the future power generation potential of rooftop PV is investigated. It is found that the solar irradiance exhibits an upward trend on national level under all the future scenarios, especially for the SSP12.6 scenario, with an increasing rate of 1.4 W m2 decade1, mainly due to a reduction in AOT. Solar irradiance increases notably in southeast China while increases little in west China, and the level for 20512060 remains lower than that for 19602014. The PV capacity factor increases in southeast China with increasing solar irradiance, with a maximum increase of about 4% compared to the average PV CF for 19602014 and the highest increasing rate being 0.37% decade1. In addition, to achieve the projected national distributed PV power generation level, >70% of the effective rooftop area needs to be utilized in 2050. This study hopes to enhance understanding of the impact of climate change on solar energy and provide recommendations for future PV planning to better achieve the long-term planetary temperature goal set by the Paris Agreement.

Research areas: Sun-Earth Interactions
A Closer Look at the Effects of Lake Area, Aquatic Vegetation, and Double-Counted Wetlands on Pan-Arctic Lake Methane Emissions Estimates (2023)

Lake methane emissions are commonly upscaled from lake area, with recognition that smaller, non-inventoried lakes emit more per unit area. There is also growing awareness of the importance of lake aquatic vegetation and potential "double-counting" with wetlands, but lack of consensus on which is most impactful. Here, we combine high-resolution data with the comprehensive lake inventory HydroLAKES to rank these three variables based on emissions sensitivity. Including non-inventoried small lakes &lt;0.1 km<SUP>2</SUP> (+30 [range: 9.0 to 82]% change) is greatest, followed by double-counting (−20 [−11 to −34]%) and lake aquatic vegetation (+14 [2.7 to 43]%). Significantly, emissions from non-inventoried lakes contribute far less than the ∼40% previously determined globally through statistical area extrapolation. We produce a first pan-Arctic estimate of lake aquatic vegetation in 1.37 million km<SUP>2</SUP> of lakes, but after correcting for persistent double-counting, its net effect is to decrease emissions estimates by 9%. Thus, previous global emissions estimates are likely too high.

Research areas: Greenhouse Gases
Variation of aerosol parameters (AI, AOD) and SO2 over Indo-Gangetic basin during COVID-19 outbreaks (2023)

To stop the spread of COVID-19 infections, idea of complete and partial lockdowns was implemented in several countries. In the present work, variation of aerosol index (AI), aerosol optical depth (AOD) and SO2 concentration over Indo-Gangetic Basin regions (over highly polluted cities: Varanasi, Kanpur and Delhi) were analyzed to see the impact of lockdown periods during 2020. AI data were taken from satellite based ozone monitoring instrument while AOD and SO2 data were taken from moderate resolution spectroradiometer (MODIS). Lockdown periods of March, April, May and June months of 2020 were compared with the same months of 2017, 2018 and 2019. Significantly large difference in AI was observed associated with decreased value of AI during lockdown periods followed by AOD values and SO2 concentrations. All these cities of Northern India (Varanasi, Kanpur and Delhi) show significant decline in aerosol index which indicate less emissions of black carbon and other absorbing aerosol particles into the atmosphere. Trend of AI and SO2 concentration were found to be negative due to the sudden decrease in their values. Decline in the aerosol parameters (AI and AOD) and air pollutant (SO2) suggest improved air quality of the highly polluted cities of India.

Research areas: Air Quality
Variation of aerosol optical properties from AERONET observation at Mt. Muztagh Ata, Eastern Pamirs (2015)

Using data from the ground-based remote sensing Aerosol Robotic Network (AERONET), aerosol optical properties, including aerosol optical depth (AOD), Angstrom exponent (), and volume size distribution were investigated for the period June to December 2011 at Mt. Muztagh Ata (Muztagata), Eastern Pamirs. The monthly average values of AOD (500 nm) and  (440870 nm) varied from 0.08  0.02 to 0.16  0.11, and from 0.56  0.06 to 0.93  0.28, respectively. The daily AOD averages 0.14  0.07, with the maximum (0.5) occurring in August and the minimum (0.05) occurring in November. A small increase in AOD is expected with a noticeable decrease in the  value. The daily  averages 0.70  0.27, and most exponents are less than 1, indicating the majority of larger aerosol particles. The volume size distribution of aerosol particles shows bimodal log-normal characteristics, with a fine mode radius of 0.2 m and a coarse mode radius of 3 m. The MODIS AOD and AERONET AOD display a similar variation, while the former is always noticeably higher than the latter with a difference of 0.10.4, indicating that the MODIS data might overestimate the aerosol load. Our results indicate that high aerosol volume concentration occurs in summer with the dominance of coarse particles over Muztagh Ata. The low AOD shows a clean atmosphere in this region, revealing that it is an atmospheric background site for continental aerosol monitoring

Research areas: Air Quality
Surface shortwave cloud radiative effect of cumulus and stratocumulus-cumulus cloud types in the Caribbean area (Camaguey Cuba, 2010-2016) (2023)

The effects of cumulus (Cu) clouds and the combination of stratocumulus-cumulus (Sc-Cu) clouds on solar radiation at the Earths surface were evaluated at Camaguey, Cuba, during a 6-yr period (from June 2010 to May 2016). Two methods to calculate the cloud radiative effect (CRE) were employed. The first method (CREm) uses solar irradiances in cloudy conditions from actinometric observations, where cloud information was also reported by visual observation. In the second method (CRE0) surface solar irradiances were estimated for both cloudy and clear sky conditions using a 1-D radiative transfer model, and cloud optical depth (COD) retrieved from an AERONET sun-photometer as the main input. A temporal correspondence criterion between COD retrievals and actinometric observations was performed in order to classify the COD of each cloud type. After the application of this criterion, the COD belonging to the optically thin clouds was removed. Finally, 255 and 732 COD observations for Cu and Sc-Cu, respectively, were found. Results show a statistically significant difference at the 95% confidence level between CRE calculated for Sc-Cu and Cu, using both methods. Mean values of CREm and CRE0 for Cu (Sc-Cu) were 442 (390) and 460 (417) Wm2, respectively. CRE0 shows a linear relation with ln(COD), with stronger correlation at a lower solar zenith angle. The shortwave cloud effect efficiency (CEE) for the two cloud types sharply decreases with the increase of the COD value up to 20. For larger COD, the CEE is less sensitive to the increase of COD.

Research areas: Sun-Earth Interactions
Summertime physical and biological controls on O2 and CO2 in the Australian Sector of the Southern Ocean (2015)

Continuous measurements of CO2 partial pressure, dissolved oxygen, and the oxygen argon ratio (O2/Ar) in surface waters, complemented by discrete observations of inorganic carbon, along a late-summer south-tonorth transect in the Australian Sector of the Southern Ocean (115E, WOCE I9S) are presented. The largest net community production (NCP, based on O2/Ar), and airsea CO2 disequilibrium (DpCO2) were found in three regions: (1) between the southern boundary of the Antarctic Circumpolar Current (63.6S) and southern extent of the Polar Front (58.6S, NCP = 30 mmol C m2 d1, pCO2 =30to50atm); (2) between the northern extent of the Sub-Antarctic Front (45.5S) and the Sub-Tropical Front (39.8S, NCP = 50 mmol C m2 d1, pCO2 =25atm); and (3) near 35S (NCP = 50 mmol C m2 d1, pCO2 =20atm). Areas of enhanced NCP were correlated with shallow mixed layer depths, suggesting that production is controlled in part by light limitation. We found good agreement between estimates of NCP based on O2/Ar measurements and those derived from seasonal (mixed layer) inorganic carbon deficits. In ice covered areas, and in areas where surface temperature changes act on shorter timescales than the equilibration of oxygen in the mixed layer, we find that physical controls on surface O2 are of equal magnitude to biological controls, which has important implications for the use of oxygen sensors on autonomous platforms to infer NCP.

Research areas: Atmospheric/Ocean Indicators
Storminess and Environmental Changes in the Mediterranean Central Area (2010)

Earth ecosystems are not static, and they respond to environmental changes, particularly climatic and anthropogenic. Precipitation varying in its extremeness, with shifts to greater or lesser intensity of individual storms and/or to change in the length and frequency of wet and dry periods, can adversely affect both urban and rural ecosystems. Here, the authors review longterm precipitation records of the central Mediterranean area and employ a Web geographical information system (GIS)-based analytical approach to compare current rainfall impact with historical data on different spatial and temporal scales. Autumn (SeptemberNovember) was recognized as the most hazardous season that marks the evidence of a changing climate, with a shift toward more intense rainfalls in recent times. In the first decade of the third millennium, areas of peninsular and insular Italy have been especially affected by extreme rains. A focus was put on the island of Sicily, where extraordinary rain events occurred in September 2009, discussed in the context of upcoming trends and climate histories. An improved knowledge and understanding of the scale at which changes on extremes occur is essential for dealing with the forthcoming challenges regarding soil and water conservation practices. The characteristics of changes in natural rainfall, its role on terrestrial ecosystems, and its effect on surface water erosion dynamics are discussed. It is argued that understanding these issues are major priorities for future research to promote a better understanding of the Earth interaction with water resources and related hydrological issues.

Research areas: Atmospheric/Ocean Indicators
Solubility of Atmospheric Nutrients over the Eastern Mediterranean: Comparison between Pure-Water and Sea-Water, Implications Regarding Marine Production (2015)

Aerosol filter samples were selected from sample library of Erdemli site; located on the coastline of the Eastern Mediterranean, in order to carry out solubility experiments. The nutrient (PO43-, Sidiss, NO3- and NH4+) solubilities were investigated by using pure-water and sea-water. The arithmetic means of phosphate and dissolved silica indicated distinct difference (larger than 50 %) between pure-water and sea-water whereas; the calculated mean concentrations of nitrate and ammonium did not reveal substantial discrepancy for pure-water and sea-water extractions. The difference for phosphate and silicate might be attributed to pH and ionic strength of sea water, size distribution and association of phosphate/silicate particles with less soluble compounds such as calcium phosphate, kaolinite, opal, quartz and origin of the aerosol species. The difference between pure-water and sea-water extractions for nitrate and ammonium was estimated to be small, corresponding to 1 % to -3 %. This similarity can be ascribed to highly soluble chemical forms such as NH4NO3, Ca(NO3)2, NaNO3 (NH4)2SO4 and NH4HSO4. Calculations revealed that atmospheric P flux would sustain 0.4 % and 0.9 % of the primary production reported for coastal and offshore waters of Cilician Basin. Whereas, atmospheric nitrogen contribution on primary production would be as high as 3.7 % and 8.4 % in coastal and offshore waters, correspondingly. The impact of atmospheric input on the marine productivity became more important particularly during the stratified periods such as summer and autumn. During these period, atmospheric P input might sustain 80 % of the new production whereas, atmospheric N input might support 8 times higher new product than that detected for surface waters.

Research areas: Ecosystems, Environmental Impacts, Validation, Air Quality, Atmospheric/Ocean Indicators, Public Health, Habitat Conversion/Fragmentation, Energy Production/Use, Severe Storms, Water Quality, Land Surface/Agriculture Indicators, Agriculture, Greenhouse Gases, Floods, Volcanic Eruptions, Droughts, Earthquakes
Seasonal dynamics in diatom and particulate export fluxes to the deep sea in the Australian sector of the southern Antarctic Zone (2015)

Particle fluxes were recorded over a one-year period (2001-02) in the southern Antarctic Zone in the Australian Sector of the Southern Ocean. Here, we present the results on the seasonal and vertical variability of biogenic particle and diatom valve fluxes. Total mass and diatom fluxes were highly seasonal, with maxima registered during the austral summer and minima during winter. Biogenic opal dominated sedimentation, followed by carbonate, and very low levels of organic carbon (annual average 1.4%). The strong correlation between opal and organic carbon at both depth levels suggests that a significant fraction of organic matter exported to the deep sea was associated with diatom sedimentation events. Seasonal diatom fluxes appear driven principally by changes in the flux of Fragilariopsis kerguelensis. The occurrence of the sea-ice affiliated diatoms Fragilariopsis cylindrus and Fragilariopsis curta in both sediment traps is considered to correspond to the sedimentation of a diatom bloom advected from an area under the influence of sea ice. Highest fluxes of the subsurface-dwelling species Thalassiothrix antarctica registered at the end of the summer bloom were linked to a drop of the light levels during the summer-autumn transition. This study provides the first annual observation on seasonal succession of diatom species in the Australian sector of the Antarctic Zone, and corresponds, in terms of magnitude and seasonality of diatom fluxes, to those in neighbouring sectors (Pacific and eastern Atlantic).

Research areas: Ecosystems
Radiative implication of a haze event over Eastern India (2015)

Aerosol haze degrades visibility by the process of absorption and scattering of aerosols. In the present study an attempt has been made to characterize the physical and optical properties of aerosols during a haze event on 29 March 2012 and assess its implication on radiative forcing. In this context representative clear (2 March 2012) and normal (19 March 2012) days were identified in terms of their Aerosol Optical Depth (AOD) loading over Hyderabad. On the hazy day, a huge spread of haze was observed over the eastern part of India by MODerate resolution Imaging Spectroradiometer (MODIS) on board Terra satellite which is represented by high Aerosol Optical Depth at 550 nm. In-situ observations on hazy day showed an enhancement of columnar AOD500 respectively by 4.5 and 1.8 fold in comparison to clear and normal days. Significant increase in the scattering coefficient and a moderate enhancement of Single Scattering Albedo (SSA) are observed on hazy day compared to normal day. Study also showed that Diffuse-to-Direct- beam irradiance Ratio (DDR) had increased 4.5 times at 496.6 nm spectral band on hazy day. LIDAR (LIght Detection And Ranging) observations on hazy night showed a threefold increase in aerosol backscattering below the Atmospheric Boundary Layer (ABL) compared to normal representative night. The hazy day is characterized by large negative surface forcing (87.82 W m2) when compared to normal day (53.90 W m2). A large positive enhancement of atmospheric forcing of 30.56 W m2 is observed on hazy day compared to normal day.

Research areas: Air Quality, Atmospheric/Ocean Indicators
pRecipe: A global precipitation climatology toolbox and database (2023)

Remote sensing data and model simulations of precipitation complemented the traditional surface measurements and offer unprecedented coverage on a global scale. However, the substantial heterogeneity among data products has hindered this unique opportunity to obtain a robust quantification of the climatologic properties of precipitation globally. Herein we present pRecipe, a package developed in R with reproducible science as our standard. pRecipe provides functions to download, explore, process, and visualize a database of 24 precipitation data sets at monthly time step and 0.25
 resolution (20CR v3, CHIRPS v2.0, CMAP, CMORPH, CPC-Global, CRU TS v4.06, EM-EARTH, ERA-20C, ERA5, GHCN v2, GLDAS-CLSM, GLDAS-NOAH, GLDAS-VIC, GPCC v2020, GPCP v2.3, GPM IMERGM v06, MSWEP v2.8, NCEP/DOE R2, NCEP/NCAR R1, PERSIANN-CDR, PREC/L, TerraClimate, TRMM 3B43 v7, UDel v5.01).

Research areas: Validation
Phytoplankton size structure in the southern Bay of Bengal modified by the Summer Monsoon Current and associated eddies: Implications on the vertical biogenic flux (2015)

The present study combines field and satellite observations to investigate how hydrographical transformations influence phytoplankton size structure in the southern Bay of Bengal during the peak Southwest Monsoon/Summer Monsoon (JulyAugust). The intrusion of the Summer Monsoon Current (SMC) into the Bay of Bengal and associated changes in sea surface chemistry, traceable eastward up to 90E along 8N, seems to influence biology of the region significantly. Both in situ and satellite (MODIS) data revealed low surface chlorophyll except in the area influenced by the SMC. During the study period, two well-developed cyclonic eddies (north) and an anti-cyclonic eddy (south), closely linked to the main eastward flow of the SMC, were sampled. Considering the capping effect of the low-saline surface water that is characteristic of the Bay of Bengal, the impact of the cyclonic eddy, estimated in terms of enhanced nutrients and chlorophyll, was mostly restricted to the subsurface waters (below 20 m depth). Conversely, the anti-cyclonic eddy aided by the SMC was characterized by considerably higher nutrient concentration and chlorophyll in the upper water column (upper 60 m), which was contrary to the general characteristic of such eddies. Albeit smaller phytoplankton predominated the southern Bay of Bengal (6095% of the total chlorophyll), the contribution of large phytoplankton was double in the regions influenced by the SMC and associated eddies. Multivariate analysis revealed the extent to which SMC-associated eddies spatially influence phytoplankton community structure. The study presents the first direct quantification of the size structure of phytoplankton from the southern Bay of Bengal and demonstrates that the SMC-associated hydrographical ramifications significantly increase the phytoplankton biomass contributed by larger phytoplankton and thereby influence the vertical opal and organic carbon flux in the region.

Research areas: Ecosystems
Peculiar weather patterns effects on air pollution and COVID-19 spread in Tokyo metropolis (2023)

As a pandemic hotspot in Japan, between March 1, 2020October 1, 2022, Tokyo metropolis experienced seven COVID-19 waves. Motivated by the high rate of COVID-19incidence and mortality during the seventh wave, and environmental/health challenges we conducted a time-series analysis to investigate the long-term interaction of air quality and climate variability with viral pandemic in Tokyo. Through daily time series geospatial and observational air pollution/climate data, and COVID-19 incidence and death cases, this study compared the environmental conditions during COVID-19 multiwaves. In spite of five State of Emergency (SOEs) restrictions associated with COVID-19 pandemic, during (20202022) period air quality recorded low improvements relative to (20152019) average annual values, namely: Aerosol Optical Depth increased by 9.13% in 2020 year, and declined by 6.64% in 2021, and 12.03% in 2022; particulate matter PM2.5 and PM10 decreased during 2020, 2021, and 2022 years by 10.22%, 62.26%, 0.39%, and respectively by 4.42%, 3.95%, 5.76%. For (20212022) period the average ratio of PM2.5/PM10 was (0.319  0.1640), showing a higher contribution to aerosol loading of traffic-related coarse particles in comparison with fine particles. The highest rates of the daily recorded COVID-19 incidence and death cases in Tokyo during the seventh COVID-19 wave (1 July 20221 October 2022) may be attributed to accumulation near the ground of high levels of air pollutants and viral pathogens due to: 1) peculiar persistent atmospheric anticyclonic circulation with strong positive anomalies of geopotential height at 500 hPa; 2) lower levels of Planetary Boundary Layer (PBL) heights; 3) high daily maximum air temperature and land surface temperature due to the prolonged heat waves (HWs) in summer 2022; 4) no imposed restrictions. Such findings can guide public decision-makers to design proper strategies to curb pandemics under persistent stable anticyclonic weather conditions and summer HWs in large metropolitan areas.

Research areas: Air Quality, Public Health
Multi-year total ozone column variability at three Norwegian sites and the influence of Northern Hemisphere Climatic indices (2023)

Total ozone column (TOC) measurements are retrieved from the Ozone Monitoring Instrument (OMI) onboard the NASA Earth Observing System (EOS) Aura satellite at the three Norwegian sites: Oslo (59.9N 10.7E, 1 m a.s. l.), Trondheim (63.4N 10.4E, 3 m a.s.l.) and Andya (69.1N 15.7E, 32 m a.s.l.). TOC data have been analysed from 2005 to 2021, in order to detect annual and multi-years total ozone variability. The relationship between geopotential height (GPH) at 250 hPa and total ozone column has been evaluated after showing that monthly anomalies in GPH and TOC are correlated amongst the three sites. The influence of the three Northern Hemisphere Tele Connection (TC) indices (North Atlantic Oscillation, Arctic Oscillation and Scandinavia) on TOC variability has been investigated. It is found that Scandinavia index plays a prominent role for the northernmost latitudes of Andya and Trondheim while North Atlantic Oscillation and Arctic Oscillation indices are weakly correlated (negatively) to TOC and (positively) to GPH at Oslo. The response of TOC variability to the solar activity at the three sites is also explored and it is noticed that in the period of increasing variation of solar activity, significant TOC anomaly events are only observed in Andya and Trondheim.

Research areas: Atmospheric/Ocean Indicators, Sun-Earth Interactions