The diurnal cycle of cloud profiles over land and ocean between 51° S and 51° N, seen by the CATS spaceborne lidar from the International Space Station

Abstract. We take advantage of 15 months of measurements from the Cloud and Aerosol Transport System (CATS) lidar on the non-sun-synchronous International Space Station (ISS) to document, for the first time, the diurnal cycle of detailed vertical profiles of Cloud Fraction between 51° S and 51° N. After processing CATS lidar data, we analyzed the diurnal cycles of the cloud profiles over ocean and over continent in two different seasons. Over the Tropical ocean in summer, the high clouds geometric thickness increases significantly from 1 km near 5 PM to 5 km near 10 PM, resulting in a high clouds maximum at nighttime. Over the summer tropical continents, CATS observations reveal the presence of a mid-level cloud layer (4–8 km ASL) persisting all-day long, with a weak diurnal cycle (minimum at noon). Over the Southern Ocean, diurnal cycles appear for the omnipresent low-level clouds (minimum between noon and 3 PM) and for the high-altitude clouds (minimum between 8 AM and 2 PM). Both cycles are time-shifted, with high-altitude clouds following the changes in low-altitude clouds by several hours. Over all continents at all latitudes during summer, the low-level clouds develop vertically and reach a maximum occurrence at about 2.5 km ASL in the early afternoon (around 2 pm). Our work also show that 1) the diurnal cycles of vertical profiles derived from CATS are consistent with those from ground-based active sensors at local scale, 2) the cloud profiles derived from CATS measurements at local times of 0130 AM and 0130 PM are consistent with those observed from CALIPSO at similar times, 3) the diurnal cycles of low and high cloud amounts derived from CATS are in general in phase with those derived from geostationary imagery but less pronounced. Finally, the diurnal variability of cloud profiles revealed by CATS strongly suggests that CALIPSO measurements at 0130 AM and PM document the daily extremes of the cloud fraction profiles over ocean and are more representative of daily averages over land, except at altitudes above 10 km where they capture part of the diurnal variability. These findings are equally applicable to other instruments with local overpass times similar to CALIPSO's, like all the other A-Train instruments and the future Earth-CARE mission.

Download Full-text

The diurnal cycle of cloud profiles over land and ocean between 51° S and 51° N, seen by the CATS spaceborne lidar from the International Space Station

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-9457-2018 ◽

2018 ◽

Vol 18 (13) ◽

pp. 9457-9473 ◽

Cited By ~ 18

Author(s):

Vincent Noel ◽

Hélène Chepfer ◽

Marjolaine Chiriaco ◽

John Yorks

Keyword(s):

High Altitude ◽

International Space Station ◽

Diurnal Cycle ◽

Space Station ◽

Cloud Fraction ◽

Vertical Profiles ◽

Diurnal Variability ◽

International Space ◽

Low Level ◽

Diurnal Cycles

Abstract. We document, for the first time, how detailed vertical profiles of cloud fraction (CF) change diurnally between 51∘ S and 51∘ N, by taking advantage of 15 months of measurements from the Cloud-Aerosol Transport System (CATS) lidar on the non-sun-synchronous International Space Station (ISS). Over the tropical ocean in summer, we find few high clouds during daytime. At night they become frequent over a large altitude range (11–16 km between 22:00 and 04:00 LT). Over the summer tropical continents, but not over ocean, CATS observations reveal mid-level clouds (4–8 km above sea level or a.s.l.) persisting all day long, with a weak diurnal cycle (minimum at noon). Over the Southern Ocean, diurnal cycles appear for the omnipresent low-level clouds (minimum between noon and 15:00) and high-altitude clouds (minimum between 08:00 and 14:00). Both cycles are time shifted, with high-altitude clouds following the changes in low-altitude clouds by several hours. Over all continents at all latitudes during summer, the low-level clouds develop upwards and reach a maximum occurrence at about 2.5 km a.s.l. in the early afternoon (around 14:00). Our work also shows that (1) the diurnal cycles of vertical profiles derived from CATS are consistent with those from ground-based active sensors on a local scale, (2) the cloud profiles derived from CATS measurements at local times of 01:30 and 13:30 are consistent with those observed from CALIPSO at similar times, and (3) the diurnal cycles of low and high cloud amounts (CAs) derived from CATS are in general in phase with those derived from geostationary imagery but less pronounced. Finally, the diurnal variability of cloud profiles revealed by CATS strongly suggests that CALIPSO measurements at 01:30 and 13:30 document the daily extremes of the cloud fraction profiles over ocean and are more representative of daily averages over land, except at altitudes above 10 km where they capture part of the diurnal variability. These findings are applicable to other instruments with local overpass times similar to CALIPSO's, such as all the other A-Train instruments and the future EarthCARE mission.

Download Full-text

Stratospheric Aerosol and Gas Experiment III on the International Space Station (SAGE III/ISS) Newly Released V5.2 Validation of Ozone and Water Vapor Data

10.5194/egusphere-egu21-8481 ◽

2021 ◽

Author(s):

Susan Kizer ◽

David Flittner ◽

Marilee Roell ◽

Robert Damadeo ◽

Carrie Roller ◽

...

Keyword(s):

Water Vapor ◽

International Space Station ◽

Space Station ◽

Stratospheric Aerosol ◽

Vertical Profiles ◽

Science Data ◽

International Space ◽

Lunar Occultation ◽

Data Continuity

<p>The Stratospheric Aerosol and Gas Experiment III (SAGE III) instrument installed on the International Space Station (ISS) has completed over three and a half years of data collection and production of science data products. The SAGE III/ISS is a solar and lunar occultation instrument that scans the light from the Sun and Moon through the limb of the Earth&#8217;s atmosphere to produce vertical profiles of aerosol, ozone, water vapor, and other trace gases. It continues the legacy of previous SAGE instruments dating back to the 1970s to provide data continuity of stratospheric constituents critical for assessing trends in the ozone layer. This presentation shows the validation results of comparing SAGE III/ISS ozone and water vapor vertical profiles from the newly released v5.2 science product with those of in situ and satellite data .</p>

Download Full-text

A Global Analysis of Dust Diurnal Variability Using CATS Observations

10.5194/acp-2020-991 ◽

2020 ◽

Author(s):

Yan Yu ◽

Olga V. Kalashnikova ◽

Michael J. Garay ◽

Huikyo Lee ◽

Myungje Choi ◽

...

Keyword(s):

Diurnal Cycle ◽

Global Analysis ◽

Space Station ◽

Dust Emission ◽

Analytical Framework ◽

Diurnal Variability ◽

Diurnal Cycles ◽

Dust Sources ◽

Dust Loading ◽

Bodele Depression

Abstract. The current study investigates the diurnal cycle of dust loading across the global tropics, sub-tropics, and mid-latitudes by analyzing aerosol extinction and typing profiles observed by the Cloud–Aerosol Transport System (CATS) lidar aboard the International Space Station. According to the comparison with ground-based and other satellite observations, CATS aerosol and dust loading observations exhibits reasonable quality but significant day–night inconsistency. To account for this day–night inconsistency in CATS data quality, the diurnal variability in dust characteristics are currently examined separately for daytime and nighttime periods. Based on an analysis of variance analytical framework, pronounced diurnal variations in dust loading are generally uncovered during daytime periods and over terrestrial areas. The current study identifies statistically significant diurnal variability in dust loading over key dust sources, including the Bodélé Depression, the West African El Djouf, Rub-al Khali Desert, and western and southern North America, confirming the previous observation-based findings regarding the diurnal cycle of dust emission and underlying meteorological processes in these regions. Significant seasonal dust diurnal variability is identified over the Iraqi and Thar deserts. The identified significant diurnal cycles in dust loading over the rainforests in Amazon and tropical southern Africa are hypothesized to be driven by enhanced dust emission due to wildfires.

Download Full-text

Evaluating the Diurnal Cycle of Upper-Tropospheric Ice Clouds in Climate Models Using SMILES Observations

Journal of the Atmospheric Sciences ◽

10.1175/jas-d-14-0124.1 ◽

2015 ◽

Vol 72 (3) ◽

pp. 1022-1044 ◽

Cited By ~ 21

Author(s):

Jonathan H. Jiang ◽

Hui Su ◽

Chengxing Zhai ◽

T. Janice Shen ◽

Tongwen Wu ◽

...

Keyword(s):

Diurnal Cycle ◽

Climate Models ◽

Space Station ◽

Temporal Patterns ◽

Spatial And Temporal Patterns ◽

Ice Clouds ◽

Diurnal Variability ◽

Diurnal Cycles ◽

Ice Cloud ◽

The Tropics

Abstract Upper-tropospheric ice cloud measurements from the Superconducting Submillimeter Limb Emission Sounder (SMILES) on the International Space Station (ISS) are used to study the diurnal cycle of upper-tropospheric ice cloud in the tropics and midlatitudes (40°S–40°N) and to quantitatively evaluate ice cloud diurnal variability simulated by 10 climate models. Over land, the SMILES-observed diurnal cycle has a maximum around 1800 local solar time (LST), while the model-simulated diurnal cycles have phases differing from the observed cycle by −4 to 12 h. Over ocean, the observations show much smaller diurnal cycle amplitudes than over land with a peak at 1200 LST, while the modeled diurnal cycle phases are widely distributed throughout the 24-h period. Most models show smaller diurnal cycle amplitudes over ocean than over land, which is in agreement with the observations. However, there is a large spread of modeled diurnal cycle amplitudes ranging from 20% to more than 300% of the observed over both land and ocean. Empirical orthogonal function (EOF) analysis on the observed and model-simulated variations of ice clouds finds that the first EOF modes over land from both observation and model simulations explain more than 70% of the ice cloud diurnal variations and they have similar spatial and temporal patterns. Over ocean, the first EOF from observation explains 26.4% of the variance, while the first EOF from most models explains more than 70%. The modeled spatial and temporal patterns of the leading EOFs over ocean show large differences from observations, indicating that the physical mechanisms governing the diurnal cycle of oceanic ice clouds are more complicated and not well simulated by the current climate models.

Download Full-text

A Global Analysis of Dust Diurnal Variability Using CATS Observations

10.5194/acp-2019-975 ◽

2019 ◽

Author(s):

Yan Yu ◽

Olga V. Kalashnikova ◽

Michael J. Garay ◽

Huikyo Lee ◽

Myungje Choi ◽

...

Keyword(s):

Diurnal Cycle ◽

Global Analysis ◽

Space Station ◽

Dust Emission ◽

Analytical Framework ◽

Diurnal Variability ◽

Diurnal Cycles ◽

Dust Sources ◽

Dust Loading ◽

Bodele Depression

Abstract. The current study investigates the diurnal cycle of dust loading across the global tropics, sub-tropics, and mid-latitudes by analyzing aerosol extinction and typing profiles observed by the Cloud-Aerosol Transport System (CATS) lidar aboard the International Space Station. According to the comparison with ground-based and other satellite observations, CATS aerosol and dust loading observations exhibits reasonable quality and insignificant day-night inconsistency, thereby supporting the current analysis of dust diurnal cycle using CATS data. Based on an analysis of variance analytical framework, statistically significant diurnal variability in dust loading is identified over key dust sources, including the Bodélé depression, West African El Djouf, Rub-al Khali desert, and western and southern North America, confirming the previous observation-based findings regarding the diurnal cycle of dust emission and underlying meteorological processes in these regions. Insignificant annual mean dust diurnal variability is identified over the Iraqi, Thar, and Taklamakan deserts. The currently identified significant diurnal cycles in dust loading over the rainforests in Amazon and tropical southern Africa, and drylands in South America and the central Australia, are hypothesized to be driven by enhanced dust emission due to wildfires and enhanced katabatic and frontal winds, respectively.

Download Full-text

A global analysis of diurnal variability in dust and dust mixture using CATS observations

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-1427-2021 ◽

2021 ◽

Vol 21 (3) ◽

pp. 1427-1447

Author(s):

Yan Yu ◽

Olga V. Kalashnikova ◽

Michael J. Garay ◽

Huikyo Lee ◽

Myungje Choi ◽

...

Keyword(s):

Diurnal Cycle ◽

Global Analysis ◽

Space Station ◽

Dust Emission ◽

Analytical Framework ◽

West African ◽

Diurnal Variability ◽

Diurnal Cycles ◽

Dust Sources ◽

Bodele Depression

Abstract. The current study investigates the diurnal cycle of dust and dust mixture loading across the global tropics, subtropics, and mid-latitudes by analyzing aerosol extinction and typing profiles observed by the Cloud-Aerosol Transport System (CATS) lidar aboard the International Space Station. According to the comparison with ground-based and other satellite observations, CATS aerosol and dust and dust mixture loading observations exhibit reasonable quality but significant day–night inconsistency. To account for this day–night inconsistency in CATS data quality, the diurnal variability in dust and dust mixture characteristics is currently examined separately for daytime and nighttime periods. Based on an analysis of variance (ANOVA) analytical framework, pronounced diurnal variations in dust and dust mixture loading are generally uncovered during daytime periods and over terrestrial areas. The current study identifies statistically significant diurnal variability in dust and dust mixture loading over key dust sources, including the Bodélé Depression, the West African El Djouf, Rub' al-Khali desert, and western and southern North America, confirming the previous observation-based findings regarding the diurnal cycle of dust emission and underlying meteorological processes in these regions. Significant seasonal and diurnal variability in dust and dust mixture is identified over the Iraqi and Thar deserts. The identified significant diurnal cycles in dust mixture loading over the vegetated regions in the Amazon and tropical southern Africa are hypothesized to be driven by enhanced dust emission due to wildfires.

Download Full-text