Daniel Toledo

Dr. Daniel Toledo


Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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23 April 2018 in Nature Astronomy
Verified
Journal Article
Closed access
PDF file
PIPatrick G. J. Irwin
Patrick G. J. Irwin
DTDaniel Toledo
Daniel Toledo
RGRyan Garland
Ryan Garland
NTNicholas A. Teanby
Nicholas A. Teanby
LFLeigh N. Fletcher
Leigh N. Fletcher
BBBruno Bézard
Bruno Bézard

26 April 2017 in Atmospheric Measurement Techniques
Verified
Journal Article
Open access
PDF file
VCVanessa Caicedo
Vanessa Caicedo
BRBernhard Rappenglück
Bernhard Rappenglück
BLBarry Lefer
Barry Lefer
GMGary Morris
Gary Morris
DTDaniel Toledo
Daniel Toledo
RDRubén Delgado
Rubén Delgado
Three algorithms for estimating the boundary layer heights are assessed: an aerosol gradient method, a cluster analysis method, and a Haar wavelet method. Over 40 daytime clear-sky radiosonde profiles are used to compare aerosol backscatter boundary layer heights retrieved by a Vaisala CL31 ceilometer. Overall good agreement between radiosonde- and aerosol-derived boundary layer heights was found for all methods. The cluster method was found to be particularly sensitive to noise in ceilometer signals and lofted aerosol layers (48.8 % of comparisons), while the gradient method showed limitations in low-aerosol-backscatter conditions. The Haar wavelet method was demonstrated to be the most robust, only showing limitations in 22.5 % of all observations. Occasional differences between thermodynamically and aerosol-derived boundary layer heights were observed.

27 May 2022 in Science Advances
Verified
Journal Article
Open access
CNClaire E. Newman
Claire E. Newman
RHRicardo Hueso
Ricardo Hueso
MLMark T. Lemmon
Mark T. Lemmon
AMAsier Munguira
Asier Munguira
AVAlvaro Vincente-Retortillo
Alvaro Vincente-Retortillo
SGScott D. Guzewich
Scott D. Guzewich
Despite the importance of sand and dust to Mars geomorphology, weather, and exploration, the processes that move sand and that raise dust to maintain Mars’ ubiquitous dust haze and to produce dust storms have not been well quantified in situ, with missions lacking either the necessary sensors or a sufficiently active aeolian environment. Perseverance rover’s novel environmental sensors and Jezero crater’s dusty environment remedy this. In Perseverance’s first 216 sols, four convective vortices raised dust locally, while, on average, four passed the rover daily, over 25% of which were significantly dusty (“dust devils”). More rarely, dust lifting by nonvortex wind gusts was produced by daytime convection cells advected over the crater by strong regional daytime upslope winds, which also control aeolian surface features. One such event covered 10 times more area than the largest dust devil, suggesting that dust devils and wind gusts could raise equal amounts of dust under nonstorm conditions.

1 March 2019 in Icarus
Verified
Journal Article
Open access
PIPatrick G.J. Irwin
Patrick G.J. Irwin
DTDaniel Toledo
Daniel Toledo
RGRyan Garland
Ryan Garland
NTNicholas A. Teanby
Nicholas A. Teanby
LFLeigh N. Fletcher
Leigh N. Fletcher
BBBruno Bézard
Bruno Bézard

9 September 2022 in Geophysical Research Letters
Verified
Journal Article
Open access
MLM. T. Lemmon
M. T. Lemmon
MSMichael Smith
Michael Smith
DVDaniel Viúdez-Moreiras
Daniel Viúdez-Moreiras
MTM. de la Torre‐Juarez
M. de la Torre‐Juarez
AVAlvaro Vincente-Retortillo
Alvaro Vincente-Retortillo
VAVictor Apestigue
Victor Apestigue
Rovers and landers on Mars have experienced local, regional, and planetary‐scale dust storms. However, in situ documentation of active lifting within storms has remained elusive. Over 5–11 January 2022 (L S 153°–156°), a dust storm passed over the Perseverance rover site. Peak visible optical depth was ∼2, and visibility across the crater was briefly reduced. Pressure amplitudes and temperatures responded to the storm. Winds up to 20 m s −1 rotated around the site before the wind sensor was damaged. The rover imaged 21 dust‐lifting events—gusts and dust devils—in one 25‐min period, and at least three events mobilized sediment near the rover. Rover tracks and drill cuttings were extensively modified, and debris was moved onto the rover deck. Migration of small ripples was seen, but there was no large‐scale change in undisturbed areas. This work presents an overview of observations and initial results from the study of the storm.

4 June 2022 in Journal of Geophysical Research: Planets
Verified
Journal Article
Open access
PIP. G. J. Irwin
P. G. J. Irwin
NTN. A. Teanby
N. A. Teanby
LFL. N. Fletcher
L. N. Fletcher
DTDaniel Toledo
Daniel Toledo
GOG. S. Orton
G. S. Orton
JDJ. Dobinson
J. Dobinson
We present a reanalysis (using the Minnaert limb‐darkening approximation) of visible/near‐infrared (0.3–2.5 μm) observations of Uranus and Neptune made by several instruments. We find a common model of the vertical aerosol distribution i.e., consistent with the observed reflectivity spectra of both planets, consisting of: (a) a deep aerosol layer with a base pressure >5–7 bar, assumed to be composed of a mixture of H2S ice and photochemical haze; (b) a layer of photochemical haze/ice, coincident with a layer of high static stability at the methane condensation level at 1–2 bar; and (c) an extended layer of photochemical haze, likely mostly of the same composition as the 1–2‐bar layer, extending from this level up through to the stratosphere, where the photochemical haze particles are thought to be produced. For Neptune, we find that we also need to add a thin layer of micron‐sized methane ice particles at ∼0.2 bar to explain the enhanced reflection at longer methane‐absorbing wavelengths. We suggest that methane condensing onto the haze particles at the base of the 1–2‐bar aerosol layer forms ice/haze particles that grow very quickly to large size and immediately “snow out” (as predicted by Carlson et al. (1988), https://doi.org/10.1175/1520-0469(1988)0452.0.CO;2), re‐evaporating at deeper levels to release their core haze particles to act as condensation nuclei for H2S ice formation. In addition, we find that the spectral characteristics of “dark spots”, such as the Voyager‐2/ISS Great Dark Spot and the HST/WFC3 NDS‐2018, are well modelled by a darkening or possibly clearing of the deep aerosol layer only.