Ari‐Matti Harri
A5039526242- Planetary Science and Exploration
- Astro and Planetary Science
- Space Exploration and Technology
- Spacecraft and Cryogenic Technologies
- Spacecraft Design and Technology
- Spaceflight effects on biology
- Space Science and Extraterrestrial Life
- Ionosphere and magnetosphere dynamics
- Scientific Research and Discoveries
- Distributed and Parallel Computing Systems
- Meteorological Phenomena and Simulations
- Atmospheric and Environmental Gas Dynamics
- Gas Dynamics and Kinetic Theory
- Solar and Space Plasma Dynamics
- Aeolian processes and effects
- Atmospheric aerosols and clouds
- Methane Hydrates and Related Phenomena
- Aerospace Engineering and Energy Systems
- Spacecraft Dynamics and Control
- Geophysics and Gravity Measurements
- Precipitation Measurement and Analysis
- Space Satellite Systems and Control
- Geology and Paleoclimatology Research
- Geomagnetism and Paleomagnetism Studies
- GNSS positioning and interference
Finnish Meteorological Institute
2016-2025
Carnegie Institution for Science
2022
University of Helsinki
2022
Johns Hopkins University Applied Physics Laboratory
2022
Johns Hopkins University
2022
Finnish Geospatial Research Institute
1998
Variable levels of methane in the martian atmosphere have eluded explanation partly because measurements are not repeatable time or location. We report situ at Gale crater made over a 5-year period by Tunable Laser Spectrometer on Curiosity rover. The background mean value 0.41 ± 0.16 parts per billion volume (ppbv) (95% confidence interval) and exhibit strong, seasonal variation (0.24 to 0.65 ppbv). This is greater than that predicted from either ultraviolet degradation impact-delivered...
The ChemCam instrument, which provides insight into martian soil chemistry at the submillimeter scale, identified two principal types along Curiosity rover traverse: a fine-grained mafic type and locally derived, coarse-grained felsic type. component is representative of widespread soils similar in composition to dust. It possesses ubiquitous hydrogen signature spectra, corresponding hydration amorphous phases found by CheMin instrument. This likely accounts for an important fraction global...
Abstract Mars Science Laboratory Curiosity rover observations of the 2018/Mars year 34 global/planet‐encircling dust storm represent first in situ measurements a global with dedicated meteorological sensors since Viking Landers. The team planned and executed science campaign lasting approximately 100 Martian sols to study involving an enhanced cadence environmental monitoring using rover's sensors, cameras, spectrometers. Mast Camera 880‐nm optical depth reached 8.5, Rover Environmental...
The Phoenix Mars Lander detected a larger number of short (∼20 s) pressure drops that probably indicate the passage convective vortices or dust devils. Near‐continuous measurements have allowed for monitoring frequency these events, and data from other instruments orbiting spacecraft give information on how events relate to seasons weather phenomena at landing site. Here 502 were identified with drop than 0.3 Pa occurring in 151 sol mission (L s 76 148). diurnal distributions show peak...
In the first 100 Martian solar days (sols) of Mars Science Laboratory mission, Rover Environmental Monitoring Station (REMS) measured seasonally evolving diurnal cycles ultraviolet radiation, atmospheric pressure, air temperature, ground relative humidity, and wind within Gale Crater on Mars.As an introduction to several REMS-based articles in this issue, we provide overview design performance REMS sensors discuss our approach mitigating some difficulties encountered following landing,...
Abstract This study uses snow events from the Biogenic Aerosols–Effects on Clouds and Climate (BAECC) 2014 campaign to investigate connection between properties of radar observations. The general hydrodynamic theory is applied video-disdrometer measurements retrieve masses falling ice particles. Errors associated with observation geometry measured particle size distribution (PSD) are addressed by devising a simple correction procedure. value factor determined comparison retrieved...
REMS‐P, the pressure measurement subsystem of Mars Science Laboratory (MSL) Rover Environmental Measurement Station (REMS), is performing accurate observations Martian atmospheric surface pressure. It has demonstrated high data quality and good temporal coverage, carrying out first in situ equatorial regions. We describe REMS‐P initial results by MSL mission sol 100 including instrument performance illustrate some interpretations observed features. The show both expected new phenomena at...
Abstract We provide a preliminary interpretation of the Rover Environmental Monitoring Station (REMS) pressure data from first 100 Martian solar days (sols) Mars Science Laboratory mission. The sensor is performing well and has revealed existence phenomena undetected by previous missions that include possible gravity waves excited evening downslope flows, relatively dust‐free convective vortices analogous in structure to dust devils, signatures indicative circulation induced Gale Crater its...
Despite the importance of sand and dust to Mars geomorphology, weather, exploration, processes that move raise maintain Mars' ubiquitous haze produce storms have not been well quantified in situ, with missions lacking either necessary sensors or a sufficiently active aeolian environment. Perseverance rover's novel environmental Jezero crater's dusty environment remedy this. In Perseverance's first 216 sols, four convective vortices raised locally, while, on average, passed rover daily, over...
Abstract NASA’s Perseverance rover’s Mars Environmental Dynamics Analyzer is collecting data at Jezero crater, characterizing the physical processes in lowest layer of Martian atmosphere. Here we present measurements from instrument’s first 250 sols operation, revealing a spatially and temporally variable meteorology Jezero. We find that temperature four heights capture response atmospheric surface to multiple phenomena. observe transition stable night-time thermal inversion daytime, highly...
Abstract The Mars Environmental Dynamics Analyzer (MEDA) on board Perseverance includes first‐of‐its‐kind sensors measuring the incident and reflected solar flux, downwelling atmospheric IR upwelling flux emitted by surface. We use these measurements for first 350 sols of 2020 mission (L s ∼ 6°–174° in Martian Year 36) to determine surface radiative budget calculate broadband albedo (0.3–3 μm) as a function illumination viewing geometry. Together with MEDA ground temperature, we thermal...
The Mars Science Laboratory (MSL) made a successful landing at Gale crater early August 2012. MSL has an environmental instrument package called the Rover Environmental Monitoring Station (REMS) as part of its scientific payload. REMS comprises instrumentation for observation atmospheric pressure, temperature air, ground temperature, wind speed and direction, relative humidity (REMS-H), UV measurements. We concentrate on describing REMS-H measurement performance initial observations during...
This paper presents a review on the PECASUS service, which provides advisories enhanced space weather activity for civil aviation. The are tailored according to Standards and Recommended Practices of International Civil Aviation Organization (ICAO). Advisories disseminated in three impact areas: radiation levels at flight altitudes, GNSS-based navigation positioning, HF communication. review, is based experiences authors from two years running pilot ICAO services, describes empirical models...
Abstract The pressure sensors on Mars rover Perseverance measure the field in Jezero crater regular hourly basis starting sol 15 after landing. present study extends up to 460 encompassing range of solar longitudes from L s ∼ 13°–241° (Martian Year (MY) 36). data show changing daily cycle, sol‐to‐sol seasonal evolution mean driven by CO 2 sublimation and deposition cycle at poles, characterization six components atmospheric tides their relationship dust content atmosphere. They also presence...
Abstract We characterize vortex and dust devils (DDs) at Jezero from pressure winds obtained with the Mars Environmental Dynamics Analyzer (MEDA) instrument on 2020 over 415 Martian days (sols) ( Ls = 6°–213°). Vortices are abundant (4.9 per sol drops >0.5 Pa correcting gaps in coverage) they peak noon. At least one every five vortices carries dust, 75% of all Δ p > 2.0 dusty. Seasonal variability was small but DDs were during a storm 152°–156°). more frequent intense terrains lower...
Abstract The Mars 2020 mission rover “Perseverance”, launched on 30 July by NASA, landed successfully 18 February 2021 at Jezero Crater, (Lon. E 77.4509° Lat. N 18.4446°). landing took place solar longitude Ls = 5.2°, close to start of the northern spring. Perseverance's payload includes relative humidity sensor MEDA HS (Mars Environmental Dynamics Analyzer Humidity Sensor), which operations, performance, and first observations from sol 80 410 (Ls 44°–210°) operations we describe. measured...
Abstract The Mars2020 Perseverance Rover landed successfully on the Martian surface Jezero Crater floor (18.44°N, 77.45°E) at solar longitude, L s , ∼5° in February 2021. Since then, it has produced highly valuable environmental measurements with a versatile scientific payload including MEDA (Mars Environmental Dynamics Analyzer) suite of sensors. One systems is PS pressure sensor system, which weighs 40 g and an estimated absolute accuracy better than 3.5 Pa resolution 0.13 Pa. We present...
The meteorological package (MET) on the Phoenix Lander is designed to provide information daily and seasonal variations in Mars near‐polar weather during Martian late spring summer. present paper provides some background temperature, pressure, wind instrumentation MET station their characterization. A separate addresses lidar instrument. Laboratory studies a tunnel confirm estimates that time constant of thermocouples should be less than 0.5 s for speeds 5 m −1 or greater. Solar radiation...