Ari-Matti Harri

Ari-Matti Harri
Finnish Meteorological Institute

PhD

About

264
Publications
40,643
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Introduction
Skills and Expertise

Publications

Publications (264)
Article
Full-text available
Modeling and observations have long demonstrated that Martian dust storms strongly interfere with global circulation patterns and change the diurnal and semidiurnal pressure variability as well as oscillations with periods greater than one sol associated with planetary waves. As of early 2022, five Mars years of pressure data have been collected by...
Article
Diurnal ground surface temperatures (Tg) and the five major terms of the surface energy budget (SEB) are displayed from hourly Mars Science Laboratory observations and from column model simulations in four contrasting cases along the Curiosity traverse. Tg and the SEB terms are otherwise well simulated on regolith near the landing spot and on rocky...
Article
Interaction between mesoscale, synoptic and planetary scale circulations on Mars can combine to produce locally complex winds that make interpretation of lander wind data a challenge. We investigate the structure of the boundary layer winds by obtaining new wind speed and directions from trajectory analysis of the Viking 1, Viking 2 and InSight lan...
Article
Full-text available
NASA’s Mars 2020 (M2020) rover mission includes a suite of sensors to monitor current environmental conditions near the surface of Mars and to constrain bulk aerosol properties from changes in atmospheric radiation at the surface. The Mars Environmental Dynamics Analyzer (MEDA) consists of a set of meteorological sensors including wind sensor, a ba...
Article
Near-surface air moisture observations from Phoenix and Curiosity display diurnal adsorption, which appears insensitive to mineralogy of regolith. To study this, adsorptive column model simulations are made for midsummer at Phoenix, validated against recalibrated TECP water vapor pressures p. Two standard-form (= obeying the van't Hoff equilibrium...
Article
Short-range forecasts (nowcasts) of rainfall facilitate providing early warning of severe rainfall and flooding, which is particularly important in densely populated urban areas. Nowcasts are conventionally obtained by extrapolation of radar echoes from a CAPPI or lowest-angle PPI. Lacking a model for growth or decay, this approach has limited abil...
Article
Two recalibrated sets of Phoenix (PHX) near-surface TECP air humidity measurements were compared with results from adsorptive single column model simulations during a warm clear-sky polar midsummer period, PHX sols 50–60. The model's 2 m temperatures were close to the observed values. Relative humidity (RH) is very low during the day but at night R...
Poster
Full-text available
The Mars MetNet mission is based on a new semi-hard landing vehicle called MetNet Lander (MNL). The scientific payload of the Mars MetNet Precursor mission is divided into three categories: Atmospheric instruments, Optical devices and Composition and structure devices. Each of the payload instruments will provide significant insights in to the Mart...
Article
Full-text available
The Rover Environmental Monitoring Station (REMS) instrument that is onboard NASA's Mars Science Laboratory (MSL) Curiosity rover. REMS has been measuring surface pressure, air and ground brightness temperature, relative humidity, and UV irradiance since MSL's landing in 2012. In Mars Year (MY) 34 (2018) a global dust storm reached Gale Crater at L...
Article
Full-text available
Plain Language Summary The 2018 Mars global dust storm was observed by six spacecraft in orbit and two rovers on the surface. This paper provides an overview and description of the Mars Science Laboratory Curiosity rover's observations during the storm. For approximately 100 Martian days (sols), the rover conducted an enhanced cadence of environmen...
Poster
Full-text available
A new kind of planetary exploration mission for Mars is under development in collaboration between the Finnish Meteorological Institute (FMI), Lavochkin Association (LA), Space Research Institute (IKI) and Institutio Nacional de Tecnica Aeroespacial (INTA). The Mars MetNet mission is based on a new semi-hard landing vehicle called MetNet Lander (MN...
Poster
Mars Environmental Dynamic Analyzer (MEDA) is a set of environmental sensors on board NASA’s Mars 2020 rover provided by Spain’s Centro de Astrobiología. MEDA’s principal goals are to provide continuous measurements that characterize the diurnal to seasonal cycles of local environmental dust properties and near-surface environment. MEDA sensor pack...
Article
Full-text available
The first of the two missions foreseen in the ExoMars program was successfully launched on 14th March 2016. It included the Trace Gas Orbiter and the Schiaparelli Entry descent and landing Demonstrator Module. Schiaparelli hosted the DREAMS instrument suite that was the only scientific payload designed to operate after the touchdown. DREAMS is a me...
Article
Full-text available
Short-term forecasting (nowcasting) of rainfall is widely used in providing early warning, and therefore, has very practical application. The CASA demonstration network deployed in the Dallas–Fort Worth (DFW) area consists of high-resolution X-band radars deployed around the National Weather Service Radar WSR-88D, and nowcasting of precipitation is...
Article
Variable levels of methane in the martian atmosphere have eluded explanation partly because the measurements are not repeatable in time or location. We report in situ measurements at Gale crater made over a 5-year period by the Tunable Laser Spectrometer on the Curiosity rover. The background levels of methane have a mean value 0.41 ± 0.16 parts pe...
Poster
Full-text available
The major scientific result of PNOWWA is the development of a new method for nowcasting snowfall based on extrapolation of movement analysed in consequent radar images, assessing the uncertainties of snowfall nowcasting related to growth and decay using the scale analysis and ensamble nowcasting technologies. Another major result towards operationa...
Poster
Full-text available
The CITYZER project develops a new open ecosystem of digital services and products to support decision making processes related to weather and air quality in cities. This includes, e.g., user-tailored early warnings and forecasts (0-24 h), which could help to avoid weather-related accidents, mitigate human distress and costs from weather-related da...
Poster
Finnish Meteorological Institute (FMI) has developed a compact instrument pair for the ExoMars 2020 mission, consisting of the METEO-P pressure and METEO-H humidity measurement devices. The devices are part of the METEO meteorological instrument package on board the Surface Platform (SP) element of the mission. The SP is a stationary lander hosting...
Poster
Finnish Meteorological Institute (FMI) provides a pressure measurement device (MEDA PS) and a relative humidity measurement device (MEDA HS) for NASA’s Mars 2020 rover. The sensors are part of Mars Environmental Dynamic Analyzer (MEDA), a suite of environmental sensors provided by Spain’s Centro de Astrobiología. MEDA’s principal goals are to provi...
Presentation
A new kind of planetary exploration mission for Mars is under development in collaboration between the Finnish Meteorological Institute (FMI), Lavochkin Association (LA), Space Research Institute (IKI) and Institutio Nacional de Tecnica Aerospacial (INTA), The Mars MetNet mission is based on a new semi-hard landing vehicle called MetNet Lander (MNL...
Article
Currently, there are several space-borne microwave instruments suitable for detection and quantitative estimation of snowfall. To test and improve retrieval snowfall algorithms, ground validation datasets that combine detailed characterization of snowfall microphysics and spatial precipitation measurements are required. To this endpoint, measuremen...
Article
Martian boundary layer wind speed and direction measurements, from a variety of locations, seasons and times, are provided. For each lander sent to Mars over the last four decades a unique record of the winds blowing during their descent is preserved at each landing site. By comparing images acquired from orbiting spacecraft of the impact points of...
Article
Full-text available
The DREAMS (Dust characterization, Risk assessment and Environment Analyser on the Martian Surface) instrument on Schiaparelli lander of ExoMars 2016 mission was an autonomous meteorological station designed to completely characterize the Martian atmosphere on surface, acquiring data not only on temperature, pressure, humidity, wind speed and its d...
Article
The Rover Environmental Monitoring Station (REMS) on the Curiosity Rover is operating in the Southern Hemisphere of Mars and is detecting synoptic period oscillations in the pressure data that we attribute to Northern Hemisphere transient eddies. We base this interpretation on the similarity in the periods of the eddies and their seasonal variation...
Article
Full-text available
The International Mars Exploration Working Group (IMEWG) was formed in 1993 to provide a forum for the international coordination of Mars exploration. In 2007, IMEWG chartered the international Mars Architecture for the Return of Samples Working Group (iMARS WG), which produced a Phase 1 report in 2008 (iMARS, 2008). In 2014, IMEWG chartered an iMA...
Poster
Full-text available
The poster presents an overview of the EOPEN project (H2020-776019) funded by the European Commission. Details can be found on the project website: http://eopen-project.eu/
Conference Paper
Full-text available
Winter Weather is a prominent reason for delays and cancellation of flights. It influences to many airport procedures Airside and Landside of airport. The SESAR (Single European Sky ATM Research) 2020 Exploratory Research (ER) Project PNOWWA (Probabilistic Nowcasting of Winter Weather for Airports) is a joint effort of Finnish Meteorological Instit...
Article
Boundary layer simulations are shown for the first sols of the two Viking landers (VL1, VL2) on Mars. The column model (with cloud/radiation interaction and Prandtl slope wind terms), used successfully for Phoenix and Curiosity, is equipped here with an adsorption-diffusion scheme for water vapor transport in porous regolith. The model's 1.6 m temp...
Article
Full-text available
We derive water vapor column abundances and aerosol properties from Mars Science Laboratory (MSL) ChemCam passive mode observations of scattered sky light. This paper covers the methodology and initial results for water vapor and also provides preliminary results for aerosols. Each ChemCam passive sky observation acquires spectra at two different e...
Article
Full-text available
We analyze the complete set of in-situ meteorological data obtained from the Viking landers in the 1970s to today’s Curiosity rover to review our understanding of the modern near-surface climate of Mars, with focus on the dust, CO2 and H2O cycles and their impact on the radiative and thermodynamic conditions near the surface. In particular, we prov...
Conference Paper
Full-text available
A new kind of planetary exploration mission for Mars is under development in collaboration between the Finnish Meteorological Institute (FMI), Lavochkin Association (LA), Space Research Institute (IKI) and Institutio Nacional de Tecnica Aerospacial (INTA). The Mars MetNet mission is based on a new semi-hard landing vehicle called MetNet Lander (MNL...
Article
Full-text available
The wind measurement sensors of Viking Lander 1 (VL1) were only fully operational for the first 45 sols of the mission. We have developed an algorithm for reconstructing the wind measurement data after the wind measurement sensor failures. The algorithm for wind reconstruction enables the processing of wind data during the complete VL1 mission. The...
Conference Paper
Full-text available
Barocap® Next Generation (NG) is a gas pressure sensor developed by Vaisala Corporation. The Finnish Meteorological Institute has qualified this sensor for space applications. It has been used in the DREAMS meteorological instrument onboard Exo-Mars Schiaparelli and selected to be used in the meteorological instruments of the Mars 2020 and ExoMars...
Article
This study investigates the connection between properties of snow and radar observations. The general hydrodynamic theory is applied to video-disdrometer measurements to retrieve masses of falling ice particles. Errors associated with the observation geometry and the measured particle size distribution (PSD) are addressed by devising a simple corre...
Article
This research letter is devoted to the two anomalous phenomena in the UHF/VHF radiowave propagation – a " twin " radiometeor backscatter from over-the-horizon (OTH) area of the E-layer. This phenomenon we can see and study in the high power large aperture (HPLA) radar data. Another phenomenon is an OTH daytime auroral backscatter. We believe that t...
Article
Full-text available
DREAMS (Dust Characterisation, Risk Assessment, and Environment Analyser on the Martian Surface) is a payload accommodated on the Schiaparelli Entry and Descent Module (EDM) of ExoMars 2016, the ESA and Roscosmos mission to Mars (Esposito (2015), Bettanini et al. (2014)). It is a meteorological station with the additional capability to perform meas...
Article
Full-text available
Investigations of global and related local phenomena on Mars such as atmospheric circulation patterns, boundary layer phenomena, water, dust and climatological cycles and investigations of the planetary interior would benefit from simultaneous, distributed in situ measurements. Practically, such an observation network would require low-mass landers...
Article
Full-text available
The wind measurement sensors of Viking Lander 1 (VL1) were only fully operational for the initial phase of the mission. We have developed an algorithm for reconstructing the wind measurement data after the wind measurement sensor failures. The algorithm for wind reconstruction enables the processing of wind data during the complete VL1 mission. The...
Article
The Rover Environmental Monitoring Station (REMS) instrument on-board the Mars Science Laboratory (MSL) has acquired unprecedented measurements of key environmental variables at the base of Gale Crater. The pressure measured by REMS shows modulations with a very structured pattern of short-time scale (of the order of seconds to several minutes) mil...
Article
Full-text available
The quality of quantitative precipitation estimation (QPE) is degraded by considerable discrepancies between radar and ground measurements, which are common due to inherent uncertainties between these two kinds of sensor systems. The causes include measurement errors and differences in sampling schemes. Nevertheless, the remaining discrepancies can...
Conference Paper
DREAMS (Dust Characterisation, Risk Assessment, and Environment Analyser on the Martian Surface) is a payload accommodated on the Schiaparelli Entry and Descent Module (EDM) of ExoMars 2016, the ESA – Roscosmos mission to Mars successfully launched on 14 March 2016. The DREAMS data will be archived and distributed to the scientific community throug...
Article
Full-text available
Investigations of global and related local phenomenon on Mars such as atmospheric circulation patterns, boundary layer phenomena, water, dust and climatological cycles and investigations of the planetary interior would benefit from simultaneous in situ measurements with a good spatial coverage. Practically, such an observation network would require...
Conference Paper
Full-text available
A new kind of planetary exploration mission for Mars is under development in collaboration between the Finnish Meteorological Institute (FMI), Lavochkin Association (LA), Space Research Institute (IKI) and Institutio Nacional de Tecnica Aerospacial (INTA). The Mars MetNet mission is based on a new semi-hard landing vehicle called MetNet Lander (MNL...
Conference Paper
Full-text available
The CITYZER project develops new digital services and products to support decision making processes related to weather and air quality in cities. This includes, e.g., early warnings and forecasts (0-24 h), which allow for avoiding weather-related accidents, mitigate human distress and costs from weather-related damage and bad air quality, and gener...
Article
As Viking Lander 1 touched down on Mars one of its footpads fully penetrated a patch of loose fine-grained drift material. The surrounding landing site, as observed by VL-1, was found to exhibit a complex terrain consisting of a crusted surface with an assortment of rocks, large dune-like drifts and smaller patches of drift material. We use a tempe...
Article
Full-text available
The Radiation Assessment Detector (RAD), on board the Mars Science Laboratory (MSL) rover Curiosity, measures the energetic charged and neutral particles and the radiation dose rate on the surface of Mars. Although charged and neutral particle spectra have been investigated in detail, the electron and positron spectra have not been investigated yet...
Article
The study of dust above the lunar surface is important for both science and technology. Dust particles are electrically charged due to impact of the solar radiation and the solar wind plasma and, therefore, they affect the plasma above the lunar surface. Dust is also a health hazard for crewed missions because micron and sub-micron sized dust parti...
Article
Atmospheric tides are the primary source of daily air pressure variation at the surface of Mars. These tides are forced by solar heating of the atmosphere and modulated by the presence of atmospheric dust, topography, and surface albedo and thermal inertia. This results in a complex mix of sun-synchronous and non-sun-synchronous tides propagating b...
Article
Hourly temperatures T, relative humidities RH and mass mixing ratios of moisture q at 1.6 m derived from the Mars Science Laboratory REMS-H and REMS-P measurements are shown for MSL sols 15-17 (Curiosity at Bradbury) and 80-82 (Curiosity at Rocknest). They are compared to column model simulations with and without adsorption to porous regolith. The...
Conference Paper
Full-text available
The inflatable entry system concept have been studied previously for higher payload masses. From 2001 to 2009 the inflatable entry descent and landing system (EDLS) for Martian atmosheric entry was developed by FMI and the MetNet team. The RITD project targeted to analyze and test the transonic behavior of a small payload entry system in Earth’s at...
Conference Paper
Full-text available
A new kind of planetary exploration mission for Mars is being developed in collaboration between the Finnish Meteorological Institute (FMI), Lavochkin Association (LA), Space Research Institute (IKI) and Institutio Nacional de Tecnica Aerospacial (INTA). The Mars MetNet mission is based on a new semi-hard landing vehicle called MetNet Lander (MNL)....
Article
The high inertia, i.e. high mass and low speed, of a landing spacecraft has the potential to drive a penetrometer into the subsurface without the need for a dedicated deployment mechanism, e.g., during Huygens landing on Titan. Such a method could complement focused subsurface exploration missions, particularly in the low gravity environments of co...
Article
Hourly observations of air temperature and relative humidity at 1.6 m height from the surface (T 1.6 m, RH 1.6 m) measured by the Mars Science Laboratory (MSL) Rover Environmental Monitoring Station relative humidity (REMS-H) device are shown for MSL solar days 15–17 and 80–82, augmented with column model simulations. The diurnal range of T 1.6 m w...
Conference Paper
Full-text available
We have developed an atmospheric re-entry and descent system concept based on inflatable hypersonic decelerator techniques that were originally developed for Mars. The ultimate goal of this EU-funded RITD-project (Re-entry: Inflatable Technology Development) was to assess the benefits of this technology when deploying small payloads from low Earth...
Conference Paper
Full-text available
An atmospheric re-entry and descent and landing system (EDLS) concept based on inflatable hypersonic decelerator techniques is highly promising for the Earth re-entry missions. We developed such EDLS for the Earth re-entry utilizing a concept that was originally developed for Mars. This EU-funded project is called RITD - Re-entry: Inflatable Techno...
Article
Water is a requirement for life as we know it1. Indirect evidence of transient liquid water has been observed from orbiter on equatorial Mars2, in contrast with expectations from large-scale climate models. The presence of perchlorate salts, which have been detected at Gale crater on equatorial Mars by the Curiosity rover3,4 , lowers the freezing t...
Article
We report on the first 360 sols (LS 150° to 5°), representing just over half a Martian year, of atmospheric monitoring movies acquired using the NavCam imager from the Mars Science Laboratory (MSL) Rover Curiosity. Such movies reveal faint clouds that are difficult to discern in single images. The data set acquired was divided into two different cl...
Conference Paper
Full-text available
To study the various celestial bodies in the solar system is supposed to use the space descent vehicles (CA) to determine the parameters of the atmosphere and the soil characteristics of the body surface. Dimensions and weight of the landing vehicle limited capacity of launch vehicles. As a device for braking is proposed to use the inflatable braki...