Improving urban weather, climate and air quality

Let us explore alternative ideas about the causes of the extremes of weather and climate. Are we creating our own weather reality? According to Quantum Mechanics, "the action of measurement changes the state of a physical system". This is derived from the superposition principle and "the Schrodinger's cat paradox", i.e., a cat put in a box with a radioactive element is both dead and alive until someone opens the box. This is to mean that the state of the cat is the superposition of the two states "death" and "life". Whether the superposition is linear or non-linear doesn't matter here. The presence of a radioactive material may favor more of death state than alive, so that the superposition sways towards the other end. Then the question is, what is the action of opening? The action of opening collapses the state into one, either death or life and not the superposition of the two. Does the action of opeing the box result in the happenned ...

Debate erupted about spectrally nudging regional climate models during summer 2016 training on regional climate modeling at National Center for Atmospheric Research (NCAR). The debate was whether nudging is valid for regional climate models. Because of the interest of many participants who were PhDs and postdocs from all over the world, special session was assigned for extended discussion. I was new to the nudging concepts at the time, but thought that it is interesting, especially whether nudging is useful for downscaling reanalysis and GCMs incorporating urban canopy models. I dropped my ear and followed the discussion. Based on the ideas raised from the organizers and participants, I also forwarded some questions of relevance for the urban climate modeling. As an extended discussion during the afternoon, many questions were raised: If a regional climate model is spectrally nudged, doesn't it lose its added value as a regional climate model because nudging forces the model t...

Under a warming climate intense heatwaves are expected that would stay for hours, days, weeks and months.  It becomes even worse under urbanization - the more cities grow , the  more natural land covers such as vegetation and soil are replaced by impervious surfaces such as concrete, asphalt roads and buildings. These impervious  urban surfaces can't retain water much longer like soil and vegetation and this would exacerbate the heating further.  Urban heat islands add more than 3 deg. C (Fig. 1) to the heatwaves. The combined effects of heatwaves and urban heat islands are heat-related illnesses and death - specifically affecting young toddlers and old people because their body regulation mechanism is lower. Figure 1. Urban heat island adds more than 3 deg. C to the heatwaves and increases the frequency or duration of the heat. Under a warming climate, it is only a matter of time before we start to seek for cooling mechanisms both for short term and long t...

My recent review paper "Review of urban surface parameterizations for numerical climate models"( https://www.sciencedirect.com/science/article/pii/S2212095517300858 ) presents the historical development of urban climate models, uncertainties and challenges  in obtaining representative urban weather and climate information. There are wide scale urban weather/climate models and the level of detail and complexity required for a particular study is oftentimes a challenge for the climate modeling communities. Weather/climate models are required for different purposes, such as understanding the teleconnections between different scale weather/climate phenomena, for weather forecasting and climate projections, and for policy purposes. Therefore, improving the performance of climate models is one of the top priorities in the climate modeling communities. On the other hand, obtaining accurate initial and boundary information is challenging. Observations data of high spatial density ...

A research conducted in 2014 during my internship at Université du Québec à Montréal (UQAM), Earth and Atmospheric Sciences. Presented at Atmospheric and Oceanic Science unit, IGSSA and Physics Department, Addis Ababa University, Ethiopia Soil organic matter plays an important role in modulating weather/climate. Increase in greenhouse gas concentrations results in considerable rise in land temperatures as indicated by climate projections. The warming of soil facilitates the decomposition of soil organic matter which further adds carbon dioxide in to the atmosphere. The impact of warming of soil if drifts towards wet soil will increase methane gas release in to the atmosphere. Methane is radiatively more active than carbon dioxide, hence results in more warming. The impact of warming of soil does not stop there. It will increase microbial activity which releases nitrogen from the soil and prompt shrub growth resulting in positive albedo feedback. This study, therefore, is star...