This manuscript addresses modeling aspects of plant atmosphere coupling and the role aerosols might play in it, with a focus on situations during the onset of the Indian summer monsoon.

This is not a mechanistic study and thus has to rely on covariances. For doing this,  it makes use if three typical situations that are classified by the variations of aerosol concentrations and temperatures.

While I think this is generally a valid idea and could work, I also see a considerable amount of uncertainties and unclear definitions which reduce the validity.

First, the examples are not so well chosen. In Fig. 1, the differerence in AOD variation during the HALT period and the LAHT period is not clear. The distance between AOD minimum and AOD maximum during both periods is almost the same, just the mean trend is different (decreasing during HALT; increasing during LAHT). Why is the fourth possible scenario (LALT), not mentioned, would it support the conclusions?

Also, plants have different water strategies which particularly determines their response to vpd. Isohydric plants readily reduce stomatal aperture with increasing vpd, as it is assumed here. However, anisohydric plants tend to keep stomata open, some of them to the extent that they (nearly) become wilty, for the benefit of keeping up CO2 uptake and photosynthesis. What kind of strategy  did the plants on the respective grassland use? Details about species are not given, apart from a semi-natural grassland with different C4 grasses representative for grasslands of the region. C4 grasses may be isohydric or anisohydric (e.g., Jardine, Thomas & Osborne, Ecology and Evolution, 2021), bringing the transpiration /EF reaction to vpd and the conclusions drawn in the manuscript into question. This point is my major criticism, as it can question the whole approach, si it must be considered.

The manuscript is very difficult to read. It should include a table with explanations for the more than 30 abbreviations used. These are too many for keeping all in mind and going back to the first mention is impractical.  

What is more, the manuscript lacks thorough definitions. The word ‘continuum‘ is used as ‚Aerosol-plant-temperature-EF continuum‘ (l. 36), as ‚‘land-atmosphere-energy balance continuum‘ (194), and as ‘aerosol-Tair-VPD-EF continuum‘ (l. 426). A thorough definition of a continuum would be something as the soil-plant-atmosphere continuum (SPAC), an established term in plant physiology, based on the water potential as a driving, unifying factor that determines the flow of water and water vapor, independent of the physical water status (Liquid water or water vapor). Maybe something like connection is meant here, but it is really difficult to guess.

Review of Observations of Aerosol-Vapor Pressure Deficit-Evaporative Fraction coupling over India

This paper is an interesting discussion of the link between aerosols, vapor pressure deficit and evapotranspiration over India. The paper presents some interesting findings: 1) sensible heat is lower under heat wave conditions, 2) latent heat is enhanced under aerosol loading due to diffuse fertilization, and 3) decoupling of the vapor pressure deficit response under high aerosol load.

These are very intersting findings, as they turn out to be different than what is common knowledge for regions that do not have the aersol load of India and provides insights into the coupled behavior of air pollution, vegetation, and weather.

Major comments:

* The finding that the evaporation response to vapor pressure deficit becomes really weak under a high aerosol optical depth is very interesting, but also controversial. The authors demonstrate the opposite findings in a modelling study, which shows that their results might be very important. At the same time: one figure (Fig. 4) does not really convince me. The explanation of it remains rather limited and I think that this finding deserves a far more thorough analysis before this paper can be accepted. Vapor pressure deficit is not the only driver of stomatal resistance, and it would be good to carefuly look into each of them. It would be nice to analyze here a few diurnal cycles into detail. I would like to see the evolution of the evapotranspiration and specific humidity, next to the radiation and the surface temperature.

* The inversion of Penman-Monteith that leads to figure 4 is not reproducible. I would like to see this method thorougly described in the paper. Furthermore, I am a little skeptical of using surface temperature here. Please also compute the stomatal resistance using the air temperature as Penman-Monteith does as well.

Minor comments:

* In my view, all acronyms could be replaced by written words in order to make the paper more readable. It does do no harm if the paper is 20 lines longer for that reason.

* The overall quality of the figures is too poor for publication. Please make sure all figures have a consistent font size, are not stretched and have either a vector format, or a high enough resolution.

* Please use units consistently, I see W/m2 as well as W m^{-2}. Please add a space between different units.

* Line 71-73: the paper of Van Heerwaarden & Teuling (2014, Biogeosciences) shows exactly the threshold where VPD increase leads to a shutdown, rather than increase in ET.

* Figure 4: Please check the units of VPD, these must be Pa for these values.