List of PPE parameters and notes
===
[Return to the main PPE albedo symmetry page](https://hackmd.io/xd8yFI0GQdikYq3-IdWL2Q)
## List of parameters
The associated modules are Cloud Layers Unified by Binomials (CLUBB), Morrison-Gettelman (M-G) microphysics, aerosols and activation (A/A), Zhang-McFarlane (Z-M) deep convection, and Parameterizations for Unified Microphysics Across Scales (PUMAS).
| | Parameter | Module | Reference |
| --- | --- | --- | --- |
| 1. | clubb_C2rt | CLUBB | [Larson (2022)](https://arxiv.org/pdf/1711.03675.pdf) |
| 2. | clubb_C6rt | CLUBB | ""; [Golaz et al. (2002)](https://doi.org/10.1175/1520-0469(2002)059%3C3540:APBMFB%3E2.0.CO;2) |
| 3. | clubb_C6rtb | CLUBB | ""; [Golaz et al. (2002)](https://doi.org/10.1175/1520-0469(2002)059%3C3540:APBMFB%3E2.0.CO;2) |
| 4. | clubb_C6thl | CLUBB | ""; [Golaz et al. (2002)](https://doi.org/10.1175/1520-0469(2002)059%3C3540:APBMFB%3E2.0.CO;2) |
| 5. | clubb_C6thlb | CLUBB | ""; [Golaz et al. (2002)](https://doi.org/10.1175/1520-0469(2002)059%3C3540:APBMFB%3E2.0.CO;2) |
| 6. | clubb_C8 | CLUBB | "" |
| 7. | clubb_beta | CLUBB | "" |
| 8. | clubb_c1 | CLUBB | "" |
| 9. | clubb_c11 | CLUBB | "" |
| 10. | clubb_c14 | CLUBB | "" |
| 11. | clubb_c_K10 | CLUBB | "" |
| 12. | clubb_gamma_coef | CLUBB | "" |
| 13. | clubb_wpxp_L_thresh | CLUBB | "" |
| 14. | micro_mg_autocon_nd_exp | M-G | [Gettelman and Morrison (2015)](https://journals.ametsoc.org/view/journals/clim/28/3/jcli-d-14-00102.1.xml); [Gettelman et al. (2015)](https://journals.ametsoc.org/view/journals/clim/28/3/jcli-d-14-00103.1.xml); [Khairoutdinov and Kogan (2000)](https://journals.ametsoc.org/view/journals/mwre/128/1/1520-0493_2000_128_0229_ancppi_2.0.co_2.xml) |
| 15. | micro_mg_dcs | M-G | ""; "" |
| 16. | micro_mg_accre_enhan_fac | M-G | ""; "" |
| 17. | micro_mg_autocon_fact | M-G | ""; "" |
| 18. | micro_mg_autocon_lwp_exp | M-G | ""; ""; [Khairoutdinov and Kogan (2000)](https://journals.ametsoc.org/view/journals/mwre/128/1/1520-0493_2000_128_0229_ancppi_2.0.co_2.xml) |
| 19. | micro_mg_berg_eff_factor | M-G | ""; "" |
| 20. | micro_mg_homog_size | M-G | ""; "" |
| 21. | dust_emis_fact | A/A | "" |
| 22. | microp_aero_npccn_scale | A/A | "" |
| 23. | microp_aero_wsub_min | A/A | "" |
| 24. | microp_aero_wsub_scale | A/A | "" |
| 25. | microp_aero_wsubi_min | A/A | "" |
| 26. | microp_aero_wsubi_scale | A/A | "" |
| 27. | seasalt_emis_scale | A/A | "" |
| 28. | sol_factb_interstitial | A/A | "" |
| 29. | sol_factic_interstitial | A/A | "" |
| 30. | cldfrc_dp1 | Z-M | [Zhang and McFarlane (1995)](https://www.tandfonline.com/doi/abs/10.1080/07055900.1995.9649539) |
| 31. | cldfrc_dp2 | Z-M | "" |
| 32. | zmconv_c0_lnd | Z-M | "" |
| 33. | zmconv_c0_ocn | Z-M | "" |
| 34. | zmconv_capelmt | Z-M | "" |
| 35. | zmconv_dmpdz | Z-M | "" |
| 36. | zmconv_ke | Z-M | "" |
| 37. | zmconv_ke_lnd | Z-M | "" |
| 38. | zmconv_momcd | Z-M | "" |
| 39. | zmconv_momcu | Z-M | "" |
| 40. | zmconv_num_cin | Z-M | "" |
| 41. | zmconv_tiedke_add | Z-M | "" |
| 42. | micro_mg_effi_factor | PUMAS | "" |
| 43. | micro_mg_iaccr_factor | PUMAS | "" |
| 44. | micro_mg_max_nicons | PUMAS | "" |
| 45. | micro_mg_vtrmi_factor | PUMAS | "" |
# Parameter notes
## CLUBB
### 1. `clubb_C2rt`
Dissipation factor for $\overline{r_t'^2}$ and $\overline{\theta_l'^2}$, the variance of total (liquid + gaseous) water mixing ratio and of liquid water potential temperature, respectively. This coefficient smooths rainfall; decreasing it makes rainfall occur more frequently and evenly, decreasing intensity. Turning this up dims clouds except in places where rainfall matters more, in which case it would brighten clouds.
Mostly impacts the tropics and to some extent the subtropics by dimming clouds, but brightens the midlatitudes. Mostly increases midlatitude cloud fraction, especially in the SH, and slightly increases LWP.
* This one shows that rainfall frequency/efficiency is really important to the albedo symmetry.
* It makes sense that causing midlatitude clouds to precipitate even less frequently would allow them to stay longer (increasing cloud fraction) and grow thicker before raining out (increasing LWP).
### 2. `clubb_C6rt`
Low skewness factor for pressure damping of $\overline{w'r_t'}$ and $\overline{w'\theta_l'}$ (vertical fluxes of total water mixing ratio and liquid water potential temperature, respectively), impacting the skewness of vertical velocities in boundary layer clouds. Decreasing this turns in-cloud scalar fluxes up, especially for Sc clouds.
Impacts the marine subtropical clouds the most, but then also SH midlatitudes heavily; increases tropical cloud brightness. This happens because LWP is decreased in the midlatitudes and increased in the tropics, while subtropical cloud fraction is reduced.
### 3. `clubb_C6rtb`
High skewness factor for pressure damping of $\overline{w'r_t'}$ and $\overline{w'\theta_l'}$, impacting the skewness of vertical velocities in boundary layer clouds. Decreasing this turns in-cloud scalar fluxes up, especially for Cu clouds.
Decreases brightness in mostly subtropical clouds. This happens because both cloud fraction and LWP are decreased.
### 4. `clubb_C6thl`
Low skewness factor for pressure damping of $\overline{w'r_t'}$ and $\overline{w'\theta_l'}$, impacting the skewness of vertical velocities in boundary layer clouds. Decreasing this turns in-cloud scalar fluxes up, especially for Sc clouds.
Decreases subtropical and midlatitude cloud brightness, increases tropical convective cloud brightness. This is because midlatitude ice fraction increases and LWP decreases. Subtropical eastern ocean basin cloud fraction is also reduced.
### 5. `clubb_C6thlb`
High skewness factor for pressure damping of $\overline{w'r_t'}$ and $\overline{w'\theta_l'}$, impacting the skewness of vertical velocities in boundary layer clouds. Decreasing this turns in-cloud scalar fluxes up, especially for Cu clouds.
Decreases subtropical and tropical cloud brightness. This decreases LWP and increases ice fraction in subtropical eastern ocean basin clouds. Subtropical eastern ocean basin cloud fraction is also reduced.
### 6. `clubb_C8`
Tuning parameter for skewness of vertical velocity. Large/positive values tend to be associated with Cu clouds, while small/negative values tend to be associated with Sc clouds. Turning this up decreases the skewness and increases the brightness of clouds.
Increases the brightness of subtropical clouds mostly, but also midlatitude clouds. This happens because cloud fraction and LWP increase (most heavily in the subtropics), and ice fraction is reduced.
### 7. `clubb_beta`
Plume width for $\theta_l$ and $r_t$, impacts the skewness of vertical distributions thereof. Turning this up increases low cloud cover, especially in Sc regions.
Seems to decrease cloud brightness over the midlatitudes. Increases cloud fraction in the tropics and decreases it in the subtropics. It decreases LWP in the tropics and increases it in the midlatitudes some This reduces ice fraction at high latitudes and increases it in low latitudes.
### 8. `clubb_c1`
Damping coefficient for $\overline{w'^2}$, or vertical wind variance. Turning this up dissipates turbulent kinetic energy and increases the skewness of vertical velocity, favoring Cu clouds over Sc clouds.
Decreases cloud brightness in the subtropical clouds by reducing LWP and cloud fraction, and in the midlatitudes by decreasing LWP. Increases ice fraction everywhere.
### 9. `clubb_c11`
Buoyancy pressure damping term. Increasing this reduces the skewness of vertical velocity, favoring brighter clouds.
Increases subtropical cloud brightness by increasing LWP and cloud fraction, and increases midlatitude cloud brightness by increasing LWP.
### 10. `clubb_c14`
Damping coefficient for $\overline{u'^2}$ and $\overline{v'^2}$, the east and west wind variance. Increasing this parameter dissipates the wind variance/turbulent kinetic energy.
Decreases cloud brightness everywhere. This happens because LWP is reduced in the midlatitudes, cloud fraction is reduced in the subtropics to midlatitudes (especially near the eastern ocean basins), and ice fraction increases in the eastern subtropical ocean basins.
* Still a mystery to me. Why should this have such a large impact on so many cloud properties?
### 11. `clubb_c_K10`
Amplification factor for eddy diffusivity of momentum, which pre-multiplies the eddy diffusivity constant. Turning this parameter up increases vertical momentum transfer.
Slightly decreases cloud brightness in the midlatitudes, greatly decreases eastern Pacific tropical cloud brightness. Decreases LWP and IWP everywhere except in the tropics, where IWP increases and cloud fraction decreases.
### 12. `clubb_gamma_coef`
Tunable parameter impacting the variance of the distributions in vertical velocity coordinates. Turning this down tends to increase liquid water path in Sc regions.
Increases tropical cloud brightness, decreases midlatitude cloud brightness. This decreases cloud fraction in the midlatitudes and increases it in the tropics and subtropics. Decreases LWP almost globally and significantly in high latitudes, but locally increases in vary narrow regions in the ITCZ. Slightly decreases droplet number concentrations in the midlatitudes. Increases ice fraction everywhere.
### 13. `clubb_wpxp_L_thresh`
Horizontal threshold for the turbulent length scale.
Increases cloud brightness in subtropical clouds and slightly brightens midlatitude clouds, and decreases tropical cloud brightness. This happens because LWP is increased in the midlatitude clouds and decreased in the ITCZ/central Pacific. Increases cloud fraction in the subtropical eastern ocean basins and decreases it in the central/western ocean basins. Decreases ice fraction globally.
## M-G microphysics
### 14. `micro_mg_autocon_nd_exp`
Exponent for autoconversion rate dependence on cloud droplet number concentration from [Khairoutdinov and Kogan (2000)](https://journals.ametsoc.org/view/journals/mwre/128/1/1520-0493_2000_128_0229_ancppi_2.0.co_2.xml). The equation for the autoconversion rate is:
$$
\big(\frac{\partial q_r}{\partial t}\big)_{AUTO} = 13.5q_c^{2.47}N_c^{-1.1}
$$
In this case, `micro_mg_autocon_nd_exp` is the factor for $N_c$, or -1.1. Therefore increasing this parameter increases autoconversion rate and thus reduces cloud albedo.
Decreases cloud brightness over midlatitudes mostly. Decreases LWP and slightly decreases cloud droplet number concentration in the midlatitudes. Decreases cloud fraction in the subtropics and midlatitudes. Increases ice fraction everywhere.
### 15. `micro_mg_dcs`
Autoconversion size threshold for ice-snow transition.
Increases cloud brightness nearly everywhere, including the midlatitudes. Increases cloud fraction and ice fraction everywhere. Increases SH midlatitude LWP. Greatly decreases Arctic cloud droplet number concentration and LWP.
* This makes sense, since if you increase the size that a cloud particle has to be in order for it to precipitate, it increases lifetime.
### 16. `micro_mg_accre_enhanc_fact`
Enhancement factor for accretion processes; turning this up increases accretion rates and should reduce cloud liquid water path. The equation for the accretion rate is:
$$
\big(\frac{\partial q_r}{\partial t}\big)_{ACCRE} = 67(q_cq_r)^{1.15}
$$
In this case, `micro_mg_accre_enhanc_fact` is the prefactor 67.
Decreases cloud brightness nearly everywhere, except in eastern Pacific tropical convective clouds. Decreases LWP in the midlatitudes and decreases IWP in the tropics. Increases ice fraction everywhere. Decreases cloud fraction over the subtropics and midlatitudes, but increases cloud fraction over the ITCZ. Slightly decreases cloud droplet number concentrations over the midlatitudes but increases it over the polar regions.
### 17. `micro_mg_autocon_fact`
Enhancement factor for autoconversion rates; turning this up increases autoconversion rates. The equation for the autoconversion rate is:
$$
\big(\frac{\partial q_r}{\partial t}\big)_{AUTO} = 13.5q_c^{2.47}N_c^{-1.1}
$$
In this case, `micro_mg_autocon_fact`is the prefactor, or 13.5. Increasing this prefactor should turn up autoconversion and decrease cloud albedo.
Decreases cloud brightness in the midlatitudes (asymmetrically impacting the SH more), and increases eastern Pacific convective cloud brightness. Decreases midlatitude LWP. Slightly decreases midlatitude cloud droplet number concentrations. Decreases midlatitude cloud fraction and increases tropical cloud fraction. Increases western Pacific IWP. Increases ice fraction everywhere.
### 18. `micro_mg_autocon_lwp_exp`
Exponent for autoconversion rate dependence on liquid water path from [Khairoutdinov and Kogan (2000)](https://journals.ametsoc.org/view/journals/mwre/128/1/1520-0493_2000_128_0229_ancppi_2.0.co_2.xml). The equation for the autoconversion rate is:
$$
\big(\frac{\partial q_r}{\partial t}\big)_{AUTO} = 13.5q_c^{2.47}N_c^{-1.1}
$$
In this case, `micro_mg_autocon_lwp_exp`is the factor for $q_c$, or 2.47. Increasing this parameter value turns up autoconversion rate and should decrease cloud albedo.
Increases cloud brightness everywhere, but most heavily the SH midlatitudes, by increasing LWP and cloud fraction (the latter most heavily in the SH midlatitudes). Decreases cloud droplet number concentration in the midlatitudes. Increases eastern Pacific and Indian Ocean tropical IWP. Decreases ice fraction everywhere.
### 19. `micro_mg_berg_eff_factor`
Efficiency factor for Bergeron processes.
Increases cloud brightness most heavily in the SH midlatitudes, and in the ITCZ. Reduces cloud brightness in the Maritime Continent. Decreases cloud fraction in the subtropics and slightly increases cloud fraction in the eastern tropical Pacific. Increases cloud fraction only in the SH midlatitudes and to a lesser extent the Pacific midlatitudes, and decreases cloud droplet number concentration only in the SH high latitudes. Decreases ice fraction everywhere. Decreases IWP in the midlatitudes. Decreases LWP only in the high SH latitudes, and increases LWP everywhere else.
* This one is really asymmetric and shows how precipitation processes differ. It seems to have a dipole where it makes the SH high latitudes very efficient at precipitating and the SH midlatitudes less efficient at precipitating.
### 20. `micro_mg_homog_size`
Homogeneous freezing ice particle size.
Increases cloud brightness over the tropics. Increases LWP in the tropics and subtropics, and slightly increases IWP in the ITCZ. Increases ice fraction everywhere in the extratropics and decreases it in the central/western tropical ocean basins. Increases cloud fraction in the tropics and subtropics and decreases it in the midlatitudes. Decreases cloud droplet number concentration at high latitudes.
## Aerosols/activation
### 21. `dust_emis_fact`
Emission scale factor for dust.
Increases cloud brightness almost everywhere except for the tropical Atlantic off of the coast of western Africa. Especially increases ITCZ cloud brightness. Increases droplet number concentration in the midlatitudes. Increases midlatitude cloud fraction and decreases subtropical and tropical cloud fraction. Increases ice fraction everywhere and decreases ice fraction in the SH subtropical eastern ocean basins. Increases tropical and to a lesser extent midlatitude IWP. Increases tropical and midlatitude LWP.
### 22. `microp_aero_npccn_scale`
Scale for liquid activation of particle numbers.
Increases cloud brightness almost everywere except very locally in the ITCZ. Increases LWP in the midlatitudes. Increases IWP everywhere except in the eastern tropical ocean basins. Decreases ice fraction in the eastern tropical ocean basins and increases it in the eastern subtropical ocean basins as well as the midlatitudes. Increases cloud fraction in the SH subtropical eastern ocean basins, and decreases it over the tropical continents. Increases droplet concentrations at high latittudes.
### 23. `microp_aero_wsub_min`
Minimum subgrid velocity required for liquid activation of aerosols.
Increases cloud brightness in the tropics and midlatitudes, most heavily in the western Pacific tropics. Decreases eastern ocean basin subtropical cloud brightness. Decreases eastern ocean basin subtropical cloud fraction, slightly increases SH midlatitude cloud fraction. Decreases ice fraction over eastern SH subtropical ocean basins and Antarctic, increases ice fraction over Arctic. Increases IWP over the tropics. Increases LWP over the midlatitudes, slightly decreases LWP over eastern subtropical ocean basins.
### 24. `microp_aero_wsub_scale`
Scaling for subgrid velocity when calculating liquid activation of aerosols.
Decreases cloud brightness over SH eastern ocean basins, and lightly increases cloud brightness everywhere else, including the SH midlatitudes. Increases tropical LWP and to a lesser degree SH midlatitude LWP, decreases Arctic LWP. Decreases tropical ice fraction and increases subtropical ice fraction; increases Arctic ice fraction. Decreases SH subtropical eastern ocean basin cloud fraction, increases central/western subtropical ocean basin cloud fraction.
### 25. `microp_aero_wsubi_min`
Minimum subgrid velocity required for freezing activation of aerosols.
Decreases cloud brightness over subtropical eastern ocean basins. Increases cloud brightness in the SH midlatitudes (much more than NH midlatitudes), by increasing both in-cloud LWP, droplet concentration, and cloud fraction. Decreases droplet number concentration, cloud fraction, and LWP in the subtropical eastern ocean basins. Decreases ice fraction everywhere.
### 26. `microp_aero_wsubi_scale`
Scaling for subgrid velocity when calculating freezing activation of aerosols.
Increases cloud brightness over subtropical eastern ocean basins. Decreases cloud brightness in the midlatitudes, by reducing mostly in-cloud LWP, and cloud fraction somewhat. Increases ice fraction everywhere. Decreases IWP along the ITCZ.
### 27. `seasalt_emis_scale`
Emission scale factor for sea salt.
Increases cloud brightness everywhere, but most heavily in the SH midlatitudes. This does so by increasing cloud fraction, LWP, and droplet number concentration. Reduces ice fraction everywhere.
### 28. `sol_factb_interstitial`
Tuning for below-cloud scavenging of non-cloudborne interstitial/non-cloud-nucleating aerosols. Assumed to represent the solubility factor.
Decreases cloud brightness over subtropical eastern ocean basins, as well as over SH midlatitudes. Decreases midlatitude LWP. Decreases IWP along the ITCZ. Increases ice fraction over the midlatitudes and decreases it in the subtropics and over continents. Decreases eastern ocean basin subtropical cloud fraction and increases it over the tropical central/western ocean basins. Decreases droplet number concentrations at mid-high latitudes.
* Increasing the solubility factor when sea salts are the most prevalent aerosols in the SH midlatitudes should indeed impact the clouds there heavily.
### 29. `sol_factic_interstitial`
Tuning for in-cloud scavenging of cloudborne interstitial/non-cloud-nucleating aerosols. Assumed to represent the solubility factor with respect to ice processes within convective clouds.
Decreases central Pacific tropical cloud brightness, increases eastern ocean basin tropical and subtropical cloud brightness. Increases subtropical eastern ocean basin cloud fraction, decreases it in the central/western ocean basins. Increases IWP along the ITCZ, and slightly everywhere else. Increases LWP in the midlatitudes. Seems to cause a northward ITCZ shift.
## Z-M convection
### 30. `cldfrc_dp1`
Cloud fraction parameter for deep convective cloud cover.
Increases cloud brightness over the tropics. Increases LWP, IWP, and cloud fraction in the tropics. Decreases droplet number concentration and increases ice fraction in the midlatitudes. Increases ice fraction in the eastern tropical Pacific, and decreases it in the western Pacific.
### 31. `cldfrc_dp2`
Cloud fraction parameter for deep convective cloud cover.
Increases cloud brightness over the tropics. Increases tropical and subtropical cloud fraction. Increases droplet number concentration at high latitudes. Increases IWP everywhere, but mostly in along the ITCZ. Increases LWP in the tropics and mid-high latitudes, and decreases LWP in the eastern subtropical ocean basins. Decreases ice fraction everywhere except for the western tropical Pacific.
### 32. `zmconv_c0_lnd`
Convective precipitation (autoconversion) efficiency over land.
Decreases cloud brightness over tropical South America, Africa, and the Maritime Continent. Increases eastern ocean basin cloud brightness in the Pacific and Atlantic. Increases (decreases) LWP over tropical and subtropical ocean (land). Decreases IWP over land. Decreases ice fraction everywhere except for over tropical land. Changes cloud fraction zonally asymmetrically in the tropics and subtropics. Decreases droplet number concentration over mid-high latitudes.
### 33. `zmconv_c0_ocn`
Convective precipitation (autoconversion) efficiency over ocean.
Decreases cloud brightness over tropical ocean. Increases tropical and subtropical ocean cloud fraction. Increases ice fraction over the tropics. Decreases ice fraction over the subtropics and midlatitudes. Decreases IWP in the tropics. Decreases LWP in the tropics. Increases droplet concentration and LWP in the midlatitudes.
### 34. `zmconv_capelmt`
Threshold value for minimum convective available potential energy needed for deep convection.
Decreases cloud brightness over tropical ocean, except for the eastern Pacific near South America. Increases LWP over the midlatitudes. Decreases ice fraction in the midlatitudes, and increases it elsewhere. Slightly increases IWP along the ITCZ. Decreases cloud fraction over western/central subtropical ocean basins and increases it in the eastern tropical Pacific. Increases droplet number concentration in the midlatitudes.
### 35. `zmconv_dmpdz`
Air parcel fractional mass entrainment rate.
Increases cloud brightness over tropical and subtropical central Pacific, western Atlantic, and western Indian Ocean. Decreases cloud fraction in the subtropical and tropical eastern ocean basins, and increases it in the central tropical and subtropical ocean basins. Decreases ice fraction in the tropics, and increases it in the eastern subtropical ocean basins. Decreases LWP in the subtropical eastern ocean basins and increases it in the tropics, as well as slightly in the mid-high latitudes.
### 36. `zmconv_ke`
Evaporation efficiency of convective precipitation.
Increases cloud brightness everywhere, but mostly in the tropical eastern Pacific and the Indian Ocean. Increases LWP in the midlatitudes. Increases IWP in the western tropical Pacific and over the Maritime Continent. Decreases ice fraction everywhere except locally in the central tropical Pacific and Atlantic Oceans. Increases cloud fraction in the tropics and subtropics. Slightly increases droplet number concentration in mid-high latitudes.
### 37. `zmconv_ke_lnd`
Evaporation efficiency of convective precipitation over land.
Increases cloud brightness everywhere in the ocean, including over the midlatitudes. This is because LWP increases. Increases droplet number concentration in the midlatitudes. Increases subtropical cloud fraction. Decreases ice fraction everywhere except over in the SH eastern subtropical ocean basins. Decreases IWP along the ITCZ.
### 38. `zmconv_momcd`
Downward convective momentum transport.
Decreases cloud brightness everywhere in the extratropics, but increases cloud brightness in the Western Pacific Warm Pool. Decreases midlatitude LWP. Increases IWP in the subtropics to midlatitudes; decreases it in the tropical central Pacific and Indian Oceans, and increases it over the Maritime Continent. Increases ice fraction everywhere. Increases tropical cloud fraction and decreases cloud fraction in the subtropics. Slightly decreases cloud droplet number concentration in the midlatitudes.
### 39. `zmconv_momcu`
Upward convective momentum transport.
The exact opposite as above.
### 40. `zmconv_num_cin`
Allowed number of negative buoyancy crossings before the routine stops calculating convective top and convective available potential energy.
Decreases cloud brightness everywhere, especially the Western Pacific Warm Pool. Decreases droplet concentration everywhere except at high latitudes. Decreases cloud fraction everywhere, especially in the subtropics. Decreases ice fraction over land and in the tropics; increases it in the midlatitude eastern ocean basins. Decreases IWP over the tropics, especially in the western Pacific. Decreases LWP everywhere, especially along the ITCZ and in the midlatitudes.
### 41. `zmconv_tiedke_add`
Initial convective parcel temperature perturbation.
Increases cloud brightness over the tropical and subtropical oceans everywhere. Decreases LWP over mid-high latitudes and increases elsewhere. Increases IWP over the western tropical Pacific and Indian Ocean; decreases it over tropical land. Decreases ice fraction over the eastern subtropical ocean basins and midlatitudes, and increases it over central/western subtropical and tropical ocean. Increases tropical and subtropical cloud fraction. Decreases droplet number concentration slightly along the ITCZ and at high latitudes.
## Parameterization for Unified Microphysics Across Scales (PUMAS)
### 42. `micro_mg_effi_factor`
Factor for calculating effective ice particle radius.
Increases cloud brightness over the SH midlatitudes. Decreases cloud brightness over the Western Pacific Warm Pool and the eastern subtropical ocean basins. Increases droplet concentration in the mid-high latitudes, especially in the SH midlatitudes. Increases midlatitude cloud fraction, especially in the SH. Decreases subtropical cloud fraction. Decreases ice fraction and IWP everywhere. Decreases (increases) tropical and subtropical (midlatitude) LWP and droplet concentration, except for the eastern subtropical NH Atlantic, where they increase.
### 43. `micro_mg_iaccr_factor`
Factor for calculating ice accretion rate.
Increases cloud brightness everywhere, especially along the ITCZ. Increases cloud fraction everywhere, especially in the tropics. Decreases tropical and midlatitude ice fraction. Increases IWP and LWP everywhere, especially in the tropics.
### 44. `micro_mg_max_nicons`
Sets a maximum number concentration for ice particles.
Increases cloud brightness everywhere. Increases LWP everywhere, especially in the midlatitudes. Increases IWP and ice fraction in the tropics. Increases (decreases) ice fraction in the NH (SH) subtropical eastern ocean basin clouds. Increases cloud fraction nearly everywhere. Increases cloud droplet number concentration in the mid-high latitudes.
### 45. `micro_mg_vtrmi_factor`
Factor for calculating ice fall velocity.
Decreases cloud brightness over eastern subtropical ocean basins and over the Western Pacific Warm Pool, increases cloud brightness over NH land areas. Decreases droplet concentration over the SH sea ice zone. Decreases tropical and subtropical cloud fraction. Decreases eastern subtropical ocean basin ice fraction and IWP, and increases them locally in the eastern tropical Pacific (seems to be an ITCZ shift though) and western subtropical NH Atlantic. Increases LWP in the tropics and midlatitudes, and decreases it in the eastern subtropical ocean basins.
# Covariance between parameters and reflected radiation
The following are maps of the covariance between individual parameters and the reflected SW radiation. The units are parameter units times W m<sup>-2</sup>, but the main point is to qualitatively study where the parameter is acting, so I have omitted color bars. These are calculated for the PD forcing set.
## TOA reflected SW radiation
[](https://i.imgur.com/nkHuRwH.jpg)
## SW Cloud radiative effect
[](https://i.imgur.com/XA5Ib00.jpg)
# PPE reference spreadsheet (from Ci)
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